I say more about this over at KCET, but I’ve found it kind of surprising that today’s barrage of coverage of the World Meteorological Organization’s official dethroning of the 1936 El Azizia, Libya temperature record didn’t mention this fascinating work that came out a few months back.
The short version of today’s news: a global group of meteorologists, including Libyan scientist, Khalid El Fadli, climate director of the Libyan National Meteorological Center, went over the old records that secured El Azizia’s spot in fifth-grade geography texts as the site of the world’s highest recorded temperature. That much-memorized datum, an air temperature peak of 136°F (or 58°C for those of you in civilized countries) 90 years ago today on September 13, 1922, turns out to have been an artifact of difficult-to-read equipment combined a newbie weather technician working at an Italian Army post. The peak actual temperature that day was likely 7°C cooler, putting it well within the range of normal hellishly hot for the neighborhood I just moved out of. That puts Death Valley’s July 10, 1913 reading of 134°F/56.7°C back in the first place spot it ought to have enjoyed for the last 90 years.
El Fadli, by the way, had to go underground for a bit during the revolution. His colleagues lauded him today for taking risks to get this study done, and we wouldn’t have had this info without his taking significant personal risks as Qaddafi’s regime went through its death throes.
The thing is that those official records have a bit of built-in sampling error: namely, they derive from the places where we’ve managed to maintain weather stations for long enough to keep records. The WMO has more than 11,000 weather stations worldwide, but “worldwide” is a big place, and that works out to an average of one weather station for every 13,000 square kilometers of land surface. Admittedly, much of the really underrepresented land surface is in Antarctica, where it’s unlikely any high air temperature records will be set anytime soon. But that’s still a lot of potentially hot land not being monitored, in the deserts of Asia, Africa, and even the Sonoran Desert in North America.
The research that made the press a few months back involved measuring Land Skin Temperature (LST), which I’d embarrassingly typoed as “Land Sin Temperature” at KCET until just now, via infrared satellite monitoring of the Earth’s surface by way of the Moderate Resolution Imaging Spectroradiometers on two NASA satellites. The researchers, led by Steve Running of the University of Montana, found a number of places well away from the nearest WMO-approved weather station that had astonishingly high surface temperatures. The record? A dark and gravelly spot in Iran’s Lut Desert, where on one particularly warm day in 2005 the LST reached 159.3°F/70.7°C. The place on Earth with the second-hottest LST was an unspecified spot in the bush in Queensland, which will no doubt delight the Strines in the crowd. That temperature: 156.7°F/69.3°C. The Turpan Basin in Xinjiang, China took third place at 152.2°F /66.8°C.
Of course air temperature and LST are different animals. The WMO requires that air temperature measurement be taken 1.2-2 meters off the ground in the shade, which means comparing air temps and LST is kind of comparing apples with the sun-baked soil at the base of the apple tree. Think walking barefoot on the beach on a nice day with air temperatures in the 80s. Differences of 50°F between air temperature and LST aren’t unheard of. And until we plant a WMO-approved weather station out on the Lut Desert, we probably won’t have a good idea how those temperatures compare with Death Valley’s.
But we do know one thing: when Running’s team listed the places on Earth with the hottest Land Skin Temperatures, Death Valley didn’t make the list. So the hottest place on Earth, according to the news today, probably isn’t. It’s just the hottest one for which we have a recorded air temperature. Which doesn’t make as snappy a headline. But that’s okay: the California Desert still has that 767 straight days without rain at Bagdad, about 40 miles north of where I’me sitting right now. It’s at most in second place after the Atacama Desert, which has some places where rain’s never been recorded, ever. But we’re’ good at being in second place around here.