Reconstruction of surface pressure fields from scatterometer wind fields: testing on measurements in the Gulf of Finland
|Author(s)||Monzikova A. K.1, Kudryavtsev V.N.1, Chapron Bertrand2|
|Affiliation(s)||1 : Russian State Hydrometeorological University, St. Petersburg 195196, Russia
2 : Institut Français de Recherche pour l’Exploitation de la Mer (IFREMER) Plouzané 29280, France
|Source||Sovremennye problemy distantsionnogo zondirovaniya Zemli iz kosmosaCurrent problems in remote sensing of the Earth from space (2411-0280) (Space Research Institute RAS), 2016 , Vol. 13 , N. 6 , P. 86-98|
|Note||Article en russe|
|Keyword(s)||Gulf of Finland, scatterometer, planetary boundary layer|
In this paper the method for reconstruction of surface pressure from satellite scatterometer measurements is discussed and tested. The method is based on the resistance laws of the planetary boundary layer (PBL), the input parameter of which is the scatterometer surface wind speed and the output – reconstructed geostrophic wind. The method is tested on the base of satellite and in situ measurements over the Gulf of Finland. The surface pressure measurements from the coastal weather stations are used as the in situ data. It was found that the geostrophic wind reconstructed from scatterometer data is lower than the geostrophic wind retrieved from pressure gradients. This is most likely caused by a feature of PBL development over the water surface when the wind speed at the upper boundary of the PBL, which is developed over the water surface, does not reach the “real” geostrophic wind speed of PBL over land. Introduction of a correction taking into account the difference between the wind speed at the upper boundary of PBL over the water surface of the “true” geostrophic speed allows to bring reconstructed from satellite measurements pressure gradients into compliance with those obtained from weather stations measurements. Taking into account the correction, the accuracy of the pressure gradient reconstruction in terms of geostrophic wind speed is within plus or minus 3 m/s, and that of direction – plus or minus 20 degrees.