Climate Essentials

This Climate Essentials multimedia gallery brings together the latest and most popular climate-related images, data visualizations and video features from Goddard Space Flight Center on one web page. Browse our top ten most popular climate resources, or select from the categories below. You can download the imagery in a variety of formats directly from this site. For more multimedia resources on climate and other topics, search the Scientific Visualization Studio. To learn more about NASA's contribution to understanding Earth's climate, visit the Global Climate Change site.

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Life on Earth

  • Feeling the Sting of Climate Change
    2009.08.25
    NASA research scientist Wayne Esaias uses honey bees as tiny data collectors to understand how climate change is affecting pollination. His citizen-scientist project, HoneyBeeNet, compares bee data from across North America to satellite imagery in order to gain a big-picture perspective of how our warming climate is affecting both plants and pollinators.
  • Science for a Hungry World: Agriculture and Climate Change
    2009.11.03
    How will climate change impact agriculture? This episode explores the need for accurate, continuous and accessible data and computer models to track and predict the challenges farmers face as they adjust to a changing climate.

    For complete transcript, click here.

  • Crop Intensity
    2009.10.05
    The U.S. Department of Agriculture (USDA) and the National Aeronautics and Space Administration (NASA) signed a Memorandum of Understanding (MOU) to strengthen collaboration. In support of this collaboration, NASA and the USDA Foreign Agricultural Service (FAS) jointly funded a new project to assimilate NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) data and products into an existing decision support system (DSS) operated by the International Production Assessment Division (IPAD) of FAS. To meet its objectives, FAS/IPAD uses satellite data and data products to monitor agriculture worldwide and to locate and keep track of natural disasters such as short and long term droughts, floods and persistent snow cover which impair agricultural productivity. FAS is the largest user of satellite imagery in the non-military sector of the U.S. government. For the last 20 years FAS has used a combination of Landsat and NOAA-AVHRR satellite data to monitor crop condition and report on episodic events.

    To successfully monitor worldwide agricultural regions and provide accurate agricultural production assessments, it is important to understand the spatial distribution of croplands. To do this a global croplands mask to identify all sites used for crop production. Croplands are highly variable both temporally and spatially. Croplands vary from year to year due to events such as drought and fallow periods, and they vastly differ across the globe in accordance with characteristics such as cropping intensity and field size. A flexible crop likelihood mask is used to help depict these varying characteristics of global crop cover. Regions featuring intensive agro-industrial farming practices such as the Maize Triangle in South Africa will have higher confidence values in the crop mask as compared to less intensively farmed regions in parts of Sub-Saharan Africa where cropland identification is partly confounded with natural background vegetation phenologies. Thus, a customized threshold can be employed to examine areas of varying cropping intensification.

  • Global Crop Production
    2009.06.05
    Satellite data can be used to monitor the health of plant life from space. The Normalized Difference Vegetation Index (NDVI) provides a simple numerical indicator of the health of vegetation which can be used to monitoring changes in vegetation over time. This animation shows the seasonal changes in vegetation by fading between average monthly NDVI data from 2004. The loop begins on September 24 and repeats six times during one full rotation of the globe at a rate of one frame per day. The fade for each month is complete on the 15th of each month.
  • Ocean Plant Life
    2007.04.23
    The SeaWiFS instrument aboard the Seastar satellite has been collecting ocean data since 1997. By monitoring the color of reflected light via satellite, scientists can determine how successfully plant life is photosynthesizing. A measurement of photosynthesis is essentially a measurement of successful growth, and growth means successful use of ambient carbon. This animation shows an average of 10 years worth of SeaWiFS data. Dark blue represents warmer areas where there tends to be a lack of nutrients, and greens and reds represent cooler nutrient-rich areas which support life. The nutrient-rich areas include coastal regions where cold water rises from the sea floor bringing nutrients along and areas at the mouths of rivers where the rivers have brought nutrients into the ocean from the land.

The Oceans

  • Phytoplankton Blooms
    2006.12.05
    The SeaWiFS instrument aboard the Seastar satellite has been collecting ocean data since 1997. By monitoring the color of reflected light via satellite, scientists can determine how successfully plant life is photosynthesizing. A measurement of photosynthesis is essentially a measurement of successful growth, and growth means successful use of ambient carbon. This animation represents nearly a decade's worth of data taken by the SeaWiFS instrument, showing the abundance of life in the sea. Dark blue represents warmer areas where there is little life due to lack of nutrients, and greens and reds represent cooler nutrient-rich areas. The nutrient-rich areas include coastal regions where cold water rises from the sea floor bringing nutrients along and areas at the mouths of rivers where the rivers have brought nutrients into the ocean from the land. Dark gray indicate areas where no data was collected.
  • Ocean Temperature, Salinity, and Density
    2009.10.09

    Sea Surface Temperature

    The oceans of the world are heated at the surface by the sun, and this heating is uneven for many reasons. The Earth's axial rotation, revolution about the sun, and tilt all play a role, as do the wind-driven ocean surface currents. The first animation in this group shows the long-term average sea surface temperature, with red and yellow depicting warmer waters and blue depicting colder waters. The most obvious feature of this temperature map is the variation of the temperature by latitude, from the warm region along the equator to the cold regions near the poles. Another visible feature is the cooler regions just off the western coasts of North America, South America, and Africa. On these coasts, winds blow from land to ocean and push the warm water away from the coast, allowing cooler water to rise up from deeper in the ocean.


    Sea Surface Salinity

    The heat of the sun also forces evaporation at the ocean's surface, which puts water vapor into the atmosphere but leaves minerals and salts behind, keeping the ocean salty. The salinity of the ocean also varies from place to place, because evaporation varies based on the sea surface temperature and wind, rivers and rain storms inject fresh water into the ocean, and melting or freezing sea ice affects the salinity of polar waters. The second animation in this group shows the long term average sea surface salinity, where white regions have the highest salinity and dark regions the lowest. Notice the higher salinity in the Atlantic than the Pacific, due to the greater rainfall amounts in the Pacific, and the lower salinity at the mouths of major rivers.


    Sea Surface Density

    The average density of sea surface water can be calculated from the average sea surface temperature and salinity using the state equation for seawater. The third animation shows the long term average sea surface density, with light blue regions having the least density and dark blue regions having the greatest density. The sea surface density variations are actually very small, less than 3% overall, but the variation is very important. There are three stable, dense regions in the ocean's surface, one in the sea around Iceland, Greenland, and Scandinavia and the other two near or under major Antarctic ice shelves. In these regions, the surface water becomes dense enough to sink and join the deep ocean currents. In fact, this sinking is thought to drive these deep currents as part of a system called the Thermohaline Circulation (see the animation The Thermohaline Circulation - The Great Ocean Conveyor Belt). This circulation has a strong effect on the Earth's climate, influencing the Gulf Stream, El Niño events, and both past and future Climate Shifts.


    Other Effects of Ocean Salinity

    The link between ocean temperature, salinity, and density also has other consequences. Research shows that over the past few decades, vast regions of abnormal sea surface salinity - called Great Salinity Anomalies - have propagated around the far north Atlantic, impacting local ecosystems and the sinking of water masses. At mid-latitudes, salinity influences the depth to which water masses sink and how far they extend through the ocean. The location and depth of these water masses controls how heat and salt are transported between the tropics and high latitudes. Like atmospheric fronts that bring unstable weather, ocean fronts found at the interface between water masses are areas of high activity often correlated with important fisheries such as tuna.

    In the tropics, sea surface salinity is primarily controlled by rainfall and river runoff; these sources of freshwater regulate how the oceans interact with the atmosphere. Affecting almost half of the world's human population each year, monsoons are driven by exchanges at the air-ocean boundary. Likewise, El Niño has profound effects on humankind and is, to an unknown extent, governed by ocean salinity. In fact, recent studies indicate that understanding salinity's effect on upper ocean buoyancy may be the key to better El Niño forecasts.

    The long term averages (or "climatologies") of sea surface temperature and salinity used in these animations come from the World Ocean Atlas 2005 (WOA2005)

  • Sea Surface Temperature 2002-2006
    2006.12.05
    A recent study indicates there is a correlation between ocean nutrients and changes in sea surface temperature (SST). The results show that when ocean water warms, marine plant life in the form of microscopic phytoplankton tend to decline. When water cools, plant life flourishes. Changes in phytoplankton growth influence fishery yields and the amount of carbon dioxide the oceans remove from the atmosphere. This could have major implications on the future of our ocean's food web and how it relates to climate change.

    The temperature data in this visualization comes from the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA's Terra and Aqua spacecraft.

    In order to see the correlation between SST and SeaWiFS data, this animation can be compared to the latter part of the 'SeaWiFS Biosphere from 1997 to 2006' animation.

  • Ocean Conveyor Belt
    2009.10.08
    The oceans are mostly composed of warm salty water near the surface over cold, less salty water in the ocean depths. These two regions don't mix except in certain special areas. The ocean currents, the movement of the ocean in the surface layer, are driven mostly by the wind. In certain areas near the polar oceans, the colder surface water also gets saltier due to evaporation or sea ice formation. In these regions, the surface water becomes dense enough to sink to the ocean depths. This pumping of surface water into the deep ocean forces the deep water to move horizontally until it can find an area on the world where it can rise back to the surface and close the current loop. This usually occurs in the equatorial ocean, mostly in the Pacific and Indian Oceans. This very large, slow current is called the thermohaline circulation because it is caused by temperature and salinity (haline) variations.

    This animation shows one of the major regions where this pumping occurs, the North Atlantic Ocean around Greenland, Iceland, and the North Sea. The surface ocean current brings new water to this region from the South Atlantic via the Gulf Stream and the water returns to the South Atlantic via the North Atlantic Deep Water current. The continual influx of warm water into the North Atlantic polar ocean keeps the regions around Iceland and southern Greenland mostly free of sea ice year round.

    The animation also shows another feature of the global ocean circulation: the Antarctic Circumpolar Current. The region around latitude 60 south is the the only part of the Earth where the ocean can flow all the way around the world with no land in the way. As a result, both the surface and deep waters flow from west to east around Antarctica. This circumpolar motion links the world's oceans and allows the deep water circulation from the Atlantic to rise in the Indian and Pacific Oceans and the surface circulation to close with the northward flow in the Atlantic.

    The color on the world's ocean's at the beginning of this animation represents surface water density, with dark regions being most dense and light regions being least dense (see the animation Sea Surface Temperature, Salinity and Density). The depths of the oceans are highly exaggerated to better illustrate the differences between the surface flows and deep water flows. The actual flows in this model are based on current theories of the thermohaline circulation rather than actual data. The thermohaline circulation is a very slow moving current that can be difficult to distinguish from general ocean circulation. Therefore, it is difficult to measure or simulate.

The Polar Regions

  • A Tour of the Cryosphere 2009
    2009.09.01
    The cryosphere consists of those parts of the Earth's surface where water is found in solid form, including areas of snow, sea ice, glaciers, permafrost, ice sheets, and icebergs. In these regions, surface temperatures remain below freezing for a portion of each year. Since ice and snow exist relatively close to their melting point, they frequently change from solid to liquid and back again due to fluctuations in surface temperature. Although direct measurements of the cryosphere can be difficult to obtain due to the remote locations of many of these areas, using satellite observations scientists monitor changes in the global and regional climate by observing how regions of the Earth's cryosphere shrink and expand.

    This animation portrays fluctuations in the cryosphere through observations collected from a variety of satellite-based sensors. The animation begins in Antarctica, showing some unique features of the Antarctic landscape found nowhere else on earth. Ice shelves, ice streams, glaciers, and the formation of massive icebergs can be seen clearly in the flyover of the Landsat Image Mosaic of Antarctica. A time series shows the movement of iceberg B15A, an iceberg 295 kilometers in length which broke off of the Ross Ice Shelf in 2000. Moving farther along the coastline, a time series of the Larsen ice shelf shows the collapse of over 3,200 square kilometers ice since January 2002. As we depart from the Antarctic, we see the seasonal change of sea ice and how it nearly doubles the apparent area of the continent during the winter.

    From Antarctica, the animation travels over South America showing glacier locations on this mostly tropical continent. We then move further north to observe daily changes in snow cover over the North American continent. The clouds show winter storms moving across the United States and Canada, leaving trails of snow cover behind. In a close-up view of the western US, we compare the difference in land cover between two years: 2003 when the region received a normal amount of snow and 2002 when little snow was accumulated. The difference in the surrounding vegetation due to the lack of spring melt water from the mountain snow pack is evident.

    As the animation moves from the western US to the Arctic region, the areas affected by permafrost are visible. As time marches forward from March to September, the daily snow and sea ice recede and reveal the vast areas of permafrost surrounding the Arctic Ocean.

    The animation shows a one-year cycle of Arctic sea ice followed by the mean September minimum sea ice for each year from 1979 through 2008. The superimposed graph of the area of Arctic sea ice at this minimum clearly shows the dramatic decrease in Artic sea ice over the last few years.

    While moving from the Arctic to Greenland, the animation shows the constant motion of the Arctic polar ice using daily measures of sea ice activity. Sea ice flows from the Arctic into Baffin Bay as the seasonal ice expands southward. As we draw close to the Greenland coast, the animation shows the recent changes in the Jakobshavn glacier. Although Jakobshavn receded only slightly from 1964 to 2001, the animation shows significant recession from 2001 through 2009. As the animation pulls out from Jakobshavn, the effect of the increased flow rate of Greenland costal glaciers is shown by the thinning ice shelf regions near the Greenland coast.

    This animation shows a wealth of data collected from satellite observations of the cryosphere and the impact that recent cryospheric changes are making on our planet.

    For more information on the data sets used in this visualization, visit NASA's EOS DAAC website.

    Note: This animation is an update of the animation 'A Short Tour of the Cryosphere', which is itself an abridged version of the animation 'A Tour of the Cryosphere'. The popularity of the earlier animations and their continuing relevance prompted us to update the datasets in parts of the animation and to remake it in high definition. In certain cases, our experiences in using the earlier work have led us to tweak the presentation of some of the material to make it clearer. Our thanks to Dr. Robert Bindschadler for suggesting and supporting this remake.

  • Temperature Trends in Antarctica
    2009.01.22
    This image shows warming of the Antartctic ice-sheet surface inland of the Antarctic Peninsula. This warming is significantly higher than previously reported, exceeding 0.1 degree C per decade over the past 50 years, and is strongest in winter and spring. The image incorporates temperature data collected over a 50-year period from 1957 to 2006. Surface color is derived from low-resolution LIMA data, while topography is from a RADARSAT 200m DEM. The ice cover is derived from 12-km AMSR-E data taken on 5/14/08.
  • Daily Arctic Sea Ice -- Summer 2009
    2009.09.07
    Sea ice is frozen seawater floating on the surface of the ocean. Some sea ice is semi-permanent, persisting from year to year, and some is seasonal, melting and refreezing from season to season. The sea ice cover reaches its minimum extent at the end of each summer and the remaining ice is called the perennial ice cover.

    Duing the summer of 2009, the arctic sea ice reached its minimum extent on September 12th. The 2009 minimum extent was the third lowest extent measured since the beginning of the satellite record in 1979. This animation shows the summer retreat of sea ice over the Arctic from 7/1/2009 through 9/12/2009. The sea ice was defined by a 3-day moving average of the AMSR-E 12.5 km sea ice concentration, showing the region where the sea ice concentration was greater than 15%. The false color of the sea ice was derived from the AMSR-E 6.25 km brightness temperature.

  • Sea Ice Yearly Minimum 1979-2008
    2008.10.29
    The continued significant reduction in the extent of the summer sea ice cover is a dramatic illustration of the pronounced impact increased global temperatures are having on the Arctic regions. There has also been a significant reduction in the relative amount of older, thicker ice. Satellite-based passive microwave images of the sea ice cover have provided a reliable tool for continuously monitoring changes in the extent of the Arctic ice cover since 1979. The ice parameters derived from satellite ice concentration data that are most relevant to climate change studies are sea ice extent and ice area. This visualization shows ice extent in the background and ice area in the foreground. Ice extent is defined here as the integrated sum of the areas of data elements (pixels) with at least 15% ice concentration while ice area is the integrated sum of the products of the area of each pixel and the corresponding ice concentration. Ice extent provides information about how far south (or north) the ice extends in winter and how far north (or south) it retreats toward the continent in the summer while the ice area provides the total area actually covered by sea ice which is useful for estimating the total volume and therefore mass, given the average ice thickness. For more information about these ice datasets, see The Journal of Geophysical Research VOL. 113, C02S07, doi:10.1029/2007JC004257, 2008
  • New Sea Ice Findings
    2009.04.13
    In commemoration of the end of the International Polar Year, Tom Wagner, NASA Cryosphere Program Scientist, appeared on television stations around the country on April 6, 2009. This video highlights his answers to questions about the IPY, climate change, and new data on the extent and thickness of sea ice covering the Arctic Ocean.

    For complete transcript, click here.

  • Jakobshavn Glacier Calving Front Recession from 1851 to 2009
    2007.01.05
    Jakobshavn Isbrae is located on the west coast of Greenland at Latitude 69 N. The ice front, where the glacier calves into the sea, receded more than 40 km between 1850 and 2006. Between 1850 and 1964 the ice front retreated at a steady rate of about 0.3 km/yr, after which it occupied approximately the same location until 2001, when the ice front began to recede again, but far more rapidly at about 3 km/yr. As more ice moves from glaciers on land into the ocean, it causes a rise in sea level. Jakobshavn Isbrae is Greenland's largest outlet glacier, draining 6.5 percent of Greenland's ice sheet area. The ice stream's speed-up and near-doubling of the ice flow from land into the ocean has increased the rate of sea level rise by about .06 millimeters (about .002 inches) per year, or roughly 4 percent of the 20th century rate of sea level increase.
  • Global Ice Albedo
    2003.12.12
    This is a conceptual animation showing how polar ice reflects light from the sun. As this ice begins to melt, less sunlight gets reflected into space. It is instead absorbed into the oceans and land, raising the overall temperature, and fueling further melting.
  • Accelerating Ice Sheet
    2007.08.29
    During the summer melt season, melt water accumulates in undulations on the surface of the Greenland ice sheet. Eventually, these melt lakes drain through crevasses or moulins (tunnels under the ice sheet surface), delivering water to the bottom of the ice sheet. This melt water lubricates the interface between the ice and the bedrock, causing the ice to flow faster toward the sea during summer. As summer melt increases and more melt water is available, the greater its effect on summer ice sheet flow rates.
  • Arctic Sea Ice
    2009.10.05
    Sea ice is frozen seawater floating on the surface of the ocean. Some sea ice is permanent, persisting from year to year, and some is seasonal, melting and refreezing from season to season. Each winter existing sea ice thickens and new, thinner ice is formed. This conceptual animation shows a cut-away view of the seasonal advance and retreat of Arctic sea ice, demonstrating the current trend toward a thinning ice pack, with less of the thicker multi-year ice surviving each summer's melt.
  • Change in Elevation Over Greenland
    2007.09.21
    Changes in the Greenland and Antarctic ice sheets are critical in quantifying forecasts for sea level rise. Since its launch in January 2003, the ICESat elevation satellite has been measuring the change in thickness of these ice sheets. This image of Greenland shows the changes in elevation over the Greenland ice sheet between 2003 and 2006, The white regions indicate a slight thickening, while the blue shades indicate a thinning of the ice sheet. Gray indicates areas where no change in elevation was measured.

The Atmosphere

  • Atmospheric Carbon Dioxide
    2008.10.08
    A NASA/university study of the first-ever global satellite maps of carbon dioxide in Earth's atmosphere has revealed new information on how this key greenhouse gas linked to climate change is distributed and moves around our world.

    Moustafa Chahine, lead study author and AIRS science team leader at NASA's Jet Propulsion Laboratory, Pasadena, Calif., said the maps, which cover from September 2002 to July 2008, will be used by scientists to refine how climate models represent the processes that transport carbon dioxide within Earth's atmosphere. 'These data capture global variations in the distribution of carbon dioxide over time that are not represented in the existing models used to determine where carbon dioxide is created and stored,' he said.

    Chahine said the previous scientific consensus was that carbon dioxide was evenly mixed in the free troposphere, decreasing as you move farther south of the equator. 'Our results show carbon dioxide there can vary by nearly one percent and that the free troposphere is like international waters-what's produced in one place is free to travel elsewhere,' he said.

    This visualization is a time-series of the global distribution and variation of the concentration of mid-tropospheric carbon dioxide observed by the Atmospheric Infrared Sounder (AIRS) on the NASA Aqua spacecraft. For comparison, it is overlain by a graph of the seasonal variation and interannual increase of carbon dioxide observed at the Mauna Loa, Hawaii observatory. The AIRS data show the average concentration (parts per million) over an altitude range of 3 km to 13 km, whereas the Mauna Loa data show the concentration at an altitude of 3.4 km and its annual increase at a rate of approximately 2 parts per million (ppmv) per year.

    The two most notable features of this visualization are the seasonal variation of CO2 and the trend of increase in its concentration from year to year. The global map clearly shows that the CO2 in the northern hemisphere peaks in April-May and then drops to a minimum in September-October. Although the seasonal cycle is less pronounced in the southern hemisphere it is opposite to that in the northern hemisphere. This seasonal cycle is governed by the growth cycle of plants. The northern hemisphere has the majority of the land masses, and so the amplitude of the cycle is greater in that hemisphere. The overall color of the map shifts toward the red with advancing time due to the annual increase of CO2.

    Although the mid-latitude jet streams are not visible in the map, we can see their influence upon the distribution of CO2 around the globe. These rivers of air occur at an altitude of about 5 km and rapidly transport CO2 around the globe at that altitude. In the northern hemisphere, the mid-latitude jet stream squirms like a released garden hose over the period of a few days due to the continental landmasses.

    In the southern hemisphere the jet stream flow is more directly West to East, and during the period from July to October the CO2 concentration is enhanced in a belt delineated by the jet stream and lofting of CO2 into the free troposphere by the high Andes is visible in this period. The zonal flow of CO2 around the globe at the latitude of South Africa, southern Australia and southern South America is readily apparent.

    Eastward flow of CO2 from Indonesia and the Celebes sea can be seen in the November to February time frame.

  • Tropospheric Ozone Impacts Climate Change
    2006.02.28
    In the first global assessment of the impact of ozone on climate warming, scientists at the NASA Goddard Institute for Space Studies (GISS), New York, evaluated how ozone in the lowest part of the atmosphere (the troposphere) changed temperatures over the past 100 years. Using the best available estimates of global emissions of gases that create ozone, the GISS computer model study reveals how much this single air pollutant and greenhouse gas has contributed to warming in specific regions of the world. Ozone was responsible for one-third to half of the observed warming trend in the Arctic during winter and spring, according to the new research. Ozone is transported from the industrialized countries in the Northern Hemisphere to the Arctic quite efficiently during these seasons. The findings will be published soon in the American Geophysical Union's Journal of Geophysical Research-Atmospheres. The impact of ozone air pollution on climate warming is difficult to pinpoint because, unlike other greenhouse gases such as carbon dioxide, ozone does not last long enough in the lower atmosphere to spread uniformly around the globe. Its warming impact is much more closely tied to the region it originated from. To capture this complex picture, the GISS scientists used a suite of three-dimensional computer models that starts with data on ozone sources and then tracks how ozone chemically evolved and moved around the world over the past century. The research was supported by NASA's Atmospheric Chemistry Modeling and Analysis Program.
  • Ozone: The World Avoided
    2009.03.17
    Led by NASA Goddard scientist Paul Newman, a team of atmospheric chemists simulated 'what might have been' if chlorofluorocarbons (CFCs) and similar ozone-depleting chemicals were not banned through the Montreal Protocol. The comprehensive model — including atmospheric chemical effects, wind changes, and solar radiation changes — simulated what would happen to global concentrations of stratospheric ozone if CFCs were continually added to the atmosphere.

    The visualizations below present two cases, from several different viewing positions: the 'world avoided' case, where the rate of CFC emission into the atmosphere is assumed to be that of the period before regulation, and the 'projected' case, which assumes the current rate of emission, post-regulation. Both cases extrapolate to the year 2065.

  • 'Smog' and Arctic Warming
    2006.02.28
    In the first global assessment of the impact of ozone on climate warming, scientists at the NASA Goddard Institute for Space Studies (GISS), New York, evaluated how ozone in the lowest part of the atmosphere (the troposphere) changed temperatures over the past 100 years. Using the best available estimates of global emissions of gases that create ozone, the GISS computer model study reveals how much this single air pollutant and greenhouse gas has contributed to warming in specific regions of the world.

    Ozone was responsible for one-third to half of the observed warming trend in the Arctic during winter and spring, according to the new research. Ozone is transported from the industrialized countries in the Northern Hemisphere to the Arctic quite efficiently during these seasons. The findings will be published soon in the American Geophysical Union's Journal of Geophysical Research-Atmospheres.

    The impact of ozone air pollution on climate warming is difficult to pinpoint because, unlike other greenhouse gases such as carbon dioxide, ozone does not last long enough in the lower atmosphere to spread uniformly around the globe. Its warming impact is much more closely tied to the region it originated from. To capture this complex picture, the GISS scientists used a suite of three-dimensional computer models that starts with data on ozone sources and then tracks how ozone chemically evolved and moved around the world over the past century.

    The research was supported by NASA's Atmospheric Chemistry Modeling and Analysis Program.

  • Hello Crud
    2009.11.04
    This segment provides an introduction to aerosols- their varied sources, brief lifetimes, and erratic behavior. Glory's APS will help researchers determine the global distribution of aerosol particles. This unique instrument will unravel the microphysical properties of aerosols, and will shed light on the chemical composition of natural and anthropogenic aerosols and clouds.

    For complete transcript, click here.

  • CO2 Growth in the Last 400,000 Years
    2005.12.31
    The animation shows a graph of carbon dioxide (on the y-axis) versus time (on the x-axis). First data is shown from about the last 400,000 years. Next, this graph slides to the left and a new graph slides on showing carbon dioxide from the last 1000 years. NOTE: the y-axis scale remains the same. Finally, a graph showing carbon dioxide from 1980 to 2005 is shown. The industrial revolution is shown as a blue line. Lake Vostok ice cores provide data from about 400,000 BC to about 4000 BC; Law Dome ice cores provide data from 1010 AD to 1975 AD; Mauna Loa observations provide data from 1980 to 2005.
  • Black Soot on Ice
    2004.02.09
    Black soot may contribute to melting glaciers and other ice on the planet and eventually a warmer Earth. Traveling potentially thousands of miles from its sources on air currents, this pollution eventually settles out of the air, onto land and into the oceans. On ice and snow, it darkens normally bright surfaces. Just as a white shirt keeps a person cooler in the summer than a black shirt, the vast stretches of polar ice covering much of the planet's top and bottom reflect large amounts of solar radiation falling on the planet's surface, helping regulate Earth's temperature. Soot lowers this albedo, or reflectivity, and the ice retains more heat, leading to increased melting. Soot-darkened ice retains more light, contributing to the process. As light is absorbed, the environment is heated, thus intensifying a feedback loop: a warmer planet yields more ice melting and thus an even warmer planet.
  • Aerosols Absorb; Aerosols Reflect
    2009.02.19
    Some aerosol particles primarily reflect solar radiation and cool the atmosphere, and others can also absorb radiation and warm the surrounding air. When aerosols heat the atmosphere, they create an unstable environment where clouds can't thrive. The suppression of clouds leads to further warming of the atmosphere by solar radiation. Aerosols are a complex but critical piece of the climate puzzle, and researchers are still working to understand the role of these curious particles.
  • Pacific Aerosols Transport
    2008.03.13
    According to measurements taken with a satellite instrument, vast quantities of industrial aerosols and smoke from biomass burning in East Asia and Russia are traveling from one side of the globe to another. Explosive economic growth in Asia has profound implications for the atmosphere worldwide. Data collected by a NASA satellite shows a dense blanket of polluted air over the Northwestern Pacific. This brown cloud is a toxic mix of ash, acids, and airborne particles from car and factory emissions, as well as from low-tech polluters like coal-burning stoves and from forest fires. This image generated by data from NASA's instrument called MODIS (Moderate Resolution Imaging Spectroradiometer) onboard the Terra satellite demonstrates how large and pervasive this transport phenomenon is across vast areas. China's exports fill shelves around the world, but according to a new NASA research paper, China also heavily exports pollution. This week, space agency scientists reveal how Chinese industrialization and Russian forest fires in combination with pollution transported eastward from Europe send roughly 18 teragrams - almost 40 billion pounds-of pollution aerosols into the atmosphere over the Northwestern Pacific every year. The MODIS instrument on NASA's Terra satellite has been tracking the particulate pollution for more than seven years, gathering data as most of it drifted east across the Pacific Ocean. About 4.5 teragrams of particulate pollution each year could reach the western boundary of North America, which is about 15% of local emissions of particulate pollutants from the U.S. and Canada. In the last two decades, China has more than doubled its pollution production. This boom may be contributing to substantial changes in climate and weather in places far from the origin of the particulates. Never in human history-anywhere-has there been industrial growth like that in modern China. But with fast growth comes unintended consequences, and from space evidence of those consequences is starting to emerge. The research relies on measurements of something called "aerosol optical thickness". It's a quantitative measurement about how well a slice of atmosphere transmits light. The greater the value of optical thickness for a given location, the less light of a particular wavelength can pass through it. Measurements of aerosol optical thickness describe quantities of tiny particles in a given volume. By measuring how much light can penetrate a region of atmosphere across a variety of wavelengths, scientists can make certain inferences about the quantity and type of particles blocking that light. This visualization shows the seasonal variations of transport of pollution aerosols across the North Pacific. The East Asian airstream carries its largest pollution loading in spring and smallest in summer and fall. With heavy concentrations of aerosols represented by shades of brown, scientists can track the origins and distribution of the particles as they travel in the atmosphere. The sequence also shows a trail of substantial aerosol concentrations from a variety of sources. These sources include heavy industrial activity in East Asia associated with high population density represented in this sequence by gradations of black covering the land surface, and intense Russian forest fires in high latitudes.
  • NO2 Concentration Over the United States
    2004.12.12
    Nitrogen dioxide, NO2, is a traffic-related pollutant. Emissions are generally highest in urban rather than rural areas. Annual mean concentrations of nitrogen dioxide in urban areas are generally in the range 10-45 ppb, and lower in rural areas. Levels vary significantly throughout the day, with peaks generally occurring twice daily as a consequence of rush hour traffic. Concentrations can be as high as 200 ppb. Particulate matter is very fine and can be carried deep into the lungs where they can cause inflammation and a worsening of the condition of people with heart and lung disease. Further, the problem is not necessarily concentrated in the inner cities. Because many major road / motorway interchange complexes are situated in semi-rural areas, under conditions of near-stationary traffic, a rapid build-up of engine exhaust pollution can occur, which if the low-level atmospheric conditions are correct, will not be dispersed.
  • Link between Carbon Dioxide Uptake and the Seasons
    2009.10.09
    This animation shows the correspondence between the drawdown of tropospheric carbon dioxide in the earth's atmosphere, and the seasonal variation of the biosphere of the earth. The pattern of white squares indicates regions where the concentration of tropospheric CO2 is higher than the trend, while regions devoid of the squares are areas where the CO2 concentrations are lower than the trend. The trend was calculated by a least-squares line fit to a moving 8-day global average of CO2 concentration provided by the AIRS instrument on the Aqua satellite, and increases over the course of the animation (Sept. 2002-Sept. 2006) from 374 ppm to 383 ppm. The biosphere data is provided by the SeaWiFS instrument aboard the SeaStar satellite.

    During spring and summer months, the consumption of of CO2 through plant respiration increases, reducing the concentration of CO2 (the white squares) over the more productive areas. In the animation, this is seen as a tendency for the CO2 concentration to drop below the trend over areas of deeper green. The cycle is especially apparent in the Northern Hemisphere.

Hurricanes

  • 27 Storms: Arlene to Zeta
    2006.05.31
    Many records were broken during the 2005 Atlantic hurricane season including the most hurricanes ever, the most category 5 hurricanes, and the most intense hurricane ever recorded in the Atlantic as measured by atmospheric pressure. This visualization shows all 27 named storms that formed in the 2005 Atlantic hurricane season and examines some of the conditions that made hurricane formation so favorable.

    The animation begins by showing the regions of warm water that are favorable for storm development advancing northward through the peak of hurricane season and then receding as the waters cool. The thermal energy in these warm waters powers the hurricanes. Strong shearing winds in the troposphere can disrupt developing young storms, but measurements indicate that there was very little shearing wind activity in 2005 to impede storm formation.

    Sea surface temperatures, clouds, storm tracks, and hurricane category labels are shown as the hurricane season progresses.

    This visualization shows some of the actual data that NASA and NOAA satellites measured in 2005 — data used to predict the paths and intensities of hurricanes. Satellite data play a vital role in helping us understand the land, ocean, and atmosphere systems that have such dramatic effects on our lives.

