Session co-organizing by programme groups
Conveners can suggest other programme groups to co-organize their session on submission. The chair of the programme group hosting the session is responsible for sending the invitations for co-organization to other programme groups. Acceptance of these suggestions lies with the receiving programme group chairs. Co-organized sessions are supposed to be truly multi-disciplinary in nature and to entail active involvement (through convenership) of members identifying with all co-organizing programme groups/divisions.

Session co-sponsoring by colleague science organizations
The EGU encourages session co-sponsoring by other colleague organizations as a means of strengthening ties and encouraging collaboration. Co-sponsoring organizations will be listed in the session subtitle (automatically set by the system). Session co-sponsoring is expected to follow these guidelines: (i) co-sponsoring is reciprocal, involving sessions at meetings of both partners, (ii) the session has conveners from both organizations, (iii) the colleague organization agrees to session co-sponsoring, and (iv) session co-sponsoring is intended for colleague scientific organizations and does not imply funding. A co-sponsoring organization should furthermore not influence the work of the conveners or the content of the session. Programme group chairs decide on co-sponsoring of a session within their respective programme group. On session submission you will be asked to indicate whether co-sponsoring is a wish of or already approved by the colleague science organization.

• The EGU strongly encourages conveners to build their teams and organize their sessions considering and promoting under-represented demographics, in particular including: (i) multiple countries and institutes, (ii) different career stages, with particular attention to the participation of Early Career Scientists, (iii) different genders and all other forms of diversity, and (iv) diverse scientific approaches. The EGU Equality, Diversion and Inclusion (EDI) Working Group created the EDI session logo to be added to your session if your convener team fulfills the 3 criteria diversity in gender, career stage, and origin. An automatic check and assignment of this EDI logo is applied, if all conveners have filled their user profile. If individual conveners have not filled their user profile, you will be asked to manually indicate whether the diversity criteria are fulfilled. We then kindly ask you to encourage your colleagues to complete their profile online.
• A convener team consists of a minimum of 2 active conveners (1 convener and 1 co-convener) and a maximum of 5 conveners (1 convener and 4 co-conveners) per session.
• Our rule is a maximum of 3 (co-)convenerships in total, with one as lead convener. One additional (co-)convenership for Union Symposia and Great Debates is allowed (that is, a maximum of 4). Short Courses are exempted from the guideline on the number of convenerships. Please check with all co-conveners that they agree to take part in the proposed session.
• Every session require at least two conveners to be onsite in Vienna. If this cannot be guaranteed, two chairpersons must be assigned and be available onsite to guide the session.

Session proposals can be submitted during the public call-for-sessions. When submitting a session, the following steps are required.

• Define your session with a title and a short description (200–2500 characters).
• Identify the lead conveners and co-conveners (more information below).
• Optionally, identify (co-)conveners as Early Career Scientists (ECS).
• Identify one of the conveners as being responsible for the Outstanding Student and PhD candidate Presentation (OSPP) competition in your session.
• Submit your session proposal to one programme group only.
• Avoid submitting session proposals that are similar to sessions already suggested. Rather, you can contact conveners of suggested sessions or directly propose modifications to already suggested sessions if you would like to be involved.
• Define keywords from the EGU23 keywords list. The keywords are used to identify potential session similarities, during building of the session programme and during session scheduling. The main target is inter-programme group overlaps. Keywords are not used to characterize sessions for online search tools.
• Indicate whether your session might be considered for Inter- and Transdisciplinary Sessions (ITS). If yes, please read the ITS guidelines and select one of the ITS' sub-programme groups.
• Indicate other programme groups for potential co-organization.
• Indicate whether your session is to be co-sponsored by a colleague science organization. Please state whether this co-sponsorship's status is proposed or approved by the colleague organization.
• Consider organizing a special issue about your session in one of the EGU's open-access journals. A subject-based selection is given in the proposal form for further information. Please take a look at the list of the EGU's topical journals as well as EGU's proceedings series Advances in Geosciences.
• Respect the session submission deadline. Last-minute submissions are difficult to handle in our large programme.

The programme group chair and officers build the session programme from the session proposals. You will be informed of acceptance of your session by email. The programme group chair can also suggest proposed sessions that are similar to merge.

Apart from regular scientific sessions, during the call-for-sessions we accept proposals for the following.

