Readers may remember a couple of weeks back when I lamented that the downward economy had finally caught up to me and my little weather business. I asked readers if they’d mind if I’d showcase a weather station or two to help drum up some business. Nobody objected and many readers were very helpful and sympathetic. Thank you sincerely.
I always like to find ways to bring meteorological and climate science to the layman, hence this blog. My specialty is instrumentation, and readers may recall back in fall 2008 when I rigged up my vehicle with an NIST calibrated data logger, window mounted Gill IR shield, and a live connection to my laptop and drove a transect to measure the surface temperature. The result was this first ever graph of Reno’s UHI (Urban Heat Island) signature:
Click for larger image
That little experiment garnered quite a few comments, and I always wanted to find an inexpensive way for others to recreate what I did without having to invest in a high priced NIST calibrated probe, IR shield, datalogger, and laptop, all told which would run about $1200. That’s beyond the means of many people who might take an interest. It’s also well beyond the means of most students who might want to do something like this for their local science fair in their own hometown.
I’m pleased to say I have devised a solution for about 1/10th the cost, and I’ve just finished testing it in my hometown of Chico, CA. The results follow.
As many readers know, I sell some nifty USB dataloggers, and you may have seen this ad on the right sidebar which links to my online store.
The dataloggers are inexpensive, mostly under $100, and work great for various monitoring applications where you want to gather and evaluate temperature data. Problem is, they had no way to be mounted to anything easily, and I couldn’t see an easy way to mount one to a vehicle like I did with the IR Gill shield:
The NIST calibrated temperature sensor (inside the Gill IR shield) mounted on the vehicle using an improvised window mount., Cable goes to datalogger inside, and datalogger connected to laptop.
My goal has always been to recreate this inexpensively and reliably so many of you could map UHI in your own city. Making this within reach of students and their parents was the ultimate goal. How does $84.95 sound compared to $1200? You don’t even need to take a laptop in the vehicle with you.
Some days, serendipity strikes. A discussion about US flags with fellow blogger Russ Steele made me think about this idea of using the window flag mounts commonly seen en-route to football and baseball games:
Except my version has no team flag, it flies a datalogger instead:
How’s that for simple?
I spent today working this product idea out and testing it to make sure it is simple enough for anyone to recreate anywhere. Then I ran some road tests. Here’s how it works.
First we start with the USB-2 Temperature and Humidity datalogger. The reason I chose this unit over a temperature-only USB-1 version is that it already has a built in mini IR shield that allows free airflow. It reacts faster for that reason.
Next I provide a modified vehicle window mount and mounting hardware specifically to keep the USB-2 datalogger affixed, click images to enlarge:
Adhesive Velcro strip plus a removable secure strap worked best:
I ran some tests to see if I could fling the datalogger off the end. It held even after inflicting a few G’s on it at arms length.
Here’s the finished product:
The next test was to see if the datalogger was far enough out of the vehicle slipstream to prevent any temperature contamination while moving. That was evident from the data right away.
I did four daytime driving transects of my town to see if there were any hiccups or gotchas with install, driving, removal, and data download. Finding none, I wrote up some instructions:
Measuring UHI in your city:
- Install the software on your Windows PC (or laptop if you bring it with you in the car). Experiment with and familiarize yourself with the datalogger.
- Choose a route you can drive in your town that provides a good north-south and/or east-west driving transect from country, through suburbs, downtown, and back to countryside again. Use Google Earth or a similar mapping tool to assist in planning your route. Try to choose a route that will not take any more than 30 minutes to minimize ambient temperature change that may occur.
- Choose a clear night with no wind or light wind if possible. Later at night like 11PM-midnight is best so as to have minimum traffic and stoplights.
- Set the data logger to start logging either immediately or at some start time in the future. Put the waterproof cap back on
- Affix the datalogger to the vehicle mount using the strap provided.
- Put the vehicle mount on the top edge of your vehicle window and close it for a tight fit.
- Drive to the start point, Either wait for the pre-programmed start time or trigger the data logger to start from your laptop. It is always best to start on an easy to check period like top of the hour, quarter hour, or half hour.
- Drive the route, trying to maintain a fixed speed.
- Have your passenger note landmarks/locations in a logbook as you drive so that you can correlate with temperatures later.
- Optional – take a logging GPS unit with you if you want exact positions and time.
