Journal Article

Assimilating GOES Brightness Temperatures. Part I: Upper-Tropospheric Moisture

Zapotocny, Tom H, Wade, Gary S, Raymond, William H

2004

Overview

Imager channel 3 (at 6.7 µm) on the Geostationary Operational Environmental Satellite (GOES) is particularly sensitive to water vapor in the atmosphere. Channel-3 data from both clear and cloudy regions are used in a new assimilation scheme to improve the initial upper-tropospheric moisture fields for modeling and numerical weather prediction purposes. In this assimilation, the navigated and calibrated radiance (brightness temperature) observations from GOES are used in combination with a forward radiative transmittance model and a numerical optimization procedure to produce modifications to the upper-tropospheric moisture field. All modifications are made proportional to the contribution weighting function, which is associated with the forward radiative model. Cloudy regions are given special consideration. When processed by a forward radiative transfer model, the assimilated moisture fields are shown to correlate better with GOES observations both initially and in 24- and 48-h forecasts. Additional merits of the proposed assimilation technique, which does not require an adjoint or linearization, are discussed. [PUBLICATION ABSTRACT]

• Publisher: American Meteorological Society
• Subject: Meteorological satellites / Meteorology / Moisture / Radiative transfer / Temperature / Troposphere / Water vapor / Weather forecasting