| DQR ID | Subject | Data Streams Affected |
|---|---|---|
| D050617.1 | PYE/MWR/M1 - Instrument computer locked up | pyemwrlosM1.b1 |
| D050725.12 | PYE/MWR/M1 - Reprocessed: Revised Retrieval Coefficients | pyemwrlosM1.b1, pyemwrtipM1.a1 |
| D050726.4 | PYE/MWR/M1 - Reprocessed: Calibration corrected | pyemwrlosM1.b1, pyemwrtipM1.a1 |
| D050927.1 | PYE/MWR/M1 - New software version (4.15) installed | pyemwrlosM1.b1, pyemwrtipM1.a1 |
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 06/09/2005 | 0000 | 06/09/2005 | 1500 |
| Subject: | PYE/MWR/M1 - Instrument computer locked up |
| DataStreams: | pyemwrlosM1.b1 |
| Description: | The MWR computer locked up and required a reboot at 00Z on June 9, 2005. When the program was restarted, water vapor, liquid path, and temps dropped to zero. They did not recover until 15Z the same day. |
| Measurements: | pyemwrlosM1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/01/2005 | 0700 | 05/06/2005 | 0000 |
| Subject: | PYE/MWR/M1 - Reprocessed: Revised Retrieval Coefficients |
| DataStreams: | pyemwrlosM1.b1, pyemwrtipM1.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). At Point Reyes, the original 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 yielded nearly identical results to the MONORTM retrievals. The MONORTM-based retrieval coefficients became active at PYE.M1 20050506. Note: The PYE.M1 MWRLOS data for 20050201-20050506 have been reprocessed to apply the MONORTM-based retrievals for all time. The reprocessed data were archived in April 2007. The TIP data have not been reprocessed. |
| Measurements: | pyemwrtipM1.a1:
pyemwrlosM1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 05/29/2005 | 0000 | 07/17/2005 | 2100 |
| Subject: | PYE/MWR/M1 - Reprocessed: Calibration corrected |
| DataStreams: | pyemwrlosM1.b1, pyemwrtipM1.a1 |
| Description: | On May 28 1:30 GMT the NFOV radiometer was placed in the field of view of the MWR tip calibration. Almost immediately calibration of the MWR was compromised resulting in incorrect brightness temperatures and overestimation of both PWV and LWP. On July 15 the NFOV radiometer was moved away from the MWR and the instantaneous calibration values jumped back to normal. The median values returned to normal on July 17 around 2100. The LOS data were reprocessed using interpolated values for the calibration coefficients. The reprocessed data are available from the ARM Archive effective December 7, 2005. NOTE: the format of the reprocessed data are slightly different than the format of the original data and the data available before and after the reprocessed data period. The quality of the data are not affected, just the format. The MWRTIP data can not be reprocessed and should be used with caution. |
| Measurements: | pyemwrtipM1.a1:
pyemwrlosM1.b1:
|
| Start Date | Start Time | End Date | End Time |
|---|---|---|---|
| 02/01/2005 | 0700 | 09/13/2005 | 1805 |
| Subject: | PYE/MWR/M1 - New software version (4.15) installed |
| DataStreams: | pyemwrlosM1.b1, pyemwrtipM1.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. As a consequence of this upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s. |
| Measurements: | pyemwrtipM1.a1:
pyemwrlosM1.b1:
|