SGP/SMOS/E27 - Instrument problem, Sensor failure

The SMOS wind sensor at E27 was reporting good wind
direction for 0 and 180 degrees, but bad wind directions 
for 090 and 270 degree (sensor problem).  This problem
was noted during the SMOS 6 month calibration check on
2003-05-15.  Sensor replacement and wiring changes
cleared the problem.

• Unit Vector Wind Direction(wdir)

• Unit Vector Wind Direction(wdir)

• Unit Vector Wind Direction(wdir)
• Standard Deviation of wind direction(sd_deg)

• Unit Vector Wind Direction(wdir)
• Standard Deviation of wind direction(sd_deg)

SGP/SMOS/E27 - 6-month Calibration Check

During the time period specified, the SMOS.E27 tower was
lowered for 6-month Calibration Check.  During this time 
wind data are incorrect and temperature and humidity data 
may be incorrect.

Note, exact times when tower was down or maintenance was
being performed is sometimes unknown.  Users should use
the remaining data from this day with caution.

• Beam 0 Temperature(temp)
• Vapor Pressure (kiloPascals)(vap_pres)
• Standard Deviation of wind direction(sd_deg)
• Wind Speed (vector averaged)(wspd_va)
• barometric pressure(bar_pres)
• Relative humidity inside the instrument enclosure(rh)
• Mean Wind Speed(wspd)
• Unit Vector Wind Direction(wdir)

• Standard Deviation of wind direction(sd_deg)
• barometric pressure(bar_pres)
• Vapor Pressure (kiloPascals)(vap_pres)
• Relative humidity inside the instrument enclosure(rh)
• Unit Vector Wind Direction(wdir)
• Mean Wind Speed(wspd)
• Wind Speed (vector averaged)(wspd_va)
• Beam 0 Temperature(temp)

• Beam 0 Temperature(temp)
• Standard Deviation of wind direction(sd_deg)
• Standard Deviation of Vapor Pressure(sd_vap_pres)
• Mean Wind Speed(wspd)
• barometric pressure(bar_pres)
• Standard Deviation of Relative Humidity(sd_rh)
• Wind Speed (vector averaged)(wspd_va)
• Vapor Pressure (kiloPascals)(vap_pres)
• Standard Deviation of Wind Speed(sd_wspd)
• Standard Deviation of Barometric Pressure(sd_bar_pres)
• Unit Vector Wind Direction(wdir)
• Relative humidity inside the instrument enclosure(rh)
• Standard Deviation of Air Temperature(sd_temp)

• Minimum Vapor Pressure(min_vap_pres)
• Time of Maximum Relative Humidity(time_max_rh)
• Time of Minimum Wind Speed(time_min_wspd)
• Maximum Relative Humidity(max_rh)
• Minimum Barometric Pressure(min_bar_pres)
• Time of Minimum Barometric Pressure(time_min_bar_pres)
• Maximum Vapor Pressure(max_vap_pres)
• Time of Minimum Temperature(time_min_temp)
• maximum wind speed (gusts)(max_wspd)
• Time of Maximum Barometric Pressure(time_max_bar_pres)
• Minimum of Wind speed(min_wspd)
• Time of Maximum Temperature(time_max_temp)
• Time of Maximum Wind Speed(time_max_wspd)
• Time of Minimum Vapor Pressure(time_min_vap_pres)
• Maximum Barometric Pressure(max_bar_pres)
• Time of Maximum Vapor Pressure(time_max_vap_pres)
• Maximum Temperature(max_temp)
• Minimum Relative Humidity(min_rh)
• Minimum Temperature(min_temp)
• Time of Minimum Relative Humidity(time_min_rh)

• Standard Deviation of Wind Speed(sd_wspd)
• Standard Deviation of Vapor Pressure(sd_vap_pres)
• Standard Deviation of Air Temperature(sd_temp)
• Vapor Pressure (kiloPascals)(vap_pres)
• Standard Deviation of Barometric Pressure(sd_bar_pres)
• Standard Deviation of wind direction(sd_deg)
• barometric pressure(bar_pres)
• Mean Wind Speed(wspd)
• Relative humidity inside the instrument enclosure(rh)
• Beam 0 Temperature(temp)
• Standard Deviation of Relative Humidity(sd_rh)
• Wind Speed (vector averaged)(wspd_va)
• Unit Vector Wind Direction(wdir)

SGP/SMOS/E27 - 6-month Calibration Checks

During the time periods specified, the SMOS.E27 tower was lowered for 6-month Calibration 
Checks.  During these times wind data are incorrect and temperature and humidity data may 
be incorrect.

