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Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union

Scheduled special issues

The following special issues are scheduled for publication in ACP:

Fifth International Workshop on Ice Nucleation (FIN) (ACP/AMT inter-journal SI)
13 Jun 2018–31 Aug 2019 | Guest editors: A. K. Bertram, M. Krämer, B. Ervens, and D. Knopf | Information

We conducted the Fifth International Workshop on Ice Nucleation (FIN) to (1) understand the microphysics of how particles nucleate ice, (2) determine the number of ice forming particles as a function of atmospheric properties such as temperature and relative humidity, (3) measure the atmospheric distribution of ice forming particles and (4) ascertain the role of anthropogenic activities in producing or changing the behaviour of ice forming particles. To accomplish these goals we held three distinct workshops on the topic of atmospheric ice nucleation. The first was an intercomparison of instruments to determine the composition of ice forming particles in a controlled laboratory setting. This took place in autumn 2014 at the location of the last ice nucleation instrument intercomparison: the Aerosol Interaction and Dynamics in the Atmosphere (AIDA) chamber located at the Karlsruhe Institute of Technology. The second was an intercomparison of instruments used to determine cloud formation conditions. This activity also took place at AIDA and was conducted in spring 2015. Because ice nucleation predominantly takes place at the low temperatures found at high altitude, a critical requirement for the third workshop was a facility that offers access to free-tropospheric air masses with minimal local particle sources. We used the Desert Research Institute’s recently renovated Storm Peak Laboratory for this workshop in autumn 2015.

Interactions between aerosols and the South West Asian monsoon
01 Jul 2018–31 Dec 2020 | Guest editors: M. K. Dubey, D. Spracklen, A. Sorooshian, J. Srinivasan, and B. V. Krishna Murthy | Information

This special issue will include papers that guide the path forward in making reliable predictions of aerosol effects on the heat budget of the South East Asian subcontinent by improving our knowledge of aerosol processes and their influence on the Indian monsoon. Several recent major studies have aimed to provide a detailed determination of aerosol physical and chemical properties across India prior to and during the Indian monsoon, and results from these studies will be welcomed. Most recently the South West Asian Monsoon Interactions project used a combination of UK and Indian research aircraft and a network of ground-based measurement sites. The analysis of data will enable assessment of aerosol composition and mixing state, provide source characterization, and help quantify aerosol optical properties such as extinction, absorption, and single scattering albedo that drive regional climate. Results that use this detailed characterization to test representations of aerosol properties in regional and global climate models will be included.

The special issue will report on evaluations of and improvements in model representations of aerosol properties with data over India.

SKYNET – the international network for aerosol, clouds, and solar radiation studies and their applications (AMT/ACP inter-journal SI) 01 Sep 2016–indefinite | Guest editors: O. Torres, T. Nakajima, S. Kazadzis, and M. Campanelli | Information

SKYNET is an international research network dedicated to aerosol—cloud—radiation interaction studies. It consists of about 60 sites located all over the world. The main instrument at each site is the sun—sky radiometer, but to strengthen the ability of SKYNET, simultaneous measurements with other instruments such as pyranometers, pirgeometers, microwave radiometers, absorption meters, cloud cameras, lidars, MAX-DOAS, and instrumentation for in situ characterisation are also conducted for some selected sites. This special issue will face issues related to the following topics: aerosol and cloud properties from radiometers; developments on instrumentation; aerosol radiative forcing and climate effects; intercomparison among radiometer networks; validation of aerosol and cloud properties from satellite and models; applications for air pollution studies; and applications for solar energy.

Arctic mixed-phase clouds as studied during the ACLOUD/PASCAL campaigns in the framework of (AC)3
09 May 2018–31 Dec 2019 | Guest editors: R. Krejci, J. Kay, M. Shupe, J. Heintzenberg, A. Solomon, T. Vihma, V. Walden, and K. Law | Information

In this special issue papers resulting from two major combined field campaigns shall be aggregated: (i) the Arctic CLoud Observations Using airborne measurements during polar Day (ACLOUD), and (ii) the Physical feedbacks of Arctic boundary layer, Sea ice, Cloud and AerosoL (PASCAL). These two concurrent campaigns took place in the vicinity of Svalbard in May and June 2017. They were designed to study processes important for explaining Arctic amplification, and, in particular, for investigating the role of microphysical and dynamical properties of Arctic low- and mid-level, mixed-phase clouds, and their interactions with atmospheric radiation and aerosol particles. Ground-based, ship-borne, tethered balloon, aircraft, and satellite observations have been combined. The research vessel (RV) Polarstern, an ice floe camp (erected close to the icebreaker) including an instrumented tethered balloon, and the two research aircraft, Polar 5 and Polar 6, were jointly operated. Polar 5 served as a mobile remote sensing observatory looking at the clouds from above, whereas Polar 6 operated as a flying in situ measurement laboratory mostly sampling inside the clouds. The permanent ground station of Ny-Ålesund observed the clouds from below, applying similar but upward-looking remote sensing equipment as Polar 5. Some of the flights were performed underneath respective satellite tracks. In this special issue we compile a number of papers reporting about the results of the observations conducted during ACLOUD/PASCAL within the framework of the (AC)3 project (http://www.ac3-tr.de/).

Hydrological cycle in the Mediterranean (ACP/AMT/GMD/HESS/NHESS/OS inter-journal SI)
01 Apr 2018–31 Dec 2021 | Guest editors: H. Wernli, G. T. Aronica, C. Barthlott, D. Cimini, V. Kotroni, E. Martin, M. Meier, R. Moussa, K. Schroeder, and V. Ducrocq | Information

The Hydrological cycle in the Mediterranean Experiment (HyMeX, https://www.hymex.org/) programme is a 10-year concerted effort at the international level started in 2010 with aims to advance the understanding of the water cycle, and with emphases on the predictability and evolution of high-impact weather events, as well as on evaluating social vulnerability to these extreme events. The special issue is jointly organized between the Atmospheric Chemistry and Physics, Hydrology and Earth System Sciences, Ocean Science, Natural Hazards and Earth System Sciences, Atmospheric Measurement Techniques, and Geoscientific Model Development journals. It aims at gathering contributions to the areas of understanding, modelling, and predicting at various timescales and spatial scales of the Mediterranean water cycle and its related extreme events, including cyclones, heavy precipitation, flash floods and impacts, drought and water resources, strong winds, and dense water formation. The special issue is not limited to studies conducted within HyMeX: any multiscale or multidisciplinary approaches related to the Mediterranean water cycle are encouraged.

Surface Ocean Aerosol Production (SOAP) (ACP/OS inter-journal SI)
01 Jul 2013–01 Jan 2019 | Guest editors: C. Law, M. Harvey, M. Smith, P. Quinn, N. Harris, and M. Hoppema | Information

Biologically active regions of the surface ocean support production of a range of compounds that influence aerosol particle production, composition and properties in the overlying marine boundary layer. In February–March 2012 the SOAP (Surface Ocean Aerosol Production) voyage examined biotic influences on aerosol production to the east of New Zealand, by targeting phytoplankton blooms along the Sub-Tropical Front, with the aim of constraining the relationships between DMS and aerosol flux and characteristics, and phytoplankton biomass and community composition, by multi-disciplinary research within three work packages:

  • WP1: surface ocean biogeochemical links with aerosol precursors;
  • WP2: exchange rate and physical drivers of the transfer of DMS & CO2;
  • WP3: organic emissions, nucleation and interactions with the aerosol distribution in the overlying marine boundary layer.

The results of this research voyage will be detailed in this special issue, which will contain invited papers only.

The CERN CLOUD experiment (ACP/AMT inter-journal SI)
20 Jun 2011–31 Aug 2019 | Guest editors: V.-M. Kerminen, J. H. Seinfeld, N. M. Donahue, K. S. Carslaw, and J. Abbatt | Information

The SI will include papers on the experimental, theoretical and modelling results related to the CERN CLOUD experiment. The scientific focus of the experiment is to make fundamental measurements of aerosol nucleation under highly controlled laboratory conditions, including the effects of natural and synthetic cosmic rays. There were two campaigns of a month long: the first (2010) focused on inorganic aerosols and cosmic ray influences (NH3/H2SO4). The second campaign (June 2011) focuses on organic impacts on nucleation. There are also detailed modelling studies, plus papers on parameterisation development and global model applications.

