Scientists' showdown with soil moisture at the O.K. corral

August 02, 2004

Tombstone, Ariz., is a dusty place known for Wyatt Earp's famous 1881 "Shootout at the O.K. Corral." This year, from August 2 to 27, it will be known as the place where scientists from NASA, the U.S. Department of Agriculture (USDA), the National Oceanic and Atmospheric Administration (NOAA), and other institutions gather and study soil moisture to improve weather forecasts and the ability to interpret satellite data.

By identifying how much moisture is retained in soils, hydrologists will be able to determine how much more water can be absorbed, and thus better estimate the potential for flooding or how much water sinks into the water table. During July and August, the U.S. Southwestern monsoon season is characterized by a wind pattern shift that exerts a strong influence on precipitation and temperatures across the Western United States, Mexico and adjacent ocean areas. This change in winds over the region creates many rainy days and heavy rainfall, which are ideal conditions for studying soil moisture.

The study, called the Soil Moisture Experiment 2004, or SMEX04, will use ground teams, airplanes and NASA satellites and instruments to measure soil moisture in Tombstone, Ariz., and Sonora, Mexico, where water supplies are critical. Researchers from NASA, USDA, NOAA, Sonora Research Institute and more than a dozen universities will be on the ground and in the air with advanced technology to get a better read on soil moisture. SMEX scientists also want to know what atmospheric conditions create long-lasting rainfalls over a large area. By knowing which factors create large or small rainfall, hydrologists can provide better forecasts and know how much water will be available to people.

"The Western U.S. relies on water from the Southwestern monsoon system to fill its aquifers. Accurate measurements of soil moisture will assist in better water supply forecasts associated with the monsoon in the water-scarce western U.S," said Tom Jackson, USDA Agricultural Research Service hydrologist and lead for SMEX.

From space, NASA's Aqua, Terra and QuikScat satellites will provide various measurements. Aqua's Advanced Microwave Scanning Radiometer (AMSR-E) instrument will measure soil moisture; Terra's Moderate Resolution Spectroradiometer (MODIS) will provide vegetation status; and Terra's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) will measure the surface temperature. The SeaWinds instrument on the QuikScat satellite will observe the monsoon winds that bring in the moisture from the Pacific Ocean to the U.S. Southwest.

Closer to Earth, microwave radiometers on the Naval Research Laboratory P-3 aircraft and the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) on NASA's ER-2 high-altitude aircraft will fly over the areas to measure soil moisture. AVIRIS will also help test new methods for remotely sensing water content in plants. Meanwhile, ground instruments will measure the temperature and percentage of moisture in soils from 2 to 40 inches deep. The satellite, airplane and ground data will be compared.

The SMEX04 mission adds to two prior SMEX experiments in 2002 and 2003, and is part of the larger North American Monsoon Experiment (NAME), led by NOAA, which is dedicated to understanding how the Southwestern U.S. monsoon season works. Monsoons need to be accurately understood and predicted by weather and climate models, because their influence on seasonal weather, including floods and droughts, can significantly disrupt regional economies and populations.

NASA's Earth Science Enterprise is dedicated to understanding the Earth as an integrated system and applying Earth System science to improve prediction of climate, weather and natural hazards using the unique vantage point of space.
-end-


NASA/Goddard Space Flight Center

Related Monsoon Articles from Brightsurf:

Air-sea coupling improves the simulation of the western North Pacific summer monsoon in the WRF4 model at a synoptic scale resolving resolution
Air-sea coupling improves the simulation of the western North Pacific summer monsoon in the WRF4 model at a synoptic scale resolving resolution

Seesaw of Indo-Pacific summer monsoons triggered by the tropical Atlantic Ocean
The increasing influences from the tropical Atlantic sea surface temperature could trigger the observed multidecadal seesaw of Indo-Pacific summer monsoons in terms of their intensity of interannual variability and monsoon-ENSO biennial relationship variability.

Without the North American monsoon, reining in wildfires gets harder
New research shows that while winter rains can temper the beginning of the wildfire season, monsoon rains are what shut them down.

Indian monsoon can be predicted better after volcanic eruptions
Large volcanic eruptions can help to forecast the monsoon over India - the seasonal rainfall that is key for the country's agriculture and thus for feeding one billion people.

Spread of monsoon circulation changes explains uncertainty in global land monsoon precipitation projection
A new study emphasizes the importance of reliable prediction of circulation changes, to ensure that future projections of global land monsoon are suitable for use by policy makers.

Wetter than wet: Global warming means more rain for Asian monsoon regions
Researchers from Tokyo Metropolitan University studied how the weather will change with global warming in Asian monsoon regions using a high-resolution climate simulation.

Divining monsoon rainfall months in advance with satellites and simulations
Researchers affiliated with The University of Texas at Austin have developed a strategy that more accurately predicts seasonal rainfall over the Asian monsoon region and could provide tangible improvements to water resource management on the Indian subcontinent, impacting more than one fifth of the world's population.

Scientists work toward more reliable prediction of South Asian summer monsoon rainfall for the upcoming 15-30 years
A large part of climate change adaptation and mitigation activities is based on prognoses delivered by climate models, so a highly robust and reliable climate prediction is the base of policy decision making.

Model simulation experiments give scientists a clearer understanding of factors that influence monsoon behavior
The Chinese Academy of Sciences (CAS) Flexible Global Ocean-Atmosphere-Land System (FGOALS-f3-L) model datasets prepared for the sixth phase of the Coupled Model Intercomparison Project (CMIP6) Global Monsoons Model Intercomparison Project (GMMIP) provide a valuable tool to assess sea surface temperature trends and its influence on monsoon circulation and precipitation patterns, while also providing a clearer understanding of how topography can affect the global monsoon system as it passes over landscapes with high altitudes.

This is what the monsoon might look like in a warmer world
In the last interglacial period on Earth about 125,000 years ago, the Indian monsoon was longer, more extreme and less reliable than it is today.

Read More: Monsoon News and Monsoon Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.