DQR ID | Subject | Data Streams Affected |
---|---|---|
D020628.1 | SGP/EBBR/E12 - 3-month Check | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D020628.15 | SGP/EBBR/E12 - T/RH Check | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D940106.2 | SGP/EBBR/E12 - Invalid data due to blown AEM fuse at E12 | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D940616.3 | SGP/EBBR/E12 - Wind Direction | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D940711.3 | SGP/EBBR/E12 - Aspirator Failure | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D940808.2 | SGP/EBBR/E12 - Stopped Ventilation Fan | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D940909.1 | SGP/EBBR/E12 - Miscellaneous Problems Affecting Data | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D941021.12 | SGP/EBBR/E12 - Net Radiometer Hemisphere Changes | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D941021.6 | SGP/EBBR/E12 - Low home_15 Values | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D950626.15 | SGP/EBBR/E12 - Wind Direction Malfunction | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D950626.16 | SGP/EBBR/E12 - Wind Direction Malfunction | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D950719.2 | SGP/EBBR/E12 - Wind Direction Malfunction | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
D950908.3 | SGP/EBBR/E12 - Wind Direction Malfunction | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
10/14/1995 | 1400 | 10/14/1995 | 1700 |
Subject: | SGP/EBBR/E12 - 3-month Check |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | During EBBR 3 month checks the Automatic Exchange Mechanism is disabled (reflected by home signals near zero) so that the two aspirator units can be placed at the same height. The measurements during this period, at least, do not produce correct outputs of bowen ratio (bowen), sensible heat flux (h), or latent heat flux (e), nor do the air temperature and relative humidity measurements indicate gradients. Checks performed before or after the AEM is disabled also lead to some incorrect data. |
Measurements: | sgp15ebbrE12.b1:
sgp30ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/23/1994 | 1515 | 11/23/1994 | 1630 |
Subject: | SGP/EBBR/E12 - T/RH Check |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | During the month of November 1994, site operations personnel conducted field comparisons of the temperature and relative humidity sensors in the EBBRs and the HMI31 portable T/RH meter (with the removable probe). As is reflected in the home signal output, the automatic exchange mechanism was disabled in order to conduct the checks. Measurements were taken every 5 minutes, for a half hour each in the aspirated radiation shields (the HMI31 was inserted into the EBBR aspirated radiation shield to provide the same aspiration as the EBBR sensors received). Measurements of aspirator flow were also recorded. This information was provided to the mentor. The mentor then compared the field checks with the data recorded by the EBBRs. The periods of data and data fields that are incorrect because of the checks are listed below. Times are those at which the data are reported. Data Fields 5 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot 15 minute: rr_thum_r, rr_thum_l, mv_hum_r, mv_hum_l, tair_r, tair_l 30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot, bowen, e, h 5 minute: 1515, 1520, 1525, 1530, 1535, 1540, 1545, 1550, 1555, 1600, 1605, 1610 15 minute: 1515, 1530, 1545, 1600, 1615 30 minute: 1530, 1600, 1630 (EDITOR'S NOTE: The following analysis refers to all EBBRs installed in Nov 1994) Results of the T/RH comparisons: The combined accuracy of the HMI31 and EBBR temperature sensors (thermocouples or PRTDs) is +/- 0.4 degrees C. The combined accuracy of the HMI31 and EBBR RH sensors is +/- 4% for RH less than 80%, and +/- 6% for RH greater than 80%. The combined accuracy for each pair of EBBR sensors of the same type is essentially the same as the quantities stated above. All of the pairs of EBBR sensors show differences that fall within the stated combined accuracies. Although this sounds wonderful, a few of the differences are close to the combined accuracy, which, because of the small differences in temperature being measured (normally smaller than the magnitude of the combined accuracy) could lead to some incorrect estimation of sensible and latent heat flux. However, unless there would be substantial differences of calibration slope of two sensors in a pair, the switching of height of the sensors every 15 minutes by the automatic