DQR ID | Subject | Data Streams Affected |
---|---|---|
D040907.1 | SGP/SIRS/C1/E13 - Incorrect calibration coefficients | sgpsirsC1.00, sgpsirsC1.b1, sgpsirsE13.00, sgpsirsE13.b1, sgpsirs20sC1.a0, sgpsirs20sE13.a0 |
D050106.4 | SGP/SIRS/C1 - Reprocess: UIR/DIR Incorrect calibration coefficients | sgpsirsC1.00, sgpsirsC1.b1 |
D050206.2 | SGP/SIRS/C1 - Monthly Summary | sgpsirsC1.b1 |
D050722.1 | SGP/MWR/C1 - REPROCESS - Revised Retrieval Coefficients | sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgpmwrtipC1.a1, sgp1mwravgC1.c1, sgp5mwravgC1.c1, sgpqmemwrcolC1.c1 |
D060630.8 | SGP/SIRS/C1 - Reprocess: Longwave Calibration error | sgpsirsC1.b1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/27/2004 | 1830 | 09/07/2004 | 2130 |
Subject: | SGP/SIRS/C1/E13 - Incorrect calibration coefficients |
DataStreams: | sgpsirsC1.00, sgpsirsC1.b1, sgpsirsE13.00, sgpsirsE13.b1, sgpsirs20sC1.a0, sgpsirs20sE13.a0 |
Description: | After the DIR changeout on 8/27, the DLH measurements at the central facility vary significantly between pyrgeometers by as much as 65 Wm^(-2). It was discovered that the two downwelling pyrgeometers destined for C1 and E13 may have been swapped during installation. The instrument mentor is unsure of applied calibration coefficients during this DQR's time period. Backing out new downwelling longwave irradiances would be difficult in this case. Fortunately, the problem period is less than a fortnight. |
Measurements: | sgpsirsE13.b1:
sgpsirsC1.b1:
sgpsirsC1.00:
sgpsirs20sE13.a0:
sgpsirs20sC1.a0:
sgpsirsE13.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
09/27/2004 | 1429 | 01/07/2005 | 1623 |
Subject: | SGP/SIRS/C1 - Reprocess: UIR/DIR Incorrect calibration coefficients |
DataStreams: | sgpsirsC1.00, sgpsirsC1.b1 |
Description: | It appears the datalogger program at SIRS/C1 was automatically updated, unbeknownst to anyone, on 9/27/20041423GMT with an older program with incorrect UIR and DIR calibration coefficients. The correct and incorrect cal coeffs for the UIR and DIR pyrgeometers during this DQR period were: incorrectUIR correctUIR K0 -12.84 -13.00 K1 .2250 0.2573 K2 1.024 1.024 K3 -1.9280 -1.8050 incorrectDIR correctDIR K0 -13.15 -26.89 K1 0.2374 0.2967 K2 1.0260 1.0560 K3 -2.478 -3.3080 |
Measurements: | sgpsirsC1.b1:
sgpsirsC1.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/01/2004 | 0000 | 01/01/2005 | 0000 |
Subject: | SGP/SIRS/C1 - Monthly Summary |
DataStreams: | sgpsirsC1.b1 |
Description: | dominant problem here is the daytime 3 component problem. Direct and Diffuse are always too high and Global is too low. The problem occurs around the time that the testing regime switches from twilight to daytime testing regimes or from daytime to twilight. The flags occur in significant numbers on the 1st - 5th, 8th - 20th, 24th - 28th, 30th, and 31st. The failures vary in magnitude and duration. The worst flags for a particular day is typically high level yellow, with respect to this problem. Global goes below daytime empirical limits on both the 5th and 6th for substantial periods of time. Diffuse also goes below daytime empirical limits on the 6th in the evening. Upwelling Longwave is below empirical limits on the 24th. This may not be a problem, as many sites exhibited the same problem on the same night. Exceptionally cold temperatures may be the cause. Direct also exceeds its daytime empirical limit on the 1st, 4th, 10th, 13th, 14th, and 20th. This occurs at the changeover from medium to high air mass and does not last for longer than 30 minutes. |
Measurements: | sgpsirsC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
04/16/2002 | 2000 | 06/28/2005 | 2300 |
Subject: | SGP/MWR/C1 - REPROCESS - Revised Retrieval Coefficients |
DataStreams: | sgpmwrlosC1.a1, sgpmwrlosC1.b1, sgpmwrtipC1.a1, sgp1mwravgC1.c1, sgp5mwravgC1.c1, sgpqmemwrcolC1.c1 |