• Short courses
• Union Symposia and Great Debates
• Inter- and Transdisciplinary Sessions

During the initial period of the abstract submission, authors are able to submit their abstracts together with a financial support application. Conveners are kindly asked to rate those applications in order to provide the support selection committee with your preferences for whom should be granted financial support. Please note that applications without a convener rating and/or without payment cannot be considered.

Please rate the applications (a) by the quality of the science, as well as (b) by the quality of the abstract. You can also mark one abstract per session as being essential. This will be shown in all the subsequent ranking and decision forms in addition to the rating value. Conveners are not allowed to rate or comment on financial support applications in which they are involved as a co-author. These applications must be handled either by another session convener or directly by the programme group chair. Following your rating your programme group chair will then provide a ranking of all applications within their programme group to the support selection committee.The support selection committee will consider this programme group ranking for the final assessment.All applicants will be informed about the final decision of the selection committee. Independent of a positive or negative decision, authors are requested to confirm their participation in the meeting by the given deadline. Abstracts without a participation confirmation will be withdrawn automatically.

During abstract submission you will see the abstracts submitted to your session when using the convener login link. Solicited presentations provide a means to highlight a specific topic within a session. Solicited authors can be added in the session modification tool during the call for abstracts period and will be shown as additional information to the session description. Our guideline is 1 solicited abstract per session. Solicited abstracts can be for oral, virtual PICO, or poster presentations, but please note that orals are not guaranteed. We ask conveners to consider diversity in country, career stage, gender, and scientific approaches when soliciting a presenter and when encouraging colleagues to submit abstracts to their session.

Authors are allowed as first author to submit either one regular abstract plus one abstract solicited by a convener, or two solicited abstracts. A second regular abstract can be submitted to sessions led by the Education and Outreach Sessions (EOS) programme group (the maximum number of abstracts, including solicited abstracts, remains two). Since the system limits submissions to one, authors will need to provide a transaction number (TAN) when submitting their second abstract, whether this second abstract is the solicited or regular one. TANs have to be provided by the convener of the session of the solicited abstract. That means, you can generate 1 TAN for your session through your session overview, send an email to your solicited author naming this TAN, and keep track of TAN assignment and usage. We suggest sending the TAN as early as possible to your solicited author to avoid last-minute problems. If you are the convener of session X and your solicited author submits first their regular abstract to session Y and then the solicited abstract to your session X, the TAN of your session X is actually used for the submission to session X. However, if the author submits first their solicited abstract to your session X (system does not ask for a TAN yet) and then submit their regular abstract to session Y, the system will ask at session Y for a TAN since it is the second abstract. Then, the author must use the TAN obtained from you for session X at session Y and must not ask the convener of session Y for a TAN. Please note that the actual abstract status solicited will be defined later in the process during presentation selection (SOIII).

Automatic cancellation of small sessions
Sessions with four (4) or less abstracts after the abstract deadline will automatically be cancelled. Authors of abstracts in withdrawn sessions will be given the opportunity to transfer their abstract to another session.

SOI tasks
During the abstract implementation phase, you are asked to review abstracts originally submitted to your session, those which are suggested to be transferred to your session, as well as abstracts without an assignment. In addition, you may upload late contributions by the strict deadline of 20 January 2023, 13:00 CET. Please note the guidelines for abstract submission. The outcome of this tool is the final list of active contributions to be scheduled in your session.

Late abstracts
Please note that late contributions uploaded by you require approval by the programme group chair in the subsequent programme committee tools. Late abstracts have a strict deadline of 20 January 2023, 13:00 CET. Abstracts sent by authors at a later stage cannot be accepted.

Late contributions uploaded by conveners have an increased abstract processing charge (APC) of €95 as regular abstracts (€50) and also need to be paid. Payment is by these options: (1) author's credit card (the author gives the convener the details), (ii) convener's credit card or PayPal (conveners cannot be reimbursed by the EGU), or (iii) the convener may request the author to pay the APC. In the latter case, a PDF invoice is sent to the author by email. First authors are required to become EGU members before submitting a late abstract.

Abstracts of public interest
In SOI, conveners have the opportunity to select 3–5% of abstracts in their session of greatest relevance to a broad audience. The abstracts of public interest check box allows you to select abstracts to be highlighted to the public.

