DQR ID | Subject | Data Streams Affected |
---|---|---|
D020509.1 | NSA/C2/VCEIL - Occasional Data Transmission Problems | nsavceil25kC2.00, nsavceil25kC2.a1, nsavceil25kC2.b1 |
D020725.5 | NSA/ISSSONDE/C1 - Reprocess: Pressure variable name unstable | nsaisssonde10sC1.a1, nsaisssondeC1.a1 |
D030312.6 | SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures | nsamwrlosC1.a1, nsamwrlosC1.b1 |
D030312.7 | NSA/MWR/C2 - Intermittent Negative Sky Brightness Temperatures | nsamwrlosC2.b1 |
D030822.7 | NSA/MWR/C1 - min/max/delta values incorrect | nsamwrlosC1.b1 |
D041208.2 | NSA/SONDE/C1 - Incorrect surface altitude | nsaisssonde10sC1.00, nsaisssonde10sC1.a1, nsaisssondeC1.00, nsaisssondeC1.a1 |
D050725.8 | NSA/MWR/C2 - Reprocessed: Revised Retrieval Coefficients | nsamwrlosC2.b1, nsamwrtipC2.a1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/07/2001 | 0000 | 01/27/2002 | 0000 |
Subject: | NSA/C2/VCEIL - Occasional Data Transmission Problems |
DataStreams: | nsavceil25kC2.00, nsavceil25kC2.a1, nsavceil25kC2.b1 |
Description: | A combination of problems lead to occasional short period loss (usually lesss than 2 minutes) of data for ceilometer during this period. |
Measurements: | nsavceil25kC2.b1:
nsavceil25kC2.a1:
nsavceil25kC2.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
04/01/2001 | 0000 | 01/13/2002 | 2359 |
Subject: | NSA/ISSSONDE/C1 - Reprocess: Pressure variable name unstable |
DataStreams: | nsaisssonde10sC1.a1, nsaisssondeC1.a1 |
Description: | During the time period referenced, the variable for pressure should have been recorded as "pres", but instead was recorded as "press" for the first 8 months and then was unstable for the next 2 months with some headers reporting pressure as "pres" and others reporting pressure as "press". From 1/14/02 onward the variable name is consistently "pres". Data quality are not affected, but the variability may prove challenging for users. A reprocessing request has been submitted. |
Measurements: | nsaisssonde10sC1.a1:
nsaisssondeC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/07/1999 | 1800 | 09/16/2002 | 1820 |
Subject: | SGP/MWR/C1 - Intermittent Negative Sky Brightness Temperatures |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1 |
Description: | Several related and recurring problems with the MWRs have been reported dating back to 1999. These problems were due to the occurrence of blackbody signals (in counts) that were half of those expected. The symptoms included noisy data, spikes in the data, negative brightness temperatures, and apparent loss of serial communication between the computer and the radiometer, which results in a self-termination of the MWR program. Because these all initially appeared to be hardware-related problems, the instrument mentor and site operations personnel (1) repeatedly cleaned and replaced the fiber optic comm. components, (2) swapped radiometers, (3) sent radiometers back to Radiometrics for evaluation (which did not revealed any instrument problems), and (4) reconfigured the computer's operating system. Despite several attempts to isolate and correct it, the problem persisted. It became apparent that some component of the Windows98 configuration conflicted with the DOS-based MWR program or affected the serial port or the contents of the serial port buffer. This problem was finally corrected by upgrading the MWR software with a new Windows-compatible program. |
Measurements: | nsamwrlosC1.a1:
nsamwrlosC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
02/15/2000 | 0600 | 09/16/2002 | 1900 |
Subject: | NSA/MWR/C2 - Intermittent Negative Sky Brightness Temperatures |
DataStreams: | nsamwrlosC2.b1 |
Description: | Several related and recurring problems with the MWRs have been reported dating back to 1999. These problems were due to the occurrence of blackbody signals (in counts) that were half of those expected. The symptoms included noisy data, spikes in the data, negative brightness temperatures, and apparent loss of serial communication between the computer and the radiometer, which results in a self-termination of the MWR program. Because these all initially appeared to be hardware-related problems, the instrument mentor and site operations personnel (1) repeatedly cleaned and replaced the fiber optic comm. components, (2) swapped radiometers, (3) sent radiometers back to Radiometrics for evaluation (which did not revealed any instrument problems), and (4) reconfigured the computer's operating system. Despite several attempts to isolate and correct it, the problem persisted. It became apparent that some component of the Windows98 configuration conflicted with the DOS-based MWR program or affected the serial port or the contents of the serial port buffer. This problem was finally corrected by upgrading the MWR software with a new Windows-compatible program. |
Measurements: | nsamwrlosC2.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
01/02/1998 | 0000 | 02/08/2003 | 2359 |
Subject: | NSA/MWR/C1 - min/max/delta values incorrect |
DataStreams: | nsamwrlosC1.b1 |
Description: | The values of valid_min, valid_max, and valid_delta for fields tkxc and tknd were incorrect. They should be 303, 333, and 0.5 K, respectively. |
Measurements: | nsamwrlosC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
05/21/1998 | 0000 | 05/10/2002 | 2359 |
Subject: | NSA/SONDE/C1 - Incorrect surface altitude |
DataStreams: | nsaisssonde10sC1.00, nsaisssonde10sC1.a1, nsaisssondeC1.00, nsaisssondeC1.a1 |
Description: | The value of the station altitude (relative to mean sea level) is incorrect in all NSA radiosonde files prior to 2/14/2004. The correct value is 8 m. The incorrect value can be different. Prior to 4/24/2002 (in platform nsaisssonde...) it was given as 12 m. From 4/24/2002 to 2/13/2004 (in platform nsasondewnpn...) it is almost always given as 27 m (sometimes [rarely] 17 m). |
Measurements: | nsaisssonde10sC1.a1:
nsaisssonde10sC1.00:
nsaisssondeC1.a1:
nsaisssondeC1.00:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
10/18/1999 | 0000 | 06/29/2005 | 0000 |
Subject: | NSA/MWR/C2 - Reprocessed: Revised Retrieval Coefficients |
DataStreams: | nsamwrlosC2.b1, nsamwrtipC2.a1 |
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 water 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). The Rosenkranz-based retrieval coefficients became active at NSA.C2 20020418.1700. The MONORTM-based retrieval coefficients became active at NSA.C2 20050629.0000. Note: The NSA.C2 MWRLOS data for 19991018-20050630 have been reprocessed to apply the MONORTM-based retrievals for all time. The reprocessed data were archived in March 2007. The TIP data have not been reprocessed. |
Measurements: | nsamwrlosC2.b1:
nsamwrtipC2.a1:
|