A new satellite instrument is sending back detailed information about the health of Earth's ozone layer, the atmospheric gas that shields life from harmful levels of the Sun's ultraviolet radiation. The Ozone Mapper and Profiler Suite, or OMPS—one of five new instruments on the Suomi National Polar-orbiting Partnership (NPP) satellite—will add to a record of space-based ozone monitoring that dates back to 1978.
The images above show the concentration of ozone in Earth's atmosphere above the South Pole on January 27, 2012. Measurements are expressed in Dobson Units, the number of molecules required to create a layer of pure ozone 0.01 millimeters thick at a temperature of 0 degrees Celsius and a pressure of 1 atmosphere (the air pressure at the surface of the Earth). The ozone layer’s average thickness is about 300 Dobson Units, a layer that is 3 millimeters thick, or the height of two U.S. pennies stacked together.
The left image above is based on data from the Ozone Monitoring Instrument (OMI) on the Aura satellite. Data collected on the first day of operations by OMPS is shown on the right. OMPS is the successor to OMI and part of a long line of ozone monitoring instruments, so it is important to have overlapping flight time. Researchers will use the coming months (perhaps years) to cross-calibrate the instruments and ensure a seamless, standardized record.
Built for the NASA satellite by scientists by the Royal Netherlands Meteorological Institute (KNMI), OMI is a spectrometer that measures the amount of sunlight scattered by Earth’s atmosphere and surface. OMI allows scientists to assess how much ozone is present at various altitudes—particularly the stratosphere—and near the ground. It has been flying since 2004.
OMPS consists of three instruments: the downward-looking nadir mapper and nadir profiler, and a limb profiler. The nadir profiler and mapper observe the vertical distribution of ozone in ways that match the three decades of existing ozone measurements. The limb profiler is an experimental instrument that measures the distribution of ozone at higher vertical resolution by looking through the atmosphere on an angle. OMPS was funded by the National Oceanic and Atmospheric Administration and the U.S. Department of Defense.
The Suomi NPP team at NASA will continue initial checkouts of OMPS and other instruments as part of its commissioning activities until early March. Operations will then be handed off to NOAA, which will continue calibration and validation activities and lead the processing and distribution of data. Suomi NPP is the result of a partnership between NASA, NOAA, and the Department of Defense.
OMI image (top left) is courtesy of NASA Ozone Hole Watch and the Royal Netherlands Meteorological Institute (KNMI). The OMPS image (top right) is by NASA/NOAA. Caption by Cynthia O'Carroll and Mike Carlowicz.
