SGP/ACSM/C1 - Water in inlet sample line

Data became progressively more noisy causing large spikes in data. These spikes started 
occurring for longer periods of time during the day before the instrument went down 
completely on 7/12.

The afternoon data (usually 15:00-24:00 UTC) was incorrect because of water condensation 
in the inlet line and aerosol collection efficiency change. The organic mass loading is 
around 0 when the condensed water was absorbing all the particles.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Pump failure

The carbon vane vacuum pump that pulls air through the instrument failed 11/13 following a 
power failure.  The pump was replaced and returned to service at 2210 GMT on 12/05/2012.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Pump failure

The carbon vane vacuum pump that pulls air through the instrument failed again and a 
section of tubing between the ACSM and pump was partially collapsed.  The pump and tubing were 
replaced and returned to service at 2223 GMT on 12/18/2012. The ACSM was then tuned 
before resuming data collection at 2130 GMT on 12/21/2012.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Sample flow restricted

This period is between two failures of the carbon vane pump that pulls air through the 
instrument. During this time the tubing between the pump and ACSM collapsed and may have 
affected the sample flow rate. The collapsed tubing was replaced with a different type, one 
that is much stiffer and less prone to collapsing under vacuum.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Missing data

Data are missing and unrecoverable.

• time_bounds
• time_offset
• qc_total_organics
• qc_ammonium
• base_time
• org_mx_err
• qc_org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• qc_org_mx
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• qc_nitrate
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• qc_sulfate
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• qc_chloride
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Altitude above mean sea level(alt)
• East longitude(lon)

SGP/ACSM/C1 - Missing data

Data are missing and unrecoverable.

• time_bounds
• time_offset
• qc_total_organics
• qc_ammonium
• base_time
• org_mx_err
• qc_org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• qc_org_mx
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• qc_nitrate
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• qc_sulfate
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• qc_chloride
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Altitude above mean sea level(alt)
• East longitude(lon)

SGP/ACSM/C1 - Data not available and unrecoverable

There are no data for this time period.  The ionization filament burned out.  The mentor 
switched to a backup filament on 2/17 and the data stream was good after it was adjusted 
and monitored on 2/19.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Windows 7 upgrade and turbo molecular pump failure.

Instrument was not operational during this period because of turbo molecular pump failure. 
 the pump was replaced and the instrument restarted.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Reprocessing Notice (RID 1237)

See below for details of reprocessing that was completed on 20150610.  Original 
DQR category: 4 (Red, Incorrect).

-----------------------------------------------------------

The data will be reprocessed with the manufacturer's software to correct errors in the 
calibration values, collection efficiencies, and instrument response. The data in the 
current form is incorrect and should not be used.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - computer software problem

There are no data for the time range specified

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Pump Failure

Turbo pump failure.  No data are available for the specified times.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Unexpected instrument shutdown

There was an unexpected shutdown of the ionizer, vaporizer, SEM, and inlet valve, possibly 
caused by a power outage. This resulted in incorrect data values.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Clogged critical orifice

Instrument was shut down overnight to clean critical orifice.  No useful data were taken 
during this time.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Critical orifice clogged

Inlet pressure was low because the critical orifice was clogged. Orifice was cleaned and 
the instrument restored to operation.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - missing data

Data for the specified periods are missing because if instrument problems.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - missing data

Data for the periods specified is missing because of instrument problems.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - missing data

Data from the specified time periods are missing because of instrument problems.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - missing data

Data are missing for the specified periods because of instrument problems.  Data for the 
period from the end of May through end of September are missing because of the failure of 
two turbo pumps and the return of the instrument to the manufacturer for service.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Vacuum pump failure

The vacuum pump used for pulling samples past the inlet of the ACSM failed.  
The instrument was operational, but not seeing any aerosol. Replacement of the pump solved 
the problem.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Sampling pump failure

The filter switching valve and sampling pump failed.  Data were collected, but no external 
air was being drawn into the system so there is no aerosol signal.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Missing data

The data acquisition program locked up during the period specified.  Program restarted and 
the instrument began collecting data.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Power outage and calibration

There was a power outage on 2015-07-06 that shut down the instrument.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Instrument inlet pressure low

The pressure at the inlet to the instrument was at least 100 torr below ambient after work 
was performed on the vacuum line serving the ACSM. The inlet pressure also dropped from 
1.3 torr to approximately 1 torr.  Examination of the data during reprocessing shows that 
aerosol loadings during the period specified are unreasonably low and suggest that the 
instrument was not sampling ambient air.  The data for the specified period are unreliable 
and should not be used.

