SGP/SMOS/E3 - 6-month Calibration Checks

During the time periods specified, the SMOS.E3 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.

Calibration results are available from the OMIS database at 
    
http://www.ops.sgp.arm.gov:591/smos6cal/default.htm 
To view all 6-month calibration reports leave the date time entry blank.

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

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

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

SGP/SMOS/E3 - 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)