Weather and climate forecasters will double their pleasure, thanks to
today’s successful launch of NASA’s SeaWinds scatterometer instrument.
The instrument, which launched at 5:31 p.m. Pacific Time from Japan’s
Tanegashima Space Center, joins another satellite already in orbit to
measure wind speed and direction over Earth’s oceans.
The SeaWinds scatterometer, developed and managed by NASA’s Jet
Propulsion Laboratory, Pasadena, Calif., will complement and
eventually replace a second, identical instrument that has been
orbiting since June 1999 aboard NASA’s Quick Scatterometer (QuikScat)
satellite. Its three- to five-year mission will augment a long-term
ocean surface wind data series that began in 1996 with the launch of
the NASA Scatterometer aboard the National Space Development Agency of
Japan’s Advanced Earth Observing Satellite (Adeos) spacecraft. This
newest SeaWinds instrument is aboard Japan’s Adeos 2 spacecraft. The
Japanese Space Agency is a partner on SeaWinds, along with the
National Oceanic and Atmospheric Administration (NOAA).
Climatologists, meteorologists and oceanographers use these detailed
snapshots of ocean winds in conjunction with data from other
Earth-monitoring satellites from NASA and other U.S. and international
entities to understand and predict severe weather patterns, climate
change and global weather abnormalities like El Nino.
Riding a 17-story-high, two-stage Japanese H-IIA rocket launched from
Japan’s Tanegashima Space Center, 115 kilometers (71.5 miles) south of
Kyushu, SeaWinds on Adeos 2 headed south over the Pacific Ocean and
separated from the rocket’s second stage approximately 16-1/2 minutes
later over the ocean between the Philippines and Indonesia on its way
to a circular, near-polar orbit about 800 kilometers (500 miles) above
Earth. Initial telemetry reports received by the Adeos 2 team show
the spacecraft to be in excellent health. The SeaWinds instrument
will be powered on 27 days after launch and 17 days later will undergo
a thorough checkout. A six-month calibration/validation phase will
begin in mid April, with nominal science operations scheduled to begin
in October 2003.
“Winds effectively ‘stir’ heat, moisture and greenhouse gases
interacting between Earth’s oceans and atmosphere, driving ocean
circulation and ultimately weather and climate,” said Dr. Ghassem
Asrar, associate administrator of NASA’s Office of Earth Science,
Washington, D.C. “Ground-based methods of monitoring winds using
ships and buoys can only provide a glimpse of this picture, whereas
space-based microwave radars like SeaWinds can continuously and
accurately map wind speed and direction under most weather conditions
across 90 percent of Earth’s ice-free oceans every two days.”
“In addition,” Asrar said, “since SeaWinds maps Earth’s land masses as
well as its oceans, its data are being used in an increasing number of
other applications, from production of daily maps of sea ice extent
around Earth’s poles; to measuring soil moisture content, vegetation
and snow cover; and detecting regional flooding.”
“With its ability to ‘see’ ocean level winds through clouds, data from
SeaWinds on Adeos 2 will be an invaluable tool for hurricane tracking
and high seas marine forecasting,”said Helen Wood, director of NOAA’s
Office of Satellite Data Processing and Distribution. “NOAA will
quickly process the data for weather forecasting use by NOAA’s
National Weather Service, the Japanese Meteorological Agency as well
as other national weather agencies around the world.”
Scatterometers operate by transmitting high-frequency microwave pulses
to the ocean surface and measuring the “backscattered,” or echoed,
radar pulses bounced back to the satellite. The instrument senses
ripples caused by winds near the ocean’s surface, from which
scientists can compute wind speed and direction.
SeaWinds on Adeos 2 is managed for NASA’s Office of Earth Science,
Washington, D.C., by JPL, which developed the instrument and performs
instrument operations and science data processing, archiving and
distribution. NASA also provides U.S. ground system support. The
Japanese Space Agency provided the Adeos 2 spacecraft, H-IIA launch
vehicle, mission operations and the Japanese ground network. NOAA
provides near-real-time data processing and distribution for SeaWinds
operational data users. The California Institute of Technology in
Pasadena manages JPL for NASA.
Additional information about SeaWinds is available at:
http://winds.jpl.nasa.gov.