************************************************************************ IERS Message No. 412 December 08, 2020 ************************************************************************ Earth rotation session at EGU 2021 Dear Colleagues, As part of the EGU General Assembly 2021 (https://www.egu2021.eu/) that will be held virtually from 19 to 30 April 2021, we like to draw your attention to session G3.1: Earth Rotation: Theoretical aspects, observation of temporal variations and physical interpretation (https://meetingorganizer.copernicus.org/EGU21/session/39900). Below you can find the detailed description. We are looking forward to your contribution by submitting an abstract to our session. Please keep in mind the abstract submission deadline: 13 January 2021, 13:00 CET through https://meetingorganizer.copernicus.org/EGU21/abstractsubmission/39900 We are looking forward to count on your participation! Best wishes, Alberto Escapa, Sigrid Boehm, Maria Karbon, David Salstein, Florian Seitz ------------------------------------------------------------------------ Rationale G3.1 Earth Rotation: Theoretical aspects, observation of temporal variations and physical interpretation Accurate modeling and prediction of Earth rotation is of paramount importance in many disciplines, e.g., geodesy, astronomy and navigation. Over the past years geodetic observation systems have made significant advances in monitoring Earth rotational motion and its variability. That progress must be accompanied by an enhancement of the theories, conventional models, etc., as was recently recognized in Resolution 5 adopted at last IAG GA (Montreal, 2019). In this session, 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 (GGOS) and respond to IAG Res. 5. 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 and analyses of Earth Orientation Parameters (EOP) series, including combinations of different geodetic and astrometric observational techniques. 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 of both the dynamical basis for links between Earth rotation, geophysical fluids, and other geodetic quantities, such as the Earth gravity field or surface deformation, and of investigations leading to detailed 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 of the geophysical fluids (e.g., atmosphere and oceans) have achieved a new maturity in recent years. Independent observations include the results of recent gravity missions like GRACE. We welcome contributions 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 and its application, e.g., spacecraft navigation; the effort to improve predictions currently is a topic of strong interest. We welcome input on the modeling, variability, and excitations of the rotation of other celestial 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/Messages ************************************************************************