Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

The TRMM rainfall mission comes to an end after 17 years

10.04.2015

In 1997 when the Tropical Rainfall Measuring Mission, or TRMM, was launched, its mission was scheduled to last just a few years. Now, 17 years later, the TRMM mission has come to an end. NASA and the Japan Aerospace Exploration Agency (JAXA) stopped TRMM's science operations and data collection on April 8 after the spacecraft depleted its fuel reserves.

TRMM observed rainfall rates over the tropics and subtropics, where two-thirds of the world's rainfall occurs. TRMM carried the first precipitation radar flown in space, which returned data that were made into 3-D imagery, enabling scientists to see the internal structure of storms for the first time.


TRMM observes the 3-D rain structure of Hurricane Katrina on Aug. 28, 2005, including the red spikes known as hot towers that appear where the storm is most intense. The center tower is located on the hurricane's eyewall.

Credit: NASA

TRMM also carried a microwave imager, a state-of-the-art instrument that had the highest resolution images of rainfall at the time. Together with three other sensors - the Visible and Infrared Scanner (VIRS), the Lightning Imaging Sensor (LIS), and the Clouds and the Earth's Radiant Energy System (CERES) instrument - scientists used TRMM data to explore weather events, climate, and Earth's water cycle.

The cutting-edge TRMM instruments arrived in orbit at the right time to take advantage of the explosion of computing power and major advances in data-sharing.

"In the early 1990s, sharing data consisted of nine-track data tapes in the mail," said research meteorologist George Huffman at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "By the time you got to the 2000s, it became possible to actually share data online. Once we got that piece in place, people were asking, 'Oh, can you send me that data?' Eventually they wanted to see it all the time."

Scientists at Goddard originally intended TRMM's data to be used purely for precipitation research, but before long, people and organizations outside NASA were using it for a variety of purposes.

"The data were being heavily used for tropical cyclone monitoring and forecasting," said TRMM Project Scientist Scott Braun at Goddard. "It was being used for flood detection and monitoring. It was also used for drought monitoring, disease monitoring -- where diseases are most prevalent in areas of heavy precipitation and flooding."

The scientific community considered TRMM's data so critical to research and many practical applications that in 2001, at the end of TRMM's primary mission, NASA wanted to extend the mission for as long as possible.

TRMM's original flight altitude was optimized for the precipitation radar. To obtain precipitation profiles through the depth of the lower atmosphere and to concentrate the measurements in the tropics, the orbit was confined to 35 degrees north to 35 degrees south latitude at an altitude of 350 km (217.5 miles). At this altitude, Earth's atmosphere is still sufficiently dense to cause drag on the spacecraft, slowing it down, which progressively lowers its altitude.

"In the early years of its mission, TRMM was burning through fuel quickly," said Eric Moyer, Goddard Earth Science Operations manager. "By design, TRMM carried fuel and had a controlled burn scheduled every few weeks to increase its speed and maintain altitude."

To extend TRMM's mission life, NASA boosted the spacecraft's orbit altitude to 402.5 km (about 250 miles) in 2001. Earth's atmosphere thins as it stretches out toward space, so a spacecraft at higher altitudes experiences less drag (that slows it down) and consumes less fuel to maintain its orbit. At this altitude, the radar would still return strong, research quality data. This maneuver extended TRMM's life four more years, and after review in 2005, NASA again extended the mission life until the satellite ran out of fuel.

TRMM's 17 years in orbit allowed the mission to grow and evolve, Huffman said.

The original goal was to provide monthly averages of rainfall over Earth's surface divided into large grid boxes, roughly 500 km (about 310 miles) square. TRMM eventually generated rainfall estimates at a higher resolution and in near-real time, every three hours.

"And it's just the same old instruments," Huffman said. "What that demonstrates is that the capability was already there. We just had to work back through the rest of the system to make it happen, starting with the thought, 'Oh gosh, we could do this.'"

Huffman and his team combined TRMM data with precipitation data from several other microwave imaging satellites in orbit, many of them weather satellites. Together with significant advances in data management they created the new TRMM product.

Now, TRMM has reached the end of its life. Battery issues complicated the operation of the spacecraft over the past year, so Braun and the mission operations team had to make decisions about how to ration what power remains. In March 2014, they decided to turn off the VIRS instruments to extend the battery life. In July 2014, the spacecraft ran out of fuel that kept it at its boosted operational altitude and TRMM slowly began to drift down, while still collecting data. The remaining fuel, initially reserved to avoid collisions with other satellites or space debris, was depleted in early March 2015.

Observations of hurricanes and precipitation from space will not end after TRMM. The Global Precipitation Measurement (GPM) mission's Core Observatory, launched in February 2014, succeeds and improves upon the TRMM project. Both missions are joint projects of NASA and JAXA.

Since TRMM's launch, many other space programs, including those in Europe and Japan, have launched precipitation measurement satellites containing microwave radiometers that measure radiated energy from rainfall and snowfall. The GPM mission harnesses the combined scope of these spacecraft and uses the GPM Core Observatory to standardize the measurements from the individual satellites. Together, they are combined into uniform data sets that are made available online. Just as with TRMM's data, anyone in the world can access the repository.

In addition to the moderate and heavy rainfall that TRMM was capable of observing in the tropics, GPM also observes light rain and falling snow. Its orbit passes above a larger portion of the world. TRMM's orbit covered the latitude ranging from 35 degrees north to 35 degrees south, which is as far north as Cape Hatteras, North Carolina, and as far south as Buenos Aires, Argentina, but GPM's coverage of latitude from 65 degrees north to 65 degrees south stretches nearly to the Arctic and Antarctic Circles.

The information these missions can provide is critical to people around the world. The data provided by precipitation-related satellite missions can save lives in cases such as landslides and tropical cyclones. They also help improve climate models, which help predict what our planet may be like years into the future.

###

Updates on the re-entry of the TRMM spacecraft will be posted to the mission website: http://trmm.gsfc.nasa.gov/

Rani Gran | EurekAlert!

More articles from Earth Sciences:

nachricht Water cooling for the Earth's crust
22.11.2017 | Helmholtz Centre for Ocean Research Kiel (GEOMAR)

nachricht Retreating permafrost coasts threaten the fragile Arctic environment
22.11.2017 | Helmholtz-Zentrum Potsdam - Deutsches GeoForschungsZentrum GFZ

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nanoparticles help with malaria diagnosis – new rapid test in development

The WHO reports an estimated 429,000 malaria deaths each year. The disease mostly affects tropical and subtropical regions and in particular the African continent. The Fraunhofer Institute for Silicate Research ISC teamed up with the Fraunhofer Institute for Molecular Biology and Applied Ecology IME and the Institute of Tropical Medicine at the University of Tübingen for a new test method to detect malaria parasites in blood. The idea of the research project “NanoFRET” is to develop a highly sensitive and reliable rapid diagnostic test so that patient treatment can begin as early as possible.

Malaria is caused by parasites transmitted by mosquito bite. The most dangerous form of malaria is malaria tropica. Left untreated, it is fatal in most cases....

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

Corporate coworking as a driver of innovation

22.11.2017 | Business and Finance

PPPL scientists deliver new high-resolution diagnostic to national laser facility

22.11.2017 | Physics and Astronomy

Quantum optics allows us to abandon expensive lasers in spectroscopy

22.11.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>