The EUMETSAT Sustainable Production of Atmospheric Motion Vectors Climate Data Records
This presentation will highlight the sustained production and usage of Climate Data Record (CDRs) of Atmospheric Motion Vectors (AMVs) from imagers on-board geostationary and polar-orbiting satellites at EUMETSAT.
The AMV CDRs are mainly used in the creation of long term reanalysis having a big impact on their quality. But it can also be used to analyse the evolution of climate patterns. AMV are one of Essential Climate Variables (ECV) defined by GCOS that can be retrieved from satellite observations. Considering the number of instruments potentially suitable to derive AMVs, only a few AMV data records are currently available or are planned for the future, as listed in the CEOS-CGMS ECV inventory. EUMETSAT is one of few agencies currently producing AMV ECV data records, it is important to improve the sustainability of the production worldwide.
Since the launch of its first generation of geostationary satellites, EUMETSAT has developed its own unique algorithms to derive AMVs in real time using images acquired from instruments on-board both polar and geostationary satellites. EUMETSAT archived all image data back to the 1970s providing a suitable data source for climate research and allowing producing AMV climate data records. In the framework of the Copernicus Climate Change Service (C3S), EUMETSAT produced AMV CDRs from its own geostationary Meteosat imagers and polar orbiting Metop and NOAA satellites.
The EUMETSAT GEO AMV CDRs are produced from 10 of the 11 Meteosat satellites located at their nominal 0° position allowing a unique almost 40-years long record. Recently a new 21-year long climate data record (1998-2019) CDR has been produced using Meteosat first and second generation located over the Indian ocean.
The full resolution images (Local Area Coverage) from the Advanced Very High Resolution Radiometer on-board the polar orbiting Metop-A and -B satellites were used to generate a CDR containing polar AMVs from single satellite retrievals and global AMVs from the combined Metop-A/B dual satellite retrieval. An adaptation of the EUMETSAT retrieval algorithm to use Global Area Coverage data allowed the creation of a 41-years polar AMVs CDR from the entire series of 16 AVHRR instruments flying on the NOAA satellites since TIROS-N in 1978.
There is very little observation prior to 1980. In the 1970’s the Temperature Humidity Infrared Radiometer (THIR) was flown on four NASA Nimbus satellites (Nimbus-4 to -7). In the framework of the first C3S, a THIR Fundamental Data Record (FDR) was produced. EUMETSAT recognised this FDR has a great opportunity and a first candidate for deriving an early-era AMV CDR. A study has started to assess its feasibility and potentiality.
In the coming years, EUMETSAT will address some of the new reprocessing challenges for AMVs for the benefit of the global and regional reanalyses produced by C3S and climate analysis of dynamical features of the atmosphere. The extension of methods to other geostationary satellites offers the potential for increased collaboration leading to improved sustainability of the production and temporal and spatial total coverage extension.
