Certain instruments are located at every Mesonet
site to measure the standard-primary variables. These variables
are as follows:
- air temperature measured at 1.5 meters above the ground,
- relative humidity measured at 1.5 meters above the ground,
- wind speed and direction measured at 10 meters above the
ground,
- barometric pressure,
- rainfall,
- incoming solar radiation, and
- soil temperatures at 10 centimeters below the ground under
both the natural sod cover and bare soil.
Additional instruments are placed at most sites to measure
standard-secondary variables. These include the following:
- air temperature at 9 meters above the ground,
- wind speed at 2 and 9 meters above the ground,
- soil moisture at 5, 25, and, 60 centimeters below
the ground,
- soil temperatures at 5 and 30 centimeters below the ground
under the natural sod cover, and
- soil temperature at 5 centimeters below the bare ground.
All above-ground measurements are sampled every 3 s and with
the exception of the barometer (which is 12 s) and the rain gauge
(which is event driven). The above ground measurements are averaged
over 5 min. Soil temperature measurements are sampled every
30 s and averaged into 15-min observations. Soil moisture is
sampled once every 30 min. Every 5 minutes, all available observations
are sent from the site to the Central Operations Facility in
Norman. |
