Comparing the 9/11 shutdown to before and after is akin to a one-point line. Looking at station pairs where there are contrails and where there are not begs a long discussion on UHI and how they resolved that potential difference. A very weak hypothesis.
High in the sky where the cirrus ice crystal clouds form, jet contrails draw their crisscross patterns. Now researchers have found that these elevated ice cloud trails can influence temperatures on the ground and affect local climate, according to a team of Penn State geographers. Video follows.
“Research done regarding September 2001, during the three days following 9-11 when no commercial jets were in the sky, suggested that contrails had an effect,” said Andrew M. Carleton, professor of geography. “But that was only three days. We needed to look longer, while jets were in the air, to determine the real impact of contrails on temperature and in terms of climate.”
“Certain regions of the U.S. have more favorable atmospheric conditions for contrails than others, “
said Jase Bernhardt, graduate student in geography.
For contrails to form…
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