NSA/MWRP/C1 - Missing data

Data are missing and unrecoverable.

• Expected root-mean-square error in liquid water path retrieval(liquidWaterPathRmsError)
• Derived relative humidity(relativeHumidity)
• Internal blackbody reference temperature(blackbodyTemperature)
• Expected root-mean-square error in temperature retrieval(temperatureRmsError)
• Retrieved liquid water path(liquidWaterPath)
• Ambient surface pressure(surfacePressure)
• atmospheric pressure at mean sea level and at tropopause (NGM250 predicted)(pressure)
• Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
• Data quality flags(dataQualityFlags)
• Surface water vapor density at instrument(surfaceWaterVaporDensity)
• Derived virtual temperature(virtualTemperature)
• Expected root-mean-square error in water vapor density retrieval(waterVaporDensityRmsError)
• Equilibrium level pressure(equilibriumLevelPres)
• base time(base_time)
• Zenith-pointing infrared temperature at 10um(infraredTemperature)
• Array of heights for the range gates(height)
• lat(lat)
• Dummy altitude for Zeb(alt)
• Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)
• Interpolated dewpoint temperature(dewpointTemperature)
• azimuth(azimuth)
• Cloud base height(cloudBaseHeight)
• Expected root-mean-square error in precipitable water retrieval using only
  23.835 and 30.0 GHz(totalPrecipitableWater2RmsError)
• Expected root-mean-square error in precipitable water retrieval(totalPrecipitableWaterRmsError)
• elevation(elevation)
• Lifting condensation level pressure(liftingCondensationLevelPres)
• Level of free convection pressure(levelFreeConvectionPres)
• Retrieved water vapor density(waterVaporDensity)
• lon(lon)
• Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
• Microwave brightness temperature(brightnessTemperature)
• Frequency(frequency)
• Convective Available Potential Energy(cape)
• Flag indicating moisture sensor status(wetWindowFlag)
• Expected root-mean-square error in liquid water content retrieval(liquidWaterContentRmsError)
• Lifting condensation level(liftingCondensationLevel)
• Level of free convection(levelFreeConvection)
• air temperature (NGM250 predicted)(temperature)
• Ambient surface absolute temperature(surfaceTemperature)
• 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)
• Time offset of tweaks from base_time(time_offset)
• Ambient surface relative humidity(surfaceRelativeHumidity)
• Interpolated water vapor mixing ratio(waterVaporMixingRatio)
• time(time)
• Equilibrium level(equilibriumLevel)

NSA/METTWR/C2 - PWS data missing/incorrect due to maintenance.

Present Weather Sensor data was missing or incorrect due to maintenance activities 
repeated approximately daily as we were trying to correct another problem.

• Chilled Mirror Temperature(CMHTemp)
• 1 hour Present Weather Code(PWCod1hr)
• Cumulative Snow Sum(CumSnow)
• 10 minute Average Visibility(AvgVis10m)
• Present Weather Sensor Alarm(PWSAlarm)
• Precipitation Rate(PCPRate)
• Instant Present Weather Code(InstPWCod)
• Cumulative Water Sum(CumH2O)
• 15 minute Present Weather Code(PWcod15mi)
• 1 minute Average Visibility(AvgVis1mi)

NSA/SONDE/C1 - RH values offset due to error in ground check

Background: After installation of the latest software update , we began performing formal 
ground checks on RS92 radiosondes.  By comparing the radiosonde readings with reference 
values in a controlled environment, the ground check is intended to ensure that the 
radiosonde sensors are in calibration before launch.  The radisonde values during the ground 
check process are recorded automatically; the reference values are entered by the operator. 
 If the radiosonde readings vary from the reference values, the system 'corrects' the 
radiosonde values.  In the case of RH, the correction is applied as an offset (true RH = 
indicated RH + correction).

Problem: Some operators misunderstood the ground-check procedure and entered the 
radiosonde values of RH rather than the reference value (assumed 0%RH), thus, some soundings done 
during this period have RH values that are different from what they would be if the 
ground check procedure had been done correctly.

Consequence:  Because the RH corrections generally are small (averaging about 0.5% RH) and 
the precision of the reported RH data during this time period is 1% RH, some values will 
not be affected at all; others will be off by about 1% RH (still within the stated 
accuracy of the sensor).  Furthermore, because entering the radiosonde value as the reference 
value results in a near zero 'correction,' one may view these soundings as being done 
without the ground check correction.  Also note that the dew point value will be suspect as well.

