Tropical Rainfall Measuring Mission

Last updated

Tropical Rainfall Measuring Mission
TRMM SATELLITE.blurred.medium.jpg
Artist conception of the TRMM satellite
Mission type Environmental research
Operator NASA
COSPAR ID 1997-074A
SATCAT no. 25063
Mission duration18 years
Spacecraft properties
Launch mass3524 kg
Dry mass2634 kg [1]
Power1100 watts
Start of mission
Launch date27 November 1997, 21:27 UTC
RocketH-II
Launch site Tanegashima, LA-Y1
Contractor Mitsubishi Heavy Industries
End of mission
DisposalDeorbited
Deactivated15 April 2015
Decay date6 June 2015, 06:54 UTC [2]
Orbital parameters
Reference system Geocentric orbit [2]
Regime Low Earth orbit
Perigee altitude 366 km (227 mi)
Apogee altitude 381 km (237 mi)
Inclination 35.0°
Period 92.0 minutes
Programme NASA Earth Probe
 

The Tropical Rainfall Measuring Mission (TRMM) was a joint space mission between NASA and the Japan Aerospace Exploration Agency JAXA designed to monitor and study tropical rainfall. The term refers to both the mission itself and the satellite that the mission used to collect data. TRMM was part of NASA's Mission to Planet Earth, a long-term, coordinated research effort to study the Earth as a global system. The satellite was launched on 27 November 1997 from the Tanegashima Space Center in Tanegashima, Japan. TRMM operated for 17 years, including several mission extensions, before being decommissioned on 15 April 2015. TRMM re-entered Earth's atmosphere on 16 June 2015.

Contents

Background

Tropical precipitation is a difficult parameter to measure, due to large spatial and temporal variations. However, understanding tropical precipitation is important for weather and climate prediction, as this precipitation contains three-fourths of the energy that drives atmospheric wind circulation. [3] Prior to TRMM, the distribution of rainfall worldwide was known to only a 50% of certainty. [4]

The concept for TRMM was first proposed in 1984. The science objectives, as first proposed, were: [3]

Japan joined the initial study for the TRMM mission in 1986. [3] Development of the satellite became a joint project between the space agencies of the United States and Japan, with Japan providing the Precipitation Radar (PR) and H-II launch vehicle, and the United States providing the satellite bus and remaining instruments. [5] The project received formal support from the United States Congress in 1991, followed by spacecraft construction from 1993 through 1997. TRMM launched from Tanegashima Space Center on 27 November 1997. [3]

Spacecraft

The Tropical Rainfall Measuring Mission (TRMM), one of the spacecraft in the NASA Earth Probe series of research satellites, is a highly-focused, limited-objective program aimed at measuring monthly and seasonal rainfall over the global tropics and subtropics. TRMM is a joint project between the USA and Japan to measure rainfall between 35.0° North and 35.0° South at 350 km altitude. [6]

Mission extensions and de-orbit

To extend TRMM's mission life beyond its primary mission, NASA boosted the spacecraft's orbit altitude to 402.5 km in 2001. [7]

In 2005, NASA director Michael Griffin decided to extend the mission again by using the propellant originally intended for a controlled descent. This came after a 2002 NASA risk review put the probability of a human injury or death caused by TRMM's uncontrolled re-entry at 1-in-5,000, about twice the casualty risk deemed acceptable for re-entering NASA satellites; and a subsequent recommendation from the National Research Council panel that the mission be extended despite the risk of an uncontrolled entry. [8]

Battery issues began to limit the spacecraft in 2014 and the mission operations team had to make decisions about how to ration power. In March 2014, the VIRS instruments was turned off to extend the battery life. [7]

In July 2014, with propellant on TRMM running low, NASA decided to cease station-keeping maneuvers and allow the spacecraft's orbit to slowly decay, while continuing to collect data. The remaining fuel, initially reserved to avoid collisions with other satellites or space debris, was depleted in early March 2015. [7] Re-entry was originally expected sometime between May 2016 and November 2017, but occurred sooner due to heightened solar activity. [9] The probe's primary sensor, the precipitation radar, was switched off for the final time on 1 April 2015 and the final scientific sensor, LIS, was turned off on 15 April 2015. [8] Re-entry occurred on 16 June 2015 at 06:54 UTC. [10]

Instruments aboard the TRMM

Precipitation Radar

The Precipitation Radar (PR) was the first space-borne instrument designed to provide three-dimensional maps of storm structure. The measurements yielded information on the intensity and distribution of the rain, on the rain type, on the storm depth and on the height at which the snow melts into rain. The estimates of the heat released into the atmosphere at different heights based on these measurements can be used to improve models of the global atmospheric circulation. The PR operated at 13.8 GHz and measured the 3-D rainfall distribution over land and ocean surfaces. It defined a layer depth of perception and hence measured rainfall that actually reached the latent heat of atmosphere. It had a 4.3 km resolution at radii with 220 km swath.

