My 2011 experiment of comparing the Urban Heat Island (UHI) in my region is proceeding and the very interesting summer results are starting to show up. The results are pretty clear that urban areas do impact the anomaly data for an area and using such contaminated data will give a false warming bias that is not being properly accounted for in the temperature records. Feel free to review the earlier articles on this.
The two temperature records continue to show that they are in fact comparable for weather. Warming and cooling fronts reach both places nearly simultaneously. In this manner weather is removed as a variable for the two locations leaving only the warming and cooling that take place each day.
One of the main reasons I am breaking the year down in the way that I am is to really show the difference between temperature anomaly data and temperature data. It also highlights the issue related to the Urban Heat Island (UHI) effect. I have been comparing the temperature of Boise, Idaho to that of McCall, Idaho. The two places are ~100 miles apart and share the same weather. A warm front will cause both places to warm up and a cold front the reverse. This is easily shown in the daily temperature data for both locations year to date.
Posted July 1st, 2011. 3 comments
In the Northwestern US 2011 has not been a fun year. At least it hasn’t been if you want to be outside enjoying the weather. I have been tracking the temperature and the anomaly for two locations. One is the urban Boise, Idaho area and the other is a low impact, non urban area. This is a good way to show the Urban Heat Island effect and to also show how daily temperature data is converted into sterile anomaly data.
One reason people are unhappy around here with the weather is that it has not been warm. So far in 2011 there have been 2 days over 25 °C. As recently as a couple of days ago the high temperature was 11 °C. McCall has not even had it that nice as it has had only two days this year above 20 °C. Here are the daily temperatures as calculated in the same manner as used to determine the station data.
Earlier this week I was commenting on the very cool spring that Boise has been experiencing. Living in Boise I happen to know how built up the area has become over the past 20 years. That it is in a valley as well only makes the potential Urban Heat Island effect even greater. I have often wondered how much of the warming that Boise experiencing is due to the change in the area. Since I had done the analysis for Boise already, I decided to compare it to a region that was close area that was not an urban or agricultural area.
McCall is even a little town, but having been there plenty of times I know that it isn’t very built up, at least not yet. It is a higher altitude that Boise so the temperatures are lower, but this is where anomaly is once again useful. The locations are near enough that major storm systems will effect both places in a similar manner, but a difference in the anomaly could be an indication of the UHI.
Posted April 27th, 2011. 1 comment