Saturday, July 23, 2011

West Virginia combined temperatures

This series, which has been looking at the temperatures of the different states around the country, is now beginning to approach an initial end, as I look at the data for West Virginia, which IIRC is the last state to complete that does not border on the Atlantic. (Foregoing for the moment looking at Alaska and Hawaii) West Virginia comes after looking at a few states along that littoral, ending last week with North Carolina. One of the features that was clear in those states was that there was a significant drop in temperature around 1950, while on the other side of the mountains, there were a number of states where the temperature has been falling since 1900. It will be interesting to see which of these categories West Virginia falls into.

There are thirteen USHCN stations in West Virginia, and three GISS stations on the list, Beckley which only carried data from 1951, Charleston which only has data from 1949, and Huntington which also only has data since 1948.

Location if the USHCN stations in West Virginia (CDIAC )

In passing it is interesting to note that this is the second week that those going to the USHCN site are faced with this comment:
PLEASE NOTE: CDIAC is currently experiencing hardware/software issues that are affecting the performance of the USHCN web interface.

We hope to have these issues resolved shortly. Accessing data via the FTP area is working normally. We appreciate your patience and understanding. (7/14/2011
)
And when I try and access data for the different stations, I cannot. However, having had similar trouble earlier in the summer (starting when I was working on Arkansas in April. That hiatus lasted through Louisiana but was cleared up by the time I got to Wisconsin so that the site was down for about three weeks. This time I had already acquired the West Virginia data, and so the post can proceed.

Taking a quick look at the GISS stations, it is, of course, now no longer possible to see the temperatures in the 1930’s when, until recently, it was recognized that the USA had it’s highest temperatures. Nor is it as easy to monitor for this state the transition from the possible rising temperatures pre-1950 to the possibly falling ones of the 50’s and 60’s.

Temperature change with time for Beckley WV as recorded at the GISS station

Temperature change with time for Charleston WV as recorded at the GISS station

There is a drop in temperature for this station, which is more distinct than that for Beckley.

Temperature change with time for Huntington WV as recorded at the GISS station

This shows more clearly the peak and fall of temperature until about 1965, followed by a weak rise which we have seen in the states to the South along the Atlantic.

Looking at the average USHCN temperatures, using the homogenized data set, there is relatively little temperature change for the state over the century, though the drop and then recovery of temperatures shown in the GISS data also holds for this series.

Average temperature in the state of West Virginia since 1895 using the homogenized temperatures from the USHCN.

The temperature rise in that time has been 0.04 degrees per century, which is hardly significant. Looking at the Time of Observation corrected raw data for the state:

Average temperature in the state of West Virginia since 1895 using the raw temperatures modified to account for the time of observation, from the USHCN.

West Virginia is 240 miles long and 130 miles wide, running from 77.67 deg W to 82.67 deg W, and from 37.17 deg N to 40.67 deg N. The mean latitude is 38.6 deg W, that of the USHCN stations is 38.8 deg N, and that of the GISS stations is at 38.17 deg N. The highest point in West Virginia is at 1,482 m at Spruce Knob, while the lowest is at 73 m on the Potomac. The average elevation is at 457.2 m. The average elevation of the USHCN stations is 369.8 m, while that of the GISS stations is 364.8 m.

All the stations save Pickens WV were in the citi-data set, for Pickens which was too small, I had to get the population (125) from Zip-codes.com.

Looking at the effect of geography on temperature for the state:

The effect of station latitude on temperature in West Virginia

Looking at the effect of longitude, as I have mentioned several times earlier, this is an artifact of elevation changes, included now only for completeness.

The effect of station longitude on temperature in West Virginia

As one sees the temperature, which fell with longitude on the other side of the mountains, now rises with longitude as the mountains reduce in size to the west. The correlation is with elevation:

The effect of station elevation on temperature in West Virginia.

Looking at population, the GISS stations, as is the apparent custom in the states around the Union, are located in cities with the largest population of the stations recorded for the state. The average population is 38,718, while the population around the USHCN stations is 9,872. (That would make a difference of perhaps 0.6 deg F). As a reminder the citi-data information on population is relatively recent, and I have correlated it with the average of the temperature at the stations over the past 5-years.

The effect of adjacent population on the station temperature in West Virginia.

Finally a look at the effect that homogenization of the data has on the average values:

Changes in average station temperature as a result of homogenizing the data.

The impact is focused around 1955, before then the homogenization increasingly added temperatures the further from that date, and similarly from that time forward. Wonder why?

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