HFE/MWR/M1 - Insufficient calibration stability

The noise diode temperature suddenly jumped to > 60 C after a power outage. Following 
additional power problems the noise diode injection temperature drifted fast and the 
radiometer was not able to calibrate properly.

Data during the indicated time periods are poorly calibrated and sometimes erratic. Users 
should be aware that the accuracy of the measurements is dramatically degraded. 

Users can use the microwave profiler (MWRP) data to supplement the MWR data.

• tc23
• Total water vapor along LOS path(vap)
• tnd31
• tc31
• tknd
• tnd_nom31
• tkxc
• 31.4 GHz sky brightness temperature(tbsky31)
• Total liquid water along LOS path(liq)
• tnd23
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• tnd_nom23

• tbsky31tip
• tc31
• tnd23
• tnd_nom23
• tnd23I
• tnd31I
• tbsky23tip
• tc23
• tkxc
• tnd_nom31
• tknd
• tnd31
• liqtip
• vaptip

HFE/MWRHF/M1 - 150-GHz data drop out

The sky brightness temperature at 150 GHz (tbsky150) dropped to zero at 12:29 GMT on 
20080804 and stayed flat lined until 23:40 GMT on 20081002.

• Sky brightness temperature (150 GHz)(tbsky150)

HFE/MWRHF/M1 - Frosting/Condensation

The heater module was installed on 6/4/2008. Before this time there is condensation on the 
window during night time and early morning. On 8/18 the heater appears to have failed 
and nighttime condensation re-occurred on the radome during conditions of high humidity.

Users can identify the segments affected by observing a smooth steady increase in the 
brightness temperature (BT). BT values can increase to more than 250 K and then smoothly 
decrease. The RH during these events is usually above 70%. Users should disregard data 
affected by condensation.

• Sky brightness temperature (90 GHz)(tbsky90)
• Sky brightness temperature (150 GHz)(tbsky150)

HFE/MWRHF/M1 - Calibration updates

The MWRHF calibration algorithm updates the calibration parameters every time a new 
successful tip curve is acquired. 

This results in small jumps (1-2 K) in the brightness temperatures each time calibration 
is updated. During times of frequent calibrations the data appear discontinuous with short 
data segments interrupted by small jumps.

• Sky brightness temperature (90 GHz)(tbsky90)
• Sky brightness temperature (150 GHz)(tbsky150)

HFE/MWRHF/M1 - Rain sensor failure

The rain sensor failed and the rain flag was always on.  When the rain flag is on the 
radiometer does not perform tip curves. The rain sensor was replaced 8/4.

• Rain flag(rain_flag)

HFE/MWRP/M1 - Reprocess: Bias in LWP retrievals

Since local radiosondes were not available, radiosondes from a different site were used to 
develop retrieval coefficients. LWP retrievals are biased in the summer months 
(June-September).  Data in May and December are not affected.

Additional analysis will be conducted to derive new retrieval coefficients and the data 
will be reprocessed.

• Liquid water path, from Tbright at 23.835 and 30.0 GHz only, using stat. retrvl.(liquidWaterPath2)
• Liquid water path, from brightness temperatures using statistical retrieval(liquidWaterPath)

HFE/NFOV/M1 - Over-ranging data

The instrument was incorrectly installed with an incorrect range setting in the logger 
program.  The program for lamp calibrating the instrument was used, and not the operational 
program. The scale ranges are different, and this resulted in over-ranging conditions 
when the signal exceeded the upper end of the measurement scale.  Affected times are 
centered around solar noon, nominally +/- one-hour around solar noon.  This lasted until 
mid-Aug, when the highest signals were no longer exceeding the logger range.

• raw_counts_673nm
• raw_counts_870nm
• Calibrated Zenith Radiance, 673nm(radiance_673nm)
• Calibrated Zenith Radiance, 870nm(radiance_870nm)

HFE/MWRHF/M1 - Elevated noise in 150 GHz data

The noise level of the 150 GHz channel was about 4 times higher than expected, likely due 
to failure of the noise diode.  Disregard the 150 GHz data.

• Sky brightness temperature (150 GHz)(tbsky150)

HFE/MWR/M1 - Missing data

Data are missing and unrecoverable.