Holistic Analysis of Aerosol in Littoral Environments – A Multidisciplinary University Research Initiative (ACP/AMT inter-journal SI)
12 Feb 2018–01 Sep 2018 | Guest editors: S. D. Miller and J. C. Chiu | Information

The Holistic Analysis of Aerosols in Littoral Environments Multidisciplinary University Research Initiative (HAALE-MURI) ACP/AMT special issue aims to advance our understanding and ability to observe and predict the complex distribution and properties of aerosol in the coastal zones. Specific foci of this ongoing 5-year (2015–2020) project are (1) the relative roles and interactions of key environmental factors influencing aerosol distributions impacting electro-optical propagation, (2) methods of characterizing the littoral zone aerosol distribution and properties via next-generation satellite observations and algorithms, and (3) how state-of-the-art data assimilation and visualization methods can exploit this information to provide representative high-resolution quantitative and qualitative analyses. This special issue will highlight progress made on these fronts at the mid-term of this project, showing examples of how traditionally disparate disciplines can provide deeper insight when considered in synergy.

Greenhouse gAs Uk and Global Emissions (GAUGE) project (ACP/AMT inter-journal SI)
17 Jan 2018–30 Sep 2018 | Guest editors: B. N. Duncan, D. Brunner, M. Chipperfield, and N. R. P. Harris | Information

The special issue collects together publications arising from the NERC-funded (grant no. NE/K002449/1) Greenhouse gAs Uk and Global Emissions (GAUGE) project. GAUGE was designed to quantify nationwide greenhouse gas emissions of the UK (CO2, CH4, and N2O), bringing together a range of measurements and atmospheric transport models. GAUGE will inform the blueprint for countries that are building a measurement infrastructure in preparation for global stocktakes that are a key part of the Paris Agreement.

Layered phenomena in the mesopause region (ACP/AMT inter-journal SI)
01 Jan 2018–30 Jun 2018 | Guest editors: W. Ward, M. Dameris, A. Engel, B. Funke, and R. E. Hibbins | Information

This is also the title of a well-established science meeting which we hosted at IAP on 18–22 September 2017. Special issues from former LPMR meetings were mainly published in JASTP, but for various reasons we prefer ACP this time. The special issue arises from the LPMR meeting, but it should be open for all submissions within its scope. The main science topics covered during the LPMR meeting are as follows: 1. Mesospheric phenomena and related sciences, including noctilucent clouds (NLCs), polar mesospheric clouds (PMCs), and polar mesospheric summer echoes (PMSEs). Measurements of these ice layers and related parameters by modern technologies such as lidars, radars, imagers, interferometers, spectrometers, rocket-borne sensors, and satellite-borne instruments, e.g. on AIM. 2. Long-term trends and solar-cycle-induced variations of layered phenomena and the role of these ice layers in the study of climate change in the middle atmosphere. 3. Neutral and ionized metal layers of meteoric origin and related parameters such as cosmic dust, meteors, meteoroids, meteorites, and ablation physics. 4. The physics and application of airglow to study the thermal and dynamical structure in the mesopause region. 5. Using layered phenomena in the mesopause region as tracers to study gravity waves and turbulence. 6. Related atmospheric phenomena such as ionospheric layers and dynamic coupling between atmospheric layers.

Developments in the science and history of tides (OS/ACP/HGSS/NPG/SE inter-journal SI)
01 Jan 2018–31 Dec 2019 | Guest editors: P. L. Woodworth, R. D. Ray, M. Green, and T. Dunkerton | Information

The issue is open to any aspect of the subject including the present accuracy of coastal, regional and global tide models; tidal dissipation and its role in geophysics; internal tides and their role in mixing the ocean and in the global ocean circulation; secular changes in tides; and new techniques for measuring tides and analysing the data. The issue also welcomes new findings on earth and atmospheric tides, the role of tides in the origin of life on earth, palaeotides, lake and planetary tides and many other aspects of tides.

The launch of the special issue coincides with the upcoming 100th anniversary of the founding of the Liverpool Tidal Institute (LTI). The LTI was established in 1919 and for many years was the world centre for knowledge of the tides, with Joseph Proudman taking the lead in dynamical theories and Arthur Doodson in the analysis of tidal information from around the world, and tidal prediction. The year 2019 is also the 100th anniversary of the International Union of Geodesy and Geophysics (IUGG), which will meet in Montreal during 9–18 July 2019. The Montreal IUGG will include a Joint Symposium on Tides (with IAPSO as the lead Association) that will be open to all of the aspects of tidal science mentioned above. The symposium will provide a fitting recognition of the anniversaries of both the LTI and IUGG. Contributors to the symposium would be encouraged to write up their work for publication in the special issue.

The special issue is open for contributions now and will stay open until the end of 2019, thereby taking advantage of new findings presented at the IUGG. It is open to any contributor, not only those with links to the LTI or attending the IUGG in Montreal.

Shipping and the Environment – From Regional to Global Perspectives (ACP/OS inter-journal SI)
01 Feb 2018–31 Dec 2018 | Guest editors: X. Querol, A. Petzold, J. Moldanová, and M. Quante | Information

Exhaust emissions from shipping originating from combustion of marine fuels contribute significantly to the anthropogenic burden of air pollutants which have negative effects on human health and ecosystems, including increased human mortality and morbidity, and acidification and eutrophication of freshwaters and marine waters. There is also a rising awareness of the negative impact from shipping on the marine environment. To summarize, the impact of shipping on induced seawater pollution is challenging as the stressors (nutrients, hazardous substances, particulate contaminants, acidifying substances, and invasive species) come from many different activities related to shipping, and act differently, and it is difficult to find a common denominator to assess the total impact. It is recognized that anthropogenic noise might also have adverse effects on the marine environment. The ambition to reduce the negative environmental impacts of international shipping is an overarching objective of international and macro-regional conventions, directives, and national legislation.

Recognition of the topic's importance has resulted in growing research momentum on the environmental consequences of shipping. An international conference, "Shipping and the Environment – From Regional to Global Perspectives", which took place in Gothenburg, Sweden, 23–24 October, was a joint activity of the BONUS SHEBA (Shipping and the environment of the Baltic Sea Region) and SOLAS international projects. The large interest in the conference (118 participants from 15 countries) showed that an initiative covering a wide range of natural and social sciences involved in assessment of impacts of shipping has been very timely. As a follow-up of the conference, this proposed special issue aims to address a wide range of impacts of shipping on air pollution, seawater pollution, underwater noise and climate, environmental impacts of these pressures, as well as the socio-economic consequences of these. It would be open not only to papers presented at the conference, but also to others addressing the topic.

To illustrate the range of topics to be covered by the special issue and the need for a joint issue between ACP and OS, the topics covered at the conference included experimental characterization of emissions to air and water and of underwater noise from shipping, emission inventories including the scenario emissions and impact of legislation, economic instruments and technological development on these, air quality and oceanic modelling of fates and effects of pollutants from shipping, assessment of impacts of emissions on human health, land, and marine ecosystems, and assessment of socioeconomic consequences of the environmental impacts and abatement measures.

Flow in complex terrain: the Perdigão campaigns (WES/ACP/AMT inter-journal special issue)
17 Aug 2017–31 Dec 2018 | Guest editors: J. B. Brandt, J. Laginha Palma, and S. Oncley | Information

The Perdigão field campaigns probed atmospheric flow in and around a double-ridge valley in Portugal equipped with one turbine, collecting data critical for improving fundamental insights into flow in complex terrain as well as methods for quantifying wind resources. While the Perdigão 2015 campaign pioneered coordinated scans from three scanning lidars, Perdigão 2017 included an unprecedented array of instrumentation, including 30 scanning and profiling lidars to map the valley's atmosphere. An array of approximately 50 towers, equipped with sonic anemometers and ranging in height from 10 to 100 m, provided in situ measurements to measure air flow and turbulence. Radiosondes, thermistor arrays, microwave radiometers, and an Atmospheric Emitted Radiance Interferometer (AERI) measure temperature structure. Acoustic measurements, seismographic measurements, and tethered systems measuring high-rate turbulence data also provide unique insights into the numerous flow phenomena observed in the valley.