- Once completing the first transect, turn around and drive it again. You may wish to do several transects if time allows so that you can create an average profile later.
- Remove the USB-2 datalogger from the vehicle mount, plug into your PC, launch the included software and plot your results! Export the data to a spreadsheet for further analysis.
Saturday night, April 3rd, I ran my first for real UHI transect on Highway 99 from Garner Lane North of town to Neal Road South of town. I chose these points because they were safe places to turnaround and because they were both well enough removed from the population center that I expected they would approximate “rural” conditions.
After driving a transect and reverse driving it again, here is what the datalogger showed from the program that ships with the datalogger:
As you can see, the red temperature curve shows two humps, these are the two transects mirrored. First one was driving NW to SE, and the reverse (second) was SE to NW. Humidity and dewpoint are also displayed. The temperature looks a little blocky becuase the resolution of the datalogger is 0.5°C. However, given the world’s surface data is measured to the nearest degree, this is more than adequate for the purpose.
My home weather station (in town) showed light winds less than 5mph from the southeast and 50°F (10°C) when I left. Skies were clear. It was a good evening to measure UHI.
I took a voice recorder with me to note the time I started driving and the time I turned around and reversed the transect. I drove the reverse transect about 10mph faster because the first transect I didn’t want to pass a semi truck (speed limit 55mph for trucks through town) and pick up any waste heat, so I held well behind it.
Next I exported that data into my favorite graphing program ( DPlot ) and edited the starting and ending data times based on my recorder notes. I had set the datalogger at home to automatically start at 8:45 PM and I hadn’t reached my Garner lane start point yet. My actual transect began at 8:47 PM from Garner Lane at Highway 99 intersection.
Then I pulled up my Google Earth and started exporting some images for reference. Here’s the normal map view of the transect with starting and ending points:
And here’s the NW to SE driving transect overlaid onto a Google Earth 3D image looking NE so that Highway 99 appears as a “x- axis”:
As you can see, the graph matches the infrastructure character of the town fairly well, with the peak coinciding with the center of town (marked by the crosshair and label). The temperature is less in the rural outskirts of town.
So there we have it, it appears that my small college town of ~ 80,000 people has a UHI value of about 1.5°C (2.7°F) via this transect. The second return transect from SE to NW has the same magnitude, but is offset due to ambient temperature drop that occurred during the drive. When I returned home at 9:30PM, and hour later my home weather station had dropped to 44°F.
So would you like to do this for your hometown? Do you have a son/daughter nephew/niece that would benefit from a weekend science project learning about how to measure temperature and graph it to show UHI? Or, maybe you just want to do it yourself for fun and quantify what you’ve noticed for years via your automobile thermometer.
I’ll be happy to post any results here.
The only real caveat to this experiment is: don’t stop your vehicle if you can help it. Without a constant airstream, some waste heat from the vehicle might make its way to the sensor. Choose your driving route to avoid long stoplights, and I’ve found that in many cities after 11PM certain thoroughfares are “greenlighted”.
If you like this little idea or know somebody who would, please feel free to buy my little UHI measurement kit at a price most anyone can afford: $84.95 It helps me and provides more data that shows UHI to be a real, measurable, effect.
Here is the link to purchase the kit: http://weathershop.com/usb2-UHI.htm
And yes, I do ship internationally.
Thanks for your consideration, happy motoring! – Anthony
UPDATE: Hu McCulloch reminds me of the similar experiment Warren Meyer and his son did a couple of years ago which you can read about here:
http://www.climate-skeptic.com/2008/02/measureing-the.html
Some commenters were concerned about contamination of the data due to the vehicle. This is possible, even likely, at a dead stop. But at highway speeds of 60 mph or even street speeds of 30 mph any such contamination gets swept away in the slipstream. Essentially the thermometer has turbocharged aspiration, and is measuring the true temperature of the air being intersected. There may be issues with wast heat from vehicles ahead, but if you drive carefully and avoid tailgating, this can be avoided. Doing multiple transsects over time and averagign the runs is another way to minimize such biases.
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The raw data from the USB datalogger is below, note the date format is dd/mm/yyyy.
