European AMV expert meeting 2017

The European Atmospheric Motion Vectors (AMVs) expert meeting takes place every two years, prior and after the international wind workshops. Experts from across Europe meet to discuss latest developments on AMVs — EUMETSAT AMV production at EUMETSAT and the AMV assimilation at the numerical weather prediction (NWP) centres.

Objectives and outcomes

The themes of this user meeting were:

• The use of Optical Cloud Analysis (OCA) product/AMV altitude.
• The AMV problems identified in NWP SAF monitoring.
• The use of Nested Tracking algorithm with GOES-15.
• The use of Quality Index (QI) with and without forecast check in NWP model.
• The development of 3D winds from IR sounders.

The outcomes of the meeting can be summarised as follows:

• Use of OCA to set AMV altitude needs to be further investigated at EUMETSAT, since the impact of using OCA is less than expected. EUMETSAT has to modify the Meteorological Product Extraction Facility (MPEF) AMV output files to include a Quality Index based on OCA, in order to better estimate the impact of OCA product. The current nominal MPEF QI is based on Cloud Analysis (CLA), not on OCA.
• The Met-8 AMVs perform better than the Met-7 AMVs over the Indian Ocean Data Coverage (IODC) at ECMWF. The Met-8 All Sky Radiance (ASR) assimilation also showed a positive impact.
• Error characteristics and new estimates of quality regarding the altitude, speed and direction have been widely discussed. EUMETSAT is going to work on speed and direction quality indexes based on level-1 product navigation errors.
• Differences of the QI estimated with or without Forecast (FC) test in NWP model has been studied by the Met Office. QI without FC test result in more data available for assimilation, but performances against background deteriorated somewhat. However, they can be slightly improved by adding background tight check and slow speed check.
• The latest updates and plans for the Satellite Application Facility on Support to Nowcasting & Very Short Range Forecasting (NWC SAF) HRW software have been presented.
• The Met Office asked if there would be any interest in the provision of high resolution simulated model data to help with MTG-IRS preparations, potentially as part of a wider inter-comparison study with the Cooperative Institute for Meteorological Satellite Studies (CIMSS) University of Wisconsin-Madison and the NWC SAF on hyperspectral wind derivation.
• NWP SAF AMV analyses showed some current and past case studies to investigate features seen in the AMV O-B monitoring, indicating areas that would benefit from more investigations and potential improvements to AMV production and/or assimilation.
• GOES-R nested tracking algorithm has been implemented on GOES-15 by NOAA. Currently the results of the impact tests performed by the Met Office are disappointing, and more neutral at ECMWF.
• Met Norway showed an interest in testing 3D winds.

Programme

Topic Day 1: 10 October 2017

Topic Day 2: 11 October 2017