###------------------------------------------------------------------------------------###
PROCESSING CAPMON DETAILS              

DENE BOWDALO, Updated 29th April 2018

###------------------------------------------------------------------------------------###
PROCESSING NOTES

NONE

###------------------------------------------------------------------------------------###
NETWORK DESCRIPTION

The Canadian Air and Precipitation Monitoring Network (CAPMoN), operated by Environment 
and Climate Change Canada (ECCC), is designed to study the regional patterns and trends of 
atmospheric pollutants such as acid rain, smog, particulate matter and mercury, 
in both air and precipitation. The network began operating in 1983. CAPMoN updated and 
replaced two older networks known as the Canadian Network for Sampling Precipitation 
(CANSAP) and the Air and Precipitation Network (APN). The integration of APN as part of 
CAPMoN extended the data record as far back as 1978.

The Network was originally designed to help Canadians understand the sources and impacts 
of acid rain. This included integrated measurements of wet deposition (through rain or 
snow) and (inferential) dry deposition, as well as the ambient concentrations of 
acid-forming gases and particles. The regionally representative sites required to 
understand the sources and how long range transport impacts the Canadian environment have 
proven invaluable for a wide range of atmospheric issues.

DESCRIPTION URL: https://www.canada.ca/en/environment-climate-change/services/
                 air-pollution/monitoring-networks-data/canadian-air-precipitation.html
                 
DATA URL: http://donnees.ec.gc.ca/data/air/monitor/monitoring-of-atmospheric-gases/
          ground-level-ozone/?lang=en
   
###------------------------------------------------------------------------------------###
QUALITY ASSESSMENT LEVEL (Source: Details in header of data files)

Level 2 - a complete, externally consistent data set of specified quality that consists of 
research products that have undergone interpretative and diagnostic analyses by the 
project staff or user community. 

###------------------------------------------------------------------------------------###
CONTACT

CAPMoN Manager, 4905 Dufferin St., Toronto ON, CANADA, M3H 5T4 
ec.rcepa-capmon.ec@canada.ca'

###------------------------------------------------------------------------------------###
AVAIALABLE SPECIES (DATA LAST ACCESSED: 26TH APRIL)

Ozone (1988-2016)

###------------------------------------------------------------------------------------###
FORMAT

The data files are single annual csv files, including all sites, for a single species

Each row gives an hourly measurement at one site, for a single species

Metadata is included in each annual data file, with data for each specific site included 
on separate lines in the header

###------------------------------------------------------------------------------------###
METADATA/DETAIL FILES

CORE
NONE

OTHER
sites_map.png
AtmosphericGases_Description.pdf 

INSTRUMENT MANUALS

O3

Dasibi_1008_Manual.pdf
Thermo_49C_Manual.pdf
Thermo_49i_Manual.pdf

###------------------------------------------------------------------------------------###
DATAFILE VARIABLES

 SiteID - Site abbreviation (standard) 
 DateStartLocalTime - Date start (local) 
 TimeStartLocalTime - Time start (local) 
 DateEndLocalTime - Date end (local) 
 TimeEndLocalTime - Time end (local) 
 TimeZone - Time zone (local) 
 DateStartUTC - Date start (UTC) 
 TimeStartUTC - Time start (UTC)
 DateEndUTC - Date end (UTC)
 TimeEndUTC - Time end (UTC)
 O3_ppbv - Ozone Concentration (ppbv)
 O3_ppbv_Flag - Data Flag
 O3_ppbv_DetL - Ozone Detection Limit (ppbv) 

###------------------------------------------------------------------------------------###
METADATA VARIABLES

SiteID - Site identification (network or study) 
SiteID_original - Original site identification (network or study)  
SiteName - Site name (network or study )
CountryCode - Country code 
ProvinceStateCode - Province or state code 
Latitude_deg - Latitude (decimal degrees) 
Longitude_deg - Longitude (decimal degrees) 
GroundElevAMSL_m - Ground elevation (above mean sea level) 
LatLonRefDatum - Latitude/longitude reference datum 
Timezone - Time zone (local) 
StartDateOfSite - Start date of site 
EndDateOfSite - End date of site  
SiteLandUse - Site land use (dominant within 1 km) 
SamplingHeightAG - Sampling height above ground (m)

###------------------------------------------------------------------------------------###
UNITS (Source: Details in header of data files)

Ozone    ppbv 

                                             
###------------------------------------------------------------------------------------###
REPRESENTIVITY (Source: Details in header of data files)