ChicoUHILogger,Time,Celsius(°C),Humidity(%rh),dew point(°C),Serial Number 1,03/04/2010 20:45:00,9.5,58.5,1.8,010004039 2,03/04/2010 20:45:10,9.5,59.0,1.9 3,03/04/2010 20:45:20,9.5,59.5,2.0 4,03/04/2010 20:45:30,9.5,59.5,2.0 5,03/04/2010 20:45:40,9.0,60.5,1.8 6,03/04/2010 20:45:50,9.0,60.5,1.8 7,03/04/2010 20:46:00,9.0,61.0,1.9 8,03/04/2010 20:46:10,9.0,60.5,1.8 9,03/04/2010 20:46:20,9.0,61.0,1.9 10,03/04/2010 20:46:30,9.0,61.0,1.9 11,03/04/2010 20:46:40,9.0,61.5,2.0 12,03/04/2010 20:46:50,9.0,61.5,2.0 13,03/04/2010 20:47:00,8.5,62.5,1.8 14,03/04/2010 20:47:10,8.5,63.0,1.9 15,03/04/2010 20:47:20,8.5,63.0,1.9 16,03/04/2010 20:47:30,8.5,62.5,1.8 17,03/04/2010 20:47:40,8.5,62.0,1.6 18,03/04/2010 20:47:50,8.5,60.5,1.3 19,03/04/2010 20:48:00,8.5,60.5,1.3 20,03/04/2010 20:48:10,8.5,60.5,1.3 21,03/04/2010 20:48:20,9.0,60.0,1.7 22,03/04/2010 20:48:30,9.0,59.5,1.5 23,03/04/2010 20:48:40,9.0,59.0,1.4 24,03/04/2010 20:48:50,9.0,58.5,1.3 25,03/04/2010 20:49:00,9.0,58.0,1.2 26,03/04/2010 20:49:10,9.0,58.0,1.2 27,03/04/2010 20:49:20,9.5,57.5,1.5 28,03/04/2010 20:49:30,9.5,57.0,1.4 29,03/04/2010 20:49:40,9.5,57.0,1.4 30,03/04/2010 20:49:50,9.5,56.5,1.3 31,03/04/2010 20:50:00,9.5,56.5,1.3 32,03/04/2010 20:50:10,9.5,56.5,1.3 33,03/04/2010 20:50:20,10.0,56.5,1.8 34,03/04/2010 20:50:30,10.0,56.5,1.8 35,03/04/2010 20:50:40,10.0,56.0,1.6 36,03/04/2010 20:50:50,10.0,55.5,1.5 37,03/04/2010 20:51:00,10.0,55.5,1.5 38,03/04/2010 20:51:10,10.0,55.5,1.5 39,03/04/2010 20:51:20,10.0,55.5,1.5 40,03/04/2010 20:51:30,10.0,55.5,1.5 41,03/04/2010 20:51:40,10.0,55.5,1.5 42,03/04/2010 20:51:50,10.0,56.0,1.6 43,03/04/2010 20:52:00,10.0,56.5,1.8 44,03/04/2010 20:52:10,10.0,56.0,1.6 45,03/04/2010 20:52:20,10.0,56.5,1.8 46,03/04/2010 20:52:30,10.0,56.0,1.6 47,03/04/2010 20:52:40,10.0,55.5,1.5 48,03/04/2010 20:52:50,10.0,55.0,1.4 49,03/04/2010 20:53:00,10.0,54.5,1.3 50,03/04/2010 20:53:10,10.0,54.5,1.3 51,03/04/2010 20:53:20,10.0,54.5,1.3 52,03/04/2010 20:53:30,10.0,55.0,1.4 53,03/04/2010 20:53:40,10.0,54.5,1.3 54,03/04/2010 20:53:50,10.0,54.5,1.3 55,03/04/2010 20:54:00,10.0,54.5,1.3 56,03/04/2010 20:54:10,10.0,55.0,1.4 57,03/04/2010 20:54:20,10.0,55.5,1.5 58,03/04/2010 20:54:30,10.0,55.5,1.5 59,03/04/2010 20:54:40,10.0,57.0,1.9 60,03/04/2010 20:54:50,10.0,57.0,1.9 61,03/04/2010 20:55:00,10.0,57.5,2.0 62,03/04/2010 20:55:10,9.5,58.0,1.7 63,03/04/2010 20:55:20,9.5,58.0,1.7 64,03/04/2010 20:55:30,9.5,58.0,1.7 65,03/04/2010 20:55:40,9.5,57.5,1.5 66,03/04/2010 20:55:50,9.5,57.5,1.5 67,03/04/2010 