Note, exact times when tower was down or maintenance was being performed is sometimes 
unknown.  Users should use the remaining data from these days with caution.

• Beam 0 Temperature(temp)
• Standard Deviation of wind direction(sd_deg)
• Wind Speed (vector averaged)(wspd_va)
• barometric pressure(bar_pres)
• Relative humidity inside the instrument enclosure(rh)
• Mean Wind Speed(wspd)
• Unit Vector Wind Direction(wdir)
• Vapor Pressure (kiloPascals)(vap_pres)

• Standard Deviation of Relative Humidity(sd_rh)
• Beam 0 Temperature(temp)
• Wind Speed (vector averaged)(wspd_va)
• Vapor Pressure (kiloPascals)(vap_pres)
• Standard Deviation of wind direction(sd_deg)
• Standard Deviation of Vapor Pressure(sd_vap_pres)
• Standard Deviation of Wind Speed(sd_wspd)
• Standard Deviation of Barometric Pressure(sd_bar_pres)
• Unit Vector Wind Direction(wdir)
• Relative humidity inside the instrument enclosure(rh)
• Mean Wind Speed(wspd)
• barometric pressure(bar_pres)
• Standard Deviation of Air Temperature(sd_temp)

• Time of Minimum Vapor Pressure(time_min_vap_pres)
• Time of Maximum Vapor Pressure(time_max_vap_pres)
• maximum wind speed (gusts)(max_wspd)
• Maximum Relative Humidity(max_rh)
• Maximum Vapor Pressure(max_vap_pres)
• Time of Maximum Temperature(time_max_temp)
• Minimum Temperature(min_temp)
• Maximum Temperature(max_temp)
• Time of Minimum Relative Humidity(time_min_rh)
• Maximum Barometric Pressure(max_bar_pres)
• Minimum of Wind speed(min_wspd)
• Minimum Barometric Pressure(min_bar_pres)
• Time of Maximum Relative Humidity(time_max_rh)
• Time of Minimum Wind Speed(time_min_wspd)
• Time of Maximum Barometric Pressure(time_max_bar_pres)
• Time of Minimum Temperature(time_min_temp)
• Time of Minimum Barometric Pressure(time_min_bar_pres)
• Time of Maximum Wind Speed(time_max_wspd)
• Minimum Vapor Pressure(min_vap_pres)
• Minimum Relative Humidity(min_rh)

SGP/SMOS/E27 - Reprocess: Wind direction offset

When the SGP.E27 SMOS tower was installed it was not aligned
properly resulting in a 7 degree offset.

• Unit Vector Wind Direction(wdir)

• Unit Vector Wind Direction(wdir)

• Unit Vector Wind Direction(wdir)

• Unit Vector Wind Direction(wdir)

SGP/SMOS/E27 - Reprocess: Wind direction offset

When the SGP.E27 SMOS tower was installed it was not aligned
properly resulting in a 7 degree offset.

• Unit Vector Wind Direction(wdir)

• Unit Vector Wind Direction(wdir)

SGP/SMOS/E27 - Wind Direction Data Incorrect

The wind monitor was frozen in one position during the time period.  Wind direction data 
is not representative of the actual conditions.

• Unit Vector Wind Direction(wdir)
• Standard Deviation of wind direction(sd_deg)

• Unit Vector Wind Direction(wdir)
• Standard Deviation of wind direction(sd_deg)

SGP/SMOS/E27 - Rain fall data incorrect

Rainfall data incorrect.  Technicians found gauge plugged and full of water.  Gauge was 
unplugged and all water ran through funnel.  Data appear to be measuring a massive deluge 
when in fact no rain was occurring.

• Hourly precipitation(precip)

• Hourly precipitation(precip)

SGP/SMOS/E27 - Rainfall Data Suspect

Rainfall during this time period was suspect as the gauge was found plugged on 05/09/2006 
at 15:38 GMT.  Last check of site occurred on 04/26/2006 @ 16:35 GMT.  Any rainfall data 
collected, whether the data is 0 or other than zero is suspect.

