NSA/ARSCL/C1 - Reflectivity values unreliable

Reflectivity dBZ values should not be used.  The reported cloud boundaries may 
underestimate cloud tops, particularly for high or thick clouds.  Also thin high clouds may have 
been missed entirely, especially if there were lower-level cloud layers below them. During 
this time period, the MMCR was transmitting in  circular polarization, rather than 
(correct) linear polarization. This caused reported Reflectivity values to be too low by an 
unknown amount, resulting in an effective loss of radar sensitivity.

Areas identified as have having hydrometeor detections are correct, however some areas 
marked as clear may in fact contain cloud due to the MMCR's low sensitivity during this time.

• CloudLayerTopHeightMplCloth
• MMCR Reflectivity, Best estimate, Hydrometer(ReflectivityBestEstimate)
• RadarFirstTop
• Reflectivity(Reflectivity)
• MMCR Reflectivity, clutter removed(ReflectivityNoClutter)
• CloudLayerBottomHeightMplCloth

NSA/AOS/X1 - 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 Green, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_G_Dry_1um_PSAP3W_1)
• Absorption coefficient, green wavelength, low RH, 10 um size cut(Ba_G_Dry_10um_PSAP1W_1)
• Absorption coefficient blue, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_B_Dry_1um_PSAP3W_1)
• Absorption coefficient, green wavelength, 3 wavelength PSAP, low RH, 10 um size
  cut(Ba_G_Dry_10um_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, 1 um size cut(Ba_R_Dry_1um_PSAP3W_1)
• Absorption coefficient, green wavelength, low RH, 1 um size cut(Ba_G_Dry_1um_PSAP1W_1)
• Absorption coefficient red, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_R_Dry_10um_PSAP3W_1)

NSA/ARSCL/C1 - Reflectivity too high

The calibration of the MMCR was incorrect during this period, causing large positive 
shifts in reported reflectivity values.  As a result, the reflectivies reported by ARSCL are 
also too high.  However, other radar moments (MeanDopplerVelocity and SpectralWidth) and 
cloud boundaries reported in ARSCL data files are not affected and can be used.

Do not use ReflectivityBestEstimate, Reflectivity, or ReflectivityNoClutter values during 
this period.

• MMCR Reflectivity, Best estimate, Hydrometer(ReflectivityBestEstimate)
• Reflectivity(Reflectivity)
• MMCR Reflectivity, clutter removed(ReflectivityNoClutter)

