Scientists See Much More than Weather in Images from GOES

 With a constant watch over the Western Hemisphere, Geostationary Operational Environmental Satellites (GOES) are the first to detect wild storms charging from the sea and pummeling continental coastlines. While weather-watching may put GOES on the nightly news, the satellites’ value goes way beyond tonight’s weather report and tomorrow’s forecast.

For years, scientists have taken advantage of the wide and watchful eye of GOES to study all kinds of Earth issues, from erupting volcanoes to climate-changing clouds.

Can GOES predict a Volcanic Eruption?

By using GOES as a long-distance thermometer, scientists from the University of Hawaii saw signs of an impending volcanic eruption from space for the first time in 1998. On May 20, a Guatemalan volcano named Pacaya erupted an ash cloud that blanketed Guatemala City and the local airport 19 miles (30 kilometers) away. Luke Flynn, a University of Hawaii volcanologist and his team of scientists saw it coming. Seven days before the eruption, the volcano started to heat up. GOES saw the heat in the form of radiation, and an automated computer system at the university acted as an eruption alarm by picking the hot spot out of the satellite data.

The advantage of using GOES to study volcanoes and other "hot spots" like forest fires is that an image can be sent to the ground every 30 minutes. The near real-time data is a great benefit to hazard mitigation agencies. The U.S. Geological Survey’s Hawaii Volcano Observatory uses the University of Hawaii Hot Spot Image web site: http://virtual1.pgd.hawaii.edu/goes/hawaii/latest.shtml to follow eruptions on Kilauea and Mauna Loa. Real time imagery for the continental U.S. is available at: http://www.cira.colostate.edu/ramm/goes39/cover.htm.

Can Airplanes Create Clouds and Cause the Climate to Change?

The ghostly white trails following airplanes and rockets through the sky, called contrails, are probably adding to global warming, according to scientists at NASA’s Langley Research Center, Hampton, Va. Atmospheric scientist Patrick Minnis uses GOES to track contrails that are formed when water vapor turns to ice in the exhaust of aircraft and rockets. The contrails often turn into cirrus clouds, a thin, wispy type of cloud made of ice crystals. While some clouds tend to help cool the globe and negate the affects of global warming, thin cirrus clouds are heat trappers, holding in more heat than they reflect back into space.

Because clouds come and go with the wind, GOES’ clear, constant perspective is the only way to keep tabs on the changing contrails. The Imager, an instrument aboard GOES, can tell one cloud type from another by the cloud’s temperature, revealing to scientists which clouds are doing the heating, and which are doing the cooling. The work is part of a NASA’s Atmospheric Effects of Aviation Project to study the global and regional affects of contrails and the clouds they form. http://hyperion.gsfc.nasa.gov/AEAP

Another part of the aircraft-climate equation is pollution from airplanes and rockets. Anne Thompson, an atmospheric scientist at NASA’s Goddard Space Flight Center, Greenbelt, Md., uses GOES to guide her research into the top of the troposphere, the part of the atmosphere 5.5 to 7.5 miles (9-12 kilometers) above the Earth. The sky over the Atlantic Ocean has become a superhighway for air traffic, and in 1997, Thompson tested the air there from a NASA DC-8 to see the affect of airliner exhaust gov/ http://telsci.arc.nasa.gov/~sonex/.

But pollution can also get to the troposphere during a thunderstorm, sending up man-made smog from below. GOES can identify where thunder clouds are, helping Thompson tell where thunderstorms are causing the pollution, and where smog is just the result of jet exhaust. Pollution in the troposphere is made up of gases that can trap heat from the sun and add to global warming, said Thompson. So knowing how airliners and rockets add to the picture is important for climate research. The study is also part of NASA’s Atmospheric Effects of Aviation Project.

Climate and Clouds: What’s the Connection?

If temperatures rise globally, what will the affect be on clouds, the Earth’s natural shade-makers? Since 1995, NASA Goddard climate researcher Gyula Molnar has used GOES to keep watch over low-lying stratus clouds blanketing the Eastern Pacific Ocean along the Peruvian, Chilean, and Baja California coasts. When the climate changed with El Niņo in 1997 and the Eastern Pacific sea surface warmed up, the blanket of clouds became thinner and full of larger holes, allowing more of the sun’s heat to further warm the ocean.