TRMM Microwave Imager

The TRMM Microwave Imager (TMI) was a passive microwave sensor designed to provide quantitative rainfall information over a wide swath under the TRMM satellite. By carefully measuring the minute amounts of microwave energy emitted by the Earth and its atmosphere, TMI was able to quantify the water vapor, the cloud water, and the rainfall intensity in the atmosphere. It was a relatively small instrument that consumed little power. This, combined with the wide swath and the quantitative information regarding rainfall made TMI the "workhorse" of the rain-measuring package on Tropical Rainfall Measuring Mission. TMI is not a new instrument. It is based on the design of the highly successful Special Sensor Microwave/Imager (SSM/I) which has been flying continuously on Defense Meteorological Satellites since 1987. The TMI measures the intensity of radiation at five separate frequencies: 10.7, 19.4, 21.3, 37.0, 85.5 GHz. These frequencies are similar to those of the SSM/I, except that TMI has the additional 10.7 GHz channel designed to provide a more-linear response for the high rainfall rates common in tropical rainfall. The other main improvement that is expected from TMI is due to the improved ground resolution. This improvement, however, is not the result of any instrument improvements, but rather a function of the lower altitude of TRMM 402 kilometers compared to 860 kilometers of SSM/I). TMI has a 878-kilometer wide swath on the surface. The higher resolution of TMI on TRMM, as well as the additional 10.7 GHz frequency, makes TMI a better instrument than its predecessors. The additional information supplied by the Precipitation Radar further helps to improve algorithms. The improved rainfall products over a wide swath will serve both TRMM as well as the continuing measurements being made by the SSM/I and radiometers flying on the NASA's EOS-PM (Aqua (satellite)) and the Japanese ADEOS II satellites.

Visible and Infrared Scanner

The Visible and Infrared Scanner (VIRS) was one of the three instruments in the rain-measuring package and serves as a very indirect indicator of rainfall. VIRS, as its name implies, sensed radiation coming up from the Earth in five spectral regions, ranging from visible to infrared, or 0.63 to 12 mm. VIRS was included in the primary instrument package for two reasons. First was its ability to delineate rainfall. The second, and even more important reason, was to serve as a transfer standard to other measurements that are made routinely using Polar Operational Environmental Satellites (POES) and Geostationary Operational Environmental Satellite (GOES) satellites. The intensity of the radiation in the various spectral regions (or bands) can be used to determine the brightness (visible and near infrared) or temperature (infrared) of the source.

Clouds and the Earth's Radiant Energy Sensor

Clouds and the Earth's Radiant Energy System (CERES) measured the energy at the top of the atmosphere, as well as estimates energy levels within the atmosphere and at the Earth's surface. The CERES instrument was based on the successful Earth Radiation Budget Experiment (ERBS) which used three satellites to provide global energy budget measurements from 1984 to 1993. [11] Using information from very high resolution cloud imaging instruments on the same spacecraft, CERES determines cloud properties, including cloud-amount, altitude, thickness, and the size of the cloud particles. These measurements are important to understanding the Earth's total climate system and improving climate prediction models.

It only operated during January–August 1998, and in March 2000, so the available data record is quite brief (although later CERES instruments were flown on other missions such as the Earth Observing System (EOS) AM (Terra) and PM (Aqua) satellites.)

Lightning Imaging Sensor

The Lightning Imaging Sensor (LIS) was a small, highly sophisticated instrument that detects and locates lightning over the tropical region of the globe. The lightning detector was a compact combination of optical and electronic elements including a staring imager capable of locating and detecting lightning within individual storms. The imager's field of view allowed the sensor to observe a point on the Earth or a cloud for 80 seconds, a sufficient time to estimate the flashing rate, which told researchers whether a storm was growing or decaying.

See also

Related Research Articles

Microwave radiometer

A microwave radiometer (MWR) is a radiometer that measures energy emitted at millimetre-to-centimetre wavelengths known as microwaves. Microwave radiometers are very sensitive receivers designed to measure thermally-emitted electromagnetic radiation. They are usually equipped with multiple receiving channels in order to derive the characteristic emission spectrum of planetary atmospheres, surfaces or extraterrestrial objects. Microwave radiometers are utilized in a variety of environmental and engineering applications, including remote sensing, weather forecasting, climate monitoring, radio astronomy and radio propagation studies.

