NIM/MWRP/M1 - Instrument noise problem

There are spikes and elevated noise in MWRP data. The origine of the spikes is RF 
interference from various sources.  All brightness temperatures are affected, but in particular 
the 5 K-band channels. LWP retrievals are noisy and affected by spikes as a result.

• Raw data stream - documentation not supported(raw)

• Retrieved cloud liquid water content(liquidWaterContent)
• Derived relative humidity(relativeHumidity)
• Derived virtual temperature(virtualTemperature)
• Interpolated water vapor mixing ratio(waterVaporMixingRatio)
• Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
• air temperature (NGM250 predicted)(temperature)
• Retrieved water vapor density(waterVaporDensity)
• Interpolated dewpoint temperature(dewpointTemperature)
• Retrieved liquid water path(liquidWaterPath)
• Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
• Microwave brightness temperature(brightnessTemperature)
• Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)

• Raw data stream - documentation not supported(raw)

NIM/MWRP/M1 - Reprocessed - New retrieval coefficients

Occasionally, the retrieved relative humidity was exceeding 120%. Upon reviewing the data 
it was noticed that the high values were appearing in the highest layers (above 8 km) and 
especially during spring season. Since retrievals at the highest levels are mainly 
affected by the climatology used to constrain the retrievals, we reviewed the statistical 
coefficients that were used to retrieve temperature and humidity. It was discovered that, in 
the training dataset (radiosonde), there were a few outliers (invalid radiosonde 
soundings) that had escaped the screening process and were affecting the computations of the 
retrieval coefficients.

We recomputed the retrieval coefficients with the newly screened set of radiosonde data 
and reprocessed all the previous data at Niamey.  The reprocessed data were archived in 
August 2006.

The new coefficients improve temperature and humidity profiles in two ways. The relative 
humidity will not exceed 120% in the upper layers and the temperature profiles will be in 
better agreement with the sonde in the first 4 km.

• Expected root-mean-square error in liquid water path retrieval(liquidWaterPathRmsError)
• Expected root-mean-square error in liquid water content retrieval(liquidWaterContentRmsError)
• Expected root-mean-square error in liquid water path retrieval using only 23.835
  and 30.0 GHz(liquidWaterPath2RmsError)
• Retrieved cloud liquid water content(liquidWaterContent)
• Derived relative humidity(relativeHumidity)
• Derived virtual temperature(virtualTemperature)
• Interpolated water vapor mixing ratio(waterVaporMixingRatio)
• Expected root-mean-square error in precipitable water retrieval(totalPrecipitableWaterRmsError)
• Expected root-mean-square error in water vapor density retrieval(waterVaporDensityRmsError)
• Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
• air temperature (NGM250 predicted)(temperature)
• Retrieved water vapor density(waterVaporDensity)
• Interpolated dewpoint temperature(dewpointTemperature)
• Retrieved liquid water path(liquidWaterPath)
• Cloud base height(cloudBaseHeight)
• Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
• Expected root-mean-square error in temperature retrieval(temperatureRmsError)
• Expected root-mean-square error in precipitable water retrieval using only
  23.835 and 30.0 GHz(totalPrecipitableWater2RmsError)
• Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)

NIM/MWRP/M1 - 51.25 GHz channel calibration drifted

After a power outage on May 5 the 51.25 GHz had a slight change in the calibration. The 
resulting LWP computed by using all 6 channels increased of about 0.025 mm (25 g/m2).

• Microwave brightness temperature(brightnessTemperature)

NIM/AOS/M1 - Flow controller failure

Following a power outage at the site both a PID controller for the main sample flow as 
well as a circuit board on the reference nephelometer were inoperable. The PID controller 
was replaced on 5/18 and the neph circuit board was replaced on 6/22. On a site visit in 
August the mentor found the PID had not been programmed correctly and was reading erroneous 
flows. The actual flow was at 50% of the recorded flow. Because the sample flow is 
diluted by 50% this makes most if not all of the sample flow from 5/18 to 8/11 from the diluter.

