RETRIEVING EXTREME LOW PRESSURE WITH ALTIMETRY

• Main Authors: L. Carrère, F. Mertz, J. Dor, Y. Quilfen, Chung-chi Lin
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Subjects: Indian; Pacific; North Atlantic
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.431.1708

The relationship between atmospheric Sea Level Pressure (SLP) and the Sea Level Anomaly (SLA) measurements is investigated during storms and very low pressure conditions. The S- and C-band measurements are used because they are less impacted by rain than the Ku-band. Specific altimeter treatments need to be applied to obtain a relevant along track SSH signal especially during tropical cyclones (SSB and wet troposphere correction). More accurate strong wind speeds have been computed thanks to the Young algorithm. The ocean signal not related to atmospheric pressure needs to be removed with accuracy thanks to alongtrack low-pass filtering fort extra-tropical depressions (ETD) or by removing the maps of SLA provided by SSALTO/Duacs for tropical cyclones (TC). Three different SLP-SLA regression models are proposed for north Atlantic, north Pacific and Indian oceans; the error is 5 mbars if compared to ECMWF or buoys SLP. In order to better understand the SLP-SSH relationship, and the impact of the wind, an analysis of the sea level computed by the MOG2D simulations has been performed. 1.