20:56:00,9.5,58.5,1.8 68,03/04/2010 20:56:10,9.5,58.5,1.8 69,03/04/2010 20:56:20,9.5,59.5,2.0 70,03/04/2010 20:56:30,9.5,60.0,2.1 71,03/04/2010 20:56:40,9.0,60.5,1.8 72,03/04/2010 20:56:50,9.0,60.5,1.8 73,03/04/2010 20:57:00,9.0,61.0,1.9 74,03/04/2010 20:57:10,9.0,61.0,1.9 75,03/04/2010 20:57:20,9.0,61.0,1.9 76,03/04/2010 20:57:30,9.0,61.5,2.0 77,03/04/2010 20:57:40,9.0,61.5,2.0 78,03/04/2010 20:57:50,9.0,61.5,2.0 79,03/04/2010 20:58:00,9.0,61.0,1.9 80,03/04/2010 20:58:10,9.0,61.0,1.9 81,03/04/2010 20:58:20,9.0,61.0,1.9 82,03/04/2010 20:58:30,9.0,61.0,1.9 83,03/04/2010 20:58:40,9.0,60.5,1.8 84,03/04/2010 20:58:50,9.0,61.0,1.9 85,03/04/2010 20:59:00,9.0,60.5,1.8 86,03/04/2010 20:59:10,9.0,60.5,1.8 87,03/04/2010 20:59:20,8.5,61.0,1.4 88,03/04/2010 20:59:30,8.5,62.0,1.6 89,03/04/2010 20:59:40,8.5,62.5,1.8 90,03/04/2010 20:59:50,8.5,62.5,1.8 91,03/04/2010 21:00:00,8.5,62.5,1.8 92,03/04/2010 21:00:10,8.5,62.5,1.8 93,03/04/2010 21:00:20,8.5,63.0,1.9 94,03/04/2010 21:00:30,8.5,63.0,1.9 95,03/04/2010 21:00:40,8.5,64.0,2.1 96,03/04/2010 21:00:50,8.5,64.5,2.2 97,03/04/2010 21:01:00,8.5,64.0,2.1 98,03/04/2010 21:01:10,8.5,64.0,2.1 99,03/04/2010 21:01:20,8.5,64.0,2.1 100,03/04/2010 21:01:30,8.0,64.5,1.7 101,03/04/2010 21:01:40,8.0,65.0,1.8 102,03/04/2010 21:01:50,8.0,65.5,1.9 103,03/04/2010 21:02:00,8.0,66.0,2.0 104,03/04/2010 21:02:10,8.0,66.0,2.0 105,03/04/2010 21:02:20,8.0,66.5,2.2 106,03/04/2010 21:02:30,8.0,65.5,1.9 107,03/04/2010 21:02:40,8.0,64.5,1.7 108,03/04/2010 21:02:50,8.0,65.0,1.8 109,03/04/2010 21:03:00,8.0,66.0,2.0 110,03/04/2010 21:03:10,8.0,66.0,2.0 111,03/04/2010 21:03:20,8.0,66.0,2.0 112,03/04/2010 21:03:30,8.0,66.0,2.0 113,03/04/2010 21:03:40,8.0,65.0,1.8 114,03/04/2010 21:03:50,8.0,64.0,1.6 115,03/04/2010 21:04:00,8.0,63.5,1.5 116,03/04/2010 21:04:10,8.0,63.0,1.4 117,03/04/2010 21:04:20,8.0,62.0,1.2 118,03/04/2010 21:04:30,8.5,61.0,1.4 119,03/04/2010 21:04:40,8.5,61.5,1.5 120,03/04/2010 21:04:50,8.5,61.0,1.4 121,03/04/2010 21:05:00,8.5,60.5,1.3 122,03/04/2010 21:05:10,8.5,60.5,1.3 123,03/04/2010 21:05:20,8.5,60.0,1.2 124,03/04/2010 21:05:30,9.0,60.5,1.8 125,03/04/2010 21:05:40,9.0,61.5,2.0 126,03/04/2010 21:05:50,9.0,61.0,1.9 127,03/04/2010 21:06:00,9.0,61.0,1.9 128,03/04/2010 21:06:10,9.0,61.0,1.9 129,03/04/2010 21:06:20,9.0,61.0,1.9 130,03/04/2010 21:06:30,9.0,60.5,1.8 131,03/04/2010 21:06:40,9.0,60.0,1.7 132,03/04/2010 21:06:50,9.0,59.5,1.5 133,03/04/2010 21:07:00,9.0,59.0,1.4 134,03/04/2010 21:07:10,9.0,59.0,1.4 135,03/04/2010 21:07:20,9.0,59.0,1.4 