| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D050725.2 | SGP/MWR/B1 - Reprocess: Revised Retrieval Coefficients | sgp5mwravgB1.c1, sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.a1, sgpqmemwrcolB1.c1 |
| D050822.5 | SGP/MWR/B1 - thermal instability | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D050822.6 | SGP/MWR/B1 - Reprocess: mixer temp adjustment | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D050927.2 | SGP/MWR/B1 - New software version (4.15) installed | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D060726.1 | SGP/MWR/B1 - Reprocessed: Corrected calibration | sgpmwrB1.00, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D071129.1 | SGP/MWR/B1 - Calibration failure | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| D990916.1 | SGP/MWR/B1/B4/B5/B6 - data file split at 23:59 | sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrlosB6.a1, sgpmwrlosB6.b1, sgpmwrtipB1.a1, sgpmwrtipB4.a1, sgpmwrtipB5.a1, sgpmwrtipB6.a1 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 04/12/2002 | 1600 | 06/24/2005 | 2100 |
| Subject: | SGP/MWR/B1 - Reprocess: Revised Retrieval Coefficients |
| DataStreams: | sgp5mwravgB1.c1, sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrtipB1.a1, sgpqmemwrcolB1.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 SGP.B1 20020412.1600. The MONORTM-based retrieval coefficients became active at SGP.B1 20050624.2100. 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: | sgpmwrlosB1.a1:
sgpmwrlosB1.b1:
sgp5mwravgB1.c1:
sgpmwrtipB1.a1:
sgpqmemwrcolB1.c1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/20/2005 | 1800 | 08/05/2005 | 1935 |
| Subject: | SGP/MWR/B1 - thermal instability |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | During periods of high ambient temperature, the instrument may have been thermally unstable. The problem was corrected by increasing the RF deck temperature from 50 to 52 C. |
| Measurements: | sgpmwrlosB1.b1:
sgpmwrtipB1.a1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 08/05/2005 | 2004 | 08/07/2005 | 0555 |
| Subject: | SGP/MWR/B1 - Reprocess: mixer temp adjustment |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | The RF deck temperature was increased from 50 to 52 C to prevent thermal instability in summer. This resulted in a change in the calibration. The data need to be reprocessed with the calibration coefficients that were automatically derived after the reference temperature, tkmx, was adjusted. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/16/2002 | 2200 | 09/13/2005 | 1806 |
| Subject: | SGP/MWR/B1 - New software version (4.15) installed |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | A problem began with the installation of MWR.EXE version 4.12 in July 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 9/13/2005 at 21:25. As a consequence of this upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 07/16/2006 | 0000 | 07/22/2006 | 0600 |
| Subject: | SGP/MWR/B1 - Reprocessed: Corrected calibration |
| DataStreams: | sgpmwrB1.00, sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | The radiometer was thermally unstable. Calibration coefficients for the time interval were re-derived after screening for bad values of TKxc and the data were reprocessed. Reprocessed MWRLOS data were archived January 2007. MWRTIP data will not be reprocessed. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
sgpmwrB1.00:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 11/06/2007 | 0000 | 11/26/2007 | 1733 |
| Subject: | SGP/MWR/B1 - Calibration failure |
| DataStreams: | sgpmwrlosB1.b1, sgpmwrtipB1.a1 |
| Description: | The radiometer suddenly stopped performing successful tip curve calibrations. Brightness temperatures are inaccurate during this time. The instrument was removed from service 20071126. Reprocessing is not possible. |
| Measurements: | sgpmwrtipB1.a1:
sgpmwrlosB1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 10/29/1998 | 0000 | 08/12/1999 | 2359 |
| Subject: | SGP/MWR/B1/B4/B5/B6 - data file split at 23:59 |
| DataStreams: | sgpmwrlosB1.a1, sgpmwrlosB1.b1, sgpmwrlosB4.a1, sgpmwrlosB4.b1, sgpmwrlosB5.a1, sgpmwrlosB5.b1, sgpmwrlosB6.a1, sgpmwrlosB6.b1, sgpmwrtipB1.a1, sgpmwrtipB4.a1, sgpmwrtipB5.a1, sgpmwrtipB6.a1 |
| Description: | A problem with the MWR operating software has been corrected. However, several files were generated that contain one record of data collected at midnight but labeled with the previous day's date. |
| Measurements: | sgpmwrlosB5.a1:
sgpmwrlosB1.a1:
sgpmwrtipB6.a1:
sgpmwrlosB6.b1:
sgpmwrlosB4.b1:
sgpmwrtipB4.a1:
sgpmwrtipB5.a1:
sgpmwrlosB1.b1:
sgpmwrtipB1.a1:
sgpmwrlosB4.a1:
sgpmwrlosB5.b1:
sgpmwrlosB6.a1:
|