exchange mechanism will remove the offset between the sensors. The comparisons between the EBBR sensors and the HMI31 T/RH meter showed much larger differences. The range of differences were: -2.4 to 0.0 degrees for the thermocouples, -2.1 to 0.1 degrees for the RH probe PRTDs, and -6.6 to 6.7 percent for the RH sensors. Six Thermocouples indicated differences from the HMI31 greater than the combined accuracy. Seven PRTDs indicated differences from the HMI31 greater than the combined accuracy. Four RH sensors indicated differences from the HMI31 greater than the combined accuracy. The temperature differences (for both thermocouples and PRTDs) were nearly all of one sign; the HMI31 indicated the greater temperature, which may suggest a bias in the HMI31 temperature measurement, even though a dozen differences of +/- 0.2 degrees were measured. Four differences of zero and only one positive difference (out of 40) were measured. Thirteen of the 20 RH differences were positive (HMI31 indicating the lower RH), with the differences near the level of the combined accuracies being approximately 50% positive and 50% negative. It does not appear that the HMI31 has a RH bias. Plots of EBBR sensor/HMI31 differences as a function of time from the installation of the individual sensors (a range of 10 to 30 months in the field) shows no obvious pattern of sensor drift with time. This is encouraging. |
Measurements: | sgp15ebbrE12.b1:
sgp30ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/20/1993 | 0730 | 12/22/1993 | 1500 |
Subject: | SGP/EBBR/E12 - Invalid data due to blown AEM fuse at E12 |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | On December 20, 1993, before 0730 GMT, the fuse in the AEM (Automatic Exchange Mechanism) of Pawhuska, OK (E12) EBBR blew out. The AEM remained nonfunctional until the fuse was replaced just before 1500 GMT on December 22, 1993. This situation resulted in the following invalid data: 5 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot, home 15 minute: rr_thum_r, rr_thum_l, mv_hum_r, mv_hum_l, mv_home, tair_r, tair_l 30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot, bowen, e, h, home_15, home_30 Bowen, h, and e can not be recalculated from the 15 minute and/or 5 minute data since we cannot determine the position of the sensors on the AEM from the home signal; home signal is near zero when there is no power to the AEM. |
Measurements: | sgp15ebbrE12.b1:
sgp30ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
06/03/1994 | 1200 | 06/08/1994 | 1515 |
Subject: | SGP/EBBR/E12 - Wind Direction |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | For much of the period above, a malfunction in the E12 EBBR wind direction sensor (insect larvae shorting out the circuit board) caused incorrect values for 5 minute res_ws, wind_d, and sigma_wd, 15 minute mv_wind_d, and 30 minute res_ws, wind_d, and sigma_wd. Wind direction normally indicated north (near 0 or 360 degrees); there were some times during the period when wind directions looked good, but the lack of variation in direction and sigma implies that the data is suspect. Therefore, it would be wise to flag all of the values listed above during the entire time period as incorrect. The wind direction sensor (S/N 3081) was replaced with S/N 3042 at 1515 GMT on June 8, 1994. |
Measurements: | sgp30ebbrE12.b1:
sgp15ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
06/18/1994 | 2000 | 06/22/1994 | 1600 |
Subject: | SGP/EBBR/E12 - Aspirator Failure |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | On June 18, 1994 the aspirator fan in the EBBR at E12, Pawhuska stopped working. This situation was not discovered until a Preventative Maintenance visit by site operations personnel on June 22, 1994. I determined the time of the beginning of the malfunction from close inspection of the sensible and latent heat flux data. There is no aspiration status output for the EBBRs, nor is one presently possible. Wind speeds during most of the period listed were sufficient to provide some (although inadequate) aspiration to the temperature and relative humidity probes, making it difficult for most users of the data to be able to tell (except in a few circumstances) that the sensible and latent heat flux values produced were incorrect. All of the data fields listed below are incorrect for the period listed above. Latent and Sensible heat fluxes cannot be recomputed, as the measurements that they are based on are what was corrupted. 30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot, bowen, e, h 15 minute: rr_thum_r, rr_thum_l, mv_hum_r, mv_hum_l, tair_r, tair_l 5 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot |
