Objective Analysis of Sea-Level Winds and Pressures Derived from Simulated Observations of a Satellite Radar-Radiometer and Actual Conventional Data

Abstract

A computer-based procedure is developed that combines a field of simulated satellite-derived wind speeds with a limited amount of conventional surface data so as to recover the surface pressure field and the vector wind field over the North Pacific Ocean. Wind speeds are determined from an objective analysis of high spatial density ship observations in order to simulate the anticipated output of a proposed satellite-mounted radar-radiometer system. The conventional surface data consist of sparse observations from ocean-going vessels, observations from several tropical stations, and boundary pressures from analyses over coastal areas. The simulated speeds are combined with the conventional network for various spatial distributions of ship data. The average rms departure of sea-level pressure fields analyzed by deleting from 75?94% of the available ship observations from the maximum data analysis is from 3.0?4.0 mb. Comparison of the wind components implied by the isobaric patterns to those of the withheld ship observations yields average rms differences of from 8.7?9.4 kt for a range of 75?94% data deletion.