NIM/ECOR/M1 - Flux Data Suspect for Some Wind Directions

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.

• CO2 flux(fc)
• latent heat flux(lv_e)
• h(h)
• Friction velocity(ustar)

NIM/ECOR/M1 - Effects on ECOR CO2 Flux and Concentration By Aircraft

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.

• rotated covariance vc(cvar_rot_vc)
• covariance wc(cvar_wc)
• rotated covariance wc(cvar_rot_wc)
• covariance of tc(cvar_tc)
• CO2 flux(fc)
• rotated covariance uc(cvar_rot_uc)
• variance of c(var_c)
• covariance vc(cvar_vc)
• covariance uc(cvar_uc)
• mean co2 concentration (c)(mean_c)

NIM/MET/M1 - ORG Data Underestimated Precipitation

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.

• Precipitation rate mean(precip_rate_mean)
• ORG carrier mean(org_carrier_mean)
• Precipitation rate maximum(precip_rate_max)
• Precipitation rate minimum(precip_rate_min)
• Precipitation rate standard deviation(precip_rate_sd)

NIM/MET/M1/S1 - Reprocess: ORG Data has very small rainrate values

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.

• Precipitation rate minimum(precip_rate_min)
• Precipitation rate maximum(precip_rate_max)
• Precipitation rate mean(precip_rate_mean)
• Precipitation rate standard deviation(precip_rate_sd)

NIM/MET/M1 - Reprocess: ORG Data has very small rainrate values

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.

• Precipitation rate mean(precip_rate_mean)
• Precipitation rate maximum(precip_rate_max)
• Precipitation rate minimum(precip_rate_min)
• Precipitation rate standard deviation(precip_rate_sd)

NIM/MET/M1 - Wind Speed data contain offset due to induced voltage

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.

• Wind speed arithmetic standard deviation(wind_spd_arith_sd)
• Wind speed arithmetic maximum(wind_spd_arith_max)
• Vector-averaged Wind Speed(wind_spd_vec_avg)
• Wind speed arithmetic average(wind_spd_arith_avg)
• Wind speed arithmetic minimum(wind_spd_arith_min)

NIM/MET/S1 - Wind Speed data contain offset due to induced voltage

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.

• Wind speed arithmetic minimum(wind_spd_arith_min)
• Wind speed arithmetic average(wind_spd_arith_avg)
• Vector-averaged Wind Speed(wind_spd_vec_avg)
• Wind speed arithmetic maximum(wind_spd_arith_max)
• Wind speed arithmetic standard deviation(wind_spd_arith_sd)