| DQR ID | Subject | Data Streams Affected |
|---|
| D011005.5 | SGP/MWR/E14 - calibration check | sgpmwrlosE14.a1, sgpmwrlosE14.b1 |
| D011005.6 | SGP/MWR/E14 - Upgrade of Arm Core PC Configuration | sgpmwrlosE14.a1, sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| D020119.1 | SGP/MWR/E14 - Hard disk failure | sgpmwrE14.00, sgpmwrlosE14.a1, sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| D030822.6 | SGP/MWR/E14 - min/max/delta values incorrect | sgpmwrlosE14.b1 |
| D030909.3 | SGP/MWR/E14 - thermal instability | sgpmwrlosE14.a1, sgpmwrlosE14.b1 |
| D041117.1 | SGP/MWR/E14 - Reprocess: wrong retrievals | sgpmwrlosE14.a1, sgpmwrlosE14.b1, sgpmwrtipE14.a1, sgpqmemwrcolE14.c1 |
| D050705.1 | SGP/MWR/E14 - computer problem | sgpmwrE14.00, sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| D050725.6 | SGP/MWR/E14 - Reprocess: Revised Retrieval Coefficients | sgpmwrlosE14.a1, sgpmwrlosE14.b1, sgpmwrtipE14.a1, sgpqmemwrcolE14.c1 |
| D050822.2 | SGP/MWR/E14 - Reprocess: thermal instability | sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| D051011.3 | SGP/MWR/E14 - New software version (4.15) installed | sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| D060322.1 | SGP/MWR/E14 - Instrument maintenance | sgpmwrE14.00, sgpmwrlosE14.a1, sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| D061213.5 | SGP/MWR/E14 - Radiometer testing | sgpmwrE14.00, sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| D070314.2 | SGP/MWR/C1/E14 - Freezing rain-Incorrect rain flag | sgpmwrlosC1.b1, sgpmwrlosE14.b1, sgpmwrtipC1.a1, sgpmwrtipE14.a1 |
| D070406.2 | SGP/MWR/E14 - Power supply failure | sgpmwrlosE14.b1, sgpmwrtipE14.a1 |
| Subject: | SGP/MWR/E14 - Reprocess: wrong retrievals |
| DataStreams: | sgpmwrlosE14.a1, sgpmwrlosE14.b1, sgpmwrtipE14.a1, sgpqmemwrcolE14.c1
|
| Description: | When MWR#04 was installed at EF14 (replacing MWR#33), out-of-date retrieval coefficients
were used in the configuration file.
The correct coefficients were applied when the computer, software, and configuration file
were upgraded. |
| Measurements: | sgpmwrlosE14.a1: - MWR column precipitable water vapor(vap)
- Averaged total liquid water along LOS path(liq)
sgpmwrtipE14.a1: - Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
- Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
sgpmwrlosE14.b1: - Averaged total liquid water along LOS path(liq)
- MWR column precipitable water vapor(vap)
sgpqmemwrcolE14.c1: - Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)
- Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)
|
| Subject: | SGP/MWR/E14 - Reprocess: Revised Retrieval Coefficients |
| DataStreams: | sgpmwrlosE14.a1, sgpmwrlosE14.b1, sgpmwrtipE14.a1, sgpqmemwrcolE14.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.E14
20020416.0000. The MONORTM-based retrieval coefficients became active
at SGP.E14 20050628.2300.