I am attaching below a listing of the soundings that were affected during the indicated 
time period.  Users can see the magnitude of the problem and choose whether or not to apply 
an offset in RH.  Note that application of the offset to the processed RH data (in the 
netCDF file) will not have the same effect of applying the correction to the absolutely 
raw data (before processing), but the differences should be insignificant.  Also note that 
the corrections for each sounding are included in the netCDF header information.  These 
attributes are named 'humidity_correction' and 'humidity_correction_2'.  The values of RH 
indicated by the radiosonde while it is in the ground check set are in attributes 
'humidity_gc_sonde' and 'humidity_gc_sonde_2.'  There is an RH reading for each of the two RH 
sensors used in the RS92 radiosonde.

Here is the list - RH1 and RH2 are the radiosonde readings in the ground check set.  Ref 
is the reference value entered by the operator.  The correcte reference value should be 
0%.  To obtain an approximation to the RH value that would have been recorded if the ground 
check had been done properly, subtract the Ref value from the indicated RH.

 YYYYMMDD  HHMM  SerialNo     RH1     RH2     Ref
 20060713  0532  B1924431    0.30    0.20    0.30
 20060713  1751  B1854963    0.20    0.30    0.30
 20060714  0521  B1924425    0.40    0.40    0.40
 20060714  1739  B1854206    0.30    0.30    0.30
 20060715  0522  B1715127    1.20    1.20    1.20
 20060715  1737  B1854966    0.60    0.60    0.60
 20060716  0508  B1715126    0.40    0.40    0.40
 20060716  1732  B1844098    0.50    0.50    0.50
 20060717  0517  B1914170    0.40    0.40    0.40
 20060718  0516  B1914173    0.70    0.70    0.70
 20060720  0523  B1854149    0.40    0.40    0.40
 20060721  0517  B1914153    0.40    0.40    0.40
 20060722  0521  B1844097    1.00    1.10    1.10
 20060722  1730  B1914174    0.60    0.70    0.70
 20060723  0537  B1714439    0.40    0.40    0.40
 20060723  1734  B1734155    0.50    0.50    0.50
 20060724  0529  B1134336    0.50    0.50    0.50
 20060725  0525  B1754099    0.60    0.70    0.70
 20060726  0541  B1844108    1.80    1.80    1.80
 20060727  0520  B1714382    0.70    0.80    0.70
 20060728  0531  B1854116    0.80    0.80    0.80
 20060729  0527  B1724027    1.00    1.00    1.00
 20060729  1726  B1714392    0.70    0.80    0.80
 20060730  0522  B1854100    0.70    0.80    0.80
 20060730  1724  B1854764    0.90    1.00    1.00
 20060731  0515  B1664086    0.90    0.80    0.90
 20060801  0520  B1724758    1.50    1.50    1.50
 20060801  1729  B1754116    1.10    1.10    1.10
 20060802  0518  B1724516    0.80    0.80    0.80
 20060803  0523  B1674148    0.80    0.80    0.80
 20060804  0532  B1754092    0.90    0.90    0.90
 20060804  1727  B1844117    3.50    3.50    3.50
 20060805  0531  B1714741    0.30    0.30    0.30
 20060805  1728  B1754098    0.30    0.30    0.30
 20060806  0528  B1844115    0.40    0.40    0.40
 20060806  1728  B1914161    0.20    0.20    0.20
 20060807  0530  B1714549    0.30    0.30    0.30
 20060808  0517  B1844107    0.50    0.50    0.50
 20060808  1744  B1914166    0.20    0.20    0.20
 20060809  0527  B1914164    0.30    0.40    0.40
 20060809  1736  B1914163    0.30    0.30    0.30
 20060810  0521  B1914160    0.40    0.50    0.50
 20060810  1745  B1744671    0.40    0.40    0.40
 20060811  0525  B1854965    0.50    0.50    0.50
 20060811  1753  B1724131    0.10    0.10    0.10
 20060812  0527  B1754104    0.50    0.50    0.50
 20060812  1740  B1854256    0.30    0.40    0.40
 20060813  0522  B1854240    0.30    0.40    0.40
 20060814  0525  B1714106    0.20    0.20    0.20
 20060814  1742  B1854106    0.40    0.40    0.40
 20060815  0534  B1914169    0.50    0.60    0.60
 20060815  1734  B1854233    0.60    0.70    0.70
