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August 7, 2003
NASA Ozone Satellite Improves Snowstorm Forecasts
Scientists in sunny, hot Florida are thinking cold thoughts since they
added ozone measurements from a NASA satellite into computer weather
forecast models and improved several factors in a forecast of a major
winter snowstorm that hit the United States in 2000.
When scientists added ozone measurements, predictions of snowstorm intensity,
snowfall amounts and the storm track all improved for a storm that hit
Washington, D.C. As such, they may be able to do the same for future
storms, according to a study published in a recent issue of the American
Meteorological Society's Journal of Applied Meteorology.
Kun-Il Jang and Xiaolei Zou, research scientists from Florida State
University, used data from NASA's Earth Probe/Total Ozone Mapping Spectrometer
(TOMS) satellite to create a more accurate prediction of a January 2000
snowstorm in the Washington metropolitan area. Other researchers included
Mel Shapiro of the National Oceanic and Atmospheric Administration's
(NOAA) Environmental Technology Laboratory (ETL), Manuel Pondeca of NOAA's
National Center for Environmental Prediction (NCEP), C. Davis of the
National Center for Atmospheric Research (NCAR), Boulder, Colo., and
A. Krueger of the University of Maryland, Baltimore County.
The TOMS satellite monitors daily changes in the amounts of ozone in
Earth's atmosphere stretching from the Earth's surface into the stratosphere,
as high as 30 miles up. In this study, the scientists decided to add
ozone data to an historic forecast and improved it.
The scientists added air motions in the upper atmosphere inferred from
TOMS measurements of ozone into the computer model, along with lower
troposphere readings taken during the event of temperature, humidity,
wind, and dewpoint from balloon-borne sensors called radiosondes. Together,
the two data sources created an accurate picture of the total atmosphere
where the weather occurs. Current forecast models just use the radiosonde
data of precipitation and temperature. "The 36-hour forecasts using the
radiosonde data were more accurate than those just using the computer
forecast model," Jang said. "The addition of ozone data into the forecast
model moved the storm prediction closer to the East coast, which is what
really happened." When the ozone data was added into the mix, it reduced
errors on predicted storm tracks, especially in the 12- to 24-hours period.
The findings were verified with multi-sensor hourly precipitation totals
from NOAA/NCEP. By better knowing when and where the heaviest snow will
fall during a storm, public works departments can direct their snow moving
equipment and can estimate where problem areas may occur. Other potential
uses of this forecast model include 36-hour advanced predictions of different
forms of air movement.
Previous research links atmospheric movements, such as wind, heat and
moisture to ozone measurements. These movements occur horizontally across
the Earth's surface, as well as vertically from the surface up, and sometimes
stretch over several hundred miles or more. One of the most noticeable
areas of motion is in the vicinity of the jet stream, and the movement
of ozone helps identify its location. The jet stream is a river of fast
moving air in the upper atmosphere that steers storms around the world.
Knowing the exact location of the jet stream would give forecasters a
better idea of where storms may move. In the northern hemisphere, it
moves from west to east and divides colder air from warmer air.
More case studies are being conducted to fully assess the usefulness
of assimilating TOMS ozone data for more accurate weather prediction.
NASA's Earth Science Enterprise office partially funded this research.
The Enterprise is dedicated to understanding the Earth as an integrated
system and applying Earth System Science to improve predication of climate,
weather, and natural hazards using the unique vantage point of space.
For more information and images on this research, visit:
http://www.gsfc.nasa.gov/topstory/2003/0808forecast.html
For more information about NASA: http://www.nasa.gov
For more information about NOAA: http://www.noaa.gov
For more information about NCAR: http://www.ncar.edu
For more information about NASA's Earth Science Enterprise: http://www.earth.nasa.gov
For more information about TOMS: http://toms.gsfc.nasa.gov
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Contact:
Rob Gutro
Goddard Space Flight Center, Greenbelt, Md.
(Phone: 301/286-4044) |
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Washington, D.C. Blizzard on February 24-25, 2000
This infrared image is from NOAA's GOES-8 satellite. The darker colors
show more intense snowfall. Scientists used data from this storm with
ozone measurements to arrive at a better storm track. Credit: NOAA/NCDC
Improving on a Computer Forecast
This multi-spectral false color image from NOAA's GOES-8 satellite shows
cloud cover in blue, and the center of the snow storm is just southeast
of the Delmarva Peninsula in the Mid-Atlantic as it moved up the east
coast on Feb. 25, 2000. Ozone measurements added to forecast models brought
it closer to where it really went. Credit: NOAA
Snowstorm Aftermath
Scientists hope that adding ozone measurements will be able to improve
snowstorm forecasts. This picture was taken in Germantown, Maryland from
a snowstorm on February 17, 2003. Credit: NOAA/NWS Historic Collection
How Ozone Improved a Snowstorm Forecast
These 3 model runs show how the center of the storm (Marked "L") was
originally and inaccurately forecast (left); how it was slightly improved
using only radiosonde data (middle), and how the forecast track became
most accurate when radiosonde and ozone data were added (right) as it
actually tracked closer to the U.S. East Coast. CreditT: Florida State
University
The Formation of the Surprise Blizzard
The surface low ("L" on the map) for the DC blizzard formed off the South
Carolina coast and was well underway by January 25th, The low intensified
rapidly, brushed the North Carolina coast and reached the Maryland coast
18 hours later. It then brought snows to New England on the 26th. Credit:
NOAA
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