Characterising AMV Errors Using the NWP SAF Monitoring
The NWP SAF (Satellite Application Facility for Numerical Weather Prediction) atmospheric motion vector monitoring aims to improve our understanding of AMV errors in order to enable improvements to the AMV derivation and their impact in NWP.
https://www.nwpsaf.eu/site/monitoring/winds-quality-evaluation/amv/
The monitoring provides a long-term archive of observation minus background (O-B) statistics which compare the observation with a short-range NWP model forecast, interpolated in space and time to the observation location. The NWP SAF maintains an archive of several years of O-B statistics against both the Met Office and ECMWF global models.
On a two-yearly basis, a thorough evaluation of the AMV monitoring is documented in a series of analysis reports (AR). Discrepancies between the AMVs and the models are described and catalogued. Where appropriate, detailed case studies are used to try and identify the cause of the bias and any actions that could help resolve or mitigate the problem, either in the derivation or in the assimilation.
The analysis reports are published to coincide with International Winds Working Group meetings. In this paper we present a summary of the latest analysis report (AR9) published in 2020. Topics covered in AR9 include the influence of orography on AMV quality, Meteosat-8 AMVs tracking low cloud and fog near the coast of Africa, and further investigations in the Indian Ocean. We also document O-B differences in the GOES AMVs as a result of changes introduced by NOAA/NESDIS.