In addition to studying complex terrain effects on the wind resource and wind turbine wakes, the Perdigão data enable insights into interactions between flows of different scales, effects of topographic and diurnal thermal forcing, valley/slope boundary layers, and recirculations within the valley.

This special issue is open for all submissions within its scope, addressing measurements, simulations, and case studies from both Perdigão field campaigns.

The 10th International Carbon Dioxide Conference (ICDC10) and the 19th WMO/IAEA Meeting on Carbon Dioxide, other Greenhouse Gases and Related Measurement Techniques (GGMT-2017) (AMT/ACP/BG/CP/ESD inter-journal SI)
01 Oct 2017–30 Sep 2018 | Guest editors: M. Heimann, N. Gruber, J. Randerson, C. Zellweger, and R. Law | Information

The International Carbon Dioxide Conference (ICDC) is the single largest conference organized by the global research community every four years to present the latest scientific findings on the science of the carbon cycle and its perturbation by human activities. The ICDC10 in 2017 is the 10th anniversary conference. It covers fundamental science advancement and discovery, the generation of policy relevant information, and observational and modeling approaches. ICDC10 brings together scientists from different disciplines to work towards an integrated view on the global cycle of carbon in the Earth system.

The main themes of the conference are as follows:

  1. The contemporary carbon cycle
    • Trends, variability, and time of emergence of human impacts
    • Emerging approaches and novel techniques in observations
  2. The paleo-perspective: patterns, processes, and planetary bounds
  3. Biogeochemical processes
    • Process understanding and human impacts
    • Coping with complexity: from process understanding to robust models
  4. Scenarios of the future Earth and steps toward long-term Earth system stability

GGMT-2017 is a key conference on measurement techniques for accurate observation of long- lived greenhouse and related gases, their isotopic composition in the atmosphere relevant for climate change, and global warming research findings. The biannual meeting, known as the WMO/IAEA Meeting of Experts on Carbon Dioxide, Other Greenhouse Gases and Related Tracer Measurement Techniques, is to be held for the 19th time in 2017.

Main topics:

  • Developments of the GHG networks
  • CO2 observations (measurement techniques and calibration)
  • Non-CO2 observations (measurement techniques and calibration)
  • Isotope measurement and calibration
  • Emerging techniques
  • GHG standards and comparison activities
  • Integration of observations, data products and policy

The special issue is open for papers that emerged from ICDC10 and GGMT-2017 conference contributions.

In-depth study of air pollution sources and processes within Beijing and its surrounding region (APHH-Beijing) (ACP/AMT inter-journal SI)
01 Oct 2017–30 Sep 2020 | Guest editors: P. Q. Fu, M. Zheng, J. Allan, L. K. Whalley, Li Yongjie, D. K. Farmer, J. Stutz, T. Butler, and F. N. Keutsch | Information

The air pollution problems affecting Beijing and north-eastern China are well documented, but the formulation of cost-effective solutions requires further research. In a study funded by the UK Natural Environment Research Council and Medical Research Council and the Chinese Natural Science Funding Council, researchers from the UK and China have collaborated in studies with the following aims:

  • to determine the emission fluxes of key pollutants and to measure the contributions of different sources, economic sectors and regional transport to air pollution in Beijing;
  • to assess the processes by which pollutants are transformed or removed through transport, chemical reactions and photolysis and the rates of formation and conversion of particulate matter via atmospheric reactions;
  • quantify how the detailed properties of particulate matter evolve and can influence its physical properties and behaviour in the atmosphere and elucidate the mechanisms whereby these properties may interact and feed back on urban-scale and regional meteorology;
  • to develop numerical models capable of reliably simulating air quality within Beijing and its local region and prediction of the impacts of mitigation measures;
  • to determine exposure of Beijing inhabitants to key health-related pollutants using personal air pollution monitors and assess the associated links between air pollution exposure and health impacts;
  • to determine the contribution of specific activities, environments and pollution sources to the personal exposure of the Beijing population to air pollutants derived from outdoor sources.

Implementation of the research was through two major field campaigns based in Beijing and rural sites outside of the city which took place in November–December 2016 and May–June 2017. The work involved measurements of air pollutants as well as key precursors, reactive species and meteorological variables in three spatial dimensions, with a view to creating an enhanced understanding of the processes determining pollutant concentrations, especially in relation to particulate matter and photo-oxidants.

Multiphase chemistry of secondary aerosol formation under severe haze
01 Oct 2017–01 Oct 2020 | Guest editors: H. Su, D. A. Knopf, A. Ding, J. K. Jiang, and J. Wang | Information

Fine-particle pollution associated with haze threatens the health of more than 1 billion people in China. Extremely high PM2.5 concentrations are frequently observed, especially during the winter haze event in northern China. Even after accounting for aerosol–radiation–meteorology feedback and improving the emission inventory, state-of-the-art models still fail to capture the observed high PM2.5 concentrations, suggesting that key chemistry is missing for secondary aerosol formation. To improve the prediction and control strategy of PM2.5, we are in urgent need of a better understanding of the chemistry of secondary aerosol formation. Thus, we launch the special issue "Multiphase chemistry of secondary aerosol formation under severe haze" to promote research and discussion on this topic, which is highly relevant for both atmospheric chemists and the public.

The special issue is open for all submissions which address, but are not limited to, the following questions concerning secondary aerosol formation. What are the key oxidation pathways leading to aerosol formation under clean and polluted conditions? What is the role of multiphase chemistry versus gas-phase chemistry? Are laboratory-determined kinetic data of multiphase chemistry directly applicable for ambient conditions, and if not, how can the reaction kinetics relevant for ambient conditions be derived and determined? What is the aerosol particles' and droplets' pH and how does it influence the multiphase chemistry? What is the role of the RH, temperature and aerosol phase state in multiphase chemistry, and how does aerosol mixing state play a role? What is the contribution of aqueous secondary organic aerosol (SOA) formation under highly polluted conditions?

Environmental changes and hazards in the Dead Sea region (NHESS/ACP/HESS/SE inter-journal SI)
26 Jun 2017–30 Jun 2018 | Guest editors: M. Kanakidou, C. Kottmeier, and P. Alpert | Information

The Dead Sea region constitutes a unique environmental system on Earth. Set in an extraordinary landscape and cultural area, it is central to life in this region and of great economic and ecological importance. Today, the region is faced with rapid environmental changes and a multitude of hazardous natural phenomena. The ongoing lake level decline of the Dead Sea, the desertification process, occasional flash floods, the development of numerous sinkholes, and the existing significant seismic risk indicate that the region can by affected by important human, economic, and ecologic loss in future. Due to its outstanding characteristics, such as sharp climatic gradients, extreme water salinity, its dynamics, and the combination of both natural and anthropogenic drivers, the Dead Sea region represents a unique natural laboratory in which to study multiple disciplines such as geophysics, hydrology, and meteorology.

The environmental changes in Earth, atmosphere, and water are linked to the main geomorphic feature in the region, the Dead Sea Transform fault system. Due to this active fault zone, the region is exposed to severe earthquake hazard, which in turn, considering the exposed assets and the vulnerability of the building stock, determines a significant seismic risk in the region. Knowledge about processes and structures in the underground is also required for the study of sinkholes. Sinkholes form when groundwater, undersaturated with respect to easily soluble minerals, uses faults as conduits to percolate to subsurface salt deposits. The water dissolves and flushes the salt, leading to a collapse of the underground substrate structure. Thus, the development of sinkholes is enabled. Besides triggering sinkhole formation, groundwater recharge determines the available water resources. The Dead Sea being a terminal lake, its water level decline is controlled by changes in subsurface as well as surface water inflow and evaporation. A direct link to hydrology and atmospheric sciences is thereby established. The rapid shrinking of the water surface area is accompanied by a strong local climatic change, which induces changes in atmospheric circulation patterns. Here, the Dead Sea can be viewed as a laboratory for studying effects of climate change under much accelerated conditions compared to the rest of the world.

