************************************************************************ IERS Message No. 466 December 20, 2022 ************************************************************************ Earth rotation session at EGU 2023 Dear Colleagues, The EGU General Assembly 2023 (https://www.egu2023.eu/) will be held in Vienna and online, on April 23-28, 2023. We would like to draw your attention to session G3.4 "Earth Rotation: Theoretical aspects, temporal variability, physical interpretation, and prediction" (https://meetingorganizer.copernicus.org/EGU23/session/46291). Please find below the detailed description. We are looking forward to your contribution by submitting an abstract to our session through https://meetingorganizer.copernicus.org/EGU23/session/46291 . The deadline to submit abstracts is 10 January 2023, 13:00 CET. Best regards, Sara Bruni, David Salstein, Sigrid Boehm, Alberto Escapa and Florian Seitz Session description: Accurate modeling and prediction of Earth rotation is important for geodesy, astronomy and navigation, and relates to the variability of the circulation of geophysical fluids. Over the past years, the geodetic monitoring of Earth rotational motion and its variability has significantly improved, which must be accompanied by an enhancement of theories and models. We are interested in the progress in the theory of Earth rotation. We seek contributions that are consistent internally with the accurate observations at the mm-level, to meet the requirements of Global Geodetic Observing System and respond to IAG 2019 Res. 5 and IAU 2021 Res. B2. We invite presentations within the scope of the IAU/IAG JWG Improving Theories and Models of the Earth's Rotation. We welcome contributions that highlight new determinations, analyses, and predictions of Earth Orientation Parameters (EOP), including combinations of different geodetic and astrometric observations for deriving UT1/length-of-day variations and polar motion. We welcome discussions of EOP solutions in conjunction with a consistent determination of terrestrial and celestial frames, as tackled in the IAG/IAU/IERS JWG Consistent Realization of TRF, CRF and EOP. We invite contributions investigating the dynamical basis for links between Earth rotation, geophysical fluids, and other geodetic quantities (Earth gravity field, surface deformation, ...), and explanations for the physical excitations of Earth rotation. Besides tidal influences from outside the Earth, the principal causes for variable EOP appear to be related to angular momentum exchange from variable motions and mass redistribution of the fluid portions of the planet. Observations and analyses of the geophysical fluids, including the results provided by gravity missions (e.g. GRACE) are relevant for this session. We welcome submissions about the relationship between EOP variability and current or potential variability in fluids due to climate variation or global change signals. Forecasts of these quantities are important especially for the operational determination of Earth orientation. Given the relevance of EOP predictions, we are particularly interested in results from the current 2nd EOP Prediction Comparison Campaign and in contributions exploring the potential of innovative techniques, such as the use of artificial intelligence. We also welcome input on the modeling, variability, and excitations of the rotation of other planetary bodies. ************************************************************************ IERS Messages are edited and distributed by the IERS Central Bureau. If not stated otherwise, the IERS is only the distributor of the message and is not responsible for its content. To submit texts for distribution, please write to . To subscribe or unsubscribe, please create an IERS account or modify it: https://www.iers.org/Login/Login/EN/login_node.html or write to . Archives: http://www.iers.org/IERS/Messages ************************************************************************