(BIVN) – What will the weather be like on Mauna Kea in 2050? Summer snow at the summit could be a thing of the past, for one thing.
The Mauna Kea Management Board was recently given a presentation on “Climate Downscaling for the Island of Hawaii” by University of Hawaii professor Dr. Steve Businger.
As Businger explained, a typical climate model has to run so far into the future – like a hundred years, for example – it can’t run at a resolution that can resolve Mauna Kea. “But we run a weather model every day on Mauna Kea at very high resolution, down to 250 meters,” Businger told the board, “and calculate such things as how much optical turbulence there’ll be for the telescopes, cloud cover, whether its going to snow or not at the summit.”
“Why not take the climate model output and use that as the initial condition for the weather model and run a high resolution weather model that can resolve Mauna Kea?” Businger figured.
Businger says its already getting hotter in the United States, observations over the last several decades have shown. Based on Hawaii observations made from 1920 to 2007, there is a drying trend on the leeward side of the Big Island, and its not getting much wetter anywhere else on the island.
On Mauna Kea, observations have shown it is getting warmer, solar radiation is increasing, and the amount of “zero rain days” is increasing.
“There’s a study by Zhang et all in 2017,” Businger said, “that projected that the snowfall at the summit (of Mauna Kea) will be 1/10th of the current value. Not completely gone. But at (the year) 2100 it looks like its going to be less than we currently have.”
“It looks like we’re going to – basically, in the summertime – eliminate the snow,” Businger said, pointing to a big dip in a graph projected onto a screen.
Businger calculates summit temperatures will be warmer, especially in the summer. Also, the summit will be more moist, especially in summer and during the daytime.
Winds will be lighter at the summit, Businger said, fostering stronger diurnal circulations. Tradewind inversion and the cloud base will be slightly lower, and the cloud layer will be thinner in the summer and thicker in winter.