• bb23
• tnd31
• time_offset
• tkxc
• alt
• 31.4 GHz sky brightness temperature(tbsky31)
• bb31
• tnd23
• Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
• wet_window
• tnd_nom23
• tc23
• tkbb
• sky23
• bbn23
• Total water vapor along LOS path(vap)
• tc31
• tknd
• tkair
• tnd_nom31
• bbn31
• lat
• Total liquid water along LOS path(liq)
• base_time
• lon
• sky31
• time
• IR Brightness Temperature(sky_ir_temp)

• tipsky31
• bb23
• base_time
• tc31
• tnd31I
• lon
• time_offset
• bb31
• tipsky23
• tbsky23tip
• tc23
• tkair
• wet_window
• tbsky31tip
• r31
• tnd23
• tnd_nom23
• lat
• time
• tnd23I
• actaz
• bbn31
• alt
• r23
• tnd_nom31
• tkxc
• actel
• tknd
• tkbb
• tnd31
• liqtip
• vaptip
• bbn23

HFE/AOS/M1 - Data processing problem

The AOS data was reprocessed for the AMF, SGP and NSA sites. There was an error in the 
processing of the corrections for the PSAP absorption signal such that a low pass filter was 
implemented for the scattering data used in these corrections.The difference between the 
corrected and previous data is < 0.05 Mm-1 (below the instrument detection limit) and 
should not have a significant effect on the previous data. Data will be reprocessed at a 
later time when more significant changes to the data processing are implemented.

• Absorption Coefficient Blue, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_B_Dry_1um_PSAP3W_1)
• Absorption Coefficient Red, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_R_Dry_1um_PSAP3W_1)
• Absorption Coefficient Red, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_R_Dry_10um_PSAP3W_1)
• Aerosol light absorption coefficient, green channel, 10 um particle diameter(Ba_G_Dry_10um_PSAP1W_1)
• Absorption Coefficient Green, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_G_Dry_1um_PSAP3W_1)
• Absorption Coefficient Green, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_G_Dry_10um_PSAP3W_1)
• Aerosol light absorption coefficient, green channel, 1 um particle diameter(Ba_G_Dry_1um_PSAP1W_1)
• Absorption Coefficient Blue, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_B_Dry_10um_PSAP3W_1)

• Aerosol light absorption coefficient, green channel, 10 um particle diameter(Ba_G_Dry_10um_PSAP1W_1)
• Absorption Coefficient Red, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_R_Dry_1um_PSAP3W_1)
• Absorption Coefficient Green, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_G_Dry_10um_PSAP3W_1)
• Absorption Coefficient Green, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_G_Dry_1um_PSAP3W_1)
• Absorption Coefficient Blue, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_B_Dry_10um_PSAP3W_1)
• Absorption Coefficient Red, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_R_Dry_10um_PSAP3W_1)
• Absorption Coefficient Blue, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_B_Dry_1um_PSAP3W_1)
• Aerosol light absorption coefficient, green channel, 1 um particle diameter(Ba_G_Dry_1um_PSAP1W_1)

• Aerosol light absorption coefficient, green channel, 1 um particle diameter(Ba_G_Dry_1um_PSAP1W_1)
• Aerosol light absorption coefficient, green channel, 10 um particle diameter(Ba_G_Dry_10um_PSAP1W_1)

HFE/AOS/M1 - CPC and CCN data questionable

The CPC slowly clogged and the signal declined until the instrument was cleaned at which 
point the signal would increase. The data is still a good relative measure of the daily 
changes in the CN concentration, but the absolute value may be too low.

The mentor was unable to monitor the flow rate and operation in the CCN during operation. 
The relative changes in CCN with %ss are likely fine, but the absolute values may be too 
low or too high. Dust was prevalent at the site and likely contributed to the CCN signal 
such that large dust particles appeared as droplets.

• AOS number concentration of CCN(N_CCN)
• Condensation Nuclei Concentration Number(N_CPC_1)

• CCN_Q_sheath
• AOS number concentration of CCN(N_CCN)
• CCN_Q_sample
• AOS CCN number concentration by bin(N_CCN_dN)