I visited SPG to perform ACSM tuning and calibration on 2015-10-06. While there I measured 
the flow in the line bringing sample to the ACSM. The flow was > 45 lpm. This high rate 
was pulling a vacuum on the ACSM sampling line. The vacuum was high when the cyclone was 
in line upstream of the ACSM and was the cause of the low pressure seen after the changes 
to the system were made in August. The flow past the ACSM inlet should be 3 lpm. The 
inlet pressure was ~700 torr when it should be ambient. I disconnected the sampling line 
from the Gast vacuum pump and reconnected and connected it to the Aerodyne pump which is 
part of the dryer system. The flow rate is now 3 lpm, the ambient pressure 740 torr, and the 
inlet pressure 1.3 torr. The instrument was calibrated and is now performing properly.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Instrument averaging time changed

The number of sets collected in each data write was changed when the instrument was 
restarted on 2015-08-26.  This resulted in a change in the averaging time from 30 minutes to 10 
minutes.  Users should be aware that the data during this period are 10 minute averages 
and not the standard 30 minute average.  The original settings were restored on 
2015-09-22 at 13:19.  Other than the change in averaging time the data are unaffected.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• time_offset
• org_mx
• base_time
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time

SGP/ACSM/C1 - Filter switching valve failure

Data are incorrect or not available for the period the switching valve was not working.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP Site Power Outage Due to Winter Storm

On Saturday and Sunday, December 26 and 27th a powerful winter storm (Goliath) brought 
sleet and freezing rain to much of Oklahoma with wind gusts of 45 MPH at times. The result 
was very very slick roads and mass power outages.
 
The SGP central facility lost power at 8:55 PM CDT on Sunday, December 27th.  
The power was restored on 7:56 PM CDT on Wednesday, December 30th
 
Site Emergency procedures were activated and Technicians drained water out of instrument 
reservoirs and other measures as needed, early Monday morning.
 
On Wednesdays as roads and power started was restored to much of the areas east of I-35 , 
Site Technicians performed maintenance on several Extended Facilities.

During this period, data are potentially missing, incorrect, or suspect.  Carefully 
inspect the data before use.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - Power outage

Power was out at the SGP central facility from 2015-12-28 to 2015-12-30.  The instrument 
was restarted on 2016-01-04.  There are no data for the time period specified.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/ACSM/C1 - instrument calibration

The ACSM was offline for tuning and calibration during the period specified.

• time_offset
• base_time
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• East longitude(lon)
• Altitude above mean sea level(alt)

SGP/AOS/C1 - Wildfire smoke plumes advecting over facility

Smoke from nearby wildfires advected through SGP C1 during the listed affected time 
ranges, resulting in high signals observable in many of the listed AOS datastreams.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/NEPHELOMETER/TDMA/C1 - Data Quality Evaluation Ongoing

A closure analysis is currently being perform on the ACSM, TDMA, and wet and dry NOAA 
NEPHELOMETERS at SGP C1. If problems are found during this analysis, they will be promptly 
documented through the DQR system.  The results of this analysis will be made available 
once completed.  Please contact the respective instrument mentors with any questions 
regarding these data over the specified period.

• time_bounds
• time_offset
• qc_total_organics
• qc_ammonium
• base_time
• org_mx_err
• qc_org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• qc_org_mx
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• qc_nitrate
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• qc_sulfate
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• qc_chloride
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Altitude above mean sea level(alt)
• East longitude(lon)

SGP/ACSM/C1 - Filter switching valve not operating

Filter switching valve was not operating because of a faulty circuit board.  Problem was 
fixed and data have been collected from the end of the specified time period.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Low inlet pressure in sample position

The data are suspect because the new filter switching valve was out of adjustment causing 
low inlet pressure in the sample position.  The problem was corrected by the onsite 
operator.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Instrument leak and updated for new system

The instrument developed a leak and the instrument mentor requested the instrument be 
removed and sent back for repairs and upgrades for the new AOS. The new configuration of the 
instrument would not fit into the AOS racks.

• time_bounds
• time_offset
• qc_total_organics
• qc_ammonium
• base_time
• org_mx_err
• qc_org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• qc_org_mx
• Mass concentration of ammonium, ambient aerosol in air(ammonium)
• qc_nitrate
• time
• Mass concentration of chloride, ambient aerosol in air(chloride)
• North latitude(lat)
• org_mx
• qc_sulfate
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• qc_chloride
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Altitude above mean sea level(alt)
• East longitude(lon)

SGP/AOS/C1 - Environmental Smoke

Large aerosol signal associated with local agricultural or grass fires

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)

SGP/ACSM/C1 - Critical orifice clog

Critical orifice was clogged during the period specified.  Data are corrected for reduced 
sample flow, but may be noisy because of reduced signal.

• Mass concentration of chloride, ambient aerosol in air(chloride)
• org_mx
• Mass concentration of total organics, ambient aerosol in air.(total_organics)
• amus
• org_mx_err
• Mass concentration of nitrate, ambient aerosol in air.(nitrate)
• Mass concentration of sulfate, ambient aerosol in air.(sulfate)
• Mass concentration of ammonium, ambient aerosol in air(ammonium)