    NOTE: This animation shows the named storms from the 2005 hurricane season. During a re-analysis of 2005, NOAA's Tropical Prediction Center/National Hurricane Center determined that a short-lived subtropcial storm developed near the Azores Islands in late September, increasing the 2005 tropical storm count from 27 to 28. This storm was not named and is not shown in this animation.

    '27 Storms: Arlene to Zeta' played in the SIGGRAPH 2007 Computer Animation Festival in August 2007. It was also a finalist in the 2006 NSF Science and Engineering Visualization Challenge.

  • Towers in the Tempest
    2007.05.10
    This visualization won Honorable Mention in the National Science Foundation's Science and Engineering Visualization Challenge in September 2007. It was also shown during the SIGGRAPH 2008 Computer Animation Festival in Los Angeles, CA. 'Towers in the Tempest' is a 4.5 minute narrated animation that explains recent scientific insights into how hurricanes intensify. This intensification can be caused by a phenomenon called a 'hot tower'. For the first time, research meteorologists have run complex simulations using a very fine temporal resolution of 3 minutes. Combining this simulation data with satellite observations enables detailed study of 'hot towers'. The science of 'hot towers' is described using: observed hurricane data from a satellite, descriptive illustrations, and volumetric visualizations of simulation data. The first section of the animation shows actual data from Hurricane Bonnie observed by NASA's Tropical Rainfall Measuring Mission (TRMM) spacecraft. Three dimensional precipitation radar data reveal a strong 'hot tower' in Hurricane Bonnie's internal structure. The second section uses illustrations to show the dynamics of a hurricane and the formation of 'hot towers'. 'Hot towers' are formed as air spirals inward towards the eye and is forced rapidly upwards, accelerating the movement of energy into high altitude clouds. The third section shows these processes using volumetric cloud, wind, and vorticity data from a supercomputer simulation of Hurricane Bonnie. Vertical wind speed data highlights a 'hot tower'. Arrows representing the wind field move rapidly up into the 'hot tower, boosting the energy and intensifying the hurricane. Combining satellite observations with super-computer simulations provides a powerful tool for studying Earth's complex systems. The complete script is available here . The storyboard is available here . There is also a movie of storyboard drawings with narration below.
  • 2008 Hurricane Season
    2008.11.30
    This animation depicts the 2008 hurricane season and the corresponding water temperature, for the dates 6/1/08 through 11/30/08. The colors on the ocean represent the sea surface temperatures, and satellite images of the storm clouds are laid over the temperatures to clearly show the positions of the storms. Hurricane winds are sustained by the heat energy of the warm surface waters of the ocean. As a hurricane passes over the warm surface it churns the water, drawing the deeper, cooler water to the surface. This mixing can appear in the animation as a blue pool trailing the hurricane. The sea surface temperature data was taken by the AMSR-E instrument on the Aqua satellite, while the cloud images were taken by the Imager on the GOES-12 satellite.
  • Tropical Storm Ida -- November 2009
    2009.11.09
    NASA's TRMM spacecraft observed this view of Tropical Storm Ida on November 9, 2009 at 1218 UTC (7:18 AM EST). Scattered convective thunderstorms are shown producing moderate to heavy rainfall of over 50 millimeters per hour (~2 inches) north of IDA's center of circulation and in a strong band on the eastern side. At the time of this image IDA had winds estimated at 70 knots (~80.5 mph). IDA is predicted by the National Hurricane Center in Miami, Florida to hit the Gulf coast near Pensacola, Florida on Tuesday morning. The rain structure is taken by TRMM's Tropical Microwave Imager (TMI) and TRMM's Precitation Radar(PR) instruments. TRMM looks underneath of the storm's clouds to reveal the underlying rain structure. The colored isosurface under the clouds show the rain seen by the PR instrument.
  • Model Run Shows Hurricane Katrina
    2007.12.03
    This visualization shows data from a global atmospheric assimilation model for August 2005. In early August the camera looks towards the North pole showing the swirling winds caused by the Coriolis effect; then the camera moves down towards Africa which is the birthplace of many tropical storms; finally, the camera moves across the Atlantic as many of the storms form during 2005 ending with Hurricane Katrina. This visualization was created in support of demonstrations given at the Supercomputing 2007 Conference.

The Sun

  • Striking a Solar Balance
    2008.05.07
    This short film explores the vital connection between the Earth and the Sun. NASA's Glory mission and the Total Irradiance Monitor will continue nearly three decades of solar irradiance measurments. This crucial data will contribute to the long-term climate record.

    For complete transcript, click here.

  • Sentinels of the Heliosphere
    2009.07.27
    Heliophysics is a term to describe the study of the Sun, its atmosphere or the heliosphere, and the planets within it as a system. As a result, it encompasses the study of planetary atmospheres and their magnetic environment, or magnetospheres. These environments are important in the study of space weather. As a society dependent on technology, both in everyday life, and as part of our economic growth, space weather becomes increasingly important. Changes in space weather, either by solar events or geomagnetic events, can disrupt and even damage power grids and satellite communications. Space weather events can also generate x-rays and gamma-rays, as well as particle radiations, that can jeopardize the lives of astronauts living and working in space. This visualization tours the regions of near-Earth orbit; the Earth's magnetosphere, sometimes called geospace; the region between the Earth and the Sun; and finally out beyond Pluto, where Voyager 1 and 2 are exploring the boundary between the Sun and the rest of our Milky Way galaxy. Along the way, we see these regions patrolled by a fleet of satellites that make up NASA's Heliophysics Observatory Telescopes. Many of these spacecraft do not take images in the conventional sense but record fields, particle energies and fluxes in situ. Many of these missions are operated in conjunction with international partners, such as the European Space Agency (ESA) and the Japanese Space Agency (JAXA). The Earth and distances are to scale. Larger objects are used to represent the satellites and other planets for clarity. Here are the spacecraft featured in this movie:

    Near-Earth Fleet:

    • Hinode: Observes the Sun in multiple wavelengths up to x-rays. SVS page
    • RHESSI : Observes the Sun in x-rays and gamma-rays. SVS page
    • TRACE: Observes the Sun in visible and ultraviolet wavelengths. SVS page
    • TIMED: Studies the upper layers (40-110 miles up) of the Earth's atmosphere.
    • FAST: Measures particles and fields in regions where aurora form.
    • CINDI: Measures interactions of neutral and charged particles in the ionosphere.
    • AIM: Images and measures noctilucent clouds. SVS page

    Geospace Fleet:

    • Geotail: Conducts measurements of electrons and ions in the Earth's magnetotail.
    • Cluster: This is a group of four satellites which fly in formation to measure how particles and fields in the magnetosphere vary in space and time. SVS page
    • THEMIS: This is a fleet of five satellites to study how magnetospheric instabilities produce substorms. SVS page

    L1 Fleet:

    The L1 point is a Lagrange Point, a point between the Earth and the Sun where the gravitational pull is approximately equal. Spacecraft can orbit this location for continuous coverage of the Sun.
    • SOHO: Studies the Sun with cameras and a multitude of other instruments. SVS page
    • ACE: Measures the composition and characteristics of the solar wind.
    • Wind: Measures particle flows and fields in the solar wind.