Many climate scientists predict that sea surface temperatures around the globe will heat up with man-made global warming. If marine stratus clouds around the globe act like the clouds in the Eastern Pacific, the Earth’s land and sea surfaces could be in for a lot more heat during the predicted global warming. Molnar has used GOES to get an update every three hours since 1995 on the extent and brightness of clouds in the Eastern Pacific. Color GOES images of the Peru/Chile region can be found at: http://rsd.gsfc.nasa.gov/goese/autogvar/goes8/stratus_peru/color/ and the Baja/California region images at: http://rsd.gsfc.nasa.gov/goese/autogvar/goes8/stratus_california/color/

The GOES Rain Gauge

Andrew Negri, a Goddard research meteorologist, uses GOES to determine the amount of rainfall over the Amazon, where there are very few rain gauges on the ground. GOES uses its infrared sensor as a long distance thermometer and takes the temperature of clouds. During summer thunderstorms, colder clouds produce more rain, so by measuring the temperature of clouds with GOES, Negri can estimate how much rain is falling. Some areas of the Amazon get up to 12-16 inches of rain a month.

Rainfall in the Amazon is important because when water vapor condenses into clouds and turns to rain, it warms up the tropical atmosphere. This heating provides the fuel for the engine that drives the global circulation, affecting wind patterns all over the globe. Using GOES as a rain gauge can also help with agriculture (drought/soil moisture) in North America. NOAA uses GOES data in real time to monitor flash-flood producing thunderstorms. More information can be found at this site: http://rsd.gsfc.nasa.gov/912/code912

Real-time precipitation estimates for the U.S. from the GOES satellite are available every half hour at: http://orbit-net.nesdis.noaa.gov/arad/ht/ff. Forecast offices and emergency management officials utilize this data to monitor heavy rainfall. Accumulation data is available for periods of one hour, three hours, six hours or 24 hours.

Understanding Storms from Space

From space, severe storms and hurricanes come in a variety of shapes and sizes, some are wispy, flowing sheets, some are enormous, menacing whirlpools. But it’s more than what the storm looks like from above that’s important for predicting how much damage it will do on the ground. Gerald Heymsfield, a Goddard research meteorologist uses radar aboard a high altitude NASA airplane to measure what storms are like on the inside in order to let scientists better understand what they see in 2-D images from GOES. By combining information about wind and circulation within a thunderstorm with GOES images and cloud temperature measurements, meteorologists can make more accurate forecasts about the future of a thunderstorm. Information on the radar experiment can be found at:  http://rsd.gsfc.nasa.gov/912/code912/precip.html.

Just which storms will become severe depends upon the stability of the atmosphere and the energy available to the growing clouds. GOES provides temperature and moisture information from the 19 channel sounder onboard. This information is used in NOAA’s weather prediction models and is also made into images. Static and animated views of moisture and stability information can be found at two locations: http://cimss.ssec.wisc.edu/goes/goes.html and http://orbit-net.nesdis.noaa.gov/goes/.

The amount of wind damage that might occur from thunderstorm downbursts is the focus of an experimental product by Gary Ellrod, a NOAA scientist. This product, the Wind Index (WINDEX), available hourly during the thunderstorm season on the Internet at: http://orbit-net.nesdis.noaa.gov/arad/fpdt/mb.html assists forecasters, aircraft operators and transportation officials in decision making. Downbursts have been responsible for a number of aircraft crashes.

GOES: Fire Alarm for the Western Hemisphere

In 1998, scientists at the National Oceanic and Atmospheric Administration (NOAA) assisted fire fighting efforts in drought stricken Mexico and Florida. Obscured by dense smoke in Florida and hampered by the rugged terrain and large area coverage in Mexico, GOES data was used to locate the active fire cores and aid in fire suppresion activity saving costs, lives and property.

In remote areas of the Amazon Rainforest and throughout South America, thousands of fires burn every day during the dry season – and GOES keeps tabs. Elaine Prins, a NOAA research meteorologist at the University of Wisconsin-Madison developed a way to use GOES as a fire alarm to tell scientists and government agencies where, how big, and how hot fires are burning. When GOES sees an area heat up, information on the fire is sent directly to the Internet every three hours. Scientists working to model the Earth’s climate are interested in GOES fire data because deforestation and the amount of smoke sent into the atmosphere by man-made fires in South American forests may be an important factor affecting the Earth’s climate.

In South America, most fires are caused by humans. In North America, it’s lightning that’s responsible for burning forests. In the Northern Hemisphere, it is possible to monitor changes in fire characteristics every 15 minutes. Environment Canada, a Canadian Governmental agency, uses the GOES data to help locate forest fires in remote areas of Quebec. Information on the GOES Biomass Burning Monitoring Program is described at: http://cimss.ssec.wisc.edu/goes/burn/abba.html