 20060816  0539  B1724791    0.20    0.20    0.20
 20060816  1732  B1914171    0.10    0.20    0.20
 20060817  0535  B1354283    0.10    0.10    0.10
 20060817  1740  B1354574    0.40    0.40    0.40
 20060818  0516  B1354633    0.50    0.40    0.50
 20060818  1744  B1364673    0.20    0.20    0.20
 20060819  0538  B1364126    0.20    0.30    0.30
 20060819  1745  B1354598    0.50    0.60    0.60
 20060820  0532  B1354290    1.10    1.10    1.10
 20060820  1729  B1354317    0.40    0.40    0.40
 20060821  0530  B1354545    0.60    0.70    0.70
 20060821  1728  B1354516    0.70    0.70    0.70
 20060822  0524  B1354619    0.50    0.60    0.60
 20060822  1728  B1364377    0.40    0.40    0.40
 20060823  0533  B1354309    0.30    0.30    0.30
 20060823  1730  B1354527    0.70    0.70    0.70
 20060824  0533  B1354230    0.60    0.60    0.60
 20060824  1812  B1354587    0.70    0.70    0.70
 20060825  0517  B1354614    0.70    0.70    0.70
 20060825  1730  B1354630    0.60    0.60    0.60
 20060826  0537  B1334114    0.90    0.90    0.90
 20060826  1734  B1354246    0.70    0.70    0.70
 20060827  0508  B1354534    0.70    0.70    0.70
 20060827  1729  B1354618    0.60    0.60    0.60
 20060828  0517  B1354115    0.40    0.40    0.40
 20060828  1738  B1354206    0.50    0.60    0.60
 20060829  0516  B1354617    0.50    0.60    0.60
 20060829  1717  B1354622    0.50    0.60    0.60
 20060830  0511  B1354314    0.40    0.50    0.50
 20060830  1732  B1354537    0.60    0.70    0.70
 20060831  1802  B1354239    0.60    0.80    0.80
 20060905  1724  B1354626    0.60    0.60    0.60
 20060906  0522  B1354525    0.60    0.80    0.80
 20060906  1734  B1354107    0.50    0.50    0.50
 20060907  0537  B1354543    0.70    0.70    0.70
 20060907  1803  B1354586    0.80    0.80    0.80
 20060908  0531  B1354519    0.60    0.60    0.60
 20060908  1728  B1354224    0.60    0.60    0.60
 20060909  0534  B1354532    0.70    0.80    0.80
 20060909  1732  B1354513    0.80    0.90    0.90
 20060910  0516  B1354125    0.60    0.70    0.60
 20060910  1727  B1354110    0.40    0.50    0.50
 20060911  0528  B1354235    0.90    0.90    0.90
 20060911  1849  B1354514    0.70    0.70    0.70
 20060912  0525  B1354124    0.60    0.70    0.70
 20060913  0534  B1344478    0.50    0.50    0.50
 20060914  0520  B1354226    0.70    0.70    0.70
 20060915  0529  B1344459    0.40    0.50    0.50
 20060916  0532  B1344469    0.50    0.40    0.50
 20060916  1732  B1354106    0.50    0.60    0.60
 20060917  0527  B1354210    0.70    0.70    0.70
 20060918  0533  B1354087    0.60    0.60    0.60
 20060919  0526  B1354097    0.70    0.50    0.60
 20060920  0516  B1344462    0.50    0.40    0.50
 20060920  1810  B1354536    0.70    0.70    0.70
 20060921  0534  B1354112    0.50    0.60    0.60
 20060921  1800  B1344502    0.40    0.40    0.40
 20060922  0525  B1354531    0.70    0.80    0.80
 20060922  1736  B1354541    0.70    0.70    0.70
 20060923  0519  B1354101    0.50    0.60    0.60
 20060923  1738  B1354576    0.70    0.50    0.70
 20060924  0536  B1354095    0.60    0.60    0.60
 20060925  0536  B1354098    0.60    0.60    0.60
 20060925  1755  B1354100    0.50    0.50    0.50
 20060926  0531  B1334691    0.70    0.70    0.70
 20060926  1742  B1354108    0.40    0.50    0.50

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

NSA/SONDE/C1 - Increased precision for alt, dp, pres, rh, tdry

The output precision of the following variables was increased 20060929:

   alt	changed from 1m to 0.1m
   dp	changed from 0.1degC to 0.01degC
   pres changed from 0.1 hPa to 0.01 hPa
   RH	changed from 1%RH to 0.01%RH
   tdry changed from .1degC to 0.01degC

Note that the increase in precision does not necessarily imply an increase
in accuracy.  Users are cautioned to continue to use their best scientific
judgement when using these or any other data.

• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)
• Dummy altitude for Zeb(alt)
• Retrieved pressure profile(pres)
• Surface dew point temperature(dp)

NSA/MWRP/C1 - Reprocessed: Re-calibration

After being re-installed the radiometer was calibrated with liquid nitrogen.
Data between 8/8 and 9/6 have been reprocessed to apply the revised calibrations.

• Expected root-mean-square error in liquid water path retrieval(liquidWaterPathRmsError)
• Internal blackbody reference temperature(blackbodyTemperature)
• Retrieved liquid water path(liquidWaterPath)
• Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
• Surface water vapor density at instrument(surfaceWaterVaporDensity)
• Derived virtual temperature(virtualTemperature)
• Equilibrium level pressure(equilibriumLevelPres)
• Expected root-mean-square error in water vapor density retrieval(waterVaporDensityRmsError)
• Zenith-pointing infrared temperature at 10um(infraredTemperature)
• Interpolated dewpoint temperature(dewpointTemperature)
• Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)
• Cloud base height(cloudBaseHeight)
• Expected root-mean-square error in precipitable water retrieval using only
  23.835 and 30.0 GHz(totalPrecipitableWater2RmsError)
• Expected root-mean-square error in precipitable water retrieval(totalPrecipitableWaterRmsError)
• Lifting condensation level pressure(liftingCondensationLevelPres)
• Level of free convection pressure(levelFreeConvectionPres)
• Retrieved water vapor density(waterVaporDensity)
• Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
• Convective Available Potential Energy(cape)
• Microwave brightness temperature(brightnessTemperature)
• Lifting condensation level(liftingCondensationLevel)
• Expected root-mean-square error in liquid water content retrieval(liquidWaterContentRmsError)
• Level of free convection(levelFreeConvection)
• Retrieved cloud liquid water content(liquidWaterContent)
• Expected root-mean-square error in liquid water path retrieval using only 23.835
  and 30.0 GHz(liquidWaterPath2RmsError)
• Equilibrium level(equilibriumLevel)
• Interpolated water vapor mixing ratio(waterVaporMixingRatio)

NSA/METTWR/C1 - All data from 10m Level Missing

The winch that lowers the tower booms failed.  Manual testing of the motor and winch 
allowed the booms to be lowered briefly and then raised back into position.  A heavy freezing 
rain/icing event added extra weight to the booms.  This extra weight was suspected as the 
cause as to why the 10m boom became disconnected.  After a new motor was installed and 
all booms were lowered and re-raised the 10m level came back on line.

• 10m Average Calculated Dew Point(DP10M_AVG)
• 10m Average QLI Reference Temperature(RefT10m_AVG)
• Standard Deviation of 10m Calculated Vapor Pressure(VP10M_STD)
• 10m Average Relative Humidity(RH10M_AVG)
• 10m Vector Averaged Wind Speed(WS10M_U_WVT)
• 10m Average Calculated Vapor Pressure(VP10M_AVG)
• 10m Average QLI Input Voltage(Volt10M_AVG)
• Standard Deviation of 10m Vector Averaged Wind Direction(WD10M_SDU_WVT)
• 10m Average Temperature(T10M_AVG)
• Standard Deviation of 10m Relative Humidity(RH10M_STD)
• 10m Arithmetic Mean Wind Speed(WS10M_S_WVT)
• 10m Vector Averaged Wind Direction(WD10M_DU_WVT)
• Standard Deviation of 10m Calculated Dew Point(DP10M_STD)
• Standard Deviation of 10m Temperature(T10M_STD)

NSA/SONDE/C1 - Incorrect surface values of T and RH

The radiosonde was launched too quickly after being removed from the ground check set.  As 
a result, the system did not equilibrate with the local ground conditions and the 
automatically entered surface values are incorrect.

• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)
• Surface dew point temperature(dp)

NSA/METTWR/C1 - Missing CMH data

CMH data are missing.  Corrosion in the serial data line connections caused a loss of 
communication with the CMH.