The objective of the multidisciplinary special issue "Environmental changes and hazards in the Dead Sea region" is to compile research and recent advances on the atmospheric, hydrological, and geophysical processes and dynamics of the Dead Sea and its surroundings, which are also of prototype relevance for other (semi)arid terminal basins of the world. Papers included in this special issue could address the processes of sinkhole genesis, groundwater recharge and movement, flash flooding, as well as seismic or severe meteorological events and could include topics such as the quantification of the water budget components. Moreover, contributions are invited that demonstrate how this knowledge contributes to aspects of risk assessment (or its main components like hazard, exposure, and vulnerability) and could assist in efficient risk mitigation and remediation strategies as well as to appropriate implementation of early warning systems in the region. Both measurement and modelling studies are welcome.

The planned special issue aims to address the unique conditions of the Dead Sea region from different disciplinary views. Given the fast environmental changes in the different spheres, the special issue will be of wide interest to readers from seismologists, geophysicists, engineers, and hydrologists to meteorologists. Interest will not be limited to researchers working in the region as similar changes are occurring in other parts of the world too, many on a much longer timescale.

The special issue is initiated by the Helmholtz Virtual Institute’s DEad SEa Research VEnue (DESERVE). The project brings together researchers working on diverse research fields related to the Dead Sea environment. The special issue will be open for all submissions within its scope.

Results of the project "Dynamics-aerosol-chemistry-cloud interactions in West Africa" (DACCIWA) (ACP/AMT inter-journal SI)
26 Jun 2017–31 Aug 2018 | Guest editors: M. J. Evans, D. Spracklen, S. Janicot, A. Mekonnen, and S. van den Heever | Information

DACCIWA was a large multi-national (Germany: KIT, DLR; France: CNRS, Université Blaise Pascal Clemont-Ferrand II, Université Paris Didertot, Université Paul Sabatier Toulouse III, Université Pierre et Marie Curie; UK: Met Office, University of Manchester, University of Leeds, University of York, University of Reading; Switzerland: ETH Zürich; European: ECMWF; Ghana: KNUST; Nigeria: Obafemi Awolowo University) project funded by the European Union 7th Framework Programme to investigate atmospheric processes over West Africa, ranging from the impact of air pollution on atmospheric health to the future climate of the region. Arranged around seven interlinking work packages (WP1: boundary layer dynamics; WP2: air pollution and health; WP3: atmospheric chemistry; WP4: cloud-aerosol interactions; WP5: radiative processes; WP6: radiative processes; WP7: precipitative processes; WP7: monsoon processes), the project aims to improve our scientific understanding of this region and its resilience through increased scientific understanding of key atmospheric processes.

The summer of 2016 was the focal point for the experimental activities. Highly instrumented supersites at Savé in Benin and Kumai in Ghana provided multi-week analysis of a range of meteorological parameters and targeted cloud formation, low-level jet activation, and precipitation formation. Meteorological sondes were released at regular intervals and as special observing periods from a range of cities in the region. Air quality measurements in the cities of Cotonou, Abidjan, and Akouedou provided information on pollution loads in regional cities and emission factors for emission estimates. Three research aircraft (DLR Falcon, BAS Twin Otter, SAPHIRE ATR43) were based in Lomé, Togo, for a month to make a range of observations over the coastal cities of Ivory Coast, Ghana, Togo, and Benin and inland over the rainforest, agricultural, and residential areas. The aircraft were equipped to measure a range of gas, aerosol, and meteorological parameters. A more complete list of payloads, observations collected, flight paths flown, etc. is attached as a PDF, which forms part of a paper currently being reviewed by BAMS that describes the summer campaign.

The intention of the scale issue is to bring together all of this activity into a single area to allow synergies between the papers to be more evident and to help advertise the data and science generated by the DACCIWA project in this data-poor area to the wider community.

The Polar Stratosphere in a Changing Climate (POLSTRACC) (ACP/AMT inter-journal SI)
21 Jun 2017–30 Jun 2018 | Guest editors: B.-M. Sinnhuber, M. Chipperfield, and R. Müller | Information

The special issue invites contributions based on the aircraft campaign "The Polar Stratosphere in a Changing Climate (POLSTRACC)" that took place in the Arctic in winter 2015/16 (www.polstracc.kit.edu) but is intended to be open for submissions related to the topic of the polar stratosphere in a changing climate in a broader sense.

BACCHUS – Impact of Biogenic versus Anthropogenic emissions on Clouds and Climate: towards a Holistic UnderStanding (ACP/AMT/GMD inter-journal SI)
14 Jun 2017–31 Dec 2018 | Guest editors: D. J. Cziczo, H. Grothe, A. Nenes, H. Tost, and A. K. Bertram | Information

BACCHUS is a European FP7 Collaborative Project aiming at quantifying key processes and feedbacks that control aerosol–cloud interactions by combining advanced measurement techniques of cloud and aerosol properties with emphasis on ice nucleating particles and the ice phase in clouds with state-of-the-art numerical modelling. It investigates the importance of biogenic versus anthropogenic emissions for aerosol–cloud interactions in regions that are key regulators of Earth's climate (Amazonian rainforest) or are regarded as tipping elements in the climate system (Arctic). BACCHUS advances the understanding of biosphere aerosol–cloud–climate feedbacks that occur via emission and transformation of biogenic volatile organic compounds, primary biological aerosols, secondary organic aerosols, and dust. New fundamental understanding gained during BACCHUS will be incorporated into Earth system models through new or improved parameterizations of emissions, aerosol and cloud processes, and properties, which will lead to a reduction in the uncertainty of future climate projections. A unique database linking long-term observations and field campaign data of ice nucleating particles and observed cloud microphysical properties has been generated.

The BACCHUS special issue will be simultaneously presented in the ACP, AMT, and GMD journals and is open for all submissions acknowledging the BACCHUS project. BACCHUS is a collaborative project of 21 partner institutions: ETH Zurich, University of Helsinki, Paul Scherrer Institute, Max Planck Society (MPI-M, MPI-C), University of Oxford, University of Oslo, Finnish Meteorological Institute, University of Leeds, University of Manchester, Leibniz Institute for Tropospheric Research, Goethe University Frankfurt, the University of Crete, National Research Council of Italy – Institute of Atmospheric Sciences and Climate, National University of Ireland Galway, Institute for Nuclear Research and Nuclear Energy, Hebrew University of Jerusalem, National Center for Scientific Research (France), Karlsruhe Institute of Technology, Cyprus Institute, Cyprus University of Technology, and University of Gothenburg. The project is funded by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement no. 603445.

The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP) (ESD/ACP/CP/GMD inter-journal SI)
15 May 2017–30 Apr 2019 | Guest editors: A. Schmidt and S. Bekki | Coordinators: C. Timmreck, M. Khodri, and D. Zanchettin | Information

Volcanic eruptions are one of the major natural factors influencing climate variability at interannual to multidecadal timescales. However, simulating volcanically forced climate variability is a challenging task for climate models and one of the major uncertainties in near-term climate predictions. The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP) is an endorsed contribution to the sixth phase of the Coupled Model Intercomparison Project. This multi-journal special issue on VolMIP aims at collecting relevant research results obtained within the VolMIP framework, and specifically concerning different aspects of the radiative and dynamical climatic response to volcanic forcing, detailed description of effects of different implementation of volcanic forcing in current climate models, aspects concerning the dynamical and chemical atmospheric response to volcanic aerosols simulated by global aerosol models, and comparison between reconstructed and simulated climate evolution after major eruptions. Articles in the special issue should contain the following statement: "This article is part of the special issue "The Model Intercomparison Project on the climatic response to Volcanic forcing (VolMIP) (ESD/GMD/ACP/CP inter-journal SI)". It does not belong to a conference."