NSA/AOS/CLAP/CPC/NEPHELOMETER/X1 - System maintenance

Data is either missing or instrument was being calibrated

• Aerosol total light scattering coefficient, reference nephelometer red channel,
  10 um particle diameter(Bs_R_Wet_10um_Neph3W_2)
• Absorption coefficient red, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_R_Dry_1um_PSAP3W_1)
• Aerosol total light scattering coefficient, reference nephelometer blue channel,
  1 um particle diameter(Bs_B_Wet_1um_Neph3W_2)
• Ambient air relative humidity(RH_Ambient)
• Aerosol total light scattering coefficient, ref. humidograph nephelometer red
  channel, 1 um particle diameter(Bs_R_Dry_1um_Neph3W_1)
• T_postHG
• Back-scattering coefficient, blue wavelength, low RH, 1 um size cut(Bbs_B_Dry_1um_Neph3W_1)
• base_time
• Aerosol total light scattering coefficient, Humidograph nephelometer red
  channel, 1 um particle diam(Bs_R_Wet_1um_Neph3W_2)
• Wind speed(WindSpeed)
• flags_CMDL
• Aerosol total light scattering coefficient, reference nephelometer green
  channel, 10 um particle diameter(Bs_G_Dry_10um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, Humidograph
  nephelometer blue channel, 1(Bbs_B_Wet_10um_Neph3W_2)
• Aerosol backwards-hemispheric light scattering coefficient, Ref. Humidograph
  nephelometer green chan(Bbs_G_Dry_1um_Neph3W_1)
• Aerosol total light scattering coefficient, reference nephelometer green
  channel, 1 um particle diameter(Bs_G_Wet_1um_Neph3W_2)
• P_Neph_Dry
• T_NephInlet_Dry
• Back-scattering coefficient, blue wavelength, low RH, 10 um size cut(Bbs_B_Dry_10um_Neph3W_1)
• Wind direction, relative to true North(WindDirection)
• Ambient pressure(P_Ambient)
• Cloud droplet concentration number from summation of condensation nuclei counter
  size bins(N_CCN_1)
• Aerosol backwards-hemispheric light scattering coefficient, reference
  nephelometer green channel, 10(Bbs_G_Dry_10um_Neph3W_1)
• Aerosol total light scattering coefficient, Humidograph nephelometer green
  channel, 10 um particle d(Bs_G_Wet_10um_Neph3W_2)
• RH_MainInlet
• T_MainInlet
• Total scattering coefficient, blue wavelength, low RH, 1 um size cut(Bs_B_Dry_1um_Neph3W_1)
• Aerosol total light scattering coefficient, reference nephelometer red channel,
  10 um particle diameter(Bs_R_Dry_10um_Neph3W_1)
• Absorption coefficient blue, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_B_Dry_10um_PSAP3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, Humidograph
  nephelometer green channel,(Bbs_G_Wet_1um_Neph3W_2)
• RH_NephInlet_Dry
• RH_NephVol_Wet
• Aerosol backwards-hemispheric light scattering coefficient, reference
  nephelometer blue channel, 1 um particle diameter(Bbs_B_Wet_1um_Neph3W_2)
• T_NephVol_Wet
• T_NephInlet_Wet
• Condensation nuclei concentration number(N_CPC_1)
• East longitude(lon)
• Absorption coefficient red, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_R_Dry_10um_PSAP3W_1)
• time_bounds
• Aerosol backwards-hemispheric light scattering coefficient, reference
  nephelometer red channel, 10 um particle diameter(Bbs_R_Dry_10um_Neph3W_1)
• time_offset
• Absorption coefficient, green wavelength, low RH, 10 um size cut(Ba_G_Dry_10um_PSAP1W_1)
• Absorption coefficient blue, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_B_Dry_1um_PSAP3W_1)
• RH_postHG
• Absorption coefficient, green wavelength, low RH, 1 um size cut(Ba_G_Dry_1um_PSAP1W_1)
• RH_NephInlet_Wet
• T_NephVol_Dry
• T_preHG
• time
• Aerosol total light scattering coefficient, reference nephelometer blue channel,
  10 um particle diam(Bs_B_Dry_10um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, reference
  nephelometer red channel, 1 um particle diameter(Bbs_R_Dry_1um_Neph3W_1)
• RH_NephVol_Dry
• Ambient air temperature(T_Ambient)
• Mean number concentration of N_CCN(N_CCN)
• P_Neph_Wet
• RH_preHG
• Aerosol backwards-hemispheric light scattering coefficient, Humidograph
  nephelometer red channel, 1(Bbs_R_Wet_1um_Neph3W_2)
• Altitude above mean sea level(alt)
• North latitude(lat)
• Absorption Coefficient Green, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_G_Dry_1um_PSAP3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, Humidograph
  nephelometer red channel, 10(Bbs_R_Wet_10um_Neph3W_2)
• Aerosol backwards-hemispheric light scattering coefficient, Humidograph
  nephelometer green channel,(Bbs_G_Wet_10um_Neph3W_2)
• Absorption coefficient, green wavelength, 3 wavelength PSAP, low RH, 10 um size
  cut(Ba_G_Dry_10um_PSAP3W_1)
• Aerosol total light scattering coefficient, Humidograph nephelometer blue
  channel, 10 um particle di(Bs_B_Wet_10um_Neph3W_2)
• Aerosol total light scattering coefficient, Ref. Humidograph nephelometer green
  channel, 1 um particle diameter(Bs_G_Dry_1um_Neph3W_1)