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: | sgpmwrlosE14.a1: - MWR column precipitable water vapor(vap)
- Averaged total liquid water along LOS path(liq)
sgpmwrtipE14.a1: - Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
- Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
sgpmwrlosE14.b1: - Averaged total liquid water along LOS path(liq)
- MWR column precipitable water vapor(vap)
sgpqmemwrcolE14.c1: - Ensemble average for MWR vapor in window centered about balloon release(mean_vap_mwr)
- Ensemble average for MWR liquid in window centered about balloon release(mean_liq_mwr)
|
| Subject: | SGP/MWR/E14 - New software version (4.15) installed |
| DataStreams: | sgpmwrlosE14.b1, sgpmwrtipE14.a1
|
| Description: | A problem began with the installation of MWR.EXE version 4.12 in May 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 8/1/2005. As a consequence of this
upgrade, the tip curve frequency increased. The tip cycle time decreased from ~60s to ~50s. |
| Measurements: | sgpmwrtipE14.a1: - 23.8 GHz goodness-of-fit coefficient(r23)
- (tknd)
- Temperature correction coefficient at 23.8 GHz(tc23)
- Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
- 31.4 GHz blac2body+noise injection signal(bbn31)
- 31.4 GHz blackbody(bb31)
- Total water vapor along zenith path using tip-derived brightness temperatures(vaptip)
- Mixer kinetic (physical) temperature(tkxc)
- 31.4 GHz sky signal(tipsky31)
- Noise injection temp at 31.4 GHz derived from this tip(tnd31I)
- Total liquid water along zenith path using tip-derived brightness temperatures(liqtip)
- Noise injection temp at 23.8 GHz derived from this tip(tnd23I)
- Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
- 23.8 GHz Blackbody signal(bb23)
- Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
- Ambient temperature(tkair)
- Temperature correction coefficient at 31.4 GHz(tc31)
- 31.4 GHz goodness-of-fit coefficient(r31)
- 31.8 GHz sky brightness temperature derived from tip curve(tbskytip31)
- 23.8 GHz sky brightness temperature derived from tip curve(tbskytip23)
- Blackbody kinetic temperature(tkbb)
- 23.8 GHz sky signal(tipsky23)
- Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
- 23.8 GHz blackbody+noise injection signal(bbn23)
sgpmwrlosE14.b1: - Averaged total liquid water along LOS path(liq)
- Noise injection temp at nominal temperature at 31.4 GHz(tnd_nom31)
- Sky brightness temperature at 23.8 GHz(tbsky23)
- MWR column precipitable water vapor(vap)
- 23.8 GHz blackbody+noise injection signal(bbn23)
- 31.4 GHz blac2body+noise injection signal(bbn31)
- 23.8 GHz Blackbody signal(bb23)
- Sky brightness temperature at 31.4 GHz(tbsky31)
- Noise injection temp at 23.8 GHz adjusted to tkbb(tnd23)
- Sky Infra-Red Temperature(sky_ir_temp)
- (tknd)
- 23.8 GHz sky signal(sky23)
- Blackbody kinetic temperature(tkbb)
- Temperature correction coefficient at 31.4 GHz(tc31)
- Ambient temperature(tkair)
- Noise injection temp at 31.4 GHz adjusted to tkbb(tnd31)
- Mixer kinetic (physical) temperature(tkxc)
- 31.4 GHz blackbody(bb31)
- Temperature correction coefficient at 23.8 GHz(tc23)
- Noise injection temp at nominal temperature at 23.8 GHz(tnd_nom23)
- 31.4 GHz sky signal(sky31)
|
| Subject: | SGP/MWR/C1/E14 - Freezing rain-Incorrect rain flag |
| DataStreams: | sgpmwrlosC1.b1, sgpmwrlosE14.b1, sgpmwrtipC1.a1, sgpmwrtipE14.a1
|
| Description: | Between 01/12 and 01/15 brightness temperatures show high values (Tb > 100 K) indicative
of rain, however the wet_window flag is 0 (indicative of no rain). During that time there
where freezing conditions with ice pellets that were not detected by the sensor. The high
brightness temperatures may be due to melting ice on the window. |
| Measurements: | sgpmwrtipC1.a1: - Water on Teflon window (1=WET, 0=DRY)(wet_window)
sgpmwrlosC1.b1: - Water on Teflon window (1=WET, 0=DRY)(wet_window)
sgpmwrtipE14.a1: - Water on Teflon window (1=WET, 0=DRY)(wet_window)
sgpmwrlosE14.b1: - Water on Teflon window (1=WET, 0=DRY)(wet_window)
|