I just finished testing and putting together my road kit, as seen above. Can anyone guess what it is for?
UPDATE:
Ok I think I have enough guesses. “Coyote” nailed it pretty well. Good job Warren. The road kit is packaged for getting on an airplane, hopefully I’ll be able to explain it well enough to pass airport security. I’m going to give myself an extra hour just in case they think its a “Eludium Pu-36 Explosive Space Modulator” as Robert Coté points out 😉 in comments.
It’s a UHI transect kit. I got the idea at Pielke’s August conference on land use changes. There were a couple of UHI studies presented there, both using data from existing static weather stations. The idea gelled after some observations of my vehicle air temp thermometer while crossing Denver headed to the airport returning from a station survey the next evening.
My experiment plan is this; by simultaneously logging temperature data and GPS readings on my laptop, I’ll be able the create a transect line. The Gill shield has a custom window clip which allows me to mount on the passenger window. The shield will be “aspirated” by driving. Should I have to stop for a signal. the GPS data will indicate a pause, and any temp data from that spot due to heat from the vehicle or others nearby can be excluded.
The temperature sensor and A/D converter for it both have NIST calibration, making them far better than the accuracy of an MMTS, but with the same resolution, 0.1°F.
The reason for the setup now is that I’m heading to Indianapolis next week, which was one of the cities presented in a study at Pielke’s conference. Plus that, Indianapolis is nearly perfectly flat and has transect roads that match the cardinal compass points.
According to Parker 2006, “The main impact of any urban warming is expected to be on Tmin on calm nights (Johnson et al. 1991)” so that’s what I’ll be testing. Hopefully the weather will cooperate.
Coyote brings up a valid point about “I can’t figure how you deal with the time delay issue between readings.” which I assume to mean the overall atmospheric deltaT between the start of the transect and the end. I’m hoping that at night, with little traffic, I’ll be able to drive fast enough to minimize this. I expect that the deltaT of the transect itself will be larger than the deltaT for the time it takes to drive the transect. We’ll see. Also, I should be able to determine the deltaT for the city atmosphere for the time it takes to drive the transect from the static weather stations around the city. My guess is I’ll be able to transect the city in less than 30 minutes. I used to live near there, and knowing the city and it’s roads, I believe it’s possible.
If I do it late enough at night, say after midnight, I should be able to minimize waste heat contributions from other vehicle wakes ahead of me.
I welcome ideas and suggestions. I’m sure the usual folks will “pooh pooh” the idea, but with the help of my readers, perhaps I can minimize the weak points of the experiment.
Earle,
I have it covered, there are multitudes of private weather stations in the area in addition to the official NWS readings, graphs of temp/dewp are available here:
http://www.wunderground.com/stationmaps/gmap.asp?zip=46201&magic=1&wmo=99999
and here’s a sample of individual station data,
http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KINFRANK4
they even have a comma delimited file output option at the bottom of the tabular data.
Mosh thanks for the link to the paper, nice to have precedence.
On the topic of reference stations, while the other private weather stations are good to have, what’s really needed is one of known character at each end of the transect, plus possibly one in the middle.
I’m working on a battery powered temperature logger with integrated radiation shield, that has a port to download data…should be ready in a couple of weeks.
The cost will be low enough that others can do UHI transects too, as the unit can serve as reference as well as moble station. It will be small enough to simply position on a lightweight piece of PVC or a rod pushed into ground to get a standard observing height of 1.5 meter.
Great to hear you’ve got the local data well covered. I think the methodology you describe with a data logger at each end (or a route that goes from one local weather monitoring station to another) allows you to completely remove the temporal variation. I’m already thinking about how you could interpolate the delta T as a function of distance between endpoints.
This will give you a temperature profile that will have short-term time effects removed. There is still an underlying temporal component having to do with the time of day as well as the season. It would be interesting to conduct these transects on a frequent basis throughout the year, at different times of day, to see how the profile varies.
If you’re planning on trying multiple transects, I suggest you identify what it is you wish to further nail down. Is it to create a map of the UHI? Or is it to observe how the UHI changes between the temperature high and low? If you wish to map the UHI you should limit the variables by running transects at approximately the same time every day. And of course if you’re measuring the range of UHI it should be done over the same transect at different times of day.
I just checked out the Meridian Hills station at http://www.wunderground.com/weatherstation/WXDailyHistory.asp?ID=KININDIA18 and I see it captures local wind data too. Man oh man, you could have baseline data for a city and on a particularly windy day run a few transects and you could easily test Parker’s hypothesis about UHI and wind. Indianapolis looks like a great place to test that theory out, as there doesn’t appear to be any confounding water bodies or extended urban development in the surrounding area.
Ah, science! Thanks Anthony for reviving my excitement, what with all the possibilities this test of yours brings with it. If your road kit is affordable enough, you may need to be establishing surfacetransects.org as well!
http://www.bioone.org/perlserv/?request=get-document&doi=10.2181%2F1533-6085(2006)38%5B77%3AURARCC%5D2.0.CO%3B2&ct=1
http://www.bioone.org/perlserv/?request=get-document&doi=10.2181%2F1533-6085(2005)038%5B0029%3AAOTUHI%5D2.0.CO%3B2
http://ams.confex.com/ams/AFAPURBBIO/techprogram/paper_79115.htm
( have a look at the infrared stuff)
http://asusmart.com/flash/presentations/golden_cool_pavements_2.swf
AND my favorite project: Bubble
http://pages.unibas.ch/geo/mcr/Projects/BUBBLE/textpages/md_tracer.en.htm
Boundary layers and wind in an urban enviroment
http://pages.unibas.ch/geo/mcr/Projects/BUBBLE/textpages/md_windtunnel.en.htm
Last one:
http://pages.unibas.ch/geo/mcr/Projects/BUBBLE/images/plots/t1_energy.gif
Wind and temperature: VERY COOL.
http://pages.unibas.ch/geo/mcr/Projects/BUBBLE/images/plots/t5_meteo.gif
NOTE anthony, Parker did not define “windy” in terms of velocity. I’ll explain if you like.
[…] Well I decided to test this myself tonight, since I’m driving through Reno on my return home, I arranged an overnight stay. With me is my NIST calibrated data logger, NIST Calibrated temperature probe, a vehicle mounted Gill IR shield, my laptop computer, and my trusty vehicle. See my previous post “Road Kit“ […]
I just bought a high speed data logger from dataq.com. They have 10 bit 8 channel units ±10VDC inputs + digital I/O & software for $50, for recording up to 240Hz, overkill for the application but you can slow down the sample rate. I got the one that will do 14400Hz sample rate 4 channels ($350)
You’d have to run an instrument that you can force to have 0-10VDC outputs, but that could be done with a regular old temperature controller with analog outputs. Not sure if it’s right for the application, but with some tinkering could probably be calibrated properly for useful measurements of temperature. And it would sure be fun! Quakemap.com has great software for downloading your track data from your gps onto maps and / or into excel… Definitely worth the $10 license.
http://www.dataq.com/products/startkit/di148.htm
I’ve had lots of fun tracking stuff like this but it’s usually with some other type of sensor, though I measure a lot of temperature too, but have never done mobile measurements. There are other USB temperature recorders out there also with maybe 1 second sampling rates, though probably not traceable to NIST for the cheap ones… Have fun!
Mike S.