“Blob” of warm water on Lake Michigan shows up on satellite—what caused it?
AN EYE-CATCHING “BLOB” OF WARM WATER SHOWED UP ON SATELLITE-DERIVED WATER TEMP DEPICTIONS OF LAKE MICHIGAN THIS PAST THURSDAY—Was it real—and, if so, what might have caused it?
By Meteorologist Tom Skilling (Via Facebook)
A fascinating post last Thursday out of CIMSS—the Cooperative Institute for Meteorological Satellite Studies at the University of Wisconsin-Madison—clearly shows a SMALL warm pool of water in Lake Michigan. The day had been cloud-free—so sunshine was clearly abundant at the time.
Heat sensor data indicated the blob of warm water was almost 10-degrees warmer than the surrounding Lake Michigan surface. The obvious questions raised by this small pool of comparatively warm water on the lake’s surface were: Was it some kind of quirk in the satellite data—or was it real? And if it was real, how did come into being?
In a great CIMSS blog post on the phenomenon by University of Wisconsin-Madison researcher Scott Lindstrom, he notes algorithms employed in interpreting and depicting lake surface water temps made it unlikely solar energy reflection off the lake waters were at play here. These algorithms tend to correct for such misinterpretations. So the warm pool was likely quite real.
Lindstrom goes on to establish that such highly localized (i.e. small scale) warm pools have been observed before and even offers links to the previous occurrences.
He offers an analysis on what may have produced such a warm pool, explaining:
“…such isolated warm water features are often associated with areas of very light winds — usually beneath the center of high pressure at the surface — which allows the relatively calm water surface to warm more rapidly.”
Indeed, a surface wind analysis—as well as a scan of surface winds by a polar orbiting weather satellite 6 hours earlier—indicated the warm pool sat at the center of a weak clockwise circulation suggesting the warm water may well have been occurring within the center of high pressure where winds are light.
Interestingly, Lindstrom notes buoy water temp data shortly after the 1 pm CDT satellite images you see here indicated water temps even warmer than those inferred from satellite data.
IT’S A FASCINATING PHENONMENON, an example of how weather satellites can detect small scale features of our environment which escaped detection in earlier times. You can read CIMSS UW-Madison satellite researcher Scott Lindstrom’s full analysis and blog post here: https://cimss.ssec.wisc.edu/satellite-blog/archives/58756
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