DQR ID | Subject | Data Streams Affected |
---|---|---|
D040525.3 | SGP/EBBR/E19 - Metadata errors | sgp15ebbrE19.b1, sgp30baebbrE19.c1, sgp30ebbrE19.b1 |
D061220.11 | SGP/EBBR/E19 - Wind Direction Dependency of Surface Fluxes and General Data Quality Information | sgp30ebbrE19.b1 |
D971017.3 | SGP/EBBR/E19 - Reprocess: E19 EBBR Soil heat Flow Probe #5 Upsidedown | sgp15ebbrE19.b1, sgp30ebbrE19.b1 |
D980110.1 | SGP/EBBR/E19 - Battery Voltage Drop | sgp15ebbrE19.b1, sgp30ebbrE19.b1, sgp5ebbrE19.b1 |
D980110.2 | SGP/EBBR/E19 - Noisy Sensible and Latent Heat Fluxes | sgp30ebbrE19.b1, sgp5ebbrE19.b1, sgp15ebbrE19.b1 |
D980416.15 | SGP/EBBR/E19 - 3-Month Check | sgp15ebbrE19.b1, sgp30ebbrE19.b1, sgp5ebbrE19.b1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/30/1997 | 0000 | 05/06/2003 | 2359 |
Subject: | SGP/EBBR/E19 - Metadata errors |
DataStreams: | sgp15ebbrE19.b1, sgp30baebbrE19.c1, sgp30ebbrE19.b1 |
Description: | The latitude, longitude and altitude of the El Reno (E19) site were incorrectly entered into the ARM database. The correct location of the EBBR.E19 instrument is: Lat: 35.557N Lon: 98.017W Alt: 421m |
Measurements: | sgp15ebbrE19.b1:
sgp30ebbrE19.b1:
sgp30baebbrE19.c1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/30/1997 | 1000 | 10/12/2003 | 2330 |
Subject: | SGP/EBBR/E19 - Wind Direction Dependency of Surface Fluxes and General Data Quality |
DataStreams: | sgp30ebbrE19.b1 |
Description: | Beginning in FY2006, Data Quality Reports are not written for missing data or for situations when qc flags clearly show that the data is incorrect (this is true for most of the conditions listed below). DQRs are written for periods when data is incorrect, when the situation is not represented by qc flags in the data, and it's not obvious that the data should have been flagged as incorrect. The EBBR data is only useful for particular wind directions at each Extended Facility. Please use the following resources to help in interpreting the EBBR data. 1) qc flags in the EBBR data. 2) Instrument Mentor Monthly Summaries (IMMS) at http://www.db.arm.gov/IMMS/ 3) SGP EF Surface Conditions Observations (EFSCO) at http://198.124.96.210:591/sfc_cond1/default.htm 4) Surface fluxes are valid only for the following wind directions (in degrees): 0-133, 151-360 Note that there are wind directions at most sites for which the fetch is insufficient and therefore EBBR data is invalid. Appropriate fetch was determined from a 1/40 measurement height to fetch ratio, resulting in a required minimum fetch of 120 m. Particular attention should be paid to the limited valid wind directions for the Central Facility EBBR. The surface vegetation type for the EBBRs is grazed or ungrazed grassland (refer to the EFSCO for state). 5) Some conditions that commonly cause the EBBR primary measurements to be incorrect or missing follow: a) Sensible and latent heat fluxes are not accurate during times when the Automatic Exchange Mechanism (AEM) is not functioning properly. The AEM switches the gradient measuring instrumentation between the top and bottom positions every 15 minutes; this reduces the effects of instrument offsets. Sometimes the AEM does not reach it's full extent of travel, resulting in the home signal being zero. b) Sensible and latent heat fluxes are sometimes incorrect when surface soil heat flow is out of range, as seen in the average soil heat flux (ave_shf). c) Very light winds may be seen at nights for brief periods. Wind direction flops around a lot during low wind conditions (< 1.5 m/s) and is often unreliable during those periods. d) Missing data periods occur at times; this is usually a site data system collection/communication problem; it can also occur during replacement of the system with a newly calibrated unit. Missing data is sometimes filled in later from manual or automatic re-collection of the data. |
Measurements: | sgp30ebbrE19.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/30/1997 | 1000 | 08/14/1997 | 1500 |
