EUMETSAT NWP SAF mesoscale wind data assimilation workshop - 2nd announcement


Tallinn, Estonia, Tuesday 18 September, 10:00-13:30, Tallink City Hotel

Second and last announcement

The place and time of the EUMETSAT NWP SAF mesoscale wind data assimilation workshop are now set. Those who have not registered yet for this workshop are asked to do so before June 30th by sending an email to No further announcement will be send to all.

Further communications about the workshop agenda will be send to the registered participants only. Moreover, your registration is needed to organize the meeting facilities.

2018 will see an unprecedented increase in the number of wind-measuring satellites:

  • EUMETSAT’s MetOp-C will bring the 3rd ASCAT into orbit, where the three ASCATs will provide, for the first time, close to 100% wind coverage of the seas around 9:30 local time (LT), both in the morning and evening;
  • ESA’s Aeolus mission will, also for the first time, provide wind profiles from space;
  • The Chinese-French Ocean SATellite, CFOSAT, will include a rotating fan-beam wind scatterometer, SCAT, and combine it with a wave-measuring instrument, SWIM;
  • India will launch OceanSat-3 with on-board its well-proven wind scatterometer, providing ocean wind coverage at 12:00 and 00:00 local time;
  • China will launch HY-2B, providing ocean wind coverage at 6:00 and 18:00 LT.

Satellite observations have been fundamental in improving weather forecast skill over the past two decades on all terms, while few high-quality wind observations were present in the Global Observing System. To depict and initialize the flow on scales smaller than 500 km, wind observations are essential, however, and adding satellite wind observations for predicting dynamical weather has proven to be beneficial. But how are we going to exploit all these wind observations?

The EUMETSAT NWP SAF mesoscale wind data assimilation workshop will address this question and raise expectations for the beneficial and practical use of these novel wind observing systems. It addresses the spatial scales observed and the errors in scatterometer winds. For satellite ocean winds it addresses the calibration wind reference at high and extreme winds, ambiguity removal, and a method to obtain weather-dependent error covariances, both for buoy, satellite and NWP data. For NWP models it provides examples of the spatial scales deterministically modelled, but also the spatial scales which are only realistically modelled and not well initialized. This sets the scene to discuss spatial representation errors, which often dominate wind measurement observation errors, be it from radiosondes, aircraft winds or wind scatterometers. The pros and cons of thinning, superobbing and “supermodding” will be discussed. The workshop also addresses well-known biases of weather models, but which violate the BLUE data assimilation principle: Best Linear Unbiased Estimate. While air-mass dependent bias correction schemes are fundamental to the current beneficial use of satellite observations, they are not in place for satellite winds. A way forward will be suggested and discussed with the attendees.

A meeting agenda will be provided in July. The workshop room is in the Tallink City Hotel:

Looking forward to seeing you at the workshop!

Ad Stoffelen