Image Credit:
NASA's Goddard Space Flight
Center
NASA and the Japan Aerospace Exploration Agency (JAXA) have released the
first images captured by their newest Earth-observing satellite, the Global
Precipitation Measurement (GPM) Core Observatory, which launched into space Feb.
27.
The images show precipitation falling inside a March 10 cyclone over the
northwest Pacific Ocean, approximately 1,000 miles east of Japan. The data were
collected by the GPM Core Observatory's two instruments: JAXA's Dual-frequency
Precipitation Radar (DPR), which imaged a three-dimensional cross-section of the
storm; and, NASA's GPM Microwave Imager (GMI), which observed precipitation
across a broad swath.
"It was really exciting to see this high-quality GPM data for the first
time," said GPM project scientist Gail Skofronick-Jackson at NASA's Goddard
Spaceflight Center in Greenbelt, Md. "I knew we had entered a new era in
measuring precipitation from space. We now can measure global precipitation of
all types, from light drizzle to heavy downpours to falling snow."
The satellite's capabilities are apparent in the first images of the cyclone.
Cyclones such as the one imaged -- an extra-tropical cyclone -- occur when
masses of warm air collide with masses of cold air north or south of the
tropics. These storm systems can produce rain, snow, ice, high winds, and other
severe weather. In these first images, the warm front ahead of the cyclone shows
a broad area of precipitation -- in this case, rain -- with a narrower band of
precipitation associated with the cold front trailing to the southwest. Snow is
seen falling in the northern reaches of the storm.
The GMI instrument has 13 channels that measure natural energy radiated by
Earth's surface and also by precipitation itself. Liquid raindrops and ice
particles affect the microwave energy differently, so each channel is sensitive
to a different precipitation type. With the addition of four new channels, the
GPM Core Observatory is the first spacecraft designed to detect light rain and
snowfall from space.
In addition to seeing all types of rain, GMI's technological advancements
allow the instrument to identify rain structures as small as about 3 to 9 miles
(5 to 15 kilometers) across. This higher resolution is a significant improvement
over the capability of an earlier instrument flown on the Tropical Rainfall
Measurement Mission in 1997.
"You can clearly see them in the GMI data because the resolution is that much
better," said Skofronick-Jackson.
The DPR instrument adds another dimension to the observations that puts the
data into high relief. The radar sends signals that bounce off the raindrops and
snowflakes to reveal the 3D structure of the entire storm. Like GMI, its two
frequencies are sensitive to different rain and snow particle sizes. One
frequency senses heavy and moderate rain. A new, second radar frequency is
sensitive to lighter rainfall and snowfall.
"Both return independent measurements of the size of raindrops or snowflakes
and how they are distributed within the weather system," said DPR scientist Bob
Meneghini at Goddard. "DPR allows scientists to see at what height different
types of rain and snow or a mixture occur -- details that show what is happening
inside sometimes complicated storm systems."
The DPR data, combined with data from GMI, also contribute to more accurate
rain estimates. Scientists use the data from both instruments to calculate the
rain rate, which is how much rain or snow falls to Earth. Rain rate is one of
the Core Observatory's essential measurements for understanding where water is
on Earth and where it's going.
"All this new information comes together to help us better understand how
fresh water moves through Earth's system and contributes to things like floods
and droughts," said Skofronick-Jackson.
3D view inside an extra-tropical cyclone observed
off the coast of Japan, March 10, 2014, by GPM's Dual-frequency Precipitation
Radar. The vertical cross-section approx. 4.4 mi (7 km) high show rain rates:
red areas indicate heavy rainfall while yellow and blue indicate less intense
rainfall.
Image Credit: JAXA/NASA
The Dual-frequency Precipitation Radar observes
rainfall and snowfall that occurs within clouds in three dimensions, across the
surface of Earth and upward into the atmosphere. An extra-tropical cyclone was
observed over the northwest Pacific Ocean off the coast of Japan on March 10,
2014.
Image Credit: JAXA/NASA
Feature Link:
GMI was built
by Ball Aerospace & Technologies, Corp., in Boulder, Colo., under contract
to NASA. DPR was developed by JAXA with the National Institute of Information
and Communication Technology.
These first GPM Core Observatory images were captured during the first few
weeks after launch, when mission controllers at the NASA Goddard Mission
Operations Center put the spacecraft and its science instruments through their
paces to ensure they were healthy and functioning as expected. The engineering
team calibrates the sensors, and Goddard's team at the Precipitation Processing
System verifies the accuracy of the data.
This initial science data from the GPM Core Observatory will be validated and
then released for free by September online at:
For more information and the GPM mission, visit:
and
The GPM Core Observatory was the first of five planned Earth science launches
for the agency in 2014. The joint NASA/JAXA mission will study rain and snow
around the world, joining with an international network of partner satellites to
make global observations every three hours.
NASA monitors Earth's vital signs from land, air and space with a fleet of
satellites and ambitious airborne and ground-based observation campaigns. NASA
develops new ways to observe and study Earth's interconnected natural systems
with long-term data records and computer analysis tools to better see how our
planet is changing. The agency shares this unique knowledge with the global
community and works with institutions in the United States and around the world
that contribute to understanding and protecting our home planet.
For more information about NASA's Earth science activities in 2014,
visit:
NASA
Guillermo Gonzalo Sánchez Achutegui
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