• Hourly precipitation(precip)

• Hourly precipitation(precip)

SGP/SMOS/E27 - Wind Speed Data Incorrect During Icing Conditions

Icing caused the wind speed sensor data to be artificailly low.

• Wind Speed (vector averaged)(wspd_va)
• Mean Wind Speed(wspd)

• Wind Speed (vector averaged)(wspd_va)
• Mean Wind Speed(wspd)

• maximum wind speed (gusts)(max_wspd)
• Minimum of Wind speed(min_wspd)
• Time of Maximum Wind Speed(time_max_wspd)
• Time of Minimum Wind Speed(time_min_wspd)

SGP/SMOS/E27 - Wind Direction data incorrect

The wind direction sensor was reporting a consistent value of ~360 degrees during this 
time period.  Co-located and nearby sensors were not in agreement with these values.

• Unit Vector Wind Direction(wdir)

• Unit Vector Wind Direction(wdir)

SGP/SMOS/E27 - Wind Data Incorrect Due to Icing

An ice storm caused the wind data from the RM Young wind sensor to be
incorrect.  In many instances it was frozen and unmoving, at times it
measured values but those are extremely suspect.

• Wind Speed (vector averaged)(wspd_va)
• Mean Wind Speed(wspd)
• Unit Vector Wind Direction(wdir)
• Standard Deviation of wind direction(sd_deg)

• Standard Deviation of Wind Speed(sd_wspd)
• Wind Speed (vector averaged)(wspd_va)
• Unit Vector Wind Direction(wdir)
• Standard Deviation of wind direction(sd_deg)
• Mean Wind Speed(wspd)

• maximum wind speed (gusts)(max_wspd)
• Minimum of Wind speed(min_wspd)
• Time of Minimum Wind Speed(time_min_wspd)
• Time of Maximum Wind Speed(time_max_wspd)

SGP/SMOS - Snowfall caused delayed count of precip

A snow/ice storm moved through the SGP region on 01/31/08 bringing below-freezing 
temperatures, affecting the precip field.  Data is suspect during the date/time range specified 
due to melting ice after temperatures warmed above freezing.

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

• Hourly precipitation(precip)

SGP/SMOS/E27 - Incorrect Offset for Wind Directon

An incorrect offset of 7 degrees was subtracted from the wind direction to correct for 
misalignment of the towers to true north. The wind direction data may be corrected but the 
vector averaged wind speed cannot. Subsequent audits have highlighted problems with past 
measurements of tower alignments.  All corrections to wind direction are being removed and 
Users are directed to view the Instrument Handbook for a table listing all tower 
alignment deviations from true north.  Users can adjust the data at their discretion.

• Unit Vector Wind Direction(wdir)
• Wind Speed (vector averaged)(wspd_va)

• Wind Speed (vector averaged)(wspd_va)
• Unit Vector Wind Direction(wdir)

SGP/SMOS/E27 - Incorrect Offset for Wind Directon

An incorrect offset of 7 degrees was added to the wind direction to
   correct for misalignment of the towers to true north. The wind direction data may be 
corrected but the vector averaged wind speed cannot. Subsequent audits have highlighted 
problems with past measurements of tower alignments.  All corrections to wind direction are 
being removed and Users are directed to view the Instrument Handbook for a table listing 
all tower alignment deviations from true north.  Users can adjust the data at their 
discretion.

• Unit Vector Wind Direction(wdir)
• Wind Speed (vector averaged)(wspd_va)

• Wind Speed (vector averaged)(wspd_va)
• Unit Vector Wind Direction(wdir)

SGP/SMOS/E27 - Missing Data

Data are missing and unrecoverable

• Beam 0 Temperature(temp)
• Hourly precipitation(precip)
• Vapor Pressure (kiloPascals)(vap_pres)
• Time offset of tweaks from base_time(time_offset)
• Dummy altitude for Zeb(alt)
• Standard Deviation of wind direction(sd_deg)
• lat(lat)
• base time(base_time)
• Wind Speed (vector averaged)(wspd_va)
• lon(lon)
• barometric pressure(bar_pres)
• Relative humidity inside the instrument enclosure(rh)
• Mean Wind Speed(wspd)
• Unit Vector Wind Direction(wdir)