• Chilled Mirror Calculated Vapor Pressure(VPCMH)
• Chilled Mirror Calculated Relative Humidity(CMHRH)
• Chilled Mirror Dew Point(CMHDP)
• Chilled Mirror Temperature(CMHTemp)
• Chilled Mirror Calculated Saturation Vapor Pressure(SatVPCMH)

NSA/MOLTS/X1 - Missing Data

Model Output Location Time Series (MOLTS) data has been missing since
   20061008 after NCEP upgraded its computer system. No information on the
   date when the system is back to normal.

• Specific humidity(humid)
• Mean Wind Speed(wspd)
• Turbulent kinetic energy in a layer(turb_kin)
• Station latitude(lat_stn)
• Beam 0 Temperature(temp)
• Convective latent heating rate(conv_lat_heat)
• Cloud water mixing ratio(cloud_h2o_mix)
• Omega(omega)
• Cloud cover in a layer(cloud_fract)
• Ice mixing ratio(ice_mix)
• Station longitude(lon_stn)
• Station number(num_stn)
• V-component(v_wind)
• base time(base_time)
• Unit Vector Wind Direction(wdir)
• Time offset from base_time(time_offsets)
• U-component(u_wind)
• Station altitude(alt_stn)
• Short-wave heating rate(sw_heat)
• Stable latent heating rate(stab_lat_heat)
• Long-wave heating rate(lw_heat)
• Retrieved pressure profile(pres)

• Time offset from base_time(time_offsets)
• Canopy water(canopy_water)
• Roughness length(rough_len)
• Station number(num_stn)
• Pressure at the base of the cloud(pres_base)
• Accumulated snow melt- 1 hr(snowmelt)
• Beam 0 Temperature(temp)
• Specific humidity at 10m(humid_10m)
• Temperature minimum(temp_min)
• Layer 2 soil temperature(soiltemp_lay2)
• Potential temperature at 10m(pot_temp)
• Snow ratio from explicity cloud scheme(snow_ratio)
• Accumulated Convective Precip- 1 hr(precip_conv_acc)
• Layer 1 soil temperature(soiltemp_lay1)
• Average Net Longwave Flux at Top- 1 hr(lw_net)
• Station longitude(lon_stn)
• Temperature maximum(temp_max)
• Amount of middle cloud(cloud_med)
• Storm-relative helicity(heli_storm)
• Station latitude(lat_stn)
• Accumulated Baseflow-groundwater runoff- 1hr(baseflow)
• Green vegetation cover(veg_green)
• Amount of low cloud(cloud_low)
• Average Flux of Latent Heat- 1 hr(lat_heat)
• Accumulated surface runoff- 1 hr(runoff)
• Snow water equivalent(snow_water)
• Temperature at 2 meters(temp_2m)
• Existence of ice?(ice)
• Average Flux of Snow Phase Change Heat- 1 hr(snowphase)
• Average Shortwave Downward Flux- 1 hr(sw_down)
• Total soil moisture(soil_total)
• Surface pressure(pres_surf)
• Horizontal visibility(horz_vis)
• Soil moisture availability(soilmoist)
• V-component at 10 m(V_wind)
• Existence of freezing rain?(rain_fz)
• Average Shortwave Upward Flux- 1 hr(sw_up)
• U-component at 10 m(U_wind)
• Layer 1 volumetric soil moisture(soilmoist_lay1)
• Average Longwave Downward Flux- 1 hr(lw_down)
• Specific humidity at 2 meters(humid_2m)
• Accumulated Total Precip- 1 hr(precip_acc)
• Average Flux of Sensible Heat- 1 hr(sens_heat)
• Station altitude(alt_stn)
• Average Flux of Sub-surface Heat- 1 hr(sub_heat)
• Layer 2 volumetric soil moisture(soilmoist_lay2)
• Pressure at mean sea level(pres_sea)
• U-component of storm motion(storm_U_wind)
• Average Longwave Upward Flux- 1 hr(lw_up)
• Station land/sea mask(land_sea)
• Layer 3 volumetric soil moisture(soilmoist_lay3)
• Average Net Shortwave Flux at Top- 1 hr(sw_net)
• Bottom soil temperature(soiltemp_bot)
• Average Potential Flux of Latent Heat- 1 hr(lat_heat_pot)
• Snow Depth(snow)
• Layer 4 volumetric soil moisture(soilmoist_lay4)
• Surface exchange coefficient(surf_ex_coef)
• Amount of high cloud(cloud_hi)
• Layer 3 soil temperature(soiltemp_lay3)
• base time(base_time)
• Accumulated snowfall- 1 hr(snowfall)
• Layer 4 soil temperature(soiltemp_lay4)
• surface rainfall count(rain)
• V-component of storm motion(storm_V_wind)

NSA/METTWR/C1 - 10m level loss of power

The 10 meter instrument level lost power so all variables from this level are missing.

