| Description: | During preventative maintenance, site operations personnel observed that
soil heat flow sensor #1 at Cement, OK (E26) was outputting larger values
than the other four sensors. Therefore, they replaced sensor #1. A review
of the data indicates that the sensor was not malfunctioning, but that its
calibration was just too large. The longer the sensors are in the ground,
the greater the likelihood that they will drift from their original
calibration. The difference in the average soil heat flux caused by the #1
sensor data values being included in the average will have less than a 5%
affect on the calculated latent and sensible heat fluxes. The data should
therefore not be labelled as incorrect.
However, during the replacement of sensor #1, the #1 data was spiked,
causing the following data values to be incorrect for the period listed:
15 minute: mv_hft1 at 1945 GMT.
30 minute: shf5, c_shf5, g5, ave_shf, e, h, bowen at 2000 GMT.
The latent and sensible heat fluxes can be recalculated by using only soil
heat flows 2 through 5 to calculate the average soil heat flow,
ave_shf = (g2 + g3 + g4 + g5)/4
e = -(q + ave_shf)/(1 + bowen)
h = -(e + ave_shf + q). |