Thursday, April 19, 2012

Thayne Elementary Weather Station

A Davis Weather Station was installed  at Thayne Elementary School in September 2010 and has been transmitting data since 3pm  September 22, 2010.  There has been only one interruption of data from the station which occurred from September 28,2011 until October 25, 2011.  On August 15, 2011 the sensors for both soil temperature and moisture were added to the station.

Here are some interesting graphs of some of the data thus far from the station.  Though not able to grab more than a year at a time, this first image is the daily maximum and minimum temperature for the first 12 months:




Thayne Elementary max and min temps from September 2010 to August 2011
and the most recent twelve months:

Thayne Elementary max and min temps from May 2011 to April 2012

For the short history of the station, the highest observed temperature was 94F on August 26, 2011.  The coldest occurred on February 2, 2011 when -30F was observed.  The coldest this past winter also occurred in 2011 when  -15F was hit on December 23rd.

The winter of 2010-2011 saw the temperature dip below zero on 28 days  This past winter there were 40 days  below zero.  December 2011 was particularly cold when 20 days dipped below zero.

In 2011, the first full summer of observations, there were only 6 days when the temperature exceeded 90F.

The highest wind gust thus far observed was 54 mph at 6pm, June 29,2011.

It is interesting to look at the data which has been collected with the soil moisture and temperature sensors since they were installed last August.

The first temperature sensor is located just below the surface on the school  grounds with the  2nd sensor buried at a depth of one foot and the third at 2 feet.

When looking at the sensor located just below the surface, it is surprising to see the large range of temperatures on particularly sunny days.

Near surface Thayne Elementary  temperature
There were a couple days around 100F last September and even above 80F already this spring.

However the 1 foot and 2 foot sensors tell a much different story with both dropping to freezing early in January and remaining there until the last week in March.

Thayne Soil Temperature at a depth of one foot


Thayne Soil Temperature at a depth of two feet.
The moisture sensor thus far indicates fairly high soil moisture content

Thayne 1 foot soil moisture content in centibars
The current reading of 10 centibars is a very moist soil.  It will be interesting to see how this sensor responds during summer  It can be observed any time on line at
 http://www.weatherlink.com/user/thayne/index.php?view=summary&headers=1

For additional information (as to what this measurement suggests) the following  is helpful:

General rule of thumb for interpretation:
Soil moisture is nearing a critically dry level when soil tension (indicated by the centibar meter reading) reaches a level that corresponds to more than 50 percent depletion of the plant available water at a specific soil depth.  The critical soil  tension level that corresponds with 50 percent depletion levels will vary depending upon soil type because of different soil porosity characteristics..   For example, a soil  tension reading of 35 centibars may indicate that a very sandy soil will approach 50 percent depletion of plant available soil moisture but for a loam/silt loam soil 50 percent depletion may  not be approached until tension readings approach 110 to 130 centibars.

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