DQR ID | Subject | Data Streams Affected |
---|---|---|
D050725.7 | NSA/MWR/C1 - Reprocess: Revised Calibration Coefficients | nsa5mwravgC1.c1, nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1, nsaqmemwrcolC1.c1 |
D050809.2 | NSA/MWR/C1 - Possible loss of accuracy due to missing blower | nsamwrlosC1.b1, nsamwrtipC1.a1 |
D050919.5 | NSA/MWR/C1 - Missing Data | nsa5mwravgC1.c1, nsamwrC1.00, nsamwrlosC1.b1, nsamwrtipC1.a1 |
D050928.3 | NSA/MWR/C1 - New software version (4.15) installed | nsamwrlosC1.b1, nsamwrtipC1.a1 |
D050930.1 | NSA/MWR/C1 - Reprocess: wrong calibration | nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1 |
D061114.1 | NSA/MWR/C1 - Rain sensor always on | nsamwrlosC1.b1, nsamwrtipC1.a1 |
D080512.1 | NSA/MWR/C1 - Spikes in air temperature readings | nsamwrlosC1.b1, nsamwrtipC1.a1 |
D080623.1 | NSA/MWR/C1 - Missing surface air temperature data | nsamwrlosC1.b1, nsamwrtipC1.a1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
04/25/2002 | 1900 | 06/29/2005 | 0000 |
Subject: | NSA/MWR/C1 - Reprocess: Revised Calibration Coefficients |
DataStreams: | nsa5mwravgC1.c1, nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1, nsaqmemwrcolC1.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 at NSA.C1 20020425.1900. The MONORTM-based retrieval coefficients became active at NSA.C1 20050629.0000. Note: a reprocessing effort is already underway to apply the Rosenkranz-based retrieval coefficients to all MWR prior to April 2002. An additional reprocessing task will be undertaken to apply the MONORTM retrieval to all MWR data when the first is completed. Read reprocessing comments in the netcdf file header carefully to ensure you are aware which retrieval is in play. |
Measurements: | nsamwrlosC1.a1:
nsa5mwravgC1.c1:
nsaqmemwrcolC1.c1:
nsamwrlosC1.b1:
nsamwrtipC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
07/09/2005 | 2354 | 07/20/2005 | 0000 |
Subject: | NSA/MWR/C1 - Possible loss of accuracy due to missing blower |
DataStreams: | nsamwrlosC1.b1, nsamwrtipC1.a1 |
Description: | On 7/09 the MWR blower failed. The blower prevents snow and liquid drop from accumulating on the window. Accumulation of snow or liquid results in a loss of accuracy of the instrument. The loss of accuracy has consequencies on the retrieved liquid water path and precipitable water vapor. Usually there will be an overestimation of liquid and vapor. The blower was repaired and reinstalled on 7/20. Between 7/9 and 7/20 the tkair variable is unavailable as well. |
Measurements: | nsamwrtipC1.a1:
nsamwrlosC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
08/05/2005 | 1952 | 09/01/2005 | 1945 |
Subject: | NSA/MWR/C1 - Missing Data |
DataStreams: | nsa5mwravgC1.c1, nsamwrC1.00, nsamwrlosC1.b1, nsamwrtipC1.a1 |
Description: | Instrument was removed for repair. |
Measurements: | nsa5mwravgC1.c1:
nsamwrC1.00:
nsamwrlosC1.b1:
nsamwrtipC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
09/16/2002 | 1820 | 09/15/2005 | 1702 |
Subject: | NSA/MWR/C1 - New software version (4.15) installed |
DataStreams: | nsamwrlosC1.b1, nsamwrtipC1.a1 |
Description: | A problem began with the installation of MWR.EXE version 4.12 in September 2002. The software had been upgraded from a "DOS" to a "Windows"-compiled program to address an earlier problem. The software upgrade corrected the earlier problem but introduced a new one that caused line-of-sight observing cycles to be skipped, a 15% reduction in the number of tip curves, and saturation of CPU usage. Software versions 4.13 and 4.14 also produced these problems. The new MWR software version (4.15) was installed on 9/15/2005. As a consequence of this upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s. |
Measurements: | nsamwrlosC1.b1:
nsamwrtipC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
09/01/2005 | 1945 | 09/06/2005 | 1500 |
Subject: | NSA/MWR/C1 - Reprocess: wrong calibration |
DataStreams: | nsamwrlosC1.a1, nsamwrlosC1.b1, nsamwrtipC1.a1 |
Description: | When MWR#20 was returned to service on 9/1/2005, the calibration had changed as a result of the repairs made by Radiometrics and the RF deck temperature had been set to 325K for testing. On 9/2, the temperature was decreased to 307K to prevent thermal instability in winter and the calibration was changed in the configuration file with the values supplied on the repair report. The data need to be reprocessed with the calibration coefficients that were automatically derived after these changes were put into affect. They are: tnd_nom23=185.621, tnd_nom31=158.801, tc23=-0.022, tc31=-0.039. |
Measurements: | nsamwrlosC1.a1:
nsamwrlosC1.b1:
nsamwrtipC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
10/05/2006 | 1100 | 10/23/2006 | 1600 |
Subject: | NSA/MWR/C1 - Rain sensor always on |
DataStreams: | nsamwrlosC1.b1, nsamwrtipC1.a1 |
Description: | The rain sensor was always on between 10/5 and 10/23 2006. The user should be aware that not all data flagged as rainy are actually rainy. The problem was caused by a shift in the sensitivity of the rain sensor and was corrected by changing the sensor threshold in the configuration file. |
Measurements: | nsamwrtipC1.a1:
nsamwrlosC1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
04/02/2008 | 0000 | 06/04/2008 | 2200 |
Subject: | NSA/MWR/C1 - Spikes in air temperature readings |
DataStreams: | nsamwrlosC1.b1, nsamwrtipC1.a1 |
Description: | During this month there are occasional negative spikes in the Tkair variable. The problem may be corrosion in the temperature sensor or the infiltration of water from melting snow. The dewblower was replaced and a new sensor installed |
Measurements: | nsamwrlosC1.b1:
nsamwrtipC1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
04/06/2008 | 2200 | 06/20/2008 | 0200 |
Subject: | NSA/MWR/C1 - Missing surface air temperature data |
DataStreams: | nsamwrlosC1.b1, nsamwrtipC1.a1 |
Description: | Some wires in the dewblower were not correctly configured. |
Measurements: | nsamwrlosC1.b1:
nsamwrtipC1.a1:
|