Why NASA is launching a new polar satellite

This Thursday, a new Earth observation satellite will be launched into space, where it will help scientists predict the weather and monitor increasingly frequent extreme weather events. The satellite, called Joint Polar Satellite System-2 (JPSS-2), is part of a global observation system and is a product of a collaboration between NASA and the National Oceanic and Atmospheric Administration (NOAA).

“NOAA’s weather satellites have never been more critical as extreme weather events are more common due to climate change,” Irene Parker, deputy assistant administrator for systems at NOAA’s National Environmental Satellite, Data, and Services, said in a prelaunch briefing. “From 2017 through September 2022, the US has 104 separate billion dollar disasters. In comparison, from 1987 to 1991 there were only 15.”

JPSS-2 will launch early on Nov. 10 at 4:25 a.m. ET aboard a United Launch Alliance Atlas V 401 rocket from Vandenberg Space Force Base in California. Also on board will be a test of an inflatable heat shield called AIR TIME that could help land heavier payloads on Earth or even on other planets like Mars.

NASA and NOAA have an entire network of satellites pointing toward Earth to observe the environment, including the predecessors of JPSS-2, Suomi NPP and NOAA-20. JPSS-2 joins these two satellites in polar orbit, meaning they circle the globe from pole to pole, covering the entire planet twice a day.

“To predict local weather, we need to look at the weather from this global perspective,” said Tim Walsh, director of NOAA’s JPSS Program Office. “A dust storm in Africa could affect the development of a potential hurricane that could hit the east coast. A typhoon in Japan could result in heavy rainfall here in California a few days later.”

The JPSS-2 satellite will make measurements with its four instruments, including the Visible Infrared Imaging Radiometer Suite, or VIIRS, which acts as the satellite’s “eyes.” It takes visible light and infrared images with spatial resolution of about a quarter of a mile, allowing researchers to see features such as cloud domes called shoot-out tops, which can indicate how severe a thunderstorm is. The Advanced Technology Microwave Sounder, or ATMS, can observe through clouds to see the intensity of a storm, while the Cross-track Infrared Sounder, or CrIS, generates a 3D view of the atmosphere and the Ozone Mapping and Profiler Suite, or OMPS, studies ozone in the atmosphere.

In combination, the data from these instruments will help forecast weather forecasts, particularly by monitoring the Atlantic and Pacific Oceans. On land, there are many weather stations that collect data. But measurements from the oceans have to be made by weather buoys, of which there are relatively few, so this data has to be supplemented with satellite data. Data from the JPSS program was previously used to forecast Hurricane Ian’s landfall on the Florida coast and is currently being used to track Tropical Storm Nicole.

“JPSS data is an important input to U.S. and international global numerical weather forecasting modeling systems,” Jordan Gerth, a meteorologist and satellite scientist at NOAA’s National Weather Service, said in a science briefing. “The observations are global, the predictions are local. With JPSS, the quality of local three- to seven-day forecasts is excellent.”

NOAA has yet another set of Earth monitoring satellites used in weather forecasting called Geostationary Operational Environmental Satellites, or GOES. But the GOES satellites are in a very different orbit from JPSS, in geostationary orbit 22,300 miles above the Earth’s surface. That means each GOES satellite is always pointed in the same place on the globe, compared to the JPSS satellites, which circle the globe and are much closer at just 500 miles from the surface.

“Because JPSS is much closer to the Earth’s surface, we can get different kinds of observations,” explains Gerth. “For example, if we want to determine the temperature structure of the atmosphere or the amount of water vapor, we can use instruments from the JPSS series to help us do that. JPSS also gives us information about the details under the cloud canopy, which can easily translate into storm intensity information and help with storm forecasting.”

In addition to the weather forecasting tasks, data from JPSS-2 will also be useful in studying other climate conditions. “Although the satellite is designed for weather forecasting, that’s not the only reason the satellite is being launched,” said Satya Kalluri, a program scientist with the NOAA JPSS program. “The satellite takes images of the Earth twice a day and with these images we can look at drought conditions, which are very important for predicting food productivity.”

Other uses for the satellite data include measuring ocean color, which can help monitor the health of ocean ecosystems and identify harmful algal blooms. It can also measure air quality by identifying smog or smoke from wildfires, as well as detecting changes in the polar ice caps and the hole in the ozone layer.

Having consistent measurements of these factors over decades is key to maintaining data that will allow us to understand the long-term effects of climate change, in addition to JPSS-2’s role in forecasting short-term weather events.

“We are very pleased to see this JPSS-2 launch because of the global collection of observations,” Gerth said. “To have good local weather forecasts, we need to have those global observations to inform our meteorologists.”