TWP/MWR/C3 - Sun in field of view of radiometer

Each day from approximately 9/15 to 10/9 around local noon, there is an increase in the 
brightness temperature due to the sun being in the field of view of the radiometer.

• MWR column precipitable water vapor(vap)
• Averaged total liquid water along LOS path(liq)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)

• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• 23.8 GHz sky signal(tipsky23)
• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)

TWP/MWR/C1/C2 - Sun in the field of view

Every day between around noon local time (usually between 1 and 2 AM UTC time) there is an 
increase in the brightness temperatures due to the sun in the field of vie of the 
radiometer.

• 31.4 GHz sky signal(sky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• MWR column precipitable water vapor(vap)
• 23.8 GHz sky signal(sky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)

• MWR column precipitable water vapor(vap)
• 31.4 GHz sky signal(sky31)
• Sky brightness temperature at 23.8 GHz(tbsky23)
• Sky brightness temperature at 31.4 GHz(tbsky31)
• Averaged total liquid water along LOS path(liq)
• 23.8 GHz sky signal(sky23)

• 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)
• 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
• Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
• Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)

• 31.4 GHz sky signal(tipsky31)
• 23.8 GHz sky signal(tipsky23)

TWP/SMET/C3 - Upper Wind Sensor Data Questionable

The wind_up vs. wind_low wind directions diverged, with the differences between the two 
eventually reached 45 degrees. The Upper sensor was found to be mis-aligned and loose.

• Upper sensor, wind speed maximum(up_spd_max)
• Upper sensor, wind speed arithmetic average(up_spd_arith_avg)
• Upper sensor, wind speed minimum(up_spd_min)
• Upper sensor, wind speed vector average(up_spd_vec_avg)
• Upper sensor, wind speed standard deviation(up_spd_sd)

TWP/SMET/C3 - Lower Wind Direction Intermittently Wrong

The lower wind sensor cabling had a problem causing an intermittent connection for the 
wind direction data.

• Lower sensor, wind direction vector average(lo_dir_vec_avg)
• Lower sensor, wind direction standard deviation(lo_dir_sd)

TWP/SMET/C2 - ORG rainfall measurements too large

The ORG was collecting large amounts of rainfall compared to the co-located tipping bucket 
raingauge.  The cable was chewed by mice causing the wires to make contact 
intermittently mimicking rainfall.

• Precipitation maximum(precip_max)
• Precipitation mean(precip_mean)
• precipitation minimum(precip_min)
• Precipitation standard deviation(precip_sd)

TWP/SMET/C1 - ORG Precip Data Incorrect

Moisture intrusion into the sensor body allowed condensation on the lens of the ORG.  
Continual and long-term precipitation was reported during this time.

• Precipitation mean(precip_mean)
• Precipitation maximum(precip_max)
• Precipitation standard deviation(precip_sd)
• precipitation minimum(precip_min)

TWP/SMET/C3 - Upper wind speed data incorrect

Beginning on 07/08, the upper wind sensor started reporting significantly lower wind 
speeds than the lower wind sensor.  The cable connections weather proofing failed allowing 
corrosion to occur and increasing he resistance of the cables.  This in turn lowered the 
wind speeds artificially.

• Upper sensor, wind speed maximum(up_spd_max)
• Upper sensor, wind speed arithmetic average(up_spd_arith_avg)
• Upper sensor, wind speed minimum(up_spd_min)
• Upper sensor, wind speed vector average(up_spd_vec_avg)
• Upper sensor, wind speed standard deviation(up_spd_sd)

TWP/SONDE/C2 - Bad RH values throughout sounding

RH values fluctuate largely in a stepping function throughout the sounding.  Suspect bad 
RH sensors.

• Relative humidity inside the instrument enclosure(rh)

TWP/MWR/C1 - Short periods of wrong ambient temperature

During this month there are a few intermittent instances of bad ambient temperature 
readings. I will summarize here these short time ranges:
20080909 between 02:00 and 03:00 UTC
20080909 between 09:00 and 14:00 UTC

Additionally the ambient temperature has short but frequent data gaps.  The data gaps are 
very short (less than one hour). Users could interpolate missing data or use alternative 
sensors such as the surface meteorological data available for the site.

• Ambient temperature(tkair)

• Ambient temperature(tkair)

TWP/SMET/C3 - Wind Speed data contain offset due to induced voltage

The marine model of the RM Young wind sensor needs twisted pair shielded cable.  The 
manufacturer did not originally supply the pigtail with twisted pair shielded cable.  Use of 
twisted pair shielded cable for the rest of the cable run to the logger was also not 
specified.  This caused an induced voltage in the wind speed line from the wind direction 
excitation.  The induced voltage varied from sensor to sensor and probably changed anytime 
the cable was replaced or parts of the wind sensor were repaired or replaced. The induced 
voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s.

• Upper sensor, wind speed maximum(up_spd_max)
• Lower sensor, wind speed minimum(lo_spd_min)
• Lower sensor, wind speed standard deviation(lo_spd_sd)
• Lower sensor, wind speed maximum(lo_spd_max)
• Upper sensor, wind speed arithmetic average(up_spd_arith_avg)
• Lower sensor, wind speed vector average(lo_spd_vec_avg)
• Upper sensor, wind speed minimum(up_spd_min)
• Lower sensor, wind speed arithmetic average(lo_spd_arith_avg)
• Upper sensor, wind speed vector average(up_spd_vec_avg)
• Upper sensor, wind speed standard deviation(up_spd_sd)

TWP/SMET/C2 - ORG rainrate high due to calibration.

The rainrate from the ORG was high due to calibration.  This data is not real.

• Precipitation maximum(precip_max)
• Precipitation mean(precip_mean)
• precipitation minimum(precip_min)
• Precipitation standard deviation(precip_sd)

TWP/SONDE/C2 - Defective Temperature Sensor

Temperature sensor shows a +30C offset for duration of flight.

• Dry bulb temperature(tdry)