GRW/AOS/M1 - CCN signal decline

There was a slow decline in the CCN signal from January to June of 2010 at GRW. The reason 
for this decline is unknown as all the instrument operating parameters appear normal. 
The decline was likely from a change in the CCN column thermal properties or a clogging of 
the detector inlet.

Best not to use the data.

• AOS CCN temperature of the nafion humidifier(CCN_T_nafion)
• AOS CCN temperature of sample air entering the column(CCN_T_sample)
• CCN Propotional valve voltage(CCN_ProportionalValveVoltage)
• First stage monitor voltage(CCN_FirstStageMonitorVoltage)
• CCN temperature gradient(CCN_Temperature_Gradient)
• AOS CCN volumetric flowrate of sheath air(CCN_Q_sheath)
• AOS CCN temperature at top of column(CCN_T_TEC1)
• AOS CCN temperature at middle of column(CCN_T_TEC2)
• AOS CCN OPC laser current(CCN_laser_current)
• AOS CCN logical value, indicating whether the instrument has reached thermal
  gradient stabilization and is within 0.4 degrees C of the set point(CCN_temp_unstable_flag)
• Size of upper limit of each CCN bin(CCN_UpperSizeLimit)
• AOS CCN temperature at bottom of column(CCN_T_TEC3)
• AOS CCN temperature of the optical particle counter(CCN_T_OPC)
• AOS CCN temperature of sample air at entrance to instrument(CCN_T_inlet)
• AOS CCN sample supersaturation calculated by model)(CCN_ss_calc)
• Cloud condensation nuclei number density(N_CCN)
• AOS CCN standard deviation of difference (CCN_T_TEM1 - CCN_T_TEC3)(CCN_dT_TEC3_TEC1_StdDev)
• AOS CCN sample pressure(CCN_P_sample)
• AOS CCN volumetric flowrate of sample air(CCN_Q_sample)
• AOS CCN sample saturation setpoint value reported by instrument(CCN_ss_set)
• Bin number of lowest channel of OPC include in summation of N_CCN(N_CCN_bin_number)
• AOS CCN number concentration by bin(N_CCN_dN)