• AOS CCN temperature of the optical particle counter(CCN_T_OPC)
• AOS bin number of lowest channel of OPC include in summation of N_CCN(N_CCN_bin_number)
• AOS CCN temperature at top of column(CCN_T_TEC1)
• AOS CCN volumetric flowrate of sheath air(CCN_Q_sheath)
• AOS CCN temperature of the nafion humidifier(CCN_T_nafion)
• AOS CCN volumetric flowrate of sample air(CCN_Q_sample)
• AOS CCN OPC laser current(CCN_laser_current)
• First stage monitor voltage(CCN_FirstStageMonitorVoltage)
• AOS CCN sample saturation setpoint value reported by instrument(CCN_ss_set)
• AOS CCN temperature of sample air entering the column(CCN_T_sample)
• CCN Propotional valve voltage(CCN_ProportionalValveVoltage)
• AOS CCN sample supersaturation calculated by model)(CCN_ss_calc)
• AOS CCN number concentration by bin(N_CCN_dN)
• AOS CCN standard deviation of difference (CCN_T_TEC1 - CCN_T_TEC3)(CCN_dT_TEC3_TEC1_StdDev)
• Hexadecimal flag, non-zero value means instrument is not operating stably(CCN_temp_unstable_flag)
• AOS CCN temperature at middle of column(CCN_T_TEC2)
• Size of upper limit of each CCN bin(CCN_UpperSizeLimit)
• CCN temperature gradient(CCN_Temperature_Gradient)
• AOS CCN sample pressure(CCN_P_sample)
• AOS CCN temperature of sample air at entrance to instrument(CCN_T_inlet)
• AOS number concentration of CCN(N_CCN)
• AOS CCN temperature at bottom of column(CCN_T_TEC3)

• AOS CLAP or PSAP3W transmittance, green channel(TrG)
• AOS PSAP3W transmittance, red channel(TrR)
• AOS PSAP3W transmittance, blue channel(TrB)

• Relative humidity at wet nephelometer inlet(RH_NephInlet_Wet)
• Aerosol total light scattering coefficient, blue channel, 1 um size cut,
  reference three wavelength nephelometer(Bs_B_Dry_1um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, green channel, 10 um
  size cut, reference three wavelength nephelometer(Bbs_G_Dry_10um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, red channel, 10 um
  size cut, reference three wavelength nephelometer(Bbs_R_Dry_10um_Neph3W_1)
• Aerosol light absorption coefficient, green channel, 1 um size cut(Ba_G_Dry_1um_PSAP1W_1)
• Relative humidity inside reference nephelometer inlet(RH_NephVol_Dry)
• Aerosol backwards-hemispheric light scattering coefficient, blue channel, 10 um
  size cut, wet three wavelength nephelometer(Bbs_B_Wet_10um_Neph3W_2)
• 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, 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)
• Relative humidity inside wet nephelometer inlet(RH_NephVol_Wet)
• Aerosol total light scattering coefficient, blue channel, 1 um size cut, wet
  three wavelength nephelometer(Bs_B_Wet_1um_Neph3W_2)
• Aerosol backwards-hemispheric light scattering coefficient, blue channel, 1 um
  size cut, wet three wavelength nephelometer(Bbs_B_Wet_1um_Neph3W_2)
• Aerosol total light scattering coefficient, green channel, 10 um size cut, wet
  three wavelength nephelometer(Bs_G_Wet_10um_Neph3W_2)
• Condensation Nuclei Concentration Number(N_CPC_1)
• Aerosol backwards-hemispheric light scattering coefficient, blue channel, 1 um
  size cut, reference three wavelength nephelometer(Bbs_B_Dry_1um_Neph3W_1)
• Temperature at reference nephelometer inlet(T_NephInlet_Dry)
• Aerosol total light scattering coefficient, blue channel, 10 um size cut,
  reference three wavelength nephelometer(Bs_B_Dry_10um_Neph3W_1)
• Aerosol total light scattering coefficient, green channel, 1 um size cut, wet
  three wavelength nephelometer(Bs_G_Wet_1um_Neph3W_2)
• Aerosol total light scattering coefficient, red channel, 1 um size cut,
  reference three wavelength nephelometer(Bs_R_Dry_1um_Neph3W_1)
• Temperature at wet nephelometer inlet(T_NephInlet_Wet)
• Aerosol backwards-hemispheric light scattering coefficient, green channel, 1 um
  size cut, wet three wavelength nephelometer(Bbs_G_Wet_1um_Neph3W_2)
• Aerosol total light scattering coefficient, red channel, 10 um size cut, wet
  three wavelength nephelometer(Bs_R_Wet_10um_Neph3W_2)
• Aerosol total light scattering coefficient, green channel, 10 um size cut,
  reference three wavelength nephelometer(Bs_G_Dry_10um_Neph3W_1)
• Aerosol total light scattering coefficient, blue channel, 10 um size cut, wet
  three wavelength nephelometer(Bs_B_Wet_10um_Neph3W_2)
• Aerosol backwards-hemispheric light scattering coefficient, red channel, 1 um
  size cut, reference three wavelength nephelometer(Bbs_R_Dry_1um_Neph3W_1)
• Pressure inside wet nephelometer(P_Neph_Wet)
• Aerosol backwards-hemispheric light scattering coefficient, red channel, 10 um
  size cut, wet three wavelength nephelometer(Bbs_R_Wet_10um_Neph3W_2)
• Aerosol backwards-hemispheric light scattering coefficient, green channel, 10 um
  size cut, wet three wavelength nephelometer(Bbs_G_Wet_10um_Neph3W_2)
• Temperature inside wet nephelometer inlet(T_NephVol_Wet)
• Aerosol backwards-hemispheric light scattering coefficient, green channel, 1 um
  size cut, reference three wavelength nephelometer(Bbs_G_Dry_1um_Neph3W_1)
• Absorption Coefficient Green, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_G_Dry_10um_PSAP3W_1)
• Aerosol total light scattering coefficient, red channel, 1 um size cut, wet
  three wavelength nephelometer(Bs_R_Wet_1um_Neph3W_2)
• Pressure inside reference nephelometer(P_Neph_Dry)
• Relative humidity at reference nephelometer inlet(RH_NephInlet_Dry)
• Aerosol light absorption coefficient, green channel, 10 um size cut(Ba_G_Dry_10um_PSAP1W_1)
• Aerosol total light scattering coefficient, red channel, 10 um size cut,
  reference three wavelength nephelometer(Bs_R_Dry_10um_Neph3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, red channel, 1 um
  size cut, wet three wavelength nephelometer(Bbs_R_Wet_1um_Neph3W_2)
• Temperature inside reference nephelometer inlet(T_NephVol_Dry)
• Absorption Coefficient Red, corrected for flow and sample area, 3 wavelength
  PSAP, 1 um size cut(Ba_R_Dry_1um_PSAP3W_1)
• Aerosol backwards-hemispheric light scattering coefficient, blue channel, 10 um
  size cut, reference three wavelength nephelometer(Bbs_B_Dry_10um_Neph3W_1)
• Absorption Coefficient Red, corrected for flow and sample area, 3 wavelength
  PSAP, 10 um size cut(Ba_R_Dry_10um_PSAP3W_1)
• Aerosol total light scattering coefficient, green channel, 1 um size cut,
  reference three wavelength nephelometer(Bs_G_Dry_1um_Neph3W_1)

