Picture Climate: What’s ATMS?
While it might look like something out of a science fiction film, the Advanced Technology Microwave Sounder, or ATMS, is actually a sensor onboard the NOAA/NASA Suomi National Polar-orbiting Partnership (Suomi NPP) satellite. Unlike some other satellite instruments, ATMS works in both clear and cloudy conditions to provide continuous high-resolution microwave measurements of Earth’s temperature and moisture.
In technical terms, ATMS is a 22-channel passive microwave radiometer with a swath width of 1,429 miles. A radiometer is a sensor that measures the intensity of certain types of electromagnetic radiation, for ATMS, that’s microwave radiation. The ATMS sensor monitors 22 channels or frequencies of microwave radiation, which is similar to listening to a select set of 22 radio stations. And, having a swath width of 1,429 miles means that the sensor can collect data along strips that wide as the satellite orbits around the Earth.
All objects on the Earth’s surface emit microwaves, and a “passive microwave” sensor is one that detects those microwaves naturally emitted by the Earth. Clouds do not emit much microwave radiation, which is what allows ATMS to work in both clear and cloudy conditions. The measurements that the ATMS sensor takes provide rainfall rates as well as snow and ice information.
The ATMS sensor on Suomi NPP isn’t the first instrument to take these types of measurements though. Since 1978, microwave sounders on NOAA polar-orbiting satellites have measured temperatures across the globe under all types of weather conditions. As compared to legacy instruments, ATMS offers more channels, better resolution, and a wider swath, improving the accuracy of short- and medium-term forecasting, storm tracking and, with continued measurements over time, climate prediction models.
Over the years, several scientific teams developed techniques to merge the microwave data taken by the different instruments over the past three decades. Merging the data from these instruments has allowed scientists to create a continuous record for studying trends in atmospheric temperature and other variables. The ATMS sensor will further continue the microwave record and subsequent measurements interpolated from those data, allowing scientists to better understand major climate features like El Niño and La Niña as well as better predict future climate changes. Additionally, ATMS helps collect essential data for accurate near-term weather predictions needed for farming, commercial and defense aircraft flight path planning, terrestrial extreme weather preparedness, and oceanographic inputs for civilian and defense ships.