|
Former Hourly Flags
|
|
|
The following is a description of hourly flags that were used prior to 1995. Historic pre 1995 hourly data are flagged using these flags. Also included are descriptions for the flags and the criteria used to test data quality.
|
|
|
1. Hourly Solar Radiation
|
|
|
Solar radiation data is flagged based on hourly extraterrestrial radiation.
|
|
|
|
Flag
|
Description
|
|
|
S
|
Measured hourly solar radiation is less than or equal to -50.00 Wm-2 (-103 Ly/day) or it is equal to or greater than 4,000.00 Wm-2 (8260 Ly/day).
|
|
R
|
The sun is more than 10 degrees above the horizon and the ratio of measured hourly solar radiation to calculated extraterrestrial radiation is greater than 1.00, and when measured, hourly solar radiation is equal to or less than 0 Wm-2.
The sun is less than 10 degrees above the horizon and the absolute value of measured hourly solar radiation is equal to or greater than 10.00 Wm-2 (21 Ly/day).
|
|
Y
|
The sun is more than 10 degrees above the horizon and the ratio of measured hourly solar radiation to calculated extraterrestrial radiation is greater than 0.85.
The sun is less than 10 degree above the horizon and the absolute value of measured hourly solar radiation is equal to or greater than 6.00 Wm-2 (124 Ly/day).
|
|
|
|
2. Hourly Net Radiation
|
|
|
Net radiation quality test is based on theoretical extremes, measured solar radiation, and air temperature.
|
|
|
|
Flag
|
Description
|
|
|
S
|
Net radiation is greater than or equal to 4,000 Wm-2 (8260 Ly/day).
|
|
R
|
The sun is more than 10 degrees above the horizon and net radiation is equal to or greater than 1.15 times the estimate (for a given value of solar radiation) of the maximum net radiation plus 30 Wm-2 (62 Ly/day).
The sun is more than 20 degrees above the horizon and one of the following conditions apply:
(1) Net radiation is equal to or greater than 1.3 times the maximum net radiation for a given value of solar radiation; or
(2) Net radiation is less than or equal to 0.6 times the estimate (for a given value of solar radiation) of a positive minimum daytime net radiation minus 30 Wm-2 (62 Ly/day).
|
|
Y
|
The sun is more than 10 degrees above the horizon and one of the following conditions apply:
(1) Net radiation is equal to or less than 0.7 times the estimate (for a given value of solar radiation) of a positive minimum daytime net radiation minus 20 Wm-2 (41 Ly/day).
(2) Net radiation is equal to or less than 1.25 times the estimate (for a given value of solar radiation) of a negative minimum daytime net radiation; and
(3) Net radiation is equal to or greater than 1.1 times the estimate (for a given value of solar radiation) of the maximum net radiation plus 20 Wm-2 (41 Ly/day).
The sun is less than 10 degrees above the horizon and either:(1) Net radiation is greater than -0.1 Wm-2 (0.21 Ly/day) or(2) Net radiation is less than 1.15 times the estimate of the minimum nighttime net radiation for a given value of solar radiation.
|
|
Q
|
Temperature or solar radiation is severe.
|
|
|
|
3. Hourly Air Temperature
|
|
|
Hourly air temperature quality test is based on extreme values.
|
|
|
|
Flag
|
Description
|
|
|
R
|
Temperature is less than -15 oC (5 oF) or greater than 60 oC (140 oF).
|
|
Y
|
Temperature is less than -10 oC (4 oF) or greater than 55 oC (131 oF).
|
|
|
|
4. Hourly Actual Vapor Pressure
|
|
|
Flag
|
Description
|
|
|
R
|
Actual vapor pressure is less than or equal to 0.00 kPa or actual vapor pressure is greater than 1.05 times the saturation vapor pressure.
|
|
Y
|
Relative humidity is less than 50 percent during an hour with 1.00 mm (0.04 in) or more of precipitation and when actual vapor pressure is 1.01 times the saturation vapor pressure.
|
|
Q
|
Air temperature or precipitation is severe (either or both are flagged R).
|
|
|
|
5. Hourly Wind Speed
|
|
|
Flag
|
Description
|
|
|
S
|
Wind speed less than 0.447 ms-1 (1 mph) or greater than 60 ms-1 (135 mph).
|
|
R
|
Wind speed is equal to or less than 0.447 ms-1 (1 mph) for three consecutive hours and the sun is at or greater than 20 degrees above the horizon.
|
|
Y
|
Wind speed is equal to or less than 0.447 ms-1 (1 mph) for two consecutive hours.
|
|
|
|
6. Hourly Precipitation
|
|
|
Precipitation data quality test is based on extreme values and daytime cloud conditions inferred from relationship between solar radiation and extraterrestrial radiation.
|
|
|
|
Flag
|
Description
|
|
|
Q
|
Solar radiation is severe.
|
|
R
|
Precipitation is negative, more than 100.00 mm, or is not a whole number.
Measured solar radiation is greater than 75 percent of calculated extraterrestrial radiation, the sun is 10 or more degrees above the horizon and the station shows recorded precipitation (i.e., precipitation is greater than 0.0).
|
|
Y
|
Measured solar radiation is greater than 65 percent of calculated extraterrestrial radiation, the sun is 10 or more degrees above the horizon and the station shows recorded precipitation.
|
|
|
|
7. Hourly Evapotranspiration
|
|
|
Flag
|
Description
|
|
|
R
|
Either net radiation, air temperature, vapor pressure, or wind speed is severe.
|
|
|
|
If you have questions, please contact the following:
|
|
Bekele Temesgen
Department of Water Resources
Office of Water Use Efficiency
P.O. Box 942836
Sacramento, CA 94236-0001
temesgen@water.ca.gov
|
|
Simon Eching
Department of Water Resources
Office of Water Use Efficiency
P.O. Box 942836
Sacramento, CA 94236-0001
seching@water.ca.gov
|
|
