TWP/C1/GNDRAD Net Radiometer: Cracked dome

A crack in the up-looking radiometer dome was discovered on 970227.
It is not known how long the dome was cracked.  The dome was replaced
with a spare, out of calibration unit, on 970227.  There was not an
obvious change in the instrument performance when the instrument was
replaced.

• net_max
• net_min
• net_sd
• net_mean

• net_max
• net_min
• net_sd
• net_mean

TWP/GNDRAD/C1 - Net Radiometer: Correction for negative net fluxes

The Net radiometer seems to have a calibration problem and a poor
cosine response.  The Net radiometer consistently measures low
relative to Net surface irradiance calculated from the SKYRAD and
GNDRAD Eppleys around local noon.  The relative discrepancy changes
rapidly with sun angle and the two streams typically cross in
mid-morning and mid-afternoon beyond which the Net radiometer reads
high relative to the Eppleys.

The net radiometer typically reports postive values for the net flux
during the day and negative values at night.  There are actually
different calibration coefficients that must be applied for positive
and negative fluxes.  Currently, all data are processed by applying the
positive flux coefficient.  Consequently, the negative values are in
error.  The net flux, F, is obtained by simply applying the formula F =
C*V where V is the measured voltage and C is the calibration factor.
Therefore, negative fluxes can be corrected by multiplying the
fluxes by the ratio of the negative calibration factor, C_neg to the
postive factor C_pos, so the corrected flux for negative values is
equal to F_neg = F*C_neg/C_pos where F is the flux value reported in
the data files.  Through 970227, the values for these calibration
factors are F_pos = 9.26 and F_neg = 11.43.  After 970227, the
calibration factors are F_pos = 9.33 and F_neg = 11.6.

• net_max
• net_min
• net_sd
• net_mean

• net_max
• net_min
• net_sd
• net_mean

TWP/GNDRAD/C1 - PIR: Incorrect wiring

Data from the GNDRAD PIR is not valid for this period because of an
incorrect connection to the data logger.  Collection of good data 
from the PIR resumed on 970227 at 07Z.

• pir1_mean
• pir1_max
• pir1_min
• pir1_sd

• pir1_sd
• pir1_max
• pir1_mean
• pir1_min

• pir1_voltage
• pir1_dome_therm
• pir1_case_therm

TWP/GNDRAD/C1 - PIR and IRT: surface temperature comparison

The GNDRAD continues to look nominally OK. The daily average irradiances
are about what is expected. The comparison of the downward facing IRT and
the calculated brightness temperature from the downward facing PIR show
agreement within and average of about 0.5O C. About 19981206, the daily
average agreement suddenly seems to have gotten better. We should note
to monitor this in the next data package.

• irt1_min
• irt1_mean
• pir1_mean
• pir1_max
• pir1_min
• irt1_sd
• pir1_sd
• irt1_max

• irt1_min
• irt1_max
• pir1_sd
• pir1_mean
• irt1_mean
• pir1_min
• pir1_max
• irt1_sd

• pir1_voltage
• pir1_case_therm
• pir1_dome_therm

TWP/GNDRAD/C1 - PIR: Extended data gap

The lines to the GNDRAD data logger were cut on December 2, 1996 at
approximately 1400 GMT.  No data was collected from GNDRAD until the
lines were reconnected on December 12 at approximately 0200 GMT.  The
PIR was not reconnected properly, however, and data flow from that
instrument did not resume until a RESET visit in February.  Data flow
for the PIR resumed on February 28, 1997.  The IRT and Net radiometer
appear to be operating as before, but without the downlooking PIR, we
cannot perform any internal tests.

• pir1_mean
• pir1_max
• pir1_min
• pir1_sd

• pir1_sd
• pir1_max
• pir1_mean
• pir1_min

• pir1_voltage
• pir1_dome_therm
• pir1_case_therm

TWP/GNDRAD/C1 - PSP: Comparison test

The GNDRAD PSP was turned upside-down for comparison with the SKYRAD
PSPs.

• psp1_max
• psp1_mean
• psp1_sd
• psp1_min

• psp1_mean
• psp1_sd
• psp1_min
• psp1_max

TWP/GNDRAD/C1 - Extended data gap

The lines to the GNDRAD data logger were cut on December 2, 1996 at
approximately 1400 GMT.  No data was collected from GNDRAD until the
lines were reconnected on December 12 at approximately 0200 GMT.