Measurements: | sgp15ebbrE12.b1:
sgp30ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
07/22/1994 | 1200 | 08/04/1994 | 1600 |
Subject: | SGP/EBBR/E12 - Stopped Ventilation Fan |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | On August 4, 1994, a site operator discovered the ventilation fan of the EBBR to be stopped; the fan guard was clogged with animal remains. Inspection of the EBBR data from Pawhuska, OK, E12 indicates that this condition occurred from July 22 through August 4. Lack of ventilation of the temperature and relative humidity sensors attached to the AEM results in questionable measurements of air temperature, relative humidity, and all quantities calculated from them, including sensible and latent heat fluxes. The quantities that are questionable for the period indicated are: 5 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, and vp_bot 15 minute: rr_thum_r, rr_thum_l, mv_hum_r, mv_hum_l, tair_r, tair_l 30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot, bowen, e, h |
Measurements: | sgp15ebbrE12.b1:
sgp30ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/20/1994 | 0230 | 08/31/1994 | 1542 |
Subject: | SGP/EBBR/E12 - Miscellaneous Problems Affecting Data |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | Three hardware problems occurred at E12, Pawhuska, OK in late August 1994. On August 12 the wind direction sensor malfunctioned. Therefore, all wind direction, sigma, and resultant wind speed values for the period above are incorrect. The wind direction sensor was replaced on August 31. Affected data are: 5 minute: wind_d, sigma_wd, res_ws 15 minute: mv_wind_d 30 minute: wind_d, sigma_wd, res_ws. Water accumulated in the AEM motor box and apparently caused a reduction in the voltage level of the home signal (battery condition was very good and so was not the cause); by late August 27 the hom30 level had fallen below the minimum qc check level. The AEM continued to exchange properly. The minimum qc level check is intended to help detect either a non-operating AEM or low battery condition. The Campbell CR10 software operates properly unless the hom30 signal is thirty-five or greater. So the low hom30 values do not result in any incorrect data!!!. I point this out because this situation demonstrates a condition flagged by the qc checks, even though no effect on the data has occurred. The AEM box was dried out and new dessicant placed in it on August 31. On August 28, 1994 the left AEM housing ventilation fan ceased to operate because of clogging of the ventilation system with debris. Fifteen minute data seems to indicate that the fan stopped operating just before 1245 GMT. This is at least the third such incidence of clogging this summer at different EBBRs. The clog was removed and ventilation restored on August 31. The lack of ventilation caused improper measurements of temperature and relative humidity in the left housing (these are quite obvious in the 15 minute data but difficult to detect in the 30 minute data) and therefore incorrect values of sensible and latent heat. Affected data are: 5 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot 15 minute: rr_thum_l, mv_hum_l, tair_l 30 minute: tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot, bowen, e, h. |
Measurements: | sgp30ebbrE12.b1:
sgp15ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
09/15/1994 | 1600 | 09/29/1994 | 1430 |
Subject: | SGP/EBBR/E12 - Net Radiometer Hemisphere Changes |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | The upper hemisphere of the net radiometer at the site was punctured allowing water to collect in the lower (and sometimes upper) section of the sensor. The punctures are most likely the result of migratory birds (a problem that we have experienced almost every year here at ANL also). The punctures (and water in some net radiometers) did not result in obvious invalidation of the data. Whether there is water in the lower hemisphere or not, a small puncture of the upper hemisphere would not have a major effect on the net radiation measurement. Significant amounts of water in the lower hemisphere should have a major effect on nighttime measurements particularly, although that effect is hard to detect in the data. The date when the puncture occurred is approximate - but is certainly no more than two weeks before the hemisphere was replaced. |
Measurements: | sgp30ebbrE12.b1:
sgp15ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
