E-Book Overview
n this practical guide, Santurette and Georgiev show how to interpret water vapor patterns in terms of dynamical processes in the atmosphere and their relation to diagnostics available from weather prediction models. In particular, they concentrate on the close relationship between satellite imagery and the potential vorticity fields in the upper troposphere and lower stratosphere. These applications are illustrated with color images based on real meteorological situations. The book's step-by-step pedagogy makes this an essential training manual for forecasters in meteorological services worldwide, and a valuable text for graduate students in atmospheric physics and satellite meteorology.
E-Book Content
Preface The main purpose of this book is to provide weather forecasters and operational meteorologists with a practical guide for interpreting water vapor channel imagery in combination with dynamical fields to enable weather analysis and forecasting. Recent developments in dynamic meteorology have indicated the relevancy of using potential vorticity fields in operational meteorology. This guide illustrates this approach by presenting the reader with current techniques for interpreting water vapor imagery in association with the characteristics of the synoptic situation. The book focuses on numerous examples showing superimpositions between operational model fields and satellite images and includes brief explanations, where appropriate, of the role of imagery in a forecasting environment. Conceived as a practical training manual for weather forecasters, the book will be of interest and value to university students as well.
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Acknowledgments This manual has been developed in Meteo-France in the framework of cooperation with the National Institute of Meteorology and Hydrology of Bulgaria. The authors are grateful to Jean Coiffier for many helpful suggestions and valuable discussions during the studies as well as for his assistance in the reproduction of many of the drawings. Computer and software support was provided by Fabienne Dupont. The process of potential vorticity modification and inversion for developing the material in Chapter 4 was performed with the assistance and collaboration of Philippe Arbogast. The material in Sections 4.6.2 and 4.6.3 was developed in cooperation with Francisco Martin Leon from Servicio de Tecnicas de Analisis y Prediccion (STAP) of Instituto Nacional de Meteorologia (INM), Madrid. The illustrations in Sections 3.3.2, 4.6.2, and 4.6.3, and some of those in Section 4.1.3 used output fields from the Spanish version of the HIRLAM model, which were kindly provided by STAP department of INM. All other illustrations made by using satellite imagery (Meteosat 7 satellite of EUMETSAT) and numerical model fields are the property of Meteo-France, which has funded the work on the manual. Special thanks are also due to the anonymous reviewers, as well as to the developmental editor David Couzens, for their generous contributions of time and insight.
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Introduction Water vapor (WV) channel images from Meteosat and other geostationary sateUites serve operational forecasters as a valuable tool for synoptic-scale analysis. Since WV images represent radiation emitted by water vapor in the middle and upper troposphere, they provide useful information on the flow patterns at these altitudes. Obtaining a better understanding of important large-scale atmospheric processes calls for diagnosing imagery jointly with meteorological fields showing atmospheric circulation at mid- and upper levels. Such dynamical fields include absolute vorticity or potential vorticity owing to their close relationship with WV channel radiance, and these fields can be displayed in several ways. Circulation and vorticity have been recognized as helpful quantities since the beginning of the 20th century and, on