• alt
• lat
• external_voltage
• filename
• psp1_max
• pir1_mean
• net_min
• net_max
• pir1_max
• pir1_min
• psp1_sd
• irt1_max
• base_time
• irt1_min
• net_sd
• psp1_mean
• irt1_mean
• irt1_sd
• pir1_sd
• net_mean
• logger_temp
• time_offset
• bit_data
• internal_voltage
• lon
• psp1_min

• net_max
• lon
• irt1_max
• net_sd
• pir1_min
• psp1_mean
• alt
• net_mean
• time_offset
• base_time
• irt1_min
• logger_temp
• net_min
• irt1_mean
• lat
• irt1_sd
• pir1_sd
• pir1_mean
• pir1_max
• bit_data
• psp1_min
• external_voltage
• psp1_sd
• filename
• internal_voltage
• psp1_max

• pir1_voltage
• pir1_dome_therm
• lat
• time_offset
• alt
• base_time
• pir1_case_therm
• lon
• filename

TWP/GNDRAD/C1 - GNDRAD radiometer replacement

The GNDRAD radiometers were replaced 10/25/01 from 00:00 to 01:00.

• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• up_long_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)

• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• up_short_hemisp_std
• up_long_hemisp_std

TWP/C1 - Incorrect elevation reported in Manus Data

(From Bill Clements) We have been using 6m MSL as the station
elevation of Momote (Manus).  This was based on information
posted near the station barometer in the Momote Weather Service
Office.  It turns out that the official WMO station elevation
for Momote is 4m MSL and the upper air elevation is 5m MSL.

All Manus instruments except the sonde station are at 4m MSL.
The sonde launching station is at 5m MSL.

• alt

• alt

• alt

• alt

• alt

TWP/GNDRAD/C1 - RESET 14 activities

RESET14 activities may have affected data in in subtle ways during this
period.

• Effective Surface (Skin) Temperature(sfc_ir_temp)
• up_short_hemisp_std
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• net_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• net
• net_min
• sfc_ir_temp_std
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• up_long_hemisp_std
• net_max
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)

• net_max
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Maxima(up_short_hemisp_max)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)
• Radiation, shortwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_short_hemisp)
• net_mean
• net_std
• up_long_hemisp_std
• Surface Infra-Red Temperature Maxima(sfc_ir_temp_max)
• net_min
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Upwelling Shortwave Hemispheric Irradiance, Unventilated Pyranometer, Minima(up_short_hemisp_min)
• up_short_hemisp_std
• sfc_ir_temp_std
• Surface Infra-Red Temperature Minima(sfc_ir_temp_min)
• Effective Surface (Skin) Temperature(sfc_ir_temp)

• inst_up_long_dome_resist
• inst_up_long_hemisp_tp
• inst_up_long_case_resist

TWP/GNDRAD/C1 - Incorrect dome calibration factor

The Manus GNDRAD PIR had an incorrect dome factor since installation.  The following is an 
estimate by Chris Cornwall of the magnitude of the effect of this calibration error. The 
magnitude of this error is smaller than the calibration accuracy.

"Processed the instantaneous data from ARCS2 (10, 30 and 50 seconds after the minute) 
using 4.32 as the dome factor, and also using 4.00 as the dome factor, as it should have 
been. The difference between the calculated irradiance results was negligible, as was 
expected with an instrument operating in the downward-facing direction.

Over the three days from 11/06/98 to 11/08/98, the error between the two signals averaged 
0.09%.  Overnight values were much lower than this, daytime values peaked at 0.42%. The 
statistics for these error signals were as follows:
  average error 0.000895
  standard dev  0.001119
  max error     0.004242
  min error    -0.00064

We should change ARCS1 so it is using the correct value for the groundrad pir dome 
coefficient (4.0 instead of 4.32), and we may want to include a DQR stating these findings, 
although they are much smaller than the overall uncertainty of the PIR itself."

• up_long_hemisp_std
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Minima(up_long_hemisp_min)
• Radiation, longwave, at 10-m height, upwelling hemispheric irrad., 1-min avg(up_long_hemisp)
• Upwelling Longwave Hemispheric Irradiance, Unventilated Pyrgeometer, Maxima(up_long_hemisp_max)

• pir1_sd
• pir1_max
• pir1_mean
• pir1_min

• pir1_voltage
• pir1_dome_therm
• pir1_case_therm