Geoscience Reference
In-Depth Information
8.1 Satellite meteorology
The launching of meteorological satellites revoluntionized meteorology, in terms of the near-global
view they provided of synoptic weather systems. The first meteorological satellite transmitted
pictures on 1 April 1960. The early Television and Infrared Observing Satellites (TIROS) carried
photographic camera systems and, due to their spin around an axis parallel to the earth's surface,
they photographed the surface only part of the time. The types of images that were collected had
been anticipated by some meteorologists, but the wealth of information exceeded expectations.
New procedures for interpreting cloud features, synoptic and mesoscale weather systems were
developed. Satellite pictures revealed cloud vortices, jet stream bands and other mesoscale systems
that were too large to be seen by ground observers and too small to be detected by the networks
of synoptic stations. Automatic Picture Transmission (APT) to ground stations began in 1963 and
was soon in worldwide use for weather forecasting. In 1972 the system was upgraded to provide
high-resolution (HRPT) images.
The operational polar-orbiting weather satellites in the United States were followed in 1966
by geostationary, sun-synchronous satellites positioned at fixed positions in the tropics. These
give images of a wide disc of the earth at 20-minute intervals. providing valuable information on
the diurnal development of cloud and weather systems. The U.S. Geostationary Operational
Environmental Satellites (GOES) were positioned at 75°W and 135°W from 1974 and in 1977 the
Japanese Geostationary Meteorological Satellite (GMS) and European Metosat were added at 135°E
and 0° longitude, respectively. India began the Insat series in 1983, now positioned at 93.5°E.
The early photographic systems were replaced in the mid-1960s by radiometric sensors in the
visible and infrared wavelengths. Initially, these were broad band sensors of moderate spatial
resolution. Subsequently, narrow band sensors with improved spatial resolution replaced these;
the Advanced Very High Resolution Radiometer (AVHRR) with 1.1km resolution and four channels
was initiated in 1978. A further major advance took place in 1970 with the first retrieval of
atmospheric temperature profiles from a Nimbus satellite. An operational system for temperature
and moisture profiles (the High-resolution Infrared Radiation (HIRS) sounder became operational
in 1978, followed by a system on GOES in 1980).
Satellite data are now routinely collected and exchanged between NOAA in the USA, the
European Meteorological Satellite Agency (Eumetsat) and the Japanese Meteorological Agency
(JMA). There are also ground-receiving stations in more than 170 countries collecting picture
transmission by NOAA satellites. Satellite data collected by Russia, China and India are mostly used
in those countries.
A vast suite of operational products is now available from NOAA and Department of Defense
(DoD) Defense Meteorological Satellite Program (DMSP) satellites. The DMSP series are polar
orbiting. They provide imagery from 1970 and digital products from 1992. NASA's Nimbus and Earth
Observing System (EOS) satellites provide numerous additional research products including sea
ice, vegetation indices, energy balance components, tropical rainfall amounts and surface winds.
Descriptions of available satellite data may be found at http://lwf.ncdc.naa.gov/oa/satellite/
satelliteresources.html; http://eospso.gsfc.nasa.gov/; http://www.eumetsat.de/
Reference
Purdom, J. F. W. and Menzel, P. 1996. Evolution of satellite observations in the United States and their use in meteorology,
in Fleming, J. R. (ed.) Historical Essays on Meteorology 1919-1995, Amer. Met. Soc., Boston, MA, pp. 9-155.
