Workshop on

Wind Profiles and Mesoscale Data Assimilation

Ljubljana, 19-20 September 2016

About fifty years ago the first sensitivity experiments on the importance of various observations for Numerical Weather Prediction (NWP) showed that “Not all data are equal in their information-yielding capacity. Some are more equal than others. This tells us that if there is a choice as to what can be measured, then one variable may be preferable over another.” (Smagorinsky, 1969). Wind information, the “more equal” one, remains the main missing component of the global observing system. Observations of the vertical wind profiles by the ESA ADM-Aeolus mission have been demonstrated to have the potential of providing a significant improvement in NWP, primarily in the tropics where the lack of wind information is most critical for the global NWP. The same dynamical and data issues that apply to the tropics are shared by mesoscale NWP models. 

The workshop aims to discuss some open issues in mesoscale data assimilation for NWP. In particular, the workshop is an opportunity to present latest advances and discuss new ideas related to the following topics:

  • Application of ADM-Aeolus winds in mesoscale models  
  • Wind observations and balanced initial conditions on mesoscale
  • Gravity waves versus imbalance in data assimilation  

Presentations on the operational applications and research related to the assimilation of wind observations and the balance issues in mesoscale data assimilation are welcome. 

Movie: Simulated 12-hour track of the ESA ADM-Aeolus satellite with every second location of the expected horizontal line-of-sight wind profiles.

Registration until 16 Septembert: Matic Savli, and Nedjeljka Zagar,

Workshop is sponsored by the University of Ljubljana, Faculty of mathematics and physics, project “Mesoscale wind profile and data assimilation for NWP” funded by the European Space Agency, Plan for European Cooperating States. 

Workshop flyer

Workshop program


Presentations *


Nils Gustafsson (SMHI): Mesoscale data assimilation: 49 years of perspective

Ad Stoffelen (KNMI): Mesoscale wind data assimilation and global OSE results

Gert-Jan Marseille (KNMI): Challenges in mesoscale data assimilation

Jelena Bojarova (SMHI): Assumptions behind background error statistics and the evolution of uncertainty on meso-scales

Mark Žagar et al. (Vestas): Near-surface wind variability: impacts on wind energy applications

Siebren de Haan and Ad Stoffelen (KNMI): Mode-S analysis and assimilation at KNMI

Benedikt Strajnar (ARSO/UL): Introduction of Mode-S wind and temperature profiles into ALADIN model

Tijana Janjić Pfander et al. (LMU): Assimilation of the high resolution wind data with the ensemble Kalman filter

Michael Rennie (ECMWF): Results from experiments assimilating densely sampled aircraft wind data in the ECMWF model


Michael Rennie (ECMWF): Aeolus Level-2B wind products

Gert-Jan Marseille (KNMI): Aeolus error characteristics in heterogeneous atmospheric conditions

Nedjeljka Žagar (UL): Assimilation of line-of-sight winds and balance issues: from the tropics to the mid-latitude mesoscale

Matic Šavli (UL): Results from mesoscale OSSE with simulated ADM-Aeolus winds and EnKF

Wenming Lin, Ad Stoffelen et al. (KNMI): Improved mesoscale analyses with 2DVAR

Žiga Zaplotnik (UL): Dynamics of winds and aerosols in 4D-Var

* The order of presentations is following the workshop program

Summary of the workshop discussion

Mesoscale data assimilation and the role of winds in limited-area models for NWP in Europe