• 10m Average Calculated Dew Point(DP10M_AVG)
• 10m Average QLI Reference Temperature(RefT10m_AVG)
• Standard Deviation of 10m Calculated Vapor Pressure(VP10M_STD)
• 10m Average Relative Humidity(RH10M_AVG)
• 10m Vector Averaged Wind Speed(WS10M_U_WVT)
• 10m Average Calculated Vapor Pressure(VP10M_AVG)
• 10m Average QLI Input Voltage(Volt10M_AVG)
• Standard Deviation of 10m Vector Averaged Wind Direction(WD10M_SDU_WVT)
• 10m Average Temperature(T10M_AVG)
• Standard Deviation of 10m Relative Humidity(RH10M_STD)
• 10m Arithmetic Mean Wind Speed(WS10M_S_WVT)
• 10m Vector Averaged Wind Direction(WD10M_DU_WVT)
• Standard Deviation of 10m Calculated Dew Point(DP10M_STD)
• Standard Deviation of 10m Temperature(T10M_STD)

NSA/METTWR/C1 - 2m T/RH probe aspirator fan failed

The aspirator fan for the 2m level T/RH probe failed.  This caused higher than normal 
readings for temp and RH and artificially smoothed the data.

• 2m Average Calculated Vapor Pressure(VP2M_AVG)
• Standard Deviation of 2m Calculated Dew Point(DP2M_STD)
• Standard Deviation of 2m Relative Humidity(RH2M_STD)
• 2m Average Relative Humidity(RH2M_AVG)
• Standard Deviation of 2m Calculated Vapor Pressure(VP2M_STD)
• 2m Average Temperature(T2M_AVG)
• Standard Deviation of 2m Temperature(T2M_STD)
• 2m Average Calculated Dew Point(DP2M_AVG)

NSA/SONDE/C1 - RH sensor failure

It appears that one of the two RH sensors on this radiosonde was affected by ice after 
emerging from a low cold cloud.  As a result the reported RH values oscillate by about 10 
percent until the alternate heating cycle stops.  I suspect the lower value is more close 
to correct, but can't be absolutely sure.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

NSA/METTWR/C2 - 2m Temp/RH sensor blocked with snow

The 2m RH, Dew Point and Vapor Pressure values are incorrect due to the intake of the 
aspirated shield being blocked with snow and ice.  The RH% values are artificially larger 
than the 5m and Chilled Mirror values.

• 2m Average Calculated Vapor Pressure(VP2m_AVG)
• Standard Deviation of 2m Relative Humidity(RH2m_STD)
• 2m Average Relative Humidity(RH2m_AVG)
• Standard Deviation of 2m Calculated Dew Point(DP2m_STD)
• Standard Deviation of 2m Calculated Vapor Pressure(VP2m_STD)
• 2m Average Calculated Dew Point(DP2m_AVG)

NSA/METTWR/C1 - Wind direction sensor frozen

After a power outage the 40m wind direction sensor was frozen.  Data from this sensor was 
not representative of the true winds.

• 40m Vector Averaged Wind Direction(WD40M_DU_WVT)
• Standard Deviation of 40m Vector Averaged Wind Direction(WD40M_SDU_WVT)

NSA/MWRP/C1 - Reprocessed: K-Band calibration drift

At the beginning of November, the K-band channel calibration started to drift. The MWRP 
brightness temperatures were about 1.5 K higher than the MWR-measured brightness 
temperatures. By the half of the month the differences were more than 2 K to become about 4 K by 
the end of November. On Nov 27 new calibration coefficients were derived and uploaded.

Data for 20061101-20061127 have been reprocessed with the revised calibrations and are 
available from the ARM Archive effective January 2007.