Sources, propagation, dissipation and impact of gravity waves (ACP/AMT inter-journal SI)
15 Mar 2017–30 Jun 2018 | Guest editors: M. Rapp, F.-J. Lübken, J. Gumbel, M. Taylor, and G. Zängl | Information

Gravity waves (GWs) are a ubiquitous phenomenon in a stably stratified atmosphere. GWs are excited by flow over orography and by convection or jet streams and fronts, and may propagate both horizontally and vertically over large distances. Thus, they lead to a significant vertical and horizontal transport of energy and momentum which so far is hardly appropriately accounted for in numerical weather prediction and climate models, which mainly rely on simplified parametrization schemes. In order to investigate sources, propagation, dissipation and impact of GWs, a number of large internationally coordinated research campaigns have been conducted over the past few years. These campaigns involve observations with research aircraft, satellites, research balloons, and ground-based instruments, as well as related modelling efforts. Specifically, these are the series of GW-LCYCLE (Gravity Wave Life CYCLE) campaigns conducted in northern Scandinavia in winter 2013 and 2015/16 as well as the NSF-DEEPWAVE (The DEEP PROPAGATING GRAVITY WAVE EXPERIMENT) campaign conducted in June/July 2014 from New Zealand. The German contributions to these activities were funded in the scope of the ROMIC (Role of the Middle atmosphere in Climate) research focus of the German Ministry for Education and Research as well as the MS-GWAVES (Multi Scale dynamics of Gravity WAVES) research unit funded by the German Science Foundation. For this special issue, we invite contributions describing observations and related modelling studies focusing on results achieved during these field campaigns. However, beyond studies specifically addressing results obtained in the framework of GW-LCYCLE and DEEPWAVE, we also invite any related studies dealing with GW processes and their impact on the atmosphere. Within this framework, contributions focusing on both scientific and methodological aspects will be considered.

The ACRIDICON-CHUVA campaign to study deep convective clouds and precipitation over Amazonia using the new German HALO research aircraft (ACP/AMT inter-journal SI)
11 May 2016–31 Dec 2018 | Guest editors: S. A. Penkett, S. A. Buehler, U. Schumann, and A. Heymsfield | Information

Between 1 September and 4 October 2014 a combined airborne and ground-based measurement campaign was conducted to study tropical deep convective clouds over the Brazilian rainforest. The German HALO (High Altitude and LOng range) research aircraft and extensive ground-based instrumentation were deployed in and near Manaus (state of Amazonas). The campaign was part of the German-Brazilian ACRIDICON-CHUVA venture to quantify aerosol-cloud-precipitation interactions and their thermodynamic, dynamic, and radiative effects by in situ and remote sensing measurements over Amazonia. ACRIDICON is the abbreviation for "Aerosol, Cloud, precipitation, and Radiation Interactions and DynamIcs of CONvective cloud systems", and CHUVA stands for "Cloud processes of tHe main precipitation systems in Brazil: a contribUtion to cloud resolVing modeling and to the GPM (globAl precipitation measurement)". The ACRIDICON-CHUVA field observations were carried out in cooperation with the second intensive operating period of GoAmazon 2014/15. Five scientific topics were pursued: (a) cloud vertical evolution and life cycle (cloud profiling), (b) cloud processing of aerosol particles and trace gases (inflow and outflow), (c) satellite and radar validation (cloud products), (d) vertical transport and mixing (tracer experiment), and (e) cloud formation over forested/deforested areas. Data were collected in near-pristine atmospheric conditions and in environments polluted by biomass burning and urban emissions.

Atmospheric emissions from oil sands development and their transport, transformation and deposition (ACP/AMT inter-journal SI)
22 Apr 2016–15 Mar 2018 | Guest editors: J. W. Bottenheim, J. G. Murphy, J. Liggio, J. Brook, and S.-M. Li | Information

The oil sands of Alberta, Canada, are of international interest due to the potential environmental impacts, from local to global scales, of their extraction and processing to provide non-conventional fossil fuels to consumers in North America and globally. The governments of Canada and the province of Alberta launched the Joint Oil Sands Monitoring (JOSM) program in 2012 to help address knowledge gaps regarding long-term cumulative effects of oil sands' development and production. JOSM is a regionally focused program; however, the knowledge gained is applicable to extra heavy oil production elsewhere, given the large known global reserves of heavy oil and bitumen.

The purpose of this special issue is to bring together the scientific results of atmospheric-related JOSM studies, which have been largely conducted since 2013, although some of the potential papers could involve data obtained in earlier years. Other submissions within this scope could also be considered. The results would be derived from measurements from the ground as well as aircraft and satellite overpasses. Applications and evaluations of high-resolution modeling will also be part of this research portfolio. While the studies are to be focused on emissions and ambient levels, as well as deposition, with regard to the oil sands region in Alberta, and therefore referring particularly to conditions in that area, results will have a broader relevance scientifically. This ranges from evaluation of new satellite retrievals, new trace gas and aerosol measurement methods and techniques for source apportionment and emission inventory evaluation, to process studies of deposition, secondary air pollutant formation (gas and particle) and black carbon coating and light absorption.

The 10th International Carbon Dioxide Conference (ICDC10 ) and the 19th WMO/IAEA Meeting on Carbon Dioxide, other Greenhouse Gases and Related Measurement Techniques (GGMT-2017) (ACP/AMT/CP/ESD inter-journal SI)
01 Oct 2017–30 Sep 2018 | Guest editors: M. Heimann, N. Gruber, M. Leuenberger, C. LeQuere, J. Pongratz, C. Prentice, J. Randerson, M. Steinbacher, and C. Zellweger | Information

The International Carbon Dioxide Conference (ICDC) is the single largest conference organized by the global research community every four years to present the latest scientific findings on the science of the carbon cycle and its perturbation by human activities. The ICDC10 in 2017 is the 10th anniversary conference. It covers fundamental science advancement and discovery, the generation of policy relevant information, and observational and modeling approaches. ICDC10 brings together scientists from different disciplines to work towards an integrated view on the global cycle of carbon in the Earth system.

The main themes of the conference are as follows:

  1. The contemporary carbon cycle
    • Trends, variability, and time of emergence of human impacts
    • Emerging approaches and novel techniques in observations
  2. The paleo-perspective: patterns, processes, and planetary bounds
  3. Biogeochemical processes
    • Process understanding and human impacts
    • Coping with complexity: from process understanding to robust models
  4. Scenarios of the future Earth and steps toward long-term Earth system stability

GGMT-2017 is a key conference on measurement techniques for accurate observation of long- lived greenhouse and related gases, their isotopic composition in the atmosphere relevant for climate change, and global warming research findings. The biannual meeting, known as the WMO/IAEA Meeting of Experts on Carbon Dioxide, Other Greenhouse Gases and Related Tracer Measurement Techniques, is to be held for the 19th time in 2017.

Main topics:

  • Developments of the GHG networks
  • CO2 observations (measurement techniques and calibration)
  • Non-CO2 observations (measurement techniques and calibration)
  • Isotope measurement and calibration
  • Emerging techniques
  • GHG standards and comparison activities
  • Integration of observations, data products and policy

The special issue is open for papers that emerged from ICDC10 and GGMT -2017 conference contributions.

Regional transport and transformation of air pollution in eastern China
24 Mar 2016–31 Mar 2019 | Guest editors: T. Zhu, Y. Zhang, J. Chen, D. E. Heard, Z. Li, L. T. Molina, L. Morawska, D. Parrish, H. Su, R. Zhang, and Y. Wang | Information

Eastern China is experiencing serious air pollution. North China Plain, including the megacities Beijing and Tianjin, is the region with the worst air pollution in China, followed by cities such as Shanghai, Nanjing and Wuhan along the Yangtze River basin. To understand the transport and transformation processes of atmospheric pollution, as well as to evaluate the impacts of aerosol on climate and cloud formation, many studies have been conducted in eastern China. As a follow up to CAREBEIJING 2006/2007/2008, the CAREBEIJING-NCP (Campaigns of Air Pollution Research in Megacity Beijing and North China Plain) and the Yangtze River campaign were conduced in 2013, 2014 and 2015 to address critical scientific questions, such as HOx chemistry, atmospheric oxidative capacity, chemical composition of fine particles, formation processes of new particle and secondary aerosol, multiphase reaction on the surface of fine particles, optical and hygroscopic properties of aerosol and their implications for air quality and climate impacts. The major findings from studies in this region will be reported in this special issue.