Clouds and the Earths Radiant Energy System NASA satellite climate data instruments

Clouds and the Earth's Radiant Energy System (CERES) is on-going NASA climatological experiment from Earth orbit. The CERES are scientific satellite instruments, part of the NASA's Earth Observing System (EOS), designed to measure both solar-reflected and Earth-emitted radiation from the top of the atmosphere (TOA) to the Earth's surface. Cloud properties are determined using simultaneous measurements by other EOS instruments such as the Moderate Resolution Imaging Spectroradiometer (MODIS). Results from the CERES and other NASA missions, such as the Earth Radiation Budget Experiment (ERBE), could enable nearer to real-time tracking of Earth's energy imbalance and better understanding of the role of clouds in global climate change.

Aqua (satellite) NASA scientific research satellite

Aqua is a NASA scientific research satellite in orbit around the Earth, studying the precipitation, evaporation, and cycling of water. It is the second major component of the Earth Observing System (EOS) preceded by Terra and followed by Aura.

The Special Sensor Microwave/Imager (SSM/I) is a seven-channel, four-frequency, linearly polarized passive microwave radiometer system. It is flown on board the United States Air Force Defense Meteorological Satellite Program (DMSP) Block 5D-2 satellites. The instrument measures surface/atmospheric microwave brightness temperatures (TBs) at 19.35, 22.235, 37.0 and 85.5 GHz. The four frequencies are sampled in both horizontal and vertical polarizations, except the 22 GHz which is sampled in the vertical only.

Global Change Observation Mission

GCOM, is a JAXA project of long-term observation of Earth environmental changes. As a part of Japan's contributions to GEOSS, GCOM will be continued for 10 to 15 years with observation and utilization of global geophysical data such as precipitation, snow, water vapor, aerosol, for climate change prediction, water management, and food security. On May 18, 2012, the first satellite "GCOM-W" was launched. On December 23, 2017, the second satellite "GCOM-C1" was launched.

Atmospheric infrared sounder

The atmospheric infrared sounder (AIRS) is one of six instruments flying on board NASA's Aqua satellite, launched on May 4, 2002. The instrument is designed to support climate research and improve weather forecasting.

Aquarius (SAC-D instrument) NASA instrument aboard the Argentine SAC-D spacecraft

Aquarius was a NASA instrument aboard the Argentine SAC-D spacecraft. Its mission was to measure global sea surface salinity to better predict future climate conditions.

Megha-Tropiques Indian weather satellite

Megha-Tropiques is a satellite mission to study the water cycle in the tropical atmosphere in the context of climate change A collaborative effort between Indian Space Research Organisation (ISRO) and French Centre National d’Etudes Spatiales (CNES), Megha-Tropiques was successfully deployed into orbit by a PSLV rocket in October 2011.

Soil Moisture Active Passive

Soil Moisture Active Passive (SMAP) is a NASA environmental monitoring satellite launched on 31 January 2015. It was one of the first Earth observation satellites developed by NASA in response to the National Research Council's Decadal Survey.

NOAA-7

NOAA-7, known as NOAA-C before launch, was an American operational weather satellite for use in the National Operational Environmental Satellite System (NOESS) and for the support of the Global Atmospheric Research Program (GARP) during 1978-1984. The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the atmosphere of Earth, its surface and cloud cover, and the near-space environment. An earlier launch, NOAA-B, was scheduled to become NOAA-7, however NOAA-B failed to reach its required orbit.

Frank Wentz is the CEO and director of Remote Sensing Systems, a company he founded in 1974, which specializes in satellite microwave remote sensing research. Together with Carl Mears, he is best known for developing a satellite temperature record from MSU and AMSU. Intercomparison of this record with the earlier UAH satellite temperature record, developed by John Christy and Roy Spencer, revealed deficiencies in the earlier work; specifically, the warming trend in the RSS version is larger than the University of Alabama in Huntsville (UAH) one. From 1978 to 1982, Wentz was a member of NASA's SeaSat Experiment Team involved in the development of physically based retrieval methods for microwave scatterometers and radiometers. He has also investigated the effect of climate change on satellite-derived evaporation, precipitation and surface wind values. His findings are different from most climate change model predictions.

NOAA B was an American operational weather satellite for use in the National Operational Environmental Satellite System (NOESS) and for the support of the Global Atmospheric Research Program (GARP) during 1978-1984. The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the atmosphere of Earth, its surface and cloud cover, and the near-space environment.

Global Precipitation Measurement

Global Precipitation Measurement (GPM) is a joint mission between JAXA and NASA as well as other international space agencies to make frequent observations of Earth's precipitation. It is part of NASA's Earth Systematic Missions program and works with a satellite constellation to provide full global coverage. The project provides global precipitation maps to assist researchers in improving the forecasting of extreme events, studying global climate, and adding to current capabilities for using such satellite data to benefit society. GPM builds on the notable successes of the Tropical Rainfall Measuring Mission (TRMM), which was also a joint NASA-JAXA activity.

