Skew-T Plotting Tool for AIRS Data
About Skew-T Plots
The skew-T plot, sometimes referred to as the skew-T diagram or map, is a very useful meteorological thermodynamic chart on which pressure, density, temperature, and water vapor are plotted for a point on the Earth up through the atmosphere. The skew-T plot gives a "snapshot" picture of temperature, dewpoint, air pressure, and winds in the atmosphere above a particular point on the Earth's surface to a maximum of about 16 kilometers above sea level. It is a basic tool used in forecasting not only severe storms, but also daily weather. On the skew-T plot, the "skewed" horizontal axis slants upward to the right hand side of the diagram at a 45 degree angle, and the temperature is usually in Celsius degrees; the vertical axis is atmospheric pressure in millibars. Atmospheric pressure decreases with altitude.
Every skew-T plot consists of both a static set of atmospheric calculations, which apply equally to all locations, and a dynamic set of air temperature and dew point temperature calculations obtained by the lofting of a small radiosonde instrument package, commonly referred to as a weather balloon. NASA's Atmospheric Infrared Sounder (AIRS), with the help of its sister instrument, the Advanced Microwave Sounding Unit (AMSU), have been deriving these temperature and pressure profiles remotely from space since shortly after their May 4, 2002 launch aboard NASA's Earth-orbiting Aqua satellite.
Caveats and Disclaimers
This custom skew-T tool designed to work with the AIRS data set enables you to browse weather data anywhere in the world (at least twice per day in most locations). It is NOT a research-grade software application, although the data which it reads are of this caliber. Please be aware that these data files contain substantial amounts of quality control and precision indicators that are essential to using the AIRS data in any serious scientific investigation. This skew-T web application takes a conservative approach in converting these AIRS/AMSU observations in a skew-T-appropriate data set. Therefore, for every six-minute period of time covering a particular ground track, a selected subset of the possible 1,350 individual observations may not be available. In addition, the algorithms that reconstruct the air temperature and water vapor profiles sometimes have difficulty over stretches of land or in the presence of very thick low-lying clouds.
Read the entire Caveats and Disclaimers page.
Find out More
Introduction to the Skew-T Plot
How to use the AIRS Skew-T Tool
Principles of Convection I: Buoyancy and CAPE
Contains an excellent side-by-side animation showing how the atmosphere maps onto the skew-T plot.
Forecasting Tornados: Forecasters Use Temperature, Dewpoint, and Air Pressure
Activity to practice using skew-T plots with a focus on tornados on the NOAA web site.
Description of the skew-T plot from Unisys Weather.
Your Feedback
If you use the AIRS Skew-T Tool and have suggestions for improvement or questions about the tool, please submit your question on our ASK AIRS Feedback Form.
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