| 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 |
| D060419.4 | NIM/MWR/M1 - Instrument noise problem/RF interference | nimmwrM1.00, nimmwrlosM1.b1, nimmwrtipM1.a1 |
| D060718.1 | NIM/MWR/M1 - Reprocessed: Recalibration to correct for occasional overheating. | nimmwrlosM1.b1, nimmwrtipM1.a1 |
| D060927.1 | NIM/MWR/M1 - Sun in field of view of radiometer | nimmwrlosM1.b1 |
| D080828.1 | HFE/MWR/M1 - Insufficient calibration stability | hfemwrlosM1.b1, hfemwrtipM1.a1 |
| D090311.3 | HFE/MWR/M1 - Missing data | hfemwrlosM1.b1, hfemwrtipM1.a1 |
| D090522.1 | GRW/MWR/M1 - Loose mirror | grwmwrlosM1.b1, grwmwrtipM1.a1 |
| D100224.6 | GRW/MWR/M1 - Reprocess: Biased LWP retrievals-Updated retrieval coefficients | grwmwrlosM1.b1, grwmwrtipM1.a1 |
| D100326.2 | GRW/MWR/M1 - Incorrect ambient temperature | grwmwrlosM1.b1, grwmwrtipM1.a1 |
| D100716.1 | GRW/MWR/M1 - Incorrect instrument computer set-up | grwmwrlosM1.b1, grwmwrtipM1.a1 |
| D100830.1 | GRW/MWR/M1 - Erratic brightness temperature | grwmwrlosM1.b1, grwmwrtipM1.a1 |
| D100830.3 | GRW/MWR/M1 - Missing data | grwmwrlosM1.b1, grwmwrtipM1.a1 |
| 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: | pyemwrlosM1.b1: - Total liquid water along LOS path(liq)
- Total water vapor along LOS path(vap)
pyemwrtipM1.a1:
|
| 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: | pyemwrlosM1.b1: - tnd23
- 31.4 GHz sky brightness temperature(tbsky31)
- tc31
- sky23
- tnd31
- Total liquid water along LOS path(liq)
- tnd_nom31
- tnd_nom23
- tc23
- sky31
- Total water vapor along LOS path(vap)
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
pyemwrtipM1.a1: - r31
- tc31
- tipsky31
- tc23
- r23
- tnd23
- tnd23I
- tnd_nom31
- tnd_nom23
- tnd31
- tnd31I
- vaptip
- liqtip
- tipsky23
|
| 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: | pyemwrlosM1.b1: - tnd23
- 31.4 GHz sky brightness temperature(tbsky31)
- bb23
- IR Brightness Temperature(sky_ir_temp)
- tkxc
- tc31
- sky23
- bbn31
- tnd31
- tknd
- bb31
- Total liquid water along LOS path(liq)
- tnd_nom31
- tnd_nom23
- tkbb
- tc23
- bbn23
- sky31
- Total water vapor along LOS path(vap)
- tkair
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
pyemwrtipM1.a1: - r31
- tkxc
- tbsky23tip
- tc31
- bbn31
- tipsky31
- tc23
- tkair
- bb23
- tkbb
- tbsky31tip
- r23
- tnd23
- tnd23I
- tnd_nom31
- bb31
- tnd_nom23
- tnd31I
- tnd31
- bbn23
- vaptip
- tknd
- liqtip
- tipsky23
|
| Subject: | GRW/MWR/M1 - Loose mirror |
| DataStreams: | grwmwrlosM1.b1, grwmwrtipM1.a1
|
| Description: | The data from the MWR were suspicious and became progressively worse. The problem was
traced back to the fact that the screw that keeps the mirror in place had become loose and
the mirror was freely rotating.
The mirror was tightened on 6/9/2009, however the measurements were noisy until 6/16, when
the instrument was rebooted and all the connections checked.
Measurements between 5/1 and 6/9 should not be used. Data between 6/9 and 6/16 are usable,
although they are very noisy. |
| Measurements: | grwmwrtipM1.a1: - vaptip
- bb31
- tbsky23tip
- bbn23
- bbn31
- tbsky31tip
- tipsky23
- bb23
- tipsky31
- liqtip
grwmwrlosM1.b1: - sky23
- bbn23
- Total water vapor along LOS path(vap)
- bbn31
- Total liquid water along LOS path(liq)
- sky31
- 31.4 GHz sky brightness temperature(tbsky31)
- bb31
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- bb23
|
| Subject: | GRW/MWR/M1 - Incorrect instrument computer set-up |
| DataStreams: | grwmwrlosM1.b1, grwmwrtipM1.a1
|
| Description: | Starting late on 07/11 the instrument began to have very brief (< 1 min) data outages
every few hours. By 07/12 data had become noticeably incorrect, particularly the PWV, LWP,
TB23, and TB31. At ~17 Z on 0713 the missing data / no data available flags became more
frequent.
The problem was identified as improper settings of the instrument computer and was solved
on 8/9. |
| Measurements: | grwmwrtipM1.a1: - tnd_nom31
- vaptip
- tnd31I
- r23
- tc23
- tbsky23tip
- tnd_nom23
- tbsky31tip
- tc31
- tnd23I
- r31
- tnd31
- tnd23
- liqtip
grwmwrlosM1.b1: - Total water vapor along LOS path(vap)
- tnd31
- Total liquid water along LOS path(liq)
- tnd23
- tnd_nom31
- 31.4 GHz sky brightness temperature(tbsky31)
- tnd_nom23
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- tc23
- tc31
|
| Subject: | GRW/MWR/M1 - Erratic brightness temperature |
| DataStreams: | grwmwrlosM1.b1, grwmwrtipM1.a1
|
| Description: | Around 12 Z on 7/20 both the PWV and 23.8 GHz brightness temp values began to diverge from
those of the MWRP. By 7/22 both the LWP and 31.4 GHz brightness temp had followed suit.
At 0600 Z on 7/22 multiple (10-20), brief (<=1 min) data outages began appearing hourly.
The problem persisted intermittently until 8/9.
On 8/9, changes in the settings of the computer restored the proper functionality of the
MWR software. |
| Measurements: | grwmwrtipM1.a1: - tnd_nom31
- vaptip
- tnd31I
- tc23
- tbsky23tip
- tnd_nom23
- tbsky31tip
- tc31
- tnd23I
- tnd31
- tnd23
- liqtip
grwmwrlosM1.b1: - Total water vapor along LOS path(vap)
- tnd31
- Total liquid water along LOS path(liq)
- tnd23
- tnd_nom31
- 31.4 GHz sky brightness temperature(tbsky31)
- tnd_nom23
- Radiation, longwave, brightness temperature, 23.8 GHz(tbsky23)
- tc23
- tc31
|