    Heliospheric Fleet

    • STEREO-A and B: These two satellites observe the Sun, with imagers and particle detectors, off the Earth-Sun line, providing a 3-D view of solar activity. SVS page

    Heliopause Fleet

    • Voyager 1 and 2: These spacecraft conducted the original 'Planetary Grand Tour' of the solar system in the 1970s and 1980s. They have now travelled further than any human-built spacecraft and are still returning measurements of the interplanetary medium. SVS page
    This enhanced, narrated visualization was shown at the SIGGRAPH 2009 Computer Animation Festival in New Orleans, LA in August 2009; an eariler version created for AGU was called NASA's Heliophysics Observatories Study the Sun and Geospace.
  • Rotating Tour of Solar Coronal Loops
    2005.10.27
    A slow rotating tour of a data-based coronal loop model. This version is designed for continuous loop play. The solar model is constructed from magnetogram data collected by SOHO/MDI. Because we do not see the full solar surface at any one time, the magnetograms collected over the course of a solar rotation are processed through a time-evolving solar surface model to provide a snapshot of the surface at a fixed time. The resulting magnetogram is then processed through the Potential Field Source Surface (PFSS) model. Coronal loops are visible at the higher temperatures of ultraviolet light, in this case, 195 Ångströms, the filter wavelength of SOHO/EIT.
  • The Top 5 Solar Discoveries
    2009.03.18
    A countdown of the top 5 solar discoveries from the Sun-Earth Connection Education Forum. These include the discoveries of sunspots, the solar cycle, the heliosphere, aurora formation, and space weather.
  • Earth's Energy Budget Animation
    2009.02.19
    Total solar irradiance (TSI) is the dominant driver of the Earth's climate. The global temperature of the Earth is almost completely determined by the balance between the intensity of the incident solar radiation and the response of the Earth's atmosphere via absorption, reflection, and re-radiation. Roughly 30 percent of the TSI that strikes the Earth is reflected back into space by clouds, atmospheric aerosols, snow, ice, desert sand, rooftops, and even ocean surf. The remaining 70 percent of the TSI is absorbed by the land, ocean, and atmosphere. In addition, different layers of the Earth's atmosphere absorb different wavelengths of light. Changes in either the TSI or in the composition of the atmosphere can cause climate change. Two conceptual science animations provide two different perspectives that both illustrate Earth's energy budget.

The Land

  • Global Wildfires
    2004.01.31
    From space, we can understand fires in ways that are impossible from the ground. New Earth-observing satellites capture the significant impact of fires on our planet. In this animation of fires around the globe in 2002, each red dot marks a new fire. Dots change color to yellow after a few days and to black when fires burn out. From brush fires in Africa to forest fires in North America, satellites are locating every significant fire on Earth to within one kilometer. In the summer and fall burning seasons, particularly destructive fires occurred in Colorado, Arizona, and Oregon. This version of the animation displays descriptive text labels and color bars. For a closed captioned version of this animation, see the standard definition version at animation 2707.
  • Deforestation of Rondonia, Brazil 1975-2009
    2009.10.05
    In the 1970s, Brazil's Program of National Integration built roads across the Amazon and settled land along these roads with colonists. These roads were catalysts of land use change in the Amazon.

    Brazil is also home to more than a quarter of Earth's tropical forests. Considering that the band of lush green that circles the globe through many equatorial nations is fundamental to the overall health of the whole planet's environment, careful monitoring of forest health in the tropics is essential. Tropical forests act as major carbon 'sinks', places where ambient carbon dioxide in the atmosphere can be absorbed by growing things and sequestered for years. Definitive evidence shows that excess carbon dioxide can contribute to the greenhouse effect and speed global warming. Similarly, tropical forests also act as a primary producer of oxygen. In the respiration process that absorbs gaseous carbon dioxide, trees and other plants give off oxygen.

    Data taken in 1975 and 2009 from the Landsat series of spacecraft shows enormous tracts of forest disappearing in Rondonia, Brazil.

  • Groundwater Depletion in India
    2009.08.12
    Scientists using data from NASA's Gravity Recovery and Climate Experiment (GRACE) have found that the groundwater beneath Northern India has been receding by as much as one foot per year over the past decade. After examining many environmental and climate factors, the team of hydrologists led by Matt Rodell of NASA's Goddard Space Flight Center, Greenbelt, Md. concluded that the loss is almost entirely due to human consumption.

    Groundwater comes from the natural percolation of precipitation and other surface waters down through Earth's soil and rock, accumulating in aquifers - cavities and layers of porous rock, gravel, sand, or clay. In some subterranean reservoirs, the water may be thousands to millions of years old; in others, water levels decline and rise again naturally each year. Groundwater levels do not respond to changes in weather as rapidly as lakes, streams, and rivers do. So when groundwater is pumped for irrigation or other uses, recharge to the original levels can take months or years.

    More than 109 cubic km (26 cubic miles) of groundwater disappeared from the region's aquifers between 2002 and 2008 — double the capacity of India's largest surface water reservoir, the Upper Wainganga, and triple that of Lake Mead, the largest manmade reservoir in the U.S.

    The animation shown here depicts the change in groundwater levels as measured each November between 2002 to 2008.

  • Atlanta Heat Island
    2000.02.21
    A flyby of Atlanta showing thermal imagery taken during the day by an airborne ATLAS instrument on May 11 and 12, 1997. This imagery is surrounded by Landsat Thematic Mapper data taken on June 27, 1998.
  • Biomass Burning
    2004.12.09
    Biomass burning is the burning of living and dead vegetation. It includes the human-initiated burning of vegetation for land clearing and land-use change as well as natural, lightning-induced fires. Scientists estimate that humans are responsible for about 90% of biomass burning with only a small percentage of natural fires contributing to the total amount of vegetation burned. Burning vegetation releases large amounts of particulates (solid carbon combustion particles) and gases, including greenhouse gases that help warm the Earth. Studies suggest that biomass burning has increased on a global scale over the last 100 years, and computer calculations indicate that a hotter Earth resulting from global warming will lead to more frequent and larger fires. Biomass burning particulates impact climate and can also affect human health when they are inhaled, causing respiratory problems. Here are three images of South America on October 7, 2004. The first image shows clouds and fires on that day. The second image is clouds and nitrous dioxide (NO2) concentrations in the stratosphere. The last image overlays the fires on the NO2 data.