136,03/04/2010 21:07:30,9.0,58.5,1.3 137,03/04/2010 21:07:40,9.0,58.5,1.3 138,03/04/2010 21:07:50,9.0,58.5,1.3 139,03/04/2010 21:08:00,9.0,58.0,1.2 140,03/04/2010 21:08:10,9.5,58.0,1.7 141,03/04/2010 21:08:20,9.5,57.5,1.5 142,03/04/2010 21:08:30,9.5,57.5,1.5 143,03/04/2010 21:08:40,9.5,57.0,1.4 144,03/04/2010 21:08:50,9.5,57.0,1.4 145,03/04/2010 21:09:00,9.5,57.0,1.4 146,03/04/2010 21:09:10,9.5,57.0,1.4 147,03/04/2010 21:09:20,9.5,57.0,1.4 148,03/04/2010 21:09:30,9.5,57.0,1.4 149,03/04/2010 21:09:40,9.5,57.0,1.4 150,03/04/2010 21:09:50,9.5,57.0,1.4 151,03/04/2010 21:10:00,9.5,56.5,1.3 152,03/04/2010 21:10:10,9.5,57.0,1.4 153,03/04/2010 21:10:20,9.5,57.0,1.4 154,03/04/2010 21:10:30,9.5,57.0,1.4 155,03/04/2010 21:10:40,9.5,59.0,1.9 156,03/04/2010 21:10:50,9.5,61.0,2.4 157,03/04/2010 21:11:00,9.5,61.5,2.5 158,03/04/2010 21:11:10,9.0,61.0,1.9 159,03/04/2010 21:11:20,9.0,61.0,1.9 160,03/04/2010 21:11:30,9.0,61.0,1.9 161,03/04/2010 21:11:40,9.0,62.0,2.1 162,03/04/2010 21:11:50,8.5,62.0,1.6 163,03/04/2010 21:12:00,8.5,62.5,1.8 164,03/04/2010 21:12:10,8.5,63.0,1.9 165,03/04/2010 21:12:20,8.5,63.5,2.0 166,03/04/2010 21:12:30,8.5,64.0,2.1 167,03/04/2010 21:12:40,8.5,63.5,2.0 168,03/04/2010 21:12:50,8.0,63.5,1.5 169,03/04/2010 21:13:00,8.0,64.0,1.6 170,03/04/2010 21:13:10,8.0,64.0,1.6 171,03/04/2010 21:13:20,8.0,64.5,1.7 172,03/04/2010 21:13:30,8.0,65.5,1.9 173,03/04/2010 21:13:40,8.0,65.0,1.8 174,03/04/2010 21:13:50,8.0,64.0,1.6 175,03/04/2010 21:14:00,8.0,63.5,1.5 176,03/04/2010 21:14:10,8.0,63.0,1.4 177,03/04/2010 21:14:20,8.0,62.5,1.3
Anthony replied to my wonderings about complicating the simple:
> any of those will work, but the LCD version (not LED)
> really doesn’t gain you anything, and comes with a risk.
Roger; for this specific purpose U are clearly correct.
I was also thinking of other apps, but won’t bore y’all with those thoughts.
And my bad on letting LED slip in vice LCD; LCD, of course.
> I went for simple, robust, and inexpensive.
Which in most cases is the best policy.
Thanks for answer; I’ll buy one of the data loggers from your Weather Shop.
:-]
I like this gadget… If I can find the time to run the experiment. As I was imagining my route, I recall a dip under a railroad trellis next to a swamp that is a pool of cool air at night. Maybe 10 degrees cooler than the surroundings. My house sits on a hill, and (on my motorcycle) I notice increasing warmth as I climb the hill, so topography would be a useful parameter in my final analysis.
