Comments on: An oldie but goodie – Microsite and UHI in 1952

By: Sam Urbinto

Sam Urbinto — Wed, 22 Aug 2007 23:24:21 +0000

Ah, thanks. Station pairs over almost a year. So that makes me wonder how often they measured. One reading every 6 hours is very different than one reading every 10 minutes.

Although as I said, without sunlight amount for the day, wind speed and direction, humidity/percipitation (and probably readings at other heights and locations around the area) I don’t know what total value just having the temps is, at least for figuring out the specifics here in this case.

By: Curtis

Curtis — Wed, 22 Aug 2007 22:54:29 +0000

No the paired observations are for rural/urban sites compared over 46 – 48 weeks.

By: Sam Urbinto

Sam Urbinto — Wed, 22 Aug 2007 22:42:56 +0000

I’m not sure what I’m looking at.

Around 2 readings 2 times per hour? (46 pairs of observations) Every half hour?

Or is that they took them for 46-48 weeks twice per day?

Anyway, you also have to take into account some things, I think it’s very difficult to tell what’s going on without temp, wind, humidity and sunlight figures.

By: John F. Pittman

John F. Pittman — Wed, 22 Aug 2007 21:51:03 +0000

#30, #31

I could not google it, but remember a paper in the 1970-1980 range that identified changing precipitation by seeding from exhausts of airplanes.

By: Greg Murphy

Greg Murphy — Wed, 22 Aug 2007 21:00:26 +0000

Great study, Thanks for posting it.
Greg Murphy

By: Curtis

Curtis — Wed, 22 Aug 2007 20:44:58 +0000

The data the Atlanta thermal island study talks about was obtained by remote sensor (aboard an airplane) in 1996, a similar study was going to be done in Huston TX in 1997 but I havent seen anything about that study.

What I found most interesting was this quote “In Atlanta, commercial and suburban development dramatically increased between 1973 and 1992, and nearly 380,000 acres of forest were cleared to accommodate that growth.” I couldnt help but think of how many other cities could make the same claim. In 19 years, adding 380 000 acres of urban development.

By: Murray Duffin

Murray Duffin — Wed, 22 Aug 2007 20:23:18 +0000

Re: 22 and 23.I have been living in Atlanta for about 3 months now, and can confirm that most days the News climatologists report Atlanta temperatures higher than the nearby towns. Can be from 1 or 2 degrees to as much as 8 degrees. I have had the feeling that the difference is less on weekends, but have not recorded data. Will have to start recording. Have no idea where the temp. stations are, but believe Atlanta is at the airport. They are not in the USHCN network.
Georgia is having a drought this year. We had a cooler than normal summer through late july, but have been warmer than normal during August, 11 degrees F warmer yesterday. Late afternoon clouds with some rain were frequent in late July, but it would be hard to say more frequent than in the surroundings. This effect has been almost non-existant in August. Trees are already shutting down and loosing their leaves due to the heat and lack of rain. Could be that convective heat causing rain is an inverted V. We have been sitting under a stationary high for near 3 weeks, and I would guess that the lack of convective rain is from a lack of moisture in the air because nothing is being introduced from outside the high.
Metro Atlanta population passed 5 million people in Q1 ’07. Murray

By: SteveSadlov

SteveSadlov — Wed, 22 Aug 2007 19:19:55 +0000

RE: #32 – Mitchell’s reconstruction has one interesting quirk. Instead of a 1930s peak, his has a mini peak there, and a larger peak in the 1950s. (speculation)The 1950s peak was UHI/anthropogenic direct dissipation/land use mod related. It was finally overtaken by the inarguable overall 1940s – 1970s cooling. Sodden note – both world wars were preceded by cooling.

By: Douglas Hoyt

Douglas Hoyt — Wed, 22 Aug 2007 19:10:52 +0000

I worked for Murray Mitchell for one year. He was a very careful worker and very much a gentleman. He is still missed by some of us. I believe it is his reconstruction of climate change for the Northern Hemisphere that is the right hand figure at http://farm1.static.flickr.com/180/432841209_8874753beb_b.jpg

I bet he was careful to exclude UHI effects as best as he could in his temperature reconstruction.

By: gdn

gdn — Wed, 22 Aug 2007 16:11:44 +0000

I don’t have any references handy, but as I recall, at the time, the tendency for rainy weekends was explained basically as the effect of particulate cloud-seeding. This would clearly change the temperature at ground level both through albedo level from increased cloud cover, and from the rain itself.