Possible definition of Essential Variables for the Upper Atmosphere from the perspective of the Focus Area Geodetic Space Weather Research

The visibility of geodesy as a discipline is still far too low in the public eye, but also in the scientific community. On the other hand, geodesy provides many products that are used in almost all modern applications and research areas, e.g. in navigation and climate research. Thus, there is an urgent need to promote this branch of science and its products. In other areas such as climate research or oceanography, so-called essential variables have already been defined. More specifically, the Global Climate Observing System (GCOS) introduced the Essential Climate Variables (ECV) in 2011 and the Global Ocean Observing System (GOOS) defined the Essential Ocean Variables (EOV) in 2014, both of which are now standard. One current goal of the Global Geodetic Observing System (GGOS) is to define similar essential variables for geodesy and its products. In order to realize this, the introduction of Essential Geodetic Variables (EGV) is being discussed withing the GGOS community. In this contribution, the already existing ECVs and EOVs are analyzed for their use as EGVs in relation to the atmosphere. If the usual geodetic separation into lower, mid and upper atmosphere is taken as a basis, there are major differences with respect to the definition of the various atmospheric layers considered by GCOS and GOOS. It is essential to solve these discrepancies in order to arrive at a general and unambiguous interpretation across all areas. This is the only way to avoid misinterpretations.