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 Ozone, gases |
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Changes caused by gas emissions can be viewed from spacecraft circling the globe or from spacecraft in geosyncronous orbits. The images which can be photographed are interesting. You may find images of your favorite atmospheric changes. Some examples and sources: |
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Earth science web page http://pao.gsfc.nasa.gov/gsfc/earth/pictures/earthpic.htm
Largest-Ever Ozone Hole Observed Over Antarctica http://pao.gsfc.nasa.gov/gsfc/earth/pictures/earth/environ/ozone/ozone.htm New Animation Depicts Changs in Antarctic Ice Sheet For the first time, scientists at NASA have generated a
computer model depicting changes in the Antarctic ice sheet since the peak of
the last ice age - nearly 20,000 years ago. The West Antarctic ice sheet has
lost nearly 2/3 of it's mass during this period - a volume sufficient to raise
sea level 33 feet.
Images and quicktimes can be downloaded after 8 a.m. Feb 3:
17 February 1999 Rapid Thinning of the Greenland Ice Sheet This movie depicts the airborne laser altimeter collecting data. In 1993 and 1994, NASA researchers surveyed the Greenland ice sheet using an airborne laser altimeter. Ten flight lines flown in 1993 in southern Greenland were resurveyed in 1998. Scientists used computers to create detailed maps of changes in the ice. A study of Greenland indicates a rapid thinning of glaciers along the east coast of the southern half of the island and suggests that the lower elevation portion of the ice sheet may be particularly sensitive to changes in climate. The results of this study are significant because they provide the first evidence of widespread thinning of low-elevation parts of one of the great polar ice sheets.
NASA Researchers Document Shrinking Of Greenland's Glaciers
(Details) 04 March 1999 NASA Scientists Detect Rapid Thinning of
Greenland's Coastal Ice ftp://pao.gsfc.nasa.gov/pub/pao/releases/2000/h00-112.htm Arctic Ozone Levels Significantly Low "During the preceding winter Arctic ozone levels reached their lowest point in eight years at an altitude of nearly 60,000 feet. Concentrations dropped more than 50 percent from their average. But measurements taken during the largest international campaign ever mustered to study the Arctic stratosphere are yielding better insights into the processes that control polar ozone. Called SOLVE (Stratospheric Ozone Loss and Validation Experiment), it included researchers from Europe, Russia, Canada, and the United States working together to develop better tools for predicting the state of polar ozone levels. These predictive tools will become more and more important in light of expected chlorine level declines due to the Montreal Protocol and what will likely be increasing levels of greenhouse gases in the coming decades." For more on this story, go to: 05 April 2000 05 January 2000 Total Ozone Mapping Spectrometer (TOMS) instrument is onboard the Earth Probe Satellite. While best known for mapping total column ozone on a daily basis, TOMS can also detect and track aerosols located in the troposphere. The haze is denoted by the TOMS aerosol index. For a given scene, the aerosol index is proportional to the amount of light absorbed before it reaches the ground. Light blue (0.2) indicates smaller amounts of aerosol and dark red (1.6) indicates a greater amount of aerosol (dust or smoke). For reflectivity (grayscale), the lighter tones means that more light is reflected back to space by the clouds. For more information on TOMS instruments, go to the TOMS home page at http://toms.gsfc.nasa.gov NASA Spacecraft Observes Lowest Ozone Ever in Northern Hemisphere A NASA spacecraft has observed the lowest value of ozone ever seen in the Northern Hemisphere since spacecraft first began ozone measurements in 1978. The measurement was obtained on Nov. 30, 1999 using the Total Ozone Mapping Spectrometer (TOMS) instrument aboard NASA's Earth Probe (TOMS-EP) satellite. The measurement showed an extremely low level of 165 Dobson Units (DU) over the North Sea between Scotland and Norway. The blue color indicates lower than normal levels of ozone.
Scientists believe a combination of stratospheric and tropospheric weather systems may be responsible for this extreme low ozone event. Scientists and others have a keen interest in polar ozone depletion. While this particular record low value results from a convergence of weather systems, severe depletions of ozone can result from chemical processes. Chemically caused Arctic ozone losses have also been observed, particularly in the Northern Hemisphere springs of 1996 and 1997. TOMS ozone data and pictures are available on the Internet
at: NASA Scientist Predicts Less Climate Cooling From Clouds Don't count on clouds to come to the rescue if the Earth's current climate warming trend continues. That's according to new NASA research published in the October 1st issue of the American Meteorological Society's Journal of Climate. (Details) http://www.gsfc.nasa.gov/gsfc/earth/environ/clouds.htm 1 October 2000 |
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