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| Air Temperature: |
A measure of the average kinetic energy of air
molecules at 2 meters (~6 feet) above the surface. |
| Soil Temperature: |
A measure of the average kinetic energy of air molecules
immediately below the surface. Typically varies much less than air temperature. |
| Relative Humidity: |
A measure of the amount
of water vapor in air compared with the amount of water vapor at saturation
(100%). Range between 0 to 100%. |
| Barometric Pressure: |
A measure of the force exerted on the surface by the
overlying air adjusted to sea level elevation. Typical range 950 to 1050
mBar (approximately 1000 mBar equals standard atmospheric pressure). Higher
pressures normally indicate fair weather and lower pressures stormy weather. |
| Wind Speed: |
Average
velocity of the atmosphere over a 5 minute period measured in miles per
hour. |
| Wind Direction: |
The direction in which the wind is coming from measured
in the degrees of a compass (N = 0 degrees, E = 90 degrees, S = 180 degrees,
and W = 270 degrees). |
| Rainfall: |
Liquid equivalent precipitation that
has been recorded over the last 15 minutes. |
| Solar Flux Density: |
The quantity of solar radiation that strikes a square
meter measured at the end of the five minute collection interval. |
| Total Solar Flux: |
The quantity of solar radiation accumulated
during the entire data collection interval. |
| Dew Point Temperature: |
The theoretical
temperature at which water vapor will begin to condense from the atmosphere.
When air temperature = dew point
temperature the relative humidity = 100%. For more information please consult
: (http://meted.ucar.edu/awips/validate/dewpnt.htm). |
| Wet Bulb Temperature: |
The
lowest temperature that can be obtained by evaporating water into air
at a given constant pressure. Wet
bulb temperature lies somewhere between dry bulb temperature (air temperature)
and dew point temperature. For more information please consult: (http://meted.ucar.edu/awips/validate/dewpnt.htm). |
| Heat Index: |
Is the
apparent temperature and is a measure of how hot the atmosphere feels
when relative humidity is added to the actual air
temperature. Valid only when air temperature is greater than 80 degrees F and
relative humidity is greater than 40%. |
| Wind Run: |
Is
the total distance that the wind has traveled during a particular time
in a particular direction. |
| Wind Gust: |
Maximum instantaneous velocity of the atmosphere measure
over a 5 minute period. |
| Rainfall
(since midnight): |
Liquid equivalent precipitation that
has been recorded since the previous midnight. |
| Rainfall Intensity (15m): |
Liquid equivalent precipitation rate in inches per hour
determined based on the last 15 minutes of precipitation. |
| Hourly Evapotranspiration: |
Hourly crop referenced evapotranspiration
calculated by the Penman-Montheith equation using the measurements of wind
speed, air and soil temperature, relative humidity, and solar radiation. |
| Daily Evapotranspiration: |
Is a progressive summation of hourly evapotranspiration
values. |
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Daily evapotranspiration is a value that can be used to
determine plant irrigation water needs.
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