## Land Surface Temperature Difference

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Dan_Buckler
Posts: 3
Joined: Wed Jul 17, 2019 10:37 am

### Land Surface Temperature Difference

Hello,

I am trying to wrap my head around the land-surface temperature differences for places. Is the number that is calculated for a geographic unit the average pixel value within those borders, but the actual pixel value is the difference with the scene median? I am just trying to figure out the best way of using this data when it seems like we're using means and medians. For example, can I say in Wisconsin that X of Y places have average temperatures above the surrounding area (i.e. Landsat scene)? And of those X places with higher temperatures, they average Z degrees more than their surroundings?

Thanks for any clarification.
Dan
KristaH
Posts: 4
Joined: Fri Aug 09, 2019 10:00 am

### Re: Land Surface Temperature Difference

Hi Dan - the short answer is yes: the values in the data set (each pixel) represent surface temperature in degrees above or below the median temp of the Landsat scene; for each place boundary, these values are averaged to calculate the value you can see in the table.

So yes, you could say that X number of places show an average temperature above the median for the surrounding area (and that the average temps are Z degrees higher than that median). It's worth noting that especially with place boundaries, this can be attributed to a wide variety of variations. Namely in Wisconsin, lakes make a huge difference. The difference between Sun Paririe (hotter) and Lake Koshkonong (cooler), for example, is typical. The Koshkonong boundary is much larger than Sun Prairie, but is primarily water, has a much lower population density, and actually has less canopy cover. Someone from WI might recognize that these 2 places don't represent apples to apples, but it can be worth investigating any wide temperature differences with this in mind. Hope that helps -

Krista