#research_diary
#urban_heat_islands

I was plotting a generic map of daytime urban heat island intensity (UHII) today (left, color goes from slightly below 0 to 2.8 degrees). The map turned out to be vastly different from the previously reported spatial patterns, where the UHII clearly increases from the west to the east (right, from Fig. 1 of Zhao et al. 2014, DOI: 10.1038/nature13462).

Then I realized my variable was 2m air temperature, and their variable was land surface temperature. So I recalled another paper that showed the west-east divide in UHII for 2m air temperature (Fig. 3 of Zhao et al. 2018, DOI: 10.1088/1748-9326/aa9f73). As expected, there was no east-west divide in the UHII shown in the barplot.

Are the well-known evaporative and/or convective cooling effects on UHII in the west only applicable to the land surface temperature?