NETCARE (Network on Aerosols and Climate: Addressing Key Uncertainties in Remote Canadian Environments) (ACP/AMT/BG inter-journal SI)
23 Feb 2016–28 Feb 2019 | Guest editors: L. Bopp, K. Carslaw, D. J. Cziczo, and L. M. Russell | Information

NETCARE (Network on Aerosols and Climate: Addressing Key Uncertainties in Remote Canadian Environments) is a large research network focusing on aerosol–cloud–climate interactions. While Canadian-based, it operates with many international collaborations. It is comprised of scientists working in both atmospheric science and marine biogeochemistry, with particular attention given to a suite of intensive field measurements (with both atmospheric and oceanic components) and model evaluation and development. There are three major research directions within the network: 1. Carbonaceous Aerosol, 2. Arctic Clouds, and 3. Ocean–Atmosphere Interactions. A large amount of the research has an Arctic focus, it being a region especially susceptible to anthropogenic input and experiencing a large degree of biogeochemical change. The website for the network is www.netcare-project.ca. On the website, there is more information on research activities, field campaign details, modeling activities, data products, and personnel.

EARLINET aerosol profiling: contributions to atmospheric and climate research
15 Feb 2016–31 Oct 2018 | Guest editors: V. Amiridis, L. Mona, A. Ansmann, E. Landulfo, R. Kahn, and M. Tesche | Information

The EARLINET ACP Special Issue aims to collect high-quality aerosol studies employing advanced lidar remote sensing techniques as developed within EARLINET, the European Aerosol Research Lidar Network. EARLINET was established in 2000 with the main goal of providing a comprehensive, quantitative, and statistically significant database for aerosol distribution on a continental scale. The 5-year EARLINET-ASOS (Advanced Sustainable Observation System) EC Project (2006–2011) has strongly contributed to optimizing the operation of the network. EARLINET is now a key component of the ACTRIS (Aerosols, Clouds and Trace gases Research InfraStructure Network) research infrastructure project that aims to integrate European ground-based stations equipped with advanced atmospheric probing instrumentation for aerosols, clouds and short-lived gas-phase species. The 15-year EARLINET database of aerosol profiles over Europe will be utilized in this Special Issue to reveal the network’s contribution to atmospheric and climate research.

Water vapour in the upper troposphere and middle atmosphere: a WCRP/SPARC satellite data quality assessment including biases, variability, and drifts (ACP/AMT/ESSD inter-journal SI)
10 Feb 2016–30 Sep 2019 | Guest editors: J. Russell, K. Rosenlof, S. Buehler, and G. Stiller | Information

The Water Vapour Phase II (WAVAS II), a SPARC activity, started in 2008 (SPARC Newsletter No. 30 (2008) p. 16: SPARC Water Vapour Initiative, by C. Schiller et al.). The activity includes satellite assessment and in situ comparison components. This international activity encompasses:

  1. Providing a quality assessment of upper tropospheric to lower mesospheric satellite records since the early 1990s
  2. Providing, as far as possible, absolute validation against ground-truth instruments
  3. Assessing inter-instrument biases, depending on altitude, location, and season
  4. Assessing the representation of temporal variations on various scales
  5. Including data records on isotopologues
  6. Providing recommendations for usage of available data records and for future observation systems

The main objective of WAVAS II is to assess and extend our knowledge and understanding of measurements of the vertical distribution of water vapor in the upper troposphere and middle atmosphere (UT/MA), where water has small concentrations, but significant radiative impact. This is a follow-up of the SPARC WAVAS activity, whose report was published in 2000 (SPARC Report No. 2 (2000) Upper Tropospheric and Stratospheric Water Vapour. D. Kley, J.M. Russell III, and C. Philips (eds.). WCRP-113, WMO/TD - No. 1043). Information gained from this activity will improve our ability to estimate long-term changes with associated uncertainties in UT/MA water as well as make recommendations as to what data would be most valuable for model validation and how such data should be used.

Papers will be accepted for this special issue according to the following guidelines, independent if they originate from the WAVAS II activity or other activities.

Guidelines for submissions:

  • papers covering existing UT/MA satellite water vapour measurements;
  • papers discussing comparisons of UT/MA satellite measurements, including discussion of quantities derived from these measurements, such as seasonal cycles, estimates of transport, or estimates of drifts, trends and variability;
  • papers discussing merging of water vapour measurements will be considered, although this topic is not specifically part of the WAVAS-II activity;
  • model papers that incorporate the datasets discussed and the uncertainty estimates resulting from the WAVAS-II activity will also be considered for inclusion.

 

The SPARC Reanalysis Intercomparison Project (S-RIP) (ACP/ESSD inter-journal SI)
02 Feb 2016–31 Dec 2018 | Guest editors: P. Haynes, G. Stiller, and W. Lahoz | Information

The climate research community uses reanalyses widely to understand atmospheric processes and variability in the middle atmosphere, yet different reanalyses may give very different results for the same diagnostics. For example, the global energy budget and hydrological cycle, the Brewer–Dobson circulation, stratospheric vortex weakening and intensification events, and large-scale wave activity at the tropical tropopause are known to differ among reanalyses.

The Stratosphere–troposphere Processes And their Role in Climate (SPARC) Reanalysis Intercomparison Project (S-RIP) is a coordinated activity to compare reanalysis data sets with respect to a variety of key diagnostics. The objectives of this project are

  1. to understand the causes of differences among reanalyses;
  2. to provide guidance on the appropriate usage of various reanalysis products in scientific studies;
  3. to contribute to future improvements in the reanalysis products by establishing collaborative links between the reanalysis centres and the SPARC community.

The project focuses predominantly on differences among reanalyses (although studies that include operational analyses are welcome and studies comparing reanalyses with observations are encouraged), with an emphasis on diagnostics in the upper troposphere, stratosphere and mesosphere. This special issue serves to collect research with relevance to S-RIP in preparation for the publication of the S-RIP report in 2018. Although participation in S-RIP is not a prerequisite for submission to this special issue, authors contributing to this collection are encouraged to consider contributing to the preparation of the S-RIP report.

Chemistry–Climate Modelling Initiative (CCMI) (ACP/AMT/ESSD/GMD inter-journal SI)
23 Oct 2015–30 Sep 2018 | Guest editors: B. N. Duncan, A. Gettelman, P. Hess, G. Myhre, and P. Young | Information

IGAC/SPARC CCMI (www.met.reading.ac.uk/ccmi/) consists of a wide range of researchers, including chemistry-climate modelers, observationalists, and data analysts who are investigating the historical and projected evolution of stratospheric and tropospheric composition and chemistry, including the links between those domains, and the feedbacks with the physical climate. A current CCMI activity is a series of hindcast model simulations in support of upcoming ozone and climate assessments. The goal is to quantify how well the models can reproduce the past behavior (climatology, trends and interannual variability) of tropospheric and stratospheric ozone, other oxidants, and more generally chemistry-climate interactions, as well as to understand processes that govern these interactions. An emphasis is placed on observational based evaluation of model output, including model processes. A future CCMI activity will be to analyze projections of the future evolution of tropospheric and stratospheric ozone.

Advanced Global Navigation Satellite Systems tropospheric products for monitoring severe weather events and climate (GNSS4SWEC) (AMT/ACP/ANGEO inter-journal SI)
01 Nov 2015–30 Nov 2018 | Guest editors: G. Vaughan, J. Jones, S. de Haan, E. Pottiaux, O. Bock, R. Pacione, and R. Van Malderen | Information

Since 1990, signals from global positioning system (GPS) satellites have been recorded by networks worldwide. From these GPS observations the zenith total delay (ZTD) can be computed. Using surface measurements of pressure and temperature, these ZTD values can be turned into water vapour amount and used for atmospheric research. The main aim of the COST action ES1206 “Advanced Global Navigation Satellite Systems tropospheric products for monitoring severe weather events and climate” (GNSS4SWEC) is to coordinate the research and the development of new, advanced tropospheric products derived from GNSS signal delays, exploiting the full potential of multi-GNSS (GPS, GLONASS and Galileo) water vapour estimates on a wide range of temporal and spatial scales, from real-time monitoring and forecasting of severe weather to climate research. The potential impacts of this work are great: improved severe weather forecasting, leading to a decreased risk to life and national infrastructure; improvement of climate projections also has major global significance. In addition the action will promote the use of meteorological data in GNSS positioning, navigation, and timing services.

