Lidar-Based Height Correction for the Assimilation of Atmospheric Motion Vectors

Autor(en)

Kathrin Folger, Martin Weissmann, Martin Weissmann

Abstrakt

This study uses lidar observations from the polar-orbiting Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) satellite to correct operational atmospheric motion vector (AMV) pressure heights. This intends to reduce the height assignment error of AMVs for their use in data assimilation. Additionally, AMVs are treated as winds in a vertical layer as proposed by several recent studies. Corrected and uncorrected AMV winds are evaluated using short-term forecasts of the global forecasting system of the German Weather Service. First, a direct lidar-based height reassignment of AMVs with collocated CALIPSO observations is evaluated. Assigning AMV winds from Meteosat-10 to ~120-hPa-deep layers below the lidar cloud top reduces the vector root-mean-square (VRMS) differences of AMVs from Meteosat-10 by 8%–15%. However, such a direct reassignment can only be applied to collocated AMV–CALIPSO observations that compose a comparably small subset of all AMVs. Second, CALIPSO observations are used to derive statistical height bias correction functions for a general height correction of all operational AMVs from Meteosat-10. Such a height bias correction achieves on average about 50% of the reduction of VRMS differences of the direct height reassignment. Results for other satellites are more ambiguous but still encouraging. Given that such a height bias correction can be applied to all AMVs from a geostationary satellite, the method exhibits a promising approach for the assimilation of AMVs in numerical weather prediction models in the future.

Organisation(en)

Institut für Meteorologie und Geophysik

Externe Organisation(en)

Ludwig-Maximilians-Universität München, Hans-Ertel-Zentrum für Wetterforschung

Journal

Journal of Applied Meteorology and Climatology

Band

55

Seiten

2211-2227

Anzahl der Seiten

17

ISSN

1558-8424

DOI

https://doi.org/10.1175/JAMC-D-15-0260.1

Publikationsdatum

2016

Peer-reviewed

Ja

ÖFOS 2012

105206 Meteorologie

Schlagwörter

ASJC Scopus Sachgebiete

Atmospheric Science

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/lidarbased-height-correction-for-the-assimilation-of-atmospheric-motion-vectors(d3f2ce8d-0594-475c-907e-a95dde5989c1).html