Background

22,300 miles above the Earth's surface, geostationary weather satellites continuously monitor the Earth's dynamic atmosphere. Special satellite sensors measure infrared radiation (heat) emitted by the Earth, showing the temperature of cloud-tops and land & water surfaces visible between clouds. Among other advantages, infrared weather satellite imagery (a.k.a., IR imagery) is available day and night.

GOES Satellites Geostationary Operational Environmental Satellites
http://ww2010.atmos.uiuc.edu/(Gh)/guides/rs/sat/goes/home.rxml

Explore the world through "heat-sensitive eyes" (similar to looking through night-vision binoculars) by visiting the American Meteorological Society (AMS) Interactive Infrared Weather Satellite Image. You will need a Java-capable Web browser; be patient--the Applet takes a while to load! As you move the computer cursor over the image, notice that the temperature (in degrees Celsius) and geographic location (latitude & longitude) are displayed for the point on the Earth (or above the Earth, in the case of clouds) below the cursor. Cool, huh? No, it's hot--IR sensors detect heat!

AMS Interactive Infrared Weather Satellite Image

http://www.ssec.wisc.edu/~tomw/ams/amsimage.html

For more information regarding weather satellite image interpretation, visit the UIUC Weather World 2010 Satellite Meteorology Online Remote Sensing Guide.

Satellite Meteorology Online Remote Sensing Guide

http://ww2010.atmos.uiuc.edu/(Gh)/guides/rs/sat/home.rxml

Activity Questions

Use an IR weather satellite image to demonstrate the following understandings and/or competencies (ranked in order of degree of difficulty, beginning with the easiest task):

What is the date and time of the current weather satellite image? Convert UTC to EST (or EDT, as appropriate).

Given the latitude & longitude of Washington, D.C. (39?N, 77?W), find its location on the weather satellite image. Record the current temperature (either land or cloud-top) in the vicinity of Washington, D.C. Convert the temperature from degrees Celsius to degrees Fahrenheit and kelvins.

Infer the relationship between color (black, white, and shades of gray) and temperature, as shown on IR weather satellite imagery.

Use geographic coordinates (latitude/longitude) to identify the location of an example of each of the following types of physical features: land- and water surfaces; cloud-tops, including both high- and low cloud-tops. [Hint: The temperature of the atmosphere usually decreases with increasing altitude.]

Compare land and water temperatures at the same latitude; explain possible causes for the observed temperature difference (if any). Compare land surface temperatures at different latitudes: In general, what is the relationship between surface temperature and latitude? Use geographic coordinates (latitude/longitude) to identify the locations used for comparison. [Hint: You may need to refer to a current weather map showing surface temperatures in order to "ground-truth" (verify) satellite-derived land surface temperatures. See question No. 7 (below) for guidance regarding ground-truthing Sea Surface Temperatures (SSTs).]

Infer the location of the most intense storms by searching for places on the satellite image displaying the coldest cloud-top temperatures. Access other online sources of real-time weather observations that verify your inferences; cite references that support your inferences. [Hint: Weather RADAR uses microwave radiation to "see" precipitation-sized particles within- and falling from clouds.]

Locate ocean surface currents, e.g., the Gulf Stream (warm) and/or the California Current (cold). Use geographic coordinates (latitude/longitude) to identify points located near the boundary of the ocean currents. [Hint: Sea Surface Temperature (SST) analysis requires a relatively cloud-free view of the ocean. In order to verify satellite-derived sea surface temperatures, you may need to refer to ocean buoys reporting near-real-time SSTs.]

References

[1] AMS Interactive Infrared Weather Satellite Image: http://www.ssec.wisc.edu/~tomw/ams/amsimage.html

[1] UTC/EST/EDT Time Conversion Table: http://www.wsanford.com/~wsanford/exo/TCT.html

[2] NOAA National Weather Service Forecast Office Baltimore/Washington

Weather Calculators: http://www.erh.noaa.gov/er/lwx/calculator.shtml

[2] Kelvin, the SI unit of temperature: http://en.wikipedia.org/wiki/Kelvin

[5] Current weather map, surface temperatures: http://www.ametsoc.org/amsedu/dstreme/images/sfcptemp.gif

[6] AMS DataStreme Atmosphere: http://www.ametsoc.org/amsedu/dstreme/

[6] Radar Meteorology Online Remote Sensing Guide:

http://ww2010.atmos.uiuc.edu/(Gh)/guides/rs/rad/home.rxml

[6] The Electromagnetic Spectrum:

http://www.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html

[7] Currents of the Ocean: http://www.windows.ucar.edu/tour/link=/earth/Water/ocean_currents.html

[7] NASA Goddard Space Flight Center ? The Earth Observing System

Gulf Stream Temperatures (background information): http://eospso.gsfc.nasa.gov/eos_homepage/for_educators/eos_edu_pack/p07.php

[7] NASA Jet Propulsion Laboratory

Near-Real-Time Images >> Sea Surface Temperature > Regional Images:

http://nereids.jpl.nasa.gov/cgi-bin/sst.cgi?show=LAC# (select "U.S. East Coast," "Gulf Stream," and/or "U.S. West Coast")

[7] AMS DataStreme Ocean (refer to "Physical & Chemical > Buoy Data"): http://www.ametsoc.org/amsedu/DS-Ocean/home.html