The main topics envisioned in the special issue include the following:

  • The development of advanced and new GNSS tropospheric products related to
    • multi-GNSS constellation signals for water vapour remote sensing,
    • water vapour anisotropy (horizontal gradients, satellite slant delays, tomography, etc.),
    • real-time/ultra-fast water vapour remote sensing in support of nowcasting ,
    • improvement of the temporal and spatial resolution capability of GNSS water vapour remote sensing.
  • The exploitation of these products in numerical weather prediction (NWP) and nowcasting, such as
    • the development of new initialization/assimilation methods in NWP,
    • the development of forecasting tools (water vapour maps, convective indexes, alarm systems, etc.) for nowcasting and severe weather events.
  • The assessment of these GNSS tropospheric products (see first point) derived from a common benchmark reference data set.
  • The assessment of the standardized methods/tools for NWP/nowcasting (see second point) based on the GNSS products built on the benchmark data set.
  • Exploiting re-analysed/reprocessed GNSS tropospheric products for climate studies:
    • comparison/assimilation in the regional/ global climate models,
    • comparisons with other in-situ, ground-based and satellite water vapour retrievals,
    • development and assessment of homogenization methods for GNSS-based product time series,
    • analysing the variability and trends in GNSS-based water vapour retrievals.
  • Establishment of new GNSS analysis centres for monitoring the atmosphere.

Submissions of papers dealing with broader GNSS4SWEC objectives are also encouraged:

  • synergy between GNSS and GNSS radio occultation (RO),
  • monitoring the other components of the hydrological cycle (soil moisture, snow cover, terrestrial water storage) with GNSS.

Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) (ACP/AMT/GI/GMD inter-journal SI)
01 Jun 2015–31 May 2020 | Guest editors: J. Allan, T. Petäjä, T. Karl, M. A. Silva Dias, and T. Garrett | Information

Observations and modelling of the Green Ocean Amazon (GoAmazon2014/5): the GoAmazon2014/5 campaign sought to quantify and understand how aerosol and cloud life cycles in a particularly clean background in the tropics were influenced by pollutant outflow from a large tropical city. The project addressed the susceptibility of cloud–aerosol–precipitation interactions to present-day and future pollution in the tropics. The experiment took place in central Amazonia from 1 January 2014 to 31 December 2015, including intensive operating periods and aircraft in the wet and dry seasons of 2014.

Pan-Eurasian Experiment (PEEX)
01 Jun 2015–31 Dec 2018 | Guest editors: V.-M. Kerminen, M. Heimann, D. Spracklen, T. Laurila, A. Ding, and I. Salma | Information

The Pan-Eurasian Experiment (PEEX) is a multi-disciplinary, multi-scale and multi-component research infrastructure and capacity building programme. The PEEX originated from a bottom-up approach by the science community and is aimed at resolving the major uncertainties in Earth system science and global sustainability issues concerning the Arctic and boreal Pan-Eurasian regions as well as China. The PEEX solves interlinked global, grand challenges influencing human well-being and societies in northern Eurasia and China, by establishing and maintaining long-term, coherent and coordinated research activities as well as continuous, comprehensive research and educational infrastructures. The scientific issues covered by PEEX include climate change, air quality, biodiversity loss, chemicalisation, food supply, fresh water and the use of natural resources through mining, industry, energy production and transport. Our approach is integrative and interdisciplinary, recognizing the important role of the Arctic and boreal ecosystems in the Earth system.

Amazon Tall Tower Observatory (ATTO)
20 Mar 2015–30 Apr 2019 | Guest editors: M. Kulmala, L. Ganzeveld, and G. Fisch | Information

The Amazon Tall Tower Observatory (ATTO) is a flagship long-term measurement station at a pristine location in the center of the Amazon rainforest, 160 km northeast of Manaus. It consists of a 325-meter tower and several 80-meter towers with instrumentation for meteorological, micrometeorological, trace gas, and aerosol measurements. At the ATTO site, studies on a wide range of topics – including trace gas chemistry, greenhouse gas measurements, aerosol chemistry and microphysics, biosphere–atmosphere exchange fluxes, micrometeorology, and ecology – have been conducted since its inception in early 2012. The special issue is open to articles discussing results from these studies; papers on research at related sites in central Amazonia are also welcome.

The Saharan Aerosol Long-range Transport and Aerosol-Cloud-interaction Experiment (SALTRACE) (ACP/AMT inter-journal SI)
16 Feb 2015–30 Sep 2018 | Guest editors: B. Weinzierl, U. Wandinger, C. Flamant, C. Hoose, C. Ryder, and J. Schwarz | Information

Wind-borne mineral dust can affect climate through its interaction with radiation and its role in cloud microphysical processes. In spite of this importance, there has been little research on the long-range transport of mineral dust. In particular critical understanding of the transformations of mineral dust during long-range transport including changes in physical and chemical properties of the particles and the roles of various removal processes during transport is lacking. In addition, climate change threatens to change dust emission rates and hence future dust impacts.

To investigate the long-range transport of mineral dust from the Sahara into the Caribbean, and to study the impact of aged mineral dust on both the radiation budget and cloud microphysical processes, the Saharan Aerosol Long-range Transport and Aerosol-Cloud-Interaction Experiment (SALTRACE) was conducted in June/July 2013. During SALTRACE, mineral dust from several dust outbreaks was studied under a variety of atmospheric conditions, and a comprehensive data set on chemical, microphysical and optical properties of aged mineral dust was gathered.

SALTRACE was a German initiative involving scientists from Europe, Cabo Verde , the Caribbean and the US. It was designed as a closure experiment combining ground-based, airborne, satellite and modelling efforts. Ground-based lidar, in situ aerosol and sun photometer instruments were deployed on Barbados (main SALTRACE super-site), Cabo Verde and Puerto Rico. The DLR research aircraft Falcon carried an extensive suite of in situ and remote-sensing instruments and spent more than 110 flight hours studying the long-range transport of mineral dust between Senegal, Cabo Verde, the Caribbean and Florida.

SALTRACE was highly successful and allowed the collection of a unique mineral dust data set which will be presented in this SI, including papers on the experimental, theoretical, and modelling results, as well as instrument and algorithm developments related to the SALTRACE field experiment.

The Geoengineering Model Intercomparison Project (GeoMIP): Simulations of solar radiation reduction methods (ACP/GMD inter-journal SI)
02 Oct 2014–31 Mar 2018 | Guest editors: U. Lohmann, N. Vaughan, L. M. Russell, B. Kravitz, and H. Wang | Information

The Geoengineering Model Intercomparison Project (GeoMIP) has been highly successful in identifying robust climate model response to various geoengineering scenarios. There are currently seven core GeoMIP simulations, with another four submitted as GeoMIP's contribution to CMIP6. These experiments evaluate model response to various forms of geoengineering, focusing on solar dimming, stratospheric sulfate aerosol injections, marine cloud brightening via sea spray, and cirrus cloud thinning. In this special issue, we examine results from these simulations that have been conducted by 15 climate modeling centers from around the world. The results presented here provide a key source of information about the range of potential climate effects from geoengineering, any possible unintended side effects that geoengineering may cause, and the efficacy of geoengineering as a response to climate change. These simulations also reveal fundamental climate responses to radiative forcing, illuminating various feedback processes and interactions between different components of climate models.

South AMerican Biomass Burning Analysis (SAMBBA)
01 Jan 2014–31 Dec 2018 | Guest editors: H. Coe, K. Longo, M. Andreae, S. Martin, and G. Myhre | Information

Biomass burning aerosol (BBA) exerts a considerable impact on regional radiation budgets as it significantly perturbs the surface fluxes and atmospheric heating rates and its cloud nucleating (CCN) properties perturb cloud microphysics and hence affect cloud radiative properties, precipitation and cloud lifetime. It is likely that such large influences on heating rates and CCN will affect regional weather predictions in addition to climatic changes. Amazonia is one of the most important biomass burning regions in the world, being significantly impacted by intense biomass burning during the dry season leading to highly turbid conditions, and is therefore a key environment for quantifying these processes and determining the influence of these interactions on the weather and climate of the region.

The South AMerican Biomass Burning Analyses (SAMBBA) programme is a major international consortium programme. The programme has delivered a suite of ground, aircraft and satellite measurements of Amazonian Biomass Burning Aerosol during a field study that took place in September 2012. SAMBBA has used this data in a suite of analyses that aims to:

  1. improve our knowledge of BB emissions;
  2. challenge and improve the latest aerosol process models;
  3. challenge and improve satellite retrievals;
  4. test predictions of aerosol influences on regional climate and weather over Amazonia and the surrounding regions made using the next generation of climate and NWP models with extensive prognostic aerosol schemes; and
  5. assess the impact of .biomass burning on the Amazonian biosphere.

