Subject: | SGP/SIRS/E9 - PSP dome contamination |
DataStreams: | sgpsirs20sE9.a0, sgpsirsE9.00, sgpsirsE9.b1
|
Description: | Measured values of diffuse shortwave downwelling radiation fluctuated below derived values
of downwelling shortwave radiation by 50 W/m^2 during the afternoon hours under clear
conditions.
SMOS precipitation and wind speed data reveals rain and wind the night before on 02/20/03
0100 GMT probably contaminated the PSP dome with dirt.
Precipitation of .25mm on 02/23/04 0300 seems to have effectively cleared the PSP dome
since PSP data on 02/24/04 compares correctly to direct and diffuse components. |
Measurements: | sgpsirs20sE9.a0:
sgpsirsE9.b1: - Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
- Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
- Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
- down_short_hemisp_std
sgpsirsE9.00: - Raw data stream - documentation not supported
|
Subject: | SGP/SIRS/E9 - Unknown -failed PSP ventilator fan |
DataStreams: | sgpsirs20sE9.a0, sgpsirsE9.00, sgpsirsE9.b1
|
Description: | Downwelling shortwave hemispheric (DSH) readings appear to have a slight to moderate
negative offset from derived DSH values. At night, this negative offset causes qc flags
(since values are below the minimum threshold of -10 W/m^2). Differences between derived and
actual DSH values are sometimes on the order of 50 W/m^2 due to this offset.
The offset was discovered to be due to a failed ventilator fan which is used to clear the
dome of the PSP, the instrument which measures the DSH. The ventilator likely seized or
was intermittent and heated the PSP base giving an erroneous DSH reading. Field techs
replaced the fan on 01/25/2005 1745GMT. The DSH has been reading normally since that time. |
Measurements: | sgpsirs20sE9.a0:
sgpsirsE9.b1: - Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Minima(down_short_hemisp_min)
- Downwelling Shortwave Hemispheric Irradiance, Ventilated Pyranometer, Maxima(down_short_hemisp_max)
- Radiation, shortwave, downwelling total hemispheric irradiance, 1-min avg(down_short_hemisp)
- down_short_hemisp_std
sgpsirsE9.00: - Raw data stream - documentation not supported
|