Thursday, July 17, 2008

The Natural is the Normal

For a long time I've wanted to measure the temperature differences between the Old Forest and nearby urban areas, to see the difference the green cathedral has on temperature.

On June 8th I pulled together quite the rig to do it and within the span of a little over an hour (~3:30-4:30p.m.), I measured the temperature in the following locations:

  • the Overton Square parking lot (aka, "Satan's Griddle") Memphis Temperature Test .

  • next to the Overton Square parking lot, in the shade of a lone magnolia. Memphis Temperature Test

  • In the Old Forest. 030

  • At the edge of the Teton Trek clearcut, with the cut on one side and the Old Forest on the other. Memphis Temperature Test

  • In the middle of the Overton Park Greensward. Memphis Temperature Test

While the temperature remained constant at 93 degrees at the Memphis International Airport, I measured the following temps, sorted hot to cool
  1. Overton Square parking lot, full sun, 100 degrees.

  2. Teton Trek clearcut-adjacent, full sun, 96 degrees.

  3. Greensward and tree shade in Overton Square, full sun and shade, respectively, 93 degrees.

  4. Old Forest, shade, 87 degrees.
While the official measured temps stayed constant, I measured a 13 degree difference as I traveled from parking lots and clearcuts to urban shade and sunlit greeenswards and finally to the rich shade of the Old Forest. All within a 1 mile radius of each other.

View Larger Map

Since the Old Forest is Memphis' natural state -- what we approach when we let up on the chainsaw and lawnmower -- the 87 isn't special, it's normal. We complain about the heat in Memphis, but a good chunk comes from the artificial climate we've created with bulldozers, which we then have to over-correct with the artificial climate of air-conditioning.

Of course, even with deep shade, we will still have humidity coming up from the Gulf of Mexico. But what we pay for in humidity, we get back in beauty, abundance, shade and lower temperatures.
That is, unless we knock our forests down and turn our world into a humid desert.


bridgmanpottery said...

I'm so glad you did this. Even on the hottest days, I notice a dramatic drop in temperature on North Parkway around the old forest. I just didn't know it was THAT dramatic. Long live the trees.

Stacey Greenberg said...

Truly amazing. Wow. Thanks for doing this.

Dave Barger said...

Thanks for studying and sharing this. The point about the 87 being normal is a real kicker. When I mention Memphis to a friend living out in the desert Southwest, his eyes go distant and he says through parched sunbaked smile, "yea, all those trees".

Unknown said...

This is great!!

I have always noticed the change in temp as I drive west on Poplar, as soon as I pass E.Parkway, I feel the air 5-10 degrees cooler (on those days when I have my windows open).

I wonder if it would be possible to redo your measurements- and add 2 locations: right in front of the entrance to the zoo, and at the edge of the forest right alongside Poplar a bit west of E.Parkway. Do you need another hand in getting all the measurements done?