NIM/RWP/M1 - Reprocess: Wind direction offset

A strong wind storm on June 17, 2006 toppled the RWP antenna.  After repair and 
reinstallation, the wind direction reported by the instrument was rotated counterclockwise 90 
degrees, possibly because the antenna was installed rotated by 90 deg.  This condition 
continued through the remainder of deployment.

All wind direction values need to be increased by 90 degrees.

• V-component(v_wind)
• U-component(u_wind)

NIM/MET/M1 - ORG Data Underestimated Precipitation

The ORG underestimated precipitation by about 38% during the entire NIM deployment.  No 
troubleshooting technique or replacement of gage was successful in correcting the problem.

• Precipitation rate mean(precip_rate_mean)
• ORG carrier mean(org_carrier_mean)
• Precipitation rate maximum(precip_rate_max)
• Precipitation rate minimum(precip_rate_min)
• Precipitation rate standard deviation(precip_rate_sd)

NIM/MET/M1 - Reprocess: ORG Data has very small rainrate values

The ORG data is collected via analog signal and not digital.  Therefore, we
   continuously collect data even when no rain is occurring.  We also capture
   small events such as leaves, large bugs, dust, etc blowing through the
   measurement path.  Because this discrete event occurs quickly the value is
   usually captured for 1 or 2 seconds.  This value is then averaged to the
   minute producing rainrate on the order of .009 mm/hr or less.  These values
   are not indicative of rain and should be removed from the record or summing
   over long periods can bias the climate record.  We are reprocessing the data
   to remove these small values and are adjusting the collection program to
   remove them before ingest.

• Precipitation rate mean(precip_rate_mean)
• Precipitation rate maximum(precip_rate_max)
• Precipitation rate minimum(precip_rate_min)
• Precipitation rate standard deviation(precip_rate_sd)