• Beam 0 Temperature(temp)
• Batter Voltage(vbat)
• Standard Deviation of wind direction(sd_deg)
• base time(base_time)
• Standard Deviation of Vapor Pressure(sd_vap_pres)
• Time offset of tweaks from base_time(time_offset)
• Dummy altitude for Zeb(alt)
• Mean Wind Speed(wspd)
• barometric pressure(bar_pres)
• Standard Deviation of Relative Humidity(sd_rh)
• Wind Speed (vector averaged)(wspd_va)
• Vapor Pressure (kiloPascals)(vap_pres)
• Standard Deviation of Wind Speed(sd_wspd)
• Snow Depth(snow)
• Snow Depth Sensor(snow_sen)
• Hourly precipitation(precip)
• lon(lon)
• Standard Deviation of Barometric Pressure(sd_bar_pres)
• lat(lat)
• Unit Vector Wind Direction(wdir)
• Relative humidity inside the instrument enclosure(rh)
• Standard Deviation of Air Temperature(sd_temp)

• Time of Minimum Vapor Pressure(time_min_vap_pres)
• Time of Maximum Vapor Pressure(time_max_vap_pres)
• maximum wind speed (gusts)(max_wspd)
• Maximum Relative Humidity(max_rh)
• Minimum Temperature(min_temp)
• Time of Maximum Snow Depth(time_max_snow)
• Time of Minimum Relative Humidity(time_min_rh)
• time(time)
• Maximum Barometric Pressure(max_bar_pres)
• Minimum Barometric Pressure(min_bar_pres)
• base time(base_time)
• Time offset of tweaks from base_time(time_offset)
• Time of Minimum Wind Speed(time_min_wspd)
• Time of Minimum Temperature(time_min_temp)
• Time of Minimum Barometric Pressure(time_min_bar_pres)
• Maximum Snow Depth(max_snow)
• Minimum Relative Humidity(min_rh)
• Maximum Vapor Pressure(max_vap_pres)
• lat(lat)
• Time of Minimum Snow Depth(time_min_snow)
• Time of Maximum Temperature(time_max_temp)
• Minimum Snow Depth(min_snow_depth)
• Maximum Temperature(max_temp)
• lon(lon)
• Dummy altitude for Zeb(alt)
• Minimum of Wind speed(min_wspd)
• Time of Maximum Relative Humidity(time_max_rh)
• Time of Maximum Barometric Pressure(time_max_bar_pres)
• Time of Maximum Wind Speed(time_max_wspd)
• Minimum Vapor Pressure(min_vap_pres)

SGP/SMOS/E27 - Wind data incorrect and/or suspect

A recent ice storm caused the wind speed and wind direction values to flat line to zero.  
Both values came back on 1/29/09, but wind direction flat lined at 355 degrees.  The wind 
direction values appear to recover on the 02/10/2009 but are still suspect.  The wind 
sensor was replaced on 02/24/2009.

• Wind Speed (vector averaged)(wspd_va)
• Mean Wind Speed(wspd)
• Unit Vector Wind Direction(wdir)
• qc_wspd
• qc_wspd_va
• qc_wdir

• Standard Deviation of Wind Speed(sd_wspd)
• qc_wdir
• Wind Speed (vector averaged)(wspd_va)
• Unit Vector Wind Direction(wdir)
• qc_wspd
• qc_sd_wspd
• Mean Wind Speed(wspd)

• maximum wind speed (gusts)(max_wspd)
• Minimum of Wind speed(min_wspd)
• Time of Minimum Wind Speed(time_min_wspd)
• Time of Maximum Wind Speed(time_max_wspd)

SGP/SMOS/E27 - Intermittent wind direction problems

Wind direction was intermittently sticking in the 355 degree range throughout the time 
period.

• Unit Vector Wind Direction(wdir)
• Standard Deviation of wind direction(sd_deg)
• qc_sd_deg
• qc_wdir

• qc_wdir
• Unit Vector Wind Direction(wdir)
• qc_sd_deg
• Standard Deviation of wind direction(sd_deg)