What major advantages do the interactive scientific journal ACP and its discussion forum ACPD offer to the authors of scientific papers?

• rapid publication and free dissemination;
• transparent peer review;
• immediate feedback via interactive discussion within the scientific community;
• moderate article processing charges and inclusion of colour plots, animated visualization, etc. at no extra charge;
• efficient new way of publishing special issues (no "waiting for the last paper");
• liberal copyright agreement.

What major advantages do ACP and ACPD offer to the readers and scientific community?

• free and rapid dissemination of novel concepts and data;
• fostering and documentation of scientific discussion;
• enhancement of scientific quality control by Interactive Public Peer Review^TM;
• enhanced information content of scientific papers by appended comments;
• promotion of scientific conciseness and completeness at the same time by including comprehensive abstracts rather than imposing strict page limits.

How are efficient distribution and permanent archiving and accessibility of ACP and ACPD achieved by the publisher Copernicus Publications

• ACP and ACPD are distributed via the Internet and on paper. The Internet access to articles is free of charge, and paper copies are distributed to several principal libraries around the world. Additional paper copies can be purchased by institutional and private subscribers.
• To ensure continuous online accessibility of ACP and ACPD, the website contents are updated daily on several independent Internet servers at different locations throughout the world (mirror sites).

How are discussion papers and interactive comments archived in ACPD, and are the interactive comments citable?

Discussion papers are archived in the regular volume of ACPD and receive a DOI. The short comments, referee comments, editor comments, and author comments published in the interactive discussion of the papers are archived in a supplement with pagination, which allows citation of every individual interactive comment but avoids their indexing in scientific publication databases.

Why does ACP not provide an individual category for particularly short papers ("letters" or "short communications")?

• Since the process of peer review and publication in ACP is inherently efficient and rapid for all types of manuscripts, there is no need to introduce artificial length restrictions. In traditional "letters" or "short communications" with rigid length restrictions, conciseness is frequently achieved at the expense of scientific completeness.
• To support scientific conciseness and completeness at the same time, ACP favours the inclusion of extended abstracts (preferably < 2 pages) in all manuscripts submitted for peer-reviewed publication, i.e. for both discussion papers (ACPD) and final revised papers (ACP).

Why is the quality of publications expected to be high not only for ACP but also for ACPD, even though the access peer review is not as extensive as a traditional full peer review?

• First of all, manuscripts with a clear lack of substantial results or with excessive formal deficiencies will be sorted out rigorously in the access peer review in the same way as in the peer review of conventional journals.
• Even if a low-quality paper passed the access peer review and was published in ACPD, its deficiencies would most probably be revealed in the interactive public discussion by the referees and other interested scientists. The opportunity for interactive public discussion of papers allows efficient cross-control of publication quality within the scientific community and is expected to deter deficient submissions.
• The access peer review is meant to assure the basic scientific and technical quality of the papers published in ACPD, but the opportunity for an efficient public discussion by all interested members of the scientific community immediately following publication is expected to enhance the actual quality control beyond the limits of the traditional peer review. However, even in cases where no short comments from the scientific community are received, a full peer-review process in the traditional sense, albeit in a more transparent way, is still assured before full acceptance and publication of a paper in ACP.

What happens if a manuscript that has been published as a discussion paper in ACPD is not accepted for publication as a final paper in ACP? Can the manuscript be withdrawn from ACPD?

Discussion papers published in ACPD remain permanently archived, citable, and publicly accessible. Normally, they cannot be withdrawn after publication. This approach has been chosen for a number of practical and conceptual reasons, and it has proven to be beneficial for scientific communication and quality assurance as explained above. For further information, please see the EGU Position Statement on the Status of Discussion Papers Published in EGU Interactive Open Access Journals.

Nevertheless, we are aware that the publication of a paper in ACPD and subsequent non-acceptance into ACP can be inconvenient for authors. In such cases, the authors have the following options to proceed:

• Option A

  The authors can appeal to the ACP executive editors for review and revision of the editorial decision. In this case, the executive editors will carefully review the decision of the co-editor who originally handled the manuscript. This process will normally involve the original or additional referees and an iteration of manuscript review and revision. An appeal is recommended only if the authors are firmly convinced that the editorial decision not to accept the paper for ACP was clearly erroneous and that their manuscript clearly meets all evaluation criteria for acceptance into ACP.

• Option B

  The authors can submit a rewritten manuscript for review, discussion, and publication in ACPD and ACP. If the co-editor and/or authors of a manuscript published and discussed in ACPD conclude that the manuscript can and should be rewritten in a way which goes beyond regular revisions (e.g. addition of substantial new results, etc.), a rewritten manuscript can at any time be submitted for independent review, discussion, and publication in ACPD and ACP.

• Option C

  The authors can submit the manuscript to an alternative journal. In many scientific journals, prepublication in a scientific discussion forum (like ACPD) is considered equivalent to prepublication on a scientific preprint server (like arXiv.org) and is not regarded as a reason for exclusion from (re)submission for fully peer-reviewed publication. We expect that in the long run most if not all scientific journals will adopt this policy. Normally, even very good manuscripts can be further improved by revision. In the unlikely event that a very good manuscript cannot achieve publication in ACP, a revised and further improved version is very likely to achieve publication in an alternative journal.

Overall, we are confident that the advantages of permanent archiving outweigh the potential disadvantages. For exceptional individual cases in which this policy may be disadvantageous, we regret any potential inconvenience. Nevertheless, we hope that we have the authors' understanding and continued support in the effort to improve scientific communication and quality assurance via interactive open-access publishing.