09/03/1994 | 1900 | 09/15/1994 | 1330 |
Subject: | SGP/EBBR/E12 - Low home_15 Values |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | The home signal values for the EBBR system installed at E12, Pawhuska, OK have generally been lower than for the other EBBR systems. However, during the period above the home_15 value was often lower than 35, which is then improperly interpreted by the CR10 software. A home_15 value less than 35 is interpreted as meaning that the AEM aspirated housings (which hold the temperature and relative humidity sensors) are in the opposite orientation to what they actually are. The AEM continues to exchange properly, but the resulting calculations of Bowen ratio, latent heat flux, and sensible heat flux are incorrect. On September 15, 1994 Site Operations personnel refurbished the wiring for the left housing and the home_15 signal returned to proper levels. When 30 minute home_15 values are below 35, the data fields listed below are incorrect. 5 minute: home, tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot 15 minute: mv_home 30 minute: home_15, tair_top, tair_bot, thum_top, thum_bot, hum_top, hum_bot, vp_top, vp_bot, Bowen, e, h It is possible to recalculate the Bowen ratio, e, and h by using the 15 minute data to compute the correct gradients of temperature and relative humidity (two 15 minute periods are averaged to give a half hour value); the orientation of the AEM is obvious in the 15 minute data, based on the home signal (which is largest for the first 15 minutes of the half hour). More information on performing this recalculation can be obtained from the mentor. |
Measurements: | sgp15ebbrE12.b1:
sgp30ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
04/23/1995 | 0020 | 04/26/1995 | 1630 |
Subject: | SGP/EBBR/E12 - Wind Direction Malfunction |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | For most of the period above, a malfunction in the E12 EBBR wind direction sensor caused the following data values to be incorrect: 5 minute: res_ws, wind_d, and sigma_wd 15 minute: mv_wind_d 30 minute: res_ws, wind_d, and sigma_wd. Wind direction normally indicated near north or 135 degrees (the latter indicates a malfunction). The wind direction sensor (S/N 3036) was replaced with S/N 3034 at 1620 GMT on April 26, 1995. |
Measurements: | sgp30ebbrE12.b1:
sgp15ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
06/06/1995 | 0700 | 06/07/1995 | 1830 |
Subject: | SGP/EBBR/E12 - Wind Direction Malfunction |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | For the period indicated, a malfunction in the E12 EBBR wind direction sensor caused the following data values to be incorrect: 5 minute: res_ws, wind_d, and sigma_wd 15 minute: mv_wind_d 30 minute: res_ws, wind_d, and sigma_wd. Wind direction normally indicated smaller or larger than it should have. The affected time period was determined from comparison with data from E7, Elk Falls EBBR, which is located north of E12. The wind direction sensor (S/N 3034) was replaced with S/N 3039 at 1822 GMT on June 7, 1995. |
Measurements: | sgp30ebbrE12.b1:
sgp15ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
07/03/1995 | 0600 | 07/07/1995 | 1605 |
Subject: | SGP/EBBR/E12 - Wind Direction Malfunction |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | For the period indicated, a malfunction in the E12 EBBR wind direction sensor caused the following data values to be incorrect: 5 minute: res_ws, wind_d, and sigma_wd 15 minute: mv_wind_d 30 minute: res_ws, wind_d, and sigma_wd. Wind direction normally indicated small values (15 to 25 degrees) from 3 July 1995 at 0600 GMT through 6 July 1995 at 1500 GMT (at which time the sensor was removed). No sensor was in place between 6 July 1995 at 1500 GMT and 7 July 1995 at 1605 GMT (at which time a new sensor was installed). Old sensor S/N K3039, new S/N K3033. |
Measurements: | sgp30ebbrE12.b1:
sgp15ebbrE12.b1:
sgp5ebbrE12.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/16/1995 | 0015 | 08/30/1995 | 1757 |
Subject: | SGP/EBBR/E12 - Wind Direction Malfunction |
DataStreams: | sgp5ebbrE12.b1, sgp15ebbrE12.b1, sgp30ebbrE12.b1 |
Description: | For the period above, a malfunction in the E12 EBBR wind direction sensor caused the wind direction to output a constant 212 degrees. Site operations replaced the sensor (S/N K3033) with K3042. The following data values are incorrect for the period listed: 5 minute: res_ws, wind_d, and sigma_wd 15 minute: mv_wind_d 30 minute: res_ws, wind_d, and sigma_wd. |
Measurements: | sgp30ebbrE12.b1:
sgp15ebbrE12.b1:
sgp5ebbrE12.b1:
|