************************************************************************ IERS Message No. 388 December 17, 2019 ************************************************************************ Earth rotation session at EGU 2020 Dear Colleagues, As part of the EGU General Assembly 2020 (https://www.egu2020.eu/) that will be held in Vienna 3 - 8 May 2020, 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/EGU2020/session/35334). 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: 15 January 2020, 13:00 CET. https://meetingorganizer.copernicus.org/EGU2020/abstractsubmission/35334 We are looking forevard to seeing you in Vienna! Best regards, Maria Karbon, Sigrid Boehm, Alberto Escapa, David Salstein, Florian Seitz G3.1 Earth Rotation: Theoretical aspects, observation of temporal variations and physical interpretation Over the past years significant progress has been made in the advancement of geodetic observation systems that resulted in largely improved accuracies of parameters related to the Earth's rotational motion and its variability. In this session we seek contributions in the following areas: We are interested in the progress of theories of Earth rotation. We seek contributions on theoretical developments that are consistent internally and with the highly accurate observations at the mm-level, to meet the requirements of the IAG's Global Geodetic Observing System (GGOS). In particular, we invite presentations that address questions raised in the final report of the IAU/IAG joint working group, 'Theory of Earth Rotation and Validation'. With respect to geodetic and astrometric observational techniques, we seek contributions that highlight new determinations of Earth Rotation Parameters (EOP) series and their analyses, including combinations of different observing techniques. We also invite discussions 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 also of investigations leading to more 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 the changing motions and mass redistribution of the fluid portions of the planet due to angular momentum exchange. Observations of the geophysical fluids (e.g., atmosphere, oceans) have achieved a new maturity in recent years. Independent observations include the results of recent gravity missions like GRACE. We also welcome contributions about the relationship between EOP variability and current or potential variability in fluids due to climate variation or global change signals. Besides contemporary determination of the EOP and the related geophysical excitations, forecasts of these quantities are important especially for the operational determination of Earth orientation, e.g., for spacecraft navigation; the effort to improve predictions currently is a topic of strong interest. In this sense, the session is also open to contributions dealing with the operative use of Earth orientation in different applications. In addition, we will welcome input on the modeling, characteristics, variability, and excitations of the rotation parameters of other planets or 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/Messages/ ************************************************************************