899
“— the driver (who might be breathing heavily)
— the passengers (who might also be breathing heavily)”
– gasping at straws
Back when I was young and gas was cheap car clubs used to sponsor evening car rallies with puzzling maps and clues to various checkpoints. Maybe they still do. Winners got to all the checkpoints by solving the clues to location and getting there first at legal speed. This would be a good way to get a sample UHI from several individual stations. Electric or HF vehicles would produce less ambient heat as well. After the rally everyone meets for pizza and prizes.
Just a thought for fun and science sake.
Will a police officer believe anything that you say after they pull you over for illegal survellience (such as driving past court houses, bridges, etc.)?
I live in a rural area of Southern England and have noticed, even without this interesting device, that my car thermometer in many winter conditions shows a one degree change in temperature when descending 100 feet over two miles from a friend’s property to mine. A completely rural trip without a suggestion of UHI. Keep going on this interesting subject.
A few thoughts.
The action of air molecules (which carry the temperature energy) are not as simple as one likes to think. I used to spray metal cases with cellulose paint in a cellar with a powerful extraction fan to the outside running, and the access door closed. Despite these precautions my wife could come home from work some time later when the fan was still running and her asthma would be set off by traces of the gases that had managed to reach the ground/first floor.
I am the first to admit that the fan wasn’t driving the air at even 30mph, but the suction round the door crevices was noticeable though the door was a poor fit.
It would seem obvious that there is a considerable energy spread in the air (and cellulose) molecules giving some of them sufficient energy to more than overcome the airflow. Nevertheless if the vehicle speed is reasonably even the effect is probably the same throughout the exercise.
It might be an idea to turn off air-conditioning systems and perhaps use a car with manual transmission so there is less heat emitted. When I get out of my car after a journey I am met by a blast of hot air from the front.
I see that sort of jump all the time on my car thermometer also. As mentioned above it depends on the relative humidity lapse rate can vary from about 3.5 deg F/1000 ft to about 5.5 deg F /1000 due to humidity. If you pass through an inversion layer the temperature step change can be much higher.
I recall while delivering news papers as teenager, it being shirt sleeve warm weather on one end of the route (early morning delivery) at about 55 deg F and bone chilling cold around 36 deg F a mile away and 200 ft lower in elevation as you passed into the cold air layer over a small river drainage.
Larry
Well, after reading those responses I’m given to wonder at the lack of humor some readers might be suffering. My ‘heavy breathing’ comments were meant in jest. But at low vehicle speeds, they ~could~ become biases. In the field of science, virtually NOTHING should be discarded without sufficient prior testing.
If you people are inclined to treat others with the same level of derision as you experience from the AGW idiots, then its no wonder that you don’t have all the support you’d like. Are you people always that trigger happy?
Now, it seems to me that a far better scheme of measurement might be to get a city to volunteer to place those data loggers at discrete intervals (light poles, anyone?) throughout that location and get the county to participate so that the suburban and rural measurements might be obtained as well.
If the devices are all placed at a specified height away from the easy reach of the curious, and the positioning is such the sun strikes them only in the early morning and late evening, OR if they are sufficiently shielded inside their own little enclosure, then a decent record of daily temperatures might be obtained.
In fact, such a scheme could well be used by cities to determine weather driven hot spots and help them to mitigate those.
In fact, Anthony, you might consider asking your readers to donate sufficient funds to get such a project started, with the added bonus that after the experiment is completed, the ones who donate to the project at the level of the price of the instruments, will be given one of the data loggers, with all others being prorated.
Heck, you could even start with a small town to get the feel for things.
The benefit here: There are fewer variables for which to have to control.
Anthony,
If grant funded this would easily be a multi million dollar study. Instead, you’ve turned it into a capitalistic idea of letting everyday folk buy this equipment and do it on their own. Great work. Of course if the Obama Administration finds out they’d find a away to attach a VAT and bring the consumer cost back to $1200.
Now if this were grant funded, I have to think it would be likely for the grantee to set it up as suggested previously (RalphieGM (04:36:59) : Good start on creating a global real-time dataset. No doubt the alarmists will mount the temperature sensors on the car’s exhaust pipe to achieve the results they expect.) to ensure being paid for the right results.