The main field experiment was based in Porto Velho, Brazil and investigated the dry season and onset of the wet season. The UK large research aircraft (FAAM) sampled aerosol chemical, physical and optical properties and gas phase precursor concentrations. Measurements of radiation were also made using advanced radiometers on board the aircraft and satellite data are also being used. The influences of biomass burning aerosols are highly significant at local, weather, seasonal, and climate temporal scales necessitating the use of a hierarchy of models to establish and test key processes and quantify impacts. The study is challenging models carrying detailed process descriptions of biomass burning aerosols with the new, comprehensive observations being made during SAMBBA to evaluate model performance and to improve parameterisations. Numerical Weather Prediction and Climate model simulations with a range of complexity and spatial resolution are being used to investigate the ways in which absorbing aerosol may influence dynamics and climate on regional and wider scales. At the heart of the approach is the use of a new range of models that can investigate such interactions using coupled descriptions of aerosols and clouds to fully investigate feedbacks at spatial scales that are sufficiently well resolved to assess such processes.

The community version of the Weather Research and Forecasting Model as it is coupled with Chemistry (WRF-Chem)
(GMD/ACP inter-journal SI)

20 Dec 2013–31 Dec 2018 | Guest editor: G. Grell | Information

The Weather Research and Forecast community modelling system coupled with Chemistry (WRF-Chem) provides the capability to simulate and forecast weather, trace gases, and aerosols from hemispheric to urban scales. WRF-Chem is a community model. WRF-Chem is an online modelling system which includes the treatment of the aerosol direct and indirect effect. It incorporates many choices for gas phase chemistry and aerosols with degrees of complexity that are suitable for forecasting and research applications. Due to its versatility WRF-Chem is attracting a large user and developer community world-wide. The present time-unlimited Special Issue hosts scientific technical documentation and evaluation manuscripts concerned with the community version of WRF-Chem.

Results from the ice nucleation research unit (INUIT) (ACP/AMT inter-journal SI)
18 Dec 2013–31 Dec 2018 | Guest editors: J. Abbatt, A. Bertram, D. J. Cziczo, and B. Ervens | Information

INUIT - Ice Nuclei Research Unit:

Ice crystals play an important role for the radiative properties of clouds as well as for the formation of precipitation. Mixed-phase clouds are clouds that consist of both, super-cooled liquid droplets and ice particles. They account for a large fraction of the clouds in the atmosphere but our knowledge on the microphysical properties of these clouds is still limited. An important question is how ice forms in these clouds. While it is well established that an ice nucleus is needed as a seed for the initial formation of an ice crystal in mixed-phase clouds many questions remain to be answered on the concentration and variability of atmospheric ice nuclei and their physico-chemical properties.

The Research Unit "INUIT" (Ice Nuclei research UnIT) studies heterogeneous ice formation in the atmosphere. The studies include laboratory investigations on the nature of the nucleation process and on the chemical, microphysical and biological characterization of atmospherically relevant ice nuclei as a function of temperature and water saturation. Intensive field experiments are conducted as well as monitoring surveys to study the number concentration, variability, size, chemical composition, surface properties and sources of atmospheric ice nuclei in different freezing modes. Various state-of-the-art methods and facilities are used for the characterization of the ice nuclei. Ice nucleating properties of mineral dust particles, volcanic ash, and biological ice nuclei are a focus of attention of the INUIT research unit. The results of the experimental investigations are fed into a cloud process model and a cloud-resolving meso-scale model to improve the representation of clouds in the models, to simulate cloud processes and to quantify the contribution of ice nuclei types and freezing modes.

The INUIT research unit comprises 9 research projects from 8 partner institutes (Goethe-University of Frankfurt/Main, University of Bielefeld, University of Mainz, Technical University Darmstadt, Leibniz-Institute for Tropospheric Research, Max-Planck Institute for Chemistry and Karlsruhe Institute for Technology). It is funded by the Deutsche Forschungsgemeinschaft DFG (grant no. FOR 1525).

Study of Ozone, Aerosols and Radiation over the Tibetan Plateau (SOAR-TP) (ACP/AMT inter-journal SI)
31 Oct 2013–31 Dec 2019 | Guest editors: R. Sander, H. Su, T. Wagner, T. Wang, Y. Cheng, X. Xu, W. Tian, and Y. Yin | Information

The Tibetan Plateau, also known in China as the Qinghai-Tibet Plateau, has a large influence on atmospheric circulation, hydrological cycle and climate in East Asia as well as the Northern Hemisphere. The plateau, sometimes called "the Roof of the World" or "the Third Pole", covers a huge area located in 73-105 E longitude and 26-40 N latitude, with mean surface elevation of 4000-5000 m above sea level. It has long been considered as one of the remote regions in the Eurasian continent that are relatively less influenced by pollution from human activities. While natural processes that control the temporal and spatial variations of atmospheric composition over the Tibetan Plateau are still inadequately understood, the influence of long-range transport of pollutants from surrounding areas, e.g. South and Southeast Asia, and farther regions on the background atmosphere of the Tibetan Plateau and associated climate impacts have become a scientific issue to be intensively addressed.

Long-term measurements of trace gases, aerosols and radiation have been performed at several remote sites in the Tibetan Plateau region, including e.g. the Waliguan Global Baseline Station and the Shangri-la Regional Background Station (both operated by China Meteorological Administration) and the Nam-Co Comprehensive Observation and Research Station (operated by Institute of Tibetan Plateau Research, Chinese Academy of Sciences). Intensive field campaigns were carried out based on these stations and some other sites of the region during different periods to investigate the levels and variation controlling factors of atmospheric ozone and aerosols over the plateau. Observations include in-situ measurements of ozone and related trace species, in-situ and sampling measurements of aerosol physical properties and chemical composition, sounding of ozone and water vapor, lidar measurements of aerosols, and ground-based remote sensing of selected trace gases, etc. Models are also used to compare with measurement results and interpret data. The purpose of this issue is to expand our understanding of physic-chemical and transport processes that largely influence atmospheric ozone and aerosols as well as radiation over the Tibetan Plateau.

CHemistry and AeRosols Mediterranean EXperiments (ChArMEx) (ACP/AMT inter-journal SI)
14 Oct 2013–31 Jul 2018 | Guest editors: N. Mihalopoulos, W. Lahoz, X. Querol, C. Reeves, F. Dulac, O. Dubovik, J.-L. Attie, M. Beekmann, and E. Gerasopoulos | Information

The Chemistry and Aerosol Mediterranean Experiment (ChArMEx) special issue will be simultaneously presented in the ACP and AMT journals. It aims at gathering experimental and modelling contributions to the field of atmospheric chemistry in the Mediterranean region and its impacts on regional air quality and climate, both in the recent past, present and future decades. It addresses natural and anthropogenic emissions of tropospheric reactive species, source apportionment, chemical transformations, transport processes, atmospheric deposition, aerosol optical properti

VERDI – Vertical Distribution of Ice in Arctic Clouds (ACP/AMT Inter-Journal SI)
01 Dec 2013–31 Dec 2018 | Guest editors: C. Hoose, M. Shupe, and P. Eriksson | Information

The scientific expedition VERDI (short for Vertical Distribution of Ice in Arctic Clouds) is a cooperation project of various German research institutes with the goal to measure the microphysical and optical properties of Arctic boundary-­layer clouds, and to investigate the effects that those clouds can have on the energy budget in the Arctic atmosphere. The VERDI participants have successfully performed airborne measurements of the microphysical and radiative properties of clouds in the Canadian Arctic (based in the town of Inuvik in the Northwest Territories) in April and May 2012, and are now working on the data processing and evaluation. At least seven publications on VERDI results (listed below) are planned, and it is desired to bundle these in the planned ACP/AMT inter-­journal special issue. The special issue is open for all submissions within its scope.

HCCT-2010: a complex ground-based experiment on aerosol-cloud interaction
25 Oct 2011–31 Dec 2018 | Guest editors: G. McFiggans, M. C. Facchini, C. George, and H. Herrmann

Publications Copernicus