Imaging Science in Meteorology

Abstract

Abstract Meteorologists draw upon a wealth of data from measurements and numerical weather prediction models to understand the atmosphere and forecast its evolution. A dramatic increase in the type and quantity of data available to meteorologists during the latter half of the 20 th century has required worldwide computing resources to manage efficient data processing, dissemination, and storage. Imaging and animation have become essential tools of meteorologists as they attempt to assess the current state of the atmosphere and forecast its future behavior. Meteorological measurements of atmospheric properties such as temperature, pressure, winds and moisture content are made by weather stations in towns and airports worldwide at regular time intervals, typically every 1–3 hours. Few observations exist in many parts of the world, particularly over oceans, deserts, and mountainous regions. Even in populated areas, the distances between stations is far enough that significant weather phenomena, such as thunderstorms, may not be reported. Satellite and radar imagery are therefore key sources of information used by meteorologists to detect and analyze these weather phenomena. The high temporal and spatial resolution of these images permit meteorologists to monitor the progress of weather systems, analyze the structure and evolution of storms, and determine where dangerous conditions are likely to occur. The data used to construct these images are also used to initialize numerical forecast models and to determine the quality of forecasts. The first successful meteorological satellite to acquire images of Earth was the Television and Infrared Observational Satellite 1 (TIROS 1). Many meteorological satellites followed. The launch of the Applications Technology Satellite 1 (ATS 1) was a landmark event. ATS 1 was the first meteorological satellite placed into geostationary orbit. From this vantage point, images of nearly an entire hemisphere can be acquired at high enough temporal resolution to make animation possible. For the first time, meteorologists were able to visually monitor large weather disturbances such as cyclones and hurricanes. Today, animations routinely appear on television weather broadcasts. Information acquired by satellites is also used quantitatively in numerical weather prediction models, both initialization and verification. Radars have been used for meteorological studies since World War II. The development in the early 1970s of scanning Doppler radar, which provides information on wind fields, was quickly followed by the development of color images of radar data. In 1979, several U.S. government agencies collaborated to establish a network of Doppler radars in the United States. Rapid data processing and dissemination of data from this radar network via the World Wide Web now make it possible for meteorologists as well as the public to obtain radar images in near real time. Radar applications include storm tracking, severe thunderstorm detector, precipitation measurement, aviation meteorology, wind instruments and precipitation physics.