“Ecotretas (01:38:15) :
Since the data has a timestamp, it would be great to match it with GPS data. I’m sure the WUWT community would com up with a solution that could even plot it on Google maps! Just some software for merging the GPS data and your datalogger would be needed…”
Haven’t noticed if anyone else has responded, but Garmin GPS software with show datapoints directly on GoogleEarth. I use this a lot and provided you have set the GPS to the correct dataset (country specific), you get a pretty accurate plot. You can even export the data in various formats and counld combine it with the temperature data I expect.
I’ll have to get me one of these and have a play…
thanks Anthony
Once you have your army, use it well Anthony!
It’s obvious that a UHI would be the central point of a convection cell, but this cadre of data observed in rural regions would give insight to topological, wind speed, wind direction, etc. effect to convection cell magnitude and area proportionality. Truly interesting on the point of temperature station resolution of the regional temperature signal!
Best regards, suricat.
This is a good idea. It’ll take a while to build up the database, but it should give a much better basis than anything we’ve seen before.
My educated wild guess on the results: Properly handling UHI will reduce the temperature increase up to 1998 or so by a few tenths of a degree, but won’t eliminate it. That will still be significant because it will make some of the higher prediction for where the temperature will end up in forty or fifty years less viable.
One interesting idea: If there is an airport within easy transit distance, it might be worth it to drive past it. You might not be able to get close enough to detect any airport generated “UHI” and you might need to be discrete. I don’t know if airport security would get antsy about repeated transits, but it’s a possibility.
Another possibility: If air temperatures are different between city and country, would that be reflected in ground temperatures? Is there a consistent relationship between average air temperature and soil temperature at various depth? That might be complicated. Soil composition, moisture, how compacted the local soil is, and how healthy the local earthworm and soil bacteria populations are might all have an impact.
That brings up another point–which is admitted drifting OT: One of the biggest weaknesses in the CO2 –> Global Warming position is causality. Even if there is global warming and even if it is caused by human activities, that doesn’t mean that it is caused to a significant degree by CO2. Has anyone quantified the impact of human activities on the ability of soil to retain heat? On the diffusion of surface heat downward? On the diffusion of heat from the ground to the atmosphere during the winter?
Heat stored in the atmosphere is a tiny fraction of the amount stored in the ground and in the oceans, and it’s a very transient fraction. If changing farming practices somehow increased the amount of heat stored in the ground, or allowed more of the stored heat to be released, then that could be an alternate explanation for measured global warming (if there is any after UHI and measuring weirdness is accounted for).
Farming practices have definitely changed over the years. No till. More irrigation. More use of petro-based fertilizers. It would be interesting to measure the impact of that sort of thing on temperature storage capacity of the ground.
Tying this back to the topic, it would be interesting to see if transits using Anthony’s instruments could distinguish between types of rural land use. Is a no-till field cooler or warmer on average than a traditionally cultivated one? Is an irrigated field warmer of cooler than a non-irrigated one? For that matter, is there a detectable difference between crops–corn versus soybeans versus wheat? Between croplands and lands used for grazing or kept in forest? Old growth versus second-growth forest?
Lots of potential in this beyond just the urban versus rural divide.
I just did a few of the data points but got overall enthalpy change of 1J/g from urban to suburban.
DaveE.
As for clamps, how about an earthing clamp? you can get them in various sizes.
DaveE.
Forgot to say.
Enthalpy variation was circa 5%, Temp variation circa 20%
DaveE.
Must remember that both enthalpy & temp are anomolies.
DaveE.
Hi, I’ve been following the weather on home weather stations for 30 years now. My first one was a homemade heath kit: digital weather computer, still works. Over the last several years I’ve used the Davis Vantage Pro II with good success. I love following the weather and get about 24,000 hits a year from around the community on my web page. http://home.roadrunner.com/~sherwoodweather/ If you like web sites like WUWT you will love a home weather station of any sort.
Looks like fun.
Just a few questions.
1) Any elevation changes across your transect?
2) You mention that stopping the car may lead to temperature increases. It’s normal that there are more stop signals in the centre of a town than on the outskirts. How do you know you haven’t just measured the concentration of stops across the transect?
Please tell me that there is a Mac version of the software.
Also, there must be some graphic arts types who follow WUWT. How about a collaborative effort or even one creative volunteer to come up with a WUWT flag? (and logo??)
