Assimilating visible and infrared radiances in idealized simulations of deep convection

Autor(en)
Josef Schröttle, Martin Weissmann, Leonhard Scheck, Axel Hutt
Abstrakt

Cloud-affected radiances from geostationary satellite sensors provide the first area-wide observable signal of convection with high spatial resolution in the range of kilometers and high temporal resolution in the range of minutes. However, these observations are not yet assimilated in operational convection-resolving weather prediction models as the rapid, non-linear evolution of clouds makes the assimilation of related observations very challenging.

To address these challenges, we investigate the assimilation of satellite radiances from visible and infrared channels in idealized observing system simulation experiments (OSSEs) for a day with summer-time deep convection in central Europe. This constitutes the first study assimilating a combination of all-sky observations from infrared and visible satellite channels and the experiments provide the opportunity to test various assimilation settings in an environment, where the observation forward operator and the numerical model exhibit no systematic errors.

The experiments provide insights into appropriate settings for the assimilation of cloud-affected satellite radiances in an ensemble data assimilation system and demonstrate the potential of these observations for convective-scale weather prediction. Both infrared and visible radiances individually lead to an overall forecast improvement, but best results are achieved with a combination of both observation types that provide complementary information on atmospheric clouds. This combination strongly improves the forecast of precipitation and other quantities throughout the whole range of 8 h lead time.

Organisation(en)
Institut für Meteorologie und Geophysik
Externe Organisation(en)
Ludwig-Maximilians-Universität München, Tel Aviv University, Deutscher Wetterdienst, Centre Inria Nancy-Grand Est
Journal
Monthly Weather Review
Band
148
Seiten
4357-4375
Anzahl der Seiten
18
ISSN
0027-0644
DOI
https://doi.org/10.1175/MWR-D-20-0002.1
Publikationsdatum
10-2020
Peer-reviewed
Ja
ÖFOS 2012
105206 Meteorologie
Link zum Portal
https://ucris.univie.ac.at/portal/de/publications/assimilating-visible-and-infrared-radiances-in-idealized-simulations-of-deep-convection(e63a55a2-422e-414b-b68c-8e212227672c).html