April 30, 2009 - Average Land Surface Temperature

Average Land Surface Temperature

Land surface temperature is how hot the Earth’s surface would feel to the touch. From a satellite’s point of view, the “surface” is whatever it sees when it looks through the atmosphere to the ground. It could be snow and ice, the grass on a lawn, the roof of a building, or the treetops in a forest.

If you want to know whether temperatures at some place at a specific time of year are unusually cold or warm, you need to compare them to the average temperatures for that place over many years. These maps show the average weekly or monthly daytime land surface temperatures for 2000-2008 measured by the MODIS on the Terra satellite.

Scientists monitor land surface temperature because the warmth rising off Earth’s landscapes influences (and is influenced by) our world’s weather and climate patterns. Scientists want to monitor how increasing atmospheric greenhouse gases affect land surface temperature, and how rising land surface temperatures affect glaciers, ice sheets, permafrost, and the vegetation in Earth’s ecosystems.

In winter, these maps can help citrus farmers to determine where and when orange groves could have been exposed to damaging frost. Land surface temperatures may be used for mapping urban versus rural areas or for predicting water or energy demand in farmlands or cities.

The colors on these maps represent temperature patterns of the top millimeter (or “skin”) of the land surface — including bare land, snow or ice cover, urban areas, and cropland or forest canopy — as observed by MODIS in clear-sky conditions for the time period indicated. Yellow shows the warmest temperatures (up to 45°C) and light blue shows the coldest temperatures (down to -25°C). Black means “no data.”

Here is a high resolution image.

Image Facts
Satellite: Terra
Date Acquired: 12/1/2000 to 12/31/2008
Bands Used:
Image Credit: Jesse Allen, NASA’s EO with data from MODIS Land Group