REPLY: unfortunately there isn’t, but you can likely run the software using the popular PC compatibility programs on Mac – Anthony
Please note that the ram air temperature rise while travelling at 65 mph is about 0.5 Deg C. So one would have to subtract that from readings while travelling that fast
Great job Anthony. Two ideas:
1) How much more accurate it would be to have two people drive the same course at the same time from opposite directions (assuming that traffic was light)? The drivers would pass each other twice. I think this method would allow you to do the measurement at any time of the day, and not worry about natural temperature changes. This test would help determine if a single driver is enough.
I’m thinking about getting two of these to try it if it makes sense.
2) Would there be any benefit to time a run to pass by a fixed station at it’s measuring time? You could have this scenario: Do a run into and out of the city, passing by the fixed station at various times of the day, like 7:00 am, 2:00 pm (times it will be recording). You should be able to say what UHI bias that specific station has, but not necessarily it’s microsite bias (you can’t drive that close to it).
John Finn (05:42:45) :
“The recent UK enquiry suggests I was right. The world has warmed over the past several decades. Arguing against this fact is futile.”
I’m a little confused. Who exactly is arguing that there has been no global warming at all in the past several decades? I certainly am not.
I’m sure you would agree that it is extremely important to know the amount of global warming that has actually occurred. The argument here is not about the reality of global warming. It’s about the actual amount.
The sceptical arguments about UHI seem to me to be very powerful. The way UHI has been handled – or ignored – by climate scientists and the IPCC is so bad that I hardly know where to begin. Recent research by McKitrick & Michaels showed a very strong correlation between local land use and population condition, and the local temperature record. Obviously, if the temperature record had been properly adjusted for UHI effects there should be no such correlation. If I remember correctly, they calculated that if the UHI had been properly accounted for, the average warming would only be half, at least for the last few decades.
I would also be curious to know why you thought the UK enquiry proves anything, except that most MP’s know little about climate science and can easily be misled by scientists who might be – shall we say – economical with the truth.
I seem to recall that the satellite measurements originally showed far less warming than the surface record. It was only after they had been ‘adjusted’ that they agreed, assuming that they actually do agree.
Those in charge of the satellite record vehemently deny that they calibrated the measurements against the surface record and that therefore the two records are completely independent. But I have to admit I’m a little – shall we say – sceptical about this. In climate science the word ‘independent’ has a rather different meaning, compared to what you would find in your dictionary.
At least until recently, the surface record was regarded as a gold standard, as it depended on direct temperature measurements. Of course, the satellites do have a local reference/calibration source but it’s still a huge jump to assume they can measure the surface temperature directly without some form of calibration from the surface record. One could almost argue that if they didn’t use the surface record for calibration they weren’t doing their job properly.
It would be sad if the one method of providing a reliable temperature record had been corrupted by calibration against another record that was completely unreliable.
As I said, nobody here seriously denies that global warming has occurred. Indeed, that modest warming has almost certainly been of overall benefit to mankind, just as it was in the Medieval and Roman periods, though sadly it may be coming to an end.
The warming has been noticeable in England. It was nice while it lasted, but now the winters are getting steadily colder and more unpleasent. It’s instructive to look at the CET record. It shows that the warming is completely unexceptional – there were warming trends very similar in previous centuries, and actual temperatures were also higher. CET is one of the best and longest temperature records and it shows nothing ‘unprecedented’. Of course, it raises one question: why didn’t the Met Office ‘adjust’ it to get the right answer?
Maybe they haven’t got around to adjusting it yet. But maybe they never will, given the current ‘climate’.
Chris
I am a Taxidriver in sweden, and we have experienced a cold winter.
From experince I know that winter temperatures drop 3-5 degrees in a matter of miles when travelling from a small city (20-100 thousand people) into adjacent rural areas, or forest. My thoughts have been that this phenomenon has something to do with mostly air-humidity, a greenhouse effect in essence. I have no idea where on the car the built in thermometer is fitted, close to the road I suppose.
I am now experienced enough an observer to make very good guesses, of what (higher) temperature the thermometer will read once I enter (or leave) the city by car.
A trick I use to amuse (annoy?) my customers with.
Anyway, it is great to see a more scientific approach to documenting this effect.
I wonder if someone will write an “app” for that… All the smartphones with USB ports could make the control a snap. You carry your phone with you anyway…., just keep the datalogger in the glove compartment, and you are ready to go.