TOVS Satellite Soundings of the ERICA IOP-2 Cyclone

Abstract

Satellite soundings from the TIROSN Operational Vertical Sounder (TOVS) are used to study the Experiment on Rapidly Intensifying Cyclones over the Atlantic (ERICA) Intensive Observation Period-2 (IOP-2), 13-14 Dec 88. TOVS data are compared with dropwindsondes and coastal rawinsondes, and Spectral Grid Model (SGM) analyses of stability, geopotential height, and temperature. The impact of the first guess on the TOVS retrieval is studied by comparing four first-guess methods: (1) regression without surface data; (2) regression with surface data; (3) climatology with surface data; and (4) SGM analyses with surface data. Ship reports and moored and drifting buoys were objectively analyzed to obtain the surface data for the first guess. The retrievals with 6-h old SGM analyses as a first guess best best captured the low level structure of the in situ soundings. The TOVS stability analyses defined the rapid cyclogenesis environment, in advance of the developing cyclone. The TOVS height and temperature analyses successfully described the structure of the developing cyclone, in reasonable agreement with experimental data and synoptic-scale analyses.