************************************************************************ IERS Message No. 365 December 20, 2018 ************************************************************************ EGU 2019: Session on Earth rotation Dear colleagues, We invite you to take part in our Session G3.1 on Earth rotation at the upcoming European Geosciences Union General Assembly, in Vienna, Austria, 7-12 April 2019. Abstracts can be submitted before January 10, 2019, 13:00 CET: https://meetingorganizer.copernicus.org/EGU2019/abstractsubmission/30375 This session will also be part of the planned refereed proceedings of the Geodesy sessions at EGU 2019 in the open-access journal "Advances in Geosciences" (https://www.advances-in-geosciences.net/) of the European Geosciences Union. As a participant of the session you will have the option to submit a paper to the proceedings. The tentative deadline for the submission of manuscripts is end of May 2019. Please note that the submission of a paper is not obligatory, but optional. Below you can find the session description. We are looking forward to seeing you in Vienna! Thank you! Sigrid Boehm, Maria Karbon, David Salstein, Florian Seitz and Alberto Escapa G3.1 Earth Rotation: Theoretical aspects, observation of temporal variations and physical interpretation There is great interest in the Earth's rotational motion and variability and much work on challenging problems in this field. We are looking forward to receiving your abstracts as well as learning about and discussing the ideas and findings relevant to one of the following areas: First, 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 from 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 EOP series and their analyses, including combinations of different observing techniques. We also invite discussions of the dynamical basis for links between Earth rotation, geophysical fluids, and other geodetic quantities, such as the Earth gravity field or surface deformation, and 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. Observations of the geophysical fluids, such as the atmosphere, oceans, and other hydrological reservoirs, have achieved a new maturity in recent years. Independent observations of the relevant mass fields 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 and variability 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 and to subscribe or unsubscribe, please write to . Archives: http://www.iers.org/Messages/ ************************************************************************