What did they do: The researchers took 2 sets of global surface temperature data generated from independent instruments – based on land and in space – and compared them for the first time.
- One of them included readings from AIRS, an infrared instrument from NASA's Aqua satellite.
- The other consisted of measurements of surface temperature by NASA Goddard Institute for Space Studies ground weather stations and ocean buoys, known as GISTEMP.
What they found: The AIRS data closely matched Goddard's observations during the overlap period from 2003 to 2018, with the exception of one key detail. Satellite data reveal more pronounced warming in the Arctic, especially in the Arctic Ocean, where data are scarce, suggesting that GISTEMP may underestimate global warming in this region.
- The underestimation could reach 50% in some places, NASA GISS co-author and director Gavin Schmidt told Axios, indicating that the GISTEMP dataset was based on regional temperature interpolation arctic measurements from surveys at very distant land stations. This could create a blind spot, of some sort, on the Arctic Ocean itself.
- Scientists have already concluded that the Arctic is heating up twice as fast as the rest of the world.
What they say: "These results should help dispel the lingering fears that modern warming is somehow due to the location of sensors in urban heat islands or other measurement errors at the surface," he said. Zeke Hausfather, researcher at the University of California at Berkeley. involved in the new study, told the Washington Post.
- Schmidt said that, in the future, the surface station's readings could be combined with satellite temperatures and other sources for more complete monitoring of global temperature.