Joint Polar Satellite System

The Joint Polar Satellite System (JPSS) is the latest generation of U.S. polar-orbiting, non-geosynchronous, environmental satellites. JPSS will provide the global environmental data used in numerical weather prediction models for forecasts, and scientific data used for climate monitoring. JPSS will aid in fulfilling the mission of the U.S. National Oceanic and Atmospheric Administration (NOAA), an agency of the Department of Commerce. Data and imagery obtained from the JPSS will increase timeliness and accuracy of public warnings and forecasts of climate and weather events, thus reducing the potential loss of human life and property and advancing the national economy. The JPSS is developed by the National Aeronautics and Space Administration (NASA) for the National Oceanic and Atmospheric Administration (NOAA), who is responsible for operation of JPSS. Three to five satellites are planned for the JPSS constellation of satellites. JPSS satellites will be flown, and the scientific data from JPSS will be processed, by the JPSS – Common Ground System (JPSS-CGS).

Suomi NPP

The Suomi National Polar-orbiting Partnership, previously known as the National Polar-orbiting Operational Environmental Satellite System Preparatory Project (NPP) and NPP-Bridge, is a weather satellite operated by the United States National Oceanic and Atmospheric Administration (NOAA). It was launched in 2011 and continues to operate in January 2022.

NOAA-8, known as NOAA-E before launch, was an American weather satellite operated by the National Oceanic and Atmospheric Administration (NOAA) for use in the National Environmental Satellite Data and Information Service (NESDIS). It was first of the Advanced TIROS-N series of satellites. The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the atmosphere of Earth, its surface and cloud cover, and the near-space environment.

NOAA-9

NOAA-9, known as NOAA-F before launch, was an American weather satellite operated by the National Oceanic and Atmospheric Administration (NOAA) for use in the National Environmental Satellite Data and Information Service (NESDIS). It was the second of the Advanced TIROS-N series of satellites. The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the atmosphere of Earth, its surface and cloud cover, and the near-space environment.

NOAA-10, known as NOAA-G before launch, was an American weather satellite operated by the National Oceanic and Atmospheric Administration (NOAA) for use in the National Environmental Satellite Data and Information Service (NESDIS). It was the third of the Advanced TIROS-N series of satellites. The satellite design provided an economical and stable Sun-synchronous platform for advanced operational instruments to measure the atmosphere of Earth, its surface and cloud cover, and the near-space environment.

Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats

The Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission is a NASA constellation of six small satellites, 3U CubeSat, that will measure temperature and moisture profiles and precipitation in tropical systems with unprecedented temporal frequency. This data will enable scientists to study the dynamic processes that occur in the inner core of the storm resulting in rapid genesis and intensification. William Blackwell of the Massachusetts Institute of Technology's Lincoln Laboratory in Lexington, Massachusetts is the principal investigator. The constellation will be delivered to orbit on three launches between March and May 2022.

References

  1. "Satellite Overview" JAXA Retrieved on 5 July 2015
  2. 1 2 "Trajectory: TRMM 1997-074A". NASA. 14 May 2020. Retrieved 4 November 2020.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  3. 1 2 3 4 Kummerow, C.; J. Simpson; O. Thiele; W. Barnes; A. T. C. Chang; E. Stocker; R. F. Adler; A. Hou; R. Kakar; F. Wentz; et al. (December 2000). "The Status of the Tropical Rainfall Measuring Mission (TRMM) after Two Years in Orbit". Journal of Applied Meteorology. 39 (12): 1965–1982. Bibcode:2000JApMe..39.1965K. CiteSeerX   10.1.1.332.5342 . doi:10.1175/1520-0450(2001)040<1965:TSOTTR>2.0.CO;2.
  4. "Tropical Rainfall Measuring Mission University". NASA. Retrieved 5 July 2015.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  5. "History of TRMM" JAXA Retrieved on 5 July 2015
  6. "Display: TRMM 1997-097A". NASA. 14 May 2020. Retrieved 5 November 2020.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  7. 1 2 3 "The TRMM Rainfall Mission Comes to an End after 17 Years". NASA. 9 April 2015. Retrieved 21 December 2017.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  8. 1 2 Clark, Stephen (9 April 2015). "Rain research satellite ends science mission, heads for re-entry" . Retrieved 21 December 2017.
  9. "Rainfall Research Satellite Begins Descent from Orbit" Spaceflight Now Retrieved on 17 September 2014
  10. "Rainfall Spacecraft Re-enters over Tropics". 4 June 2015.
  11. "Clouds and the Earth's Radiant Energy System (CERES)". NASA. Retrieved 9 September 2014.PD-icon.svgThis article incorporates text from this source, which is in the public domain .