• Lifting condensation level pressure(liftingCondensationLevelPres)
• Derived relative humidity(relativeHumidity)
• Retrieved liquid water path(liquidWaterPath)
• Level of free convection pressure(levelFreeConvectionPres)
• Retrieved water vapor density(waterVaporDensity)
• Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
• Retrieved total precipitable water vapor using only 23.835 and 30.0 GHz(totalPrecipitableWater2)
• Convective Available Potential Energy(cape)
• Microwave brightness temperature(brightnessTemperature)
• Lifting condensation level(liftingCondensationLevel)
• Level of free convection(levelFreeConvection)
• Interpolated dewpoint temperature(dewpointTemperature)
• Total precipitable water vapor, from microwave radiometer(totalPrecipitableWater)
• Retrieved cloud liquid water content(liquidWaterContent)
• Interpolated water vapor mixing ratio(waterVaporMixingRatio)

NSA/METTWR/C1 - CMH Sensor Calibrated Incorrectly

The CMH temp and DP were higher than the co-located T/RH probe at the 2m level.  An 
incorrect calibration along with a failing thermistor caused the readings to be incorrect for 
both measured values Temp and Dew Point.

• Chilled Mirror Calculated Vapor Pressure(VPCMH)
• Chilled Mirror Calculated Relative Humidity(CMHRH)
• Chilled Mirror Dew Point(CMHDP)
• Chilled Mirror Temperature(CMHTemp)

NSA/METTWR/C1 - 40m wind sensor heater failure

The 40m wind direction became frozen at times.  The values from the sensor were flat-lined 
(stdev = 0) much of the time and did not match sensors from other levels.

• 40m Vector Averaged Wind Direction(WD40M_DU_WVT)
• Standard Deviation of 40m Vector Averaged Wind Direction(WD40M_SDU_WVT)

NSA/SONDE/C1 - Incorrect surface RH value

For an unknown reason the surface RH was reported a 0%.  Becuase these values are entered 
automatically by the system, this is NOT likely an operator error.  Examination of the 
raw data shows that the surface RH at launch time was approximately 81.2 %RH.

• Relative humidity inside the instrument enclosure(rh)
• Surface dew point temperature(dp)

NSA/MWRP/C1 - Incorrect surface measurements

Surface measurements are spiking and not comparing well with the co-located METTWR 
measurements.

On 2/13 site operators cleaned a filter in the heater housing resolving the problem.

• Ambient surface pressure(surfacePressure)
• Surface water vapor density at instrument(surfaceWaterVaporDensity)
• Ambient surface absolute temperature(surfaceTemperature)
• Ambient surface relative humidity(surfaceRelativeHumidity)

NSA/METTWR/C1 - 40m Wind Direction Data Suspect

The 40m wind direction data was suspect due to icing on the vane or a failing shafter 
heater or a combination of both.  The affected data can be easily seen on comparison plots 
with other levels data or by checking the standard deviation of the 40m wind direction.  
Any standard deviation of less than 0.10 degrees for the 40m level suggest a sluggish/ice 
affected sensor.

• 40m Vector Averaged Wind Direction(WD40M_DU_WVT)
• Standard Deviation of 40m Vector Averaged Wind Direction(WD40M_SDU_WVT)

NSA/SONDE/C1 - Temperature sensor broke at launch

The temperature sensor on this sonde broke at launch.  As a result all the thermodynamic 
data are incorrect.  The wind data are OK, though there will be some uncertainty in the 
altitude values.  This sounding was done at a non-standard time and it isn't clear whether 
it was delayed for some reason or a RHUBC sounding.  In either case, there is no fix.

• Ascent Rate(asc)
• Relative humidity inside the instrument enclosure(rh)
• Dry bulb temperature(tdry)
• Dummy altitude for Zeb(alt)
• Surface dew point temperature(dp)

NSA/METTWR/C1 - PWS Data Questionable

There was a degradation in the PWS lenses.  New lenses were installed on 08/28/2007 but a 
proper calibration was not conducted until 10/10/2007.  Data  during the listed time 
period should be used with caution.

• 15 minute Present Weather Code(PwCod15mi)
• 1 minute Average Visibility(AvgVis1mi)
• Instant Present Weather Code(InstPwCod)
• 1 hour Present Weather Code(PwCod1hr)
• Cumulative Snow Sum(CumSnow)
• 10 minute Average Visibility(AvgVis10m)
• Precipitation Rate(PcpRate)
• Cumulative Water Sum(CumH2O)
• Present Weather Sensor Alarm(PWSAlarm)

NSA/MWRP/C1 - Incorrect surface measurements

The MWRP surface temperature and pressure readings were in disagreement with those from 
other instruments. The possible cause of the disagreement was ice buildup around the 
sensors.  Readings returned to normal March 29.