Subject: | SGP/EBBR/E19 - Reprocess: E19 EBBR Soil heat Flow Probe #5 Upsidedown |
DataStreams: | sgp15ebbrE19.b1, sgp30ebbrE19.b1 |
Description: | Soil heat flow probe #5 was installed upsidedown at the initial installation of the EBBR system. The data from it had the wrong sign. Site operations personnel reversed its orientation in the soil on August 14, 1997, thereby correcting the problem. Values affected (and thus incorrect) include: 15 minute: mv_hft5 30 minute: shf5, c_shf5, g5, ave_shf, e, h. The latent and sensible heat fluxes can be recalculated by reversing the sign of cshf5, adding it to ces5 and recomputing the average soil heat flow, ave_shf = (g1 + g2 + g3 + g4 + g5)/5 e = -(q + ave_shf)/(1 + bowen) h = -(e + ave_shf + q). |
Measurements: | sgp15ebbrE19.b1:
sgp30ebbrE19.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/30/1997 | 1500 | 12/31/1997 | 1520 |
Subject: | SGP/EBBR/E19 - Battery Voltage Drop |
DataStreams: | sgp15ebbrE19.b1, sgp30ebbrE19.b1, sgp5ebbrE19.b1 |
Description: | EBBR battery voltage at E19, El Reno, OK declined to lower than acceptable levels after long periods of clouds after initial installation. The low voltage condition worsened as Autumn progressed. In November 1997 the battery tested okay, but would not hold sufficient capacity at night or during extended periods of clouds to keep the voltage high enough for the EBBR to work properly. At my request, the battery was replaced with a brand new battery on 31 December 1997. The new battery is presently maintaining voltage level at night. The voltage dropped to 10 volts or less many days before the battery change. Voltages less than 10.3 volts affected a wide range of measured values, but at different times. When the voltage was much below 10 volts the home signal became very large (several volts), a quirk of the AEM circuitry. At various times, latent and sensible heat fluxes, soil temperature, air temperature, relative humidity, vapor pressure, wind direction, soil heat flux plate output, home signal, and atmospheric pressure (at least) were not reported correctly by the CR10 datalogger. At least the sensible and latent heat fluxes should be considered to be incorrect when the battery voltage is less than 10.3 volts. The battery voltage is found in the 15 minute data. |
Measurements: | sgp15ebbrE19.b1:
sgp5ebbrE19.b1:
sgp30ebbrE19.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/30/1997 | 1500 | 07/20/1999 | 1530 |
Subject: | SGP/EBBR/E19 - Noisy Sensible and Latent Heat Fluxes |
DataStreams: | sgp30ebbrE19.b1, sgp5ebbrE19.b1, sgp15ebbrE19.b1 |
Description: | "Noisy" sensible and latent heat fluxes often occur during daytime periods when the net radiation is smaller (less than 150 watts/m2), but this is not the only condition under which it occurs. During this condition especially, the temperature gradient, RH gradient, and thus the vapor pressure gradient are near zero; this causes the sensible and latent heat flux gradients to be inaccurately calculated. Good examples of these conditions occurred on 28 December 1997 and 6 January 1998. However, even when there is substantial net radiation the problem does sometimes occur; good examples of this are found during daytime or nighttime variously on 1, 2, 3, and 4 January 1998. The conditions occur more fequently than at other EBBR sites; they do occur at other EBBR sites, but less frequently. |
Measurements: | sgp15ebbrE19.b1:
sgp5ebbrE19.b1:
sgp30ebbrE19.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
10/09/1997 | 1528 | 10/09/1997 | 1602 |
Subject: | SGP/EBBR/E19 - 3-Month Check |
DataStreams: | sgp15ebbrE19.b1, sgp30ebbrE19.b1, sgp5ebbrE19.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 these periods 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 correct gradients. Checks performed before or after the AEM is disabled also lead to some incorrect data. Incorrect 5, 15 minute and half hour data occurs for the period indicated. |
Measurements: | sgp15ebbrE19.b1:
sgp5ebbrE19.b1:
sgp30ebbrE19.b1:
|