Description: | IN THE BEGINNING (June 1992), the retrieval coefficients used to derive the precipitable water vapor (PWV) and liquid water path (LWP) from the MWR brightness temperatures were based on the Liebe and Layton (1987) water vapor and oxygen absorption model and the Grant (1957) liquid water absorption model. Following the SHEBA experience, revised retrievals based on the more recent Rosenkranz (1998) water vapor and oxygen absorption models and the Liebe (1991) liquid waer absorption model were developed. The Rosenkranz water vapor absorption model resulted a 2 percent increase in PWV relative to the earlier Liebe and Layton model. The Liebe liquid water absorption model decreased the LWP by 10% relative to the Grant model. However, the increased oxygen absorption caused a 0.02-0.03 mm (20-30 g/m2) reduction in LWP, which was particularly significant for low LWP conditions (i.e. thin clouds encountered at SHEBA). Recently, it has been shown (Liljegren, Boukabara, Cady-Pereira, and Clough, TGARS v. 43, pp 1102-1108, 2005) that the half-width of the 22 GHz water vapor line from the HITRAN compilation, which is 5 percent smaller than the Liebe and Dillon (1969) half-width used in Rosenkranz (1998), provided a better fit to the microwave brightness temperature measurements at 5 frequencies in the range 22-30 GHz, and yielded more accurate retrievals. Accordingly, revised MWR retrieval coefficients have been developed using MONORTM, which utilizes the HITRAN compilation for its spectroscopic parameters. These new retrievals provide 3 percent less PWV and 2.6 percent greater LWP than the previous retrievals based on Rosenkranz (1998). Although the MWR data will be reprocessed to apply the new monortm-based retrievals, for most purposes it will be sufficient to correct the data using the following factors: PWV_MONORTM = 0.9695 * PWV_ROSENKRANZ LWP_MONORTM = 1.026 * LWP_ROSENKRANZ The Rosenkranz-based retrieval coefficients became active as follows (BCR 456): SGP/C1 (Lamont) 4/16/2002, 2000 SGP/B1 (Hillsboro) 4/12/2002, 1600 SGP/B4 (Vici) 4/15/2002, 2300 SGP/B5 (Morris) 4/15/2002, 2300 SGP/B6 (Purcell) 4/16/2002, 2200 SGP/E14(Lamont) 4/16/2002, 0000 NSA/C1 (Barrow) 4/25/2002, 1900 NSA/C2 (Atqasuk) 4/18/2002, 1700 TWP/C1 (Manus) 5/04/2002, 0200 TWP/C2 (Nauru) 4/27/2002, 0600 TWP/C3 (Darwin) inception The MONORTM-based retrieval coefficients became active as follows (BCR 984): SGP/C1 (Lamont) 6/28/2005, 2300 SGP/B1 (Hillsboro) 6/24/2005, 2100 SGP/B4 (Vici) 6/24/2005, 2100 SGP/B5 (Morris) 6/24/2005, 2100 SGP/B6 (Purcell) 6/24/2005, 1942 SGP/E14(Lamont) 6/28/2005, 2300 NSA/C1 (Barrow) 6/29/2005, 0000 NSA/C2 (Atqasuk) 6/29/2005, 0000 TWP/C1 (Manus) 6/30/2005, 2100 TWP/C2 (Nauru) 6/30/2005, 2100 TWP/C3 (Darwin) 6/30/2005, 2100 PYE/M1 (Pt. Reyes) 4/08/2005, 1900** ** At Pt. Reyes, the original retrieval coefficients implemented in March 2005 were based on a version of the Rosenkranz model that had been modified to use the HITRAN half-width at 22 GHz and to be consistent with the water vapor continuum in MONORTM. These retrievals yield nearly identical results to the MONORTM retrievals. Therefore the Pt. Reyes data prior to 4/08/2005 may not require reprocessing. |
Measurements: | sgpmwrtipC1.a1:
sgp5mwravgC1.c1:
sgpmwrlosC1.b1:
sgp1mwravgC1.c1:
sgpqmemwrcolC1.c1:
sgpmwrlosC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/11/2003 | 1950 | 02/16/2006 | 1901 |
Subject: | SGP/SIRS/C1 - Reprocess: Longwave Calibration error |
DataStreams: | sgpsirsC1.b1 |
Description: | Modified pyrgeometer calibration procedures were implemented beginning in December 2003. These modified procedures introduced a calibration bias in the longwave data. The previous procedures were re-implemented at all sites between December 2005 and February 2006 to restore proper calibrations. The data collected while the incorrect procedures were in place are being reprocessing to remove the calibration bias. Note, this also affected standard deviation, maximum and minimum data fields. |
Measurements: | sgpsirsC1.b1:
|