We want to share our experience by summarizing the latest results on the different subjects related to the Earth core and rotation and by putting that on the web. We are making a bibliography of existing publications on that subject. As the determination of core angular momentum is highly dependent on the approximations used in the computations (geostrophic, frozen-flux, etc.), we have given on our web site a description of the theory behind and the relevant information necessary to understand the data. The subjects treated are: core convection, core modes, core flow, core composition, geomagnetism, CMB torques, inner core differential rotation and Earth's rotation changes due to the core. We have additionally made the link between existing bodies related to the core and the IERS community. We think that this first step will improve our knowledge and will help the IERS community to understand core-related phenomena of interest for IERS.
We make available to the scientific community all the relevant data for studies of core-mantle angular momentum.
We plan to validate the models presented in the second step by using the IERS observed EOP, and to share the information with the IERS community (this web service, to be built later). This step would be separated into short period and long period time scales. For the long period time scale, observed variation of the length-of-day will be used in the validation process; on short time scale, the information from the effect of the free nutations (Free Core Nutation (FCN) and Free Inner Core Nutation (FICN)) on nutation and diurnal polar motion, as well as the information from the resonance induced in the tidal forced nutations will be used.
When one model will be validated and experienced on data, we plan to make it available, understandable and runnable on data (software should be provided) to the IERS community (future web service).
When models are run, when information are used, or when data are treated, it is expected and encouraged that the IERS scientific community interacts for an exchange of ideas and opinions, in particular, for a better understanding of the physics inside the different parts of the models (or of the potentially missing parts). Please send us an e-mail for providing us with your suggestions.