NEW MODIS LAND COVER MAP PROVIDES A CLEARER LOOK AT WHAT COVERS THE EARTH

NEW NASA'S TERRA TECHNOLOGY SATELLITE PROVIDES THE MOST DETAILED LOOK AT LAND USE COVER TO DATE

New NASA satellite-generated land cover maps are providing scientists with a detailed picture of the distribution of Earth's ecosystems and land use Scientists can better determine how vegetation is distributed and land is being used around the world with new NASA satellite-generated land-cover maps. These new maps, based on a global digital database of land cover types Earth images that is updated every 16 days, will help scientists better understand the Earth's climate and carbon budget and climate, through closer monitoring of water and land resources, including forested and agricultural areas.

These land-coverland cover maps were developed at Boston University in Boston, MA, using data from the Moderate-resolution Imaging -Spectroradiometer (MODIS) instrument aboardon NASA's Terra satellite. The prototype MODIS maps were created with data acquired between July and December 2000; but future maps will utilize one year of data.

"These maps, with a spatial resolution of 1 km, mark a significant step forward in global land cover mapping by providing a clearer, more detailed picture than previously available maps," according to Boston University Professor Mark Friedl, one of the project's investigators. Previously available global maps were produced using data acquired in from 1992 - 1993 by the National Oceanic and Atmospheric Administration's Advanced Very High Resolution Radiometer (AVHRR).

Advances in remote sensing technology allow MODIS to collect higher-quality data than previous sensors, yielding the most detailed land cover classification maps to date. The new maps are better because the quality of MODIS data is much higher than AVHRR data. The high-quality data also allow Friedl and his colleagues to They are also more current because the information content of MODIS data allowed scientists to exploit more efficient automated methods for categorizing land cover than was were previously possible, reducing the time to generate maps from months or years to about one week..

Each MODIS land-coverland cover map contains 17 different land cover types, differentiating among eleven natural vegetation types such as deciduous and evergreen forests, savannas, grasslands, and shrublands. Agricultural land use , as well as, several categories of land surfaces with little or no plant cover -- such as bare ground, urban areas and permanent snow and ice -- are also depicted in the maps.

The ability to clearly visualize vegetation, High-quality lland cover maps greatly aids scientists and policy makers involved in land and water in natural resource management as well as a range of research and global monitoring objectives. Particularly important applications include modeling global carbon exchange between the earth's terrestrial ecosystems and atmosphere ; assessing regional land use and resource exploitation, ; managing forest resources management, improving estimates of the Earth's water and energy cycles, and ; modeling global carbon exchange between the Earth's terrestrial ecosystems and atmosphere. and inventorying greenhouse gas emissions.

Carbon cycle modeling is linked to A national greenhouse gas inventories, which are estimates y is a record of the greenhouse emissions from by human sources of greenhouse gases, and their removal by greenhouse gas sinks, such as plants that absorb and store carbon dioxide carbon through photosynthesis. These inventories are important because Many nations, including the United States, produce the inventories annually in an effort to understand and predict climate change. many nations have committed themselves to producing them annually under the United Nations Framework Convention on Climate Change.

"This product will have a major impact on our carbon budget work," says Professor Steve Running of the University of Montana, Missoula, who uses the Boston University land cover maps in conjunction with other weekly observations from MODIS. . "With the MODIS land cover product we can determine current vegetation in detail for each square kilometer, . For example, whether there is mature vegetation, clear cutting, a new fire scar, or agricultural crops. This means we can produce weekly annual estimates of net change in vegetation cover. This gets us one step closer to a global picture of carbon sources and sinks," he says.

With the specific information about vegetation that the MODIS land cover maps provide for every square kilometer of the earth's surface, ecologists and climatologists will also be able to improve estimates of the earth's water and energy cycles and produce more realistic climate models.

This first map release is provisional because it is based on six months worth of data instead of a full year. This means that there are data gaps for some areas. The short day length at high latitudes and the persistent cloud cover in the topics make long periods of data collection necessary to produce the most accurate maps of those regions especially in the high latitudes and the tropics.

The Terra satellite was launched on December 18, 1999, as part of a 15-year global mission to collect data on which to base wide-ranging scientific investigations about the Earth. The Terra's MODIS instrument aboard Terra continuously observes the Earth's surface with a continuously rotating scan mirror that in a sweeping motion every 1 to 2 days, and provides a new global images of daylight-Earth's reflected solar radiation and daytime and nighttime thermal emissions over the globe.every day.

More information is available on the Internet at: http://modis.gsfc.nasa.gov