Assimilation of Satellite surface TemperatuRe In weather moDels

Short Description

Starting point / motivation

Land surface temperature is a key variable in the description of soil processes and has an important role in the soil –atmosphere energy and water cycle. And though it is an important parameter in the intersection of meteorology, hydrology, climatology and agronomy, there is no model-based, high-resolution and real-time data set currently available.

By contrast, satellite-based land surface temperature data are available. A global product in real-time with low spatial resolution is provided for example by Copernicus Global Land. With the launch of Sentinel-3 (planned for Dec., 10th, 2015 for 3A and 18 months later for 3B), spatial high-resolution data, but with lower temporal resolution, will be available for Europe soon.

Contents and goals

Main project goal is the combination of the mentioned satellite data sources with models, to combine the advantages of both worlds. On the one hand, this is mainly the high spatio-temporal resolution and the regular grid without data gaps; on the other hand it is the direct measurement of the current status of the soil.

To satisfy requirements of different potential users, two approaches will be tested to combine the data sources. 

One will be the assimilation of satellite data in the soil model SURFEX (Surface Externalisée), based on a Kalman filter approach. These improved soil temperature analyses will be the input for the convection-permitting, limited area weather prediction model AROME, producing forecast fields.

The second approach is the connection of these forecast fields with combined satellite data in the analysis tool INCA. While the weather model is updated just 8 times per day in operational mode, the analysis tool can ingest new measurements hourly, no matter if from satellite or in-situ sources to provide new temperature analyses. To estimate the uncertainty of the output, an ensemble approach is chosen for the combination mentioned above.

Expected results

Using both these models, a tested and ready to go processing chain shall be available at the end of the project runtime. It will provide level-4 products of land surface temperature in real-time, based on level-1 Sentinel-3 and MSG data sets. With a planned spatial resolution of 1km (for Austria) and a temporal resolution of 1 hour this product will set a new benchmark. Finally, this data set shall lead to fruitful collaborations with other areas of research.


Project Partners


ZAMG - Zentralanstalt für Meteorologie und Geodynamik

Contact Address

Zentralanstalt für Meteorologie und Geodynamik (ZAMG)
Hohe Warte 38
A-1190 Vienna
Tel.: +43 (1) 36 0 26
Fax: +43 (1) 369 12 33