Observing and Modeling Climate Data

  • Taking Earth's Temperature
    2009.11.23
    The Earth is a complex system with a unique climate. Many scientists are concerned that Earth's climate is changing at an unprecedented rate. Each January, scientists at NASA Goddard Institute for Space Studies release temperature data for the previous year. How do scientists study how warm our home planet is, and how do they determine what factors affect its climate? This short video explores the tools NASA scientists use to take Earth's temperature.

    For complete transcript, click here.

  • Components of the Water Cycle
    2009.10.08
    Water regulates climate, storing heat during the day and releasing it at night. Water in the ocean and atmosphere carry heat from the tropics to the poles. The process by which water moves around the earth, from the ocean, to the atmosphere, to the land and back to the ocean is called the water cycle. The animations below each portray a component of the water cycle. All use an identical view and camera motion to allow for easy compositing.

    Data for the animation of global sea surface temperature was derived from a model run of ECCO's Ocean General Circulation Model. See http://www.ecco-group.org/model.htm for more information on ECCO.

    Data for the animation of atmospheric phenomena was created using data from the GEOS-5 atmospheric model on the cubed-sphere, run at 14-km global resolution for 25-days. Variables animated here include evaporation, water vapor and precipitation.

    For more information on the GEOS-5 see http://gmao.gsfc.nasa.gov/systems/geos5.

    For more information on the cubed-sphere work see http://science.gsfc.nasa.gov/610.3/cubedsphere.html.

    All three of these animations are time synchronous throughout the animation to allow cross fades during compositing.

    The final animation shown here, a pulsing network of rivers over the continents, represents the flow of water from land back into the ocean, thereby completing the water cycle.

    A flat version of these animations can be found in item #3811.

  • Tropospheric Ozone Impacts Climate Change
    2006.02.28
    In the first global assessment of the impact of ozone on climate warming, scientists at the NASA Goddard Institute for Space Studies (GISS), New York, evaluated how ozone in the lowest part of the atmosphere (the troposphere) changed temperatures over the past 100 years. Using the best available estimates of global emissions of gases that create ozone, the GISS computer model study reveals how much this single air pollutant and greenhouse gas has contributed to warming in specific regions of the world. Ozone was responsible for one-third to half of the observed warming trend in the Arctic during winter and spring, according to the new research. Ozone is transported from the industrialized countries in the Northern Hemisphere to the Arctic quite efficiently during these seasons. The findings will be published soon in the American Geophysical Union's Journal of Geophysical Research-Atmospheres. The impact of ozone air pollution on climate warming is difficult to pinpoint because, unlike other greenhouse gases such as carbon dioxide, ozone does not last long enough in the lower atmosphere to spread uniformly around the globe. Its warming impact is much more closely tied to the region it originated from. To capture this complex picture, the GISS scientists used a suite of three-dimensional computer models that starts with data on ozone sources and then tracks how ozone chemically evolved and moved around the world over the past century. The research was supported by NASA's Atmospheric Chemistry Modeling and Analysis Program.
  • 'Smog' and Arctic Warming
    2006.02.28
    In the first global assessment of the impact of ozone on climate warming, scientists at the NASA Goddard Institute for Space Studies (GISS), New York, evaluated how ozone in the lowest part of the atmosphere (the troposphere) changed temperatures over the past 100 years. Using the best available estimates of global emissions of gases that create ozone, the GISS computer model study reveals how much this single air pollutant and greenhouse gas has contributed to warming in specific regions of the world.

    Ozone was responsible for one-third to half of the observed warming trend in the Arctic during winter and spring, according to the new research. Ozone is transported from the industrialized countries in the Northern Hemisphere to the Arctic quite efficiently during these seasons. The findings will be published soon in the American Geophysical Union's Journal of Geophysical Research-Atmospheres.

    The impact of ozone air pollution on climate warming is difficult to pinpoint because, unlike other greenhouse gases such as carbon dioxide, ozone does not last long enough in the lower atmosphere to spread uniformly around the globe. Its warming impact is much more closely tied to the region it originated from. To capture this complex picture, the GISS scientists used a suite of three-dimensional computer models that starts with data on ozone sources and then tracks how ozone chemically evolved and moved around the world over the past century.

    The research was supported by NASA's Atmospheric Chemistry Modeling and Analysis Program.

  • Greenhouse Gas Effect on Global Warming
    2007.09.07
    The 'greenhouse effect' is the warming of climate that results when the atmosphere traps heat radiating from Earth toward space. Certain gases in the atmosphere resemble glass in a greenhouse, allowing sunlight to pass into the 'greenhouse,' but blocking Earth's heat from escaping into space. The gases that contribute to the greenhouse effect include water vapor, carbon dioxide (CO2), methane, nitrous oxides, and chlorofluorocarbons (CFCs).

    On Earth, human activities are changing the natural greenhouse. Over the last century the burning of fossil fuels like coal and oil has increased the concentration of atmospheric CO2. This happens because the coal or oil burning process combines carbon (C) with oxygen (O2) in the air to make CO2. To a lesser extent, the clearing of land for agriculture, industry, and other human activities have increased the concentrations of other greenhouse gases like methane (CH4), and further increased (CO2).

    The consequences of changing the natural atmospheric greenhouse are difficult to predict, but certain effects seem likely:

    - On average, Earth will become warmer. Some regions may welcome warmer temperatures, but others may not.

    - Warmer conditions will probably lead to more evaporation and precipitation overall, but individual regions will vary, some becoming wetter and others dryer.

    - A stronger greenhouse effect will probably warm the oceans and partially melt glaciers and other ice, increasing sea level. Ocean water also will expand if it warms, contributing to further sea level rise.

    - Meanwhile, some crops and other plants may respond favorably to increased atmospheric CO2, growing more vigorously and using water more efficiently. At the same time, higher temperatures and shifting climate patterns may change the areas where crops grow best and affect the makeup of natural plant communities.

  • Carbon Dioxide Linked to Seasonal Variation of the Biosphere
    2009.10.09
    This animation shows the correspondence between the drawdown of tropospheric carbon dioxide in the earth's atmosphere, and the seasonal variation of the biosphere of the earth. The pattern of white squares indicates regions where the concentration of tropospheric CO2 is higher than the trend, while regions devoid of the squares are areas where the CO2 concentrations are lower than the trend. The trend was calculated by a least-squares line fit to a moving 8-day global average of CO2 concentration provided by the AIRS instrument on the Aqua satellite, and increases over the course of the animation (Sept. 2002-Sept. 2006) from 374 ppm to 383 ppm. The biosphere data is provided by the SeaWiFS instrument aboard the SeaStar satellite.

    During spring and summer months, the consumption of of CO2 through plant respiration increases, reducing the concentration of CO2 (the white squares) over the more productive areas. In the animation, this is seen as a tendency for the CO2 concentration to drop below the trend over areas of deeper green. The cycle is especially apparent in the Northern Hemisphere.