Session mergers
Sessions that received few submissions or are very similar in scope can be merged. Conveners can merge sessions themselves in the SOI – abstract implementation tool, after informing the programme group chair of their intention. Conveners should also inform the authors and give them some time to request a transfer to a different session. Please follow this procedure:

1. Contact your programme group chair if you need/want to merge your session.
2. Discuss between all conveners of the sessions to be merged which session is going to be used as the basis for the new merged session.
3. Update the title, abstract, and list of conveners of the base (merged) session.
4. Mark all abstracts in the other session for transfer to the new merged session.
5. Accept all those abstracts in the new session. The result is that the base session for the merge now contains the abstracts of all sessions, while the other sessions contain no abstracts and can be withdrawn, i.e. removed, in the next stage.

It is recommended that the convener list, the session title, and the description be adapted (in the session modification tool) in the case of a session merger. This is to guarantee the best representation of the ideas, topics, and targeted communities.

During session tagging, you are asked to provide the programme committee with your scheduling requests. These may include requests for no-overlap, back-to-back scheduling, a specific lecture room size, or any other information that you consider to be useful. Conveners are also asked to estimate the potential number of participants. Missing information from the SOI or SOII tools will be filled in by the programme committee.

The programme committee will schedule your session in terms of day, room, and time. Thereafter, authors will receive a letter of acceptance/rejection by email.

Publishing proceedings of special issues in EGU journals
Please consider a publication of your session's proceedings in the EGU's open-access journal Advances in Geosciences or as special issue in one of the EGU's thematic open-access journals. You can indicate your interest during session proposal or later in SOII – session tagging. The editorial support team of Copernicus Publications will be informed and will contact you for further processing.

The programme committee will schedule your session and you will be informed by email of the time and room assigned to your session. EGU strongly encourages conveners to organize their sessions considering and promoting under-represented demographics, in particular including: (i) multiple countries and institutes, (ii) different career stages, with particular attention to the participation of early career scientists, (iii) different genders and all other forms of diversity, and (iv) diverse scientific approaches. In SOIII you will be asked to do the following:

• For oral/poster sessions, subdivide the abstracts into oral, on-site poster, and virtual poster presentations. For PICO sessions, the abstracts are already marked as PICO.
• Each oral presentation has a length of 10 minutes. The presentation length includes the time for change over and discussion.
• You cannot schedule presentations for more than the time block(s) assigned to your session. You can schedule presentations for less than that time, with the remainder set aside for discussion or including a slot for an introduction. In the tool SOIII, feel free to use the button "Add subtitle" to structure your session.
• Define the ordering of the talks and posters, or PICO presentations.
• Assign solicited abstracts (see below). You should aim for no more than one solicited presentation per time block. You can (but are not obliged to) attribute a 10-minute, 20-minute, or 30-minute time slot to one solicited presentation per time block.
• Define at least two chairpersons for every time block, who will be present in-person at the conference. If none of the conveners aim to be present in-person, you can appoint a chairperson who is not a convener.

Your selections will generate a draft session programme with a subdivision of the different times for the presentations. Missing information from SOIII will be filled in by the programme committee. All authors will receive their letter of schedule by email, mentioning the actual time and location of their presentation.

Information on solicited abstracts
Solicited submissions are those abstracts that you would like to particularly highlight in your session. Please note the following:

• Authors (first and co-authors) cannot have a solicited presentation in a session they (co-)convene. (Co-)conveners cannot be the presenting author, and are discouraged from being a co-author, in oral presentations in a session they convene.
• You can indicate the names of solicited presenter(s) in the description of your session (solicited presenters: Eugene G. Underwood, EugeneG@Under.com; Janice E. Smith, janice@smith.com). This can be done by using the tool session modification with access through the convener login link in the session programme.
• You can assign the status of "solicited" to oral, poster, or PICO abstracts when you compile your final programme (see SOIII).
• You should aim for no more than one solicited presentation per time block. Programme group chairs decide on whether an exception can be made to have more than one solicited presentation per time block, with the programme committee chair mediating in any exceptional cases.
• Authors of solicited abstracts do not receive discounted abstract processing charges, registration fees, or travel reimbursement.

The main time blocks of the General Assembly are: