DQR ID | Subject | Data Streams Affected |
---|---|---|
D060112.4 | NIM/SKYRAD/M1 - IRTs do not agree with AERI | nimskyrad60sM1.b1 |
D060221.1 | NIM/MPL/M1 - False Positive Cloud Base Height Values During Solar Noon | nimmplM1.00, nimmplM1.a1 |
D060530.1 | NIM/ECOR/M1 - Flux Data Suspect for Some Wind Directions | nim30ecorM1.b1 |
D070215.5 | NIM/ECOR/M1 - Effects on ECOR CO2 Flux and Concentration By Aircraft | nim30ecorM1.b1 |
D080304.3 | NIM/MET/M1 - ORG Data Underestimated Precipitation | nimmetM1.b1 |
D080428.7 | NIM/MET/M1 - Reprocess: ORG Data has very small rainrate values | nimmetM1.b1 |
D081022.11 | NIM/MET/M1 - Wind Speed data contain offset due to induced voltage | nimmetM1.b1 |
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/26/2005 | 0000 | 06/07/2006 | 1900 |
Subject: | NIM/SKYRAD/M1 - IRTs do not agree with AERI |
DataStreams: | nimskyrad60sM1.b1 |
Description: | Since deployment at PYE, and then at NIM, the AMF SKYRAD IRT measured about 10K higher sky temperatures than the AERI and the MWRP IRT measureed about 20K higher than the AERI. Several actions were taken to diagnose the problem including confirming the correct configuration of the IRTs and data logger, cleaning the mirror and lens, and replacing the mirror. After several days of rain beginning 6/2/2006, the three instruments came into agreement. It is unknown whether this was a problem with the AERI, MWRP-IRT or SKYRAD-IRT. |
Measurements: | nimskyrad60sM1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
12/27/2005 | 0000 | 04/20/2006 | 1400 |
Subject: | NIM/MPL/M1 - False Positive Cloud Base Height Values During Solar Noon |
DataStreams: | nimmplM1.00, nimmplM1.a1 |
Description: | As the laser ages, the output reduces. This lowers the signal to noise ratio. The lower signal to noise ratio interferes with the cloud base height algorithm to correctly determine if a cloud is actually present. During solar noon the signal to noise ratio is the lowest. This condition results in many false positive values. The values start at a high altitude and progressively get lower as the sun gets to zenith. The trend reverses as the sun passes. The pattern in the data resembles a ?V? shape starting 2 hours before solar noon to 2 hour past. A low incident of false positive values exists from 20051227. However, the condition becomes prominent on 20060303 - 20060420. The cloud base calibration table was modified to compensate for the lower signal to noise levels. Note: If a cloud is actually present, the cloud base algorithm will determine the height and report correctly. The false positive values are only a concern during cloud free conditions. |
Measurements: | nimmplM1.00:
nimmplM1.a1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/26/2005 | 1530 | 01/07/2007 | 2359 |
Subject: | NIM/ECOR/M1 - Flux Data Suspect for Some Wind Directions |
DataStreams: | nim30ecorM1.b1 |
Description: | NIM: For some wind directions the horizontal fetch was not representative of the field in which the AMF was located. Therefore, for the wind direction ranges 90-170 (buildings) and 220-280 (trees) degrees, the fluxes are affected by insufficient fetch and surfaces, buildings, or vegetation that are not similar to the local field conditions. |
Measurements: | nim30ecorM1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
11/26/2005 | 1530 | 01/07/2007 | 2330 |
Subject: | NIM/ECOR/M1 - Effects on ECOR CO2 Flux and Concentration By Aircraft |
DataStreams: | nim30ecorM1.b1 |
Description: | Aircraft landings, departures, and running aircraft on the airport pad were found to produce large spikes in the half hourly CO2 flux and small spikes in CO2 concentration on many days during the entire deployment of the AMF at NIM. This influence was found on 40% of the days in March and April 2006 and sometimes for multiple periods in a day; this was typical of the year of data. The spikes range from only several micromoles s-1 m-2 to one hundred or more for flux (a typical spike was in the twenties) and near zero to 1.0 mmoles m-3 for CO2 concentration (typically around 0.15). The aircraft influence was caused by persistent easterly winds; the airport terminal pad and the nearest part of the runway were almost directly to the east of the ECOR location. Occasionally an influence on water vapor density was detected, but this was fairly rare and usually of very small magnitude. |
Measurements: | nim30ecorM1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
01/06/2006 | 0000 | 01/06/2007 | 2359 |
Subject: | NIM/MET/M1 - ORG Data Underestimated Precipitation |
DataStreams: | nimmetM1.b1 |
Description: | The ORG underestimated precipitation by about 38% during the entire NIM deployment. No troubleshooting technique or replacement of gage was successful in correcting the problem. |
Measurements: | nimmetM1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
01/06/2006 | 0000 | 01/07/2007 | 2359 |
Subject: | NIM/MET/M1 - Reprocess: ORG Data has very small rainrate values |
DataStreams: | nimmetM1.b1 |
Description: | The ORG data is collected via analog signal and not digital. Therefore, we continuously collect data even when no rain is occurring. We also capture small events such as leaves, large bugs, dust, etc blowing through the measurement path. Because this discrete event occurs quickly the value is usually captured for 1 or 2 seconds. This value is then averaged to the minute producing rainrate on the order of .009 mm/hr or less. These values are not indicative of rain and should be removed from the record or summing over long periods can bias the climate record. We are reprocessing the data to remove these small values and are adjusting the collection program to remove them before ingest. |
Measurements: | nimmetM1.b1:
|
Start Date | Start Time | End Date | End Time |
---|---|---|---|
01/06/2006 | 0000 | 01/07/2007 | 2359 |
Subject: | NIM/MET/M1 - Wind Speed data contain offset due to induced voltage |
DataStreams: | nimmetM1.b1 |
Description: | The marine model of the RM Young wind sensor needs twisted pair shielded cable. The manufacturer did not originally supply the pigtail with twisted pair shielded cable. Use of twisted pair shielded cable for the rest of the cable run to the logger was also not specified. This caused an induced voltage in the wind speed line from the wind direction excitation. The induced voltage varied from sensor to sensor and probably changed anytime the cable was replaced or parts of the wind sensor were repaired or replaced. The induced voltage has been seen to vary from 0.15 m/s to as much as 1.08 m/s. |
Measurements: | nimmetM1.b1:
|