The temperature readings were more affected. Since the readings are erratic, with large 
oscillations, it is not possible to correct them. Disregard the surface temperature and 
humidity readings during this time. The wrong readings will affect the first layer of the 
temperature and humidity profiles as well.

• Ambient surface pressure(surfacePressure)
• Surface water vapor density at instrument(surfaceWaterVaporDensity)
• Ambient surface absolute temperature(surfaceTemperature)
• Ambient surface relative humidity(surfaceRelativeHumidity)

NSA/METTWR/C1 - 20m RH Data Questionable

The 20m RH data was questionable at times.  When the data appeared to be poor was when the 
2m and 20m agreed better than the 20m and the 40m and/or 10m.

• Standard Deviation of 20m Calculated Dew Point(DP20M_STD)
• Standard Deviation of 20m Calculated Vapor Pressure(VP20M_STD)
• Standard Deviation of 20m Relative Humidity(RH20M_STD)
• 20m Average Relative Humidity(RH20M_AVG)
• 20m Average Calculated Vapor Pressure(VP20M_AVG)
• 20m Average Calculated Dew Point(DP20M_AVG)

NSA/MWRP/C1 - Reprocessed: 6-channel retrieval replaced by 5-channel retrieval

Due to repeated failure of the V-band receiver and calibration problems, the 6-channel 
retrieval was retired and a new 5-channel retrieval which uses only the K-band channels was 
implemented.

All data previously processed with the 6-channel retrieval have been reprocessed.

Please note that the 7 channels (brightness temperatures) in the V-band range (51 to 60 
GHz) should not be used.  See D080331.1 and D080331.2.

• Retrieved liquid water path(liquidWaterPath)
• Retrieved liquid water path using only 23.835 and 30.0 GHz(liquidWaterPath2)
• Microwave brightness temperature(brightnessTemperature)

NSA/MWRP/C1 - V-band Noise diode unstable

Sometimes between Jan and March 2007 the V-band noise diode started to be unstable. V-band 
channels during this period show large discrepancies with model computations. The 
problem was evident during the month of January. During February and March the problem was less 
visible, however measurement model comparisons show an increased bias. The instrument 
was calibrated with LN2 on March 15 and the calibration results showed a large drift in the 
calibration parameters.  The hardware failure will have consequences in the retrievals 
of temperature and relative humidity profiles. 

It is difficult to establish when the failure started. Disregard the V-band channels 
during this period. Vertical profiles of temperature and humidity are affected as well. Please 
note that this DQR only covers the 7 channels (brightness temperatures) in the V-band 
range (51 to 60 GHz). The 5 K-band channels (20-31 GHz) are not affected.

• Derived relative humidity(relativeHumidity)
• Retrieved water vapor density(waterVaporDensity)
• Interpolated dewpoint temperature(dewpointTemperature)
• Microwave brightness temperature(brightnessTemperature)
• Derived virtual temperature(virtualTemperature)
• Interpolated water vapor mixing ratio(waterVaporMixingRatio)

NSA/MWRP/C1 - V-band Noise diode failure

The LN2 calibration on 3/15 showed a large drift of the V-band calibration parameters. The 
radiometer was calibrated again in June and was sent out for repairs in July 2007.

Between 3/15 and 7/13 2007 the V-band data are incorrect and should be disregarded. The 
failure affects the retrieved vertical profiles of temperature and humidity as well.

Please note that the hardware failure affected the 7 V-band channels only (51-60 GHz). 
Channels in the frequency range between 20 and 30 GHz are not affected. Integrated liquid 
water (LWP) and water vapor (PWV) are not affected since they use K-band channels only.

• Derived relative humidity(relativeHumidity)
• Retrieved water vapor density(waterVaporDensity)
• air temperature (NGM250 predicted)(temperature)
• Microwave brightness temperature(brightnessTemperature)
• Derived virtual temperature(virtualTemperature)
• Interpolated water vapor mixing ratio(waterVaporMixingRatio)

NSA/TPS/C1 - Reprocess: Incorrect temporal resolution

The data were incorrectly collected and processed at 1 second temporal resolution rather 
than 1 minute resolution.  Data will be reprocessed to average to 1 minute.  Data quality 
are not compromised by this resolution error.

• Total daily accumulated liquid precipitation(precip_total)
• Precipitation rate(precip_rate)
• Mean Wind Speed(wspd)
• Air temperature(air_temp)
• Instrument enclosure temperature(enclosure_temp)