SITE TYPES:
None Given

LOCAL LAND USE CLASSIFICATION (Given as: Dominant within 1 km) 
Rural

LEVELS OF URBANISATION:
None Given

NEIGHBOURHOOD POPULATION 
None Given

SCALE OF REPRESENTATIVENESS
None Given

TERRAIN
None Given

###------------------------------------------------------------------------------------###
MEASUREMENT METHODLOGIES (Source: Details in header of data files, Dasibi_1008_Manual.pdf, 
                                  Thermo_49C_Manual.pdf and Thermo_49i_Manual.pdf)

Ozone - continuous (1 minute measurements hourly averaged), ultraviolet photometry 

###------------------------------------------------------------------------------------###
INSTRUMENT NAME/MODEL NUMBERS (Source: Details in header of data files)

Ozone:
Thermo 49i (2014-)
Thermo 49C and 49CPS calibrator (2003-2013) 
Thermo 49 and 49PS calibrator (1992-2003) 
Dasibi (make assumption it is model 1008) (1988-1992)

###------------------------------------------------------------------------------------###
NETWORK DATA FLAGS  (Source: Details in header of data files)

V0  Valid value   

V1  Valid value - The reported value is below the analytical or method or instrument 
                  detection limit. Values may be positive, zero or negative. 

V2  Valid value - The reported value is unusual (e.g., an outlier) but assessed by the 
                  Principal investigator who determined that it was valid or there was 
                  insufficient evidence for invalidation. Principal investigators may have 
                  included a textual comment to indicate possible causes for the unusual 
                  value (e.g. forest fire, volcano, dust storm). *A*

V7  Valid value - The reported value is below the analytical or method or instrument 
                  detection limit and has been substituted by the detection limit or 
                  lowest measurable value as described in the EXPLANATION OF REPORTED 
                  DETECTION LIMIT VALUES. *N*

M1  Missing value - No value was reported by the field or laboratory instrument (e.g. 
                    instrument failure, lost sample). *N* 

M2  Missing value - invalidated by Principal Investigator *N*


MISSING DATA FILL = -999 

###------------------------------------------------------------------------------------###
EXTRA DETAILS

Ozone Measurement Description

In CAPMoN, measurements are made every minute and averaged at five minute intervals. Every 
30 days a remote calibration is performed using an on-site secondary reference traceable 
to a primary standard (a Canadian standard referenced to the National Institute of 
Standards and Technology (NIST), at Gaithersburg, Maryland, USA) and all measurements are 
corrected back to the primary standard.

Explanation of Below Detection Limit Values

From 1988 to 1991, ozone mixing ratios measured as less than the detection limit of 4 ppbv 
were reported in one of two ways: (1) values less than 2 ppbv were set to 2 ppbv and 
flagged as V7, (2) values less than the detection limit but greater than or equal to 2 
ppbv were reported and flagged as V1. The detection limit of 4 ppbv was specified by the 
instrument manufacturer (Dasibi). All Dasibi analyzers were replaced in 1991 but the 
specific changeover dates were not recorded, so December 31, 1991 was chosen as the change 
date for all detection limits. From January 1, 1992 to April 30, 2013, the detection limit 
of the analyzers was 2 ppbv and all mixing ratios of less than 2 ppbv were reported as 2 
ppbv and flagged as V7. Between May 2013 and July 2014, depending on the site, new 
analyzers were installed and the following changes were made: the mixing ratios were 
reported to one decimal place, the detection limit changed to 1 ppbv, and all less than 
the detection limit mixing ratios were flagged as V1 and reported as-measured by the 
instrument (i.e., not censored at the detection limit). Note that the method of applying 
calibration factors to the data sometimes produces zero or negative mixing ratios. 

Explanation of Reported Uncertainty

Uncertainty of hourly average concentrations = ± 0.6 ppb (± 0.8 ppb in warm season; ± 0.5 
ppb in cold season); daily and monthly average concentrations = ± 0.6 ppb;  annual average 
concentrations = ± 0.5 ppb. The uncertainty is based on simultaneous field measurements of 
two collocated instruments both adjusted to National Institute of Standards and Technology 
Standard Reference Photometer (NIST/SRP) #16. The uncertainty was calculated as the 
standard deviation of differences from the true value assumed equal to the mean of the two 
instruments.

Explanation of Zero or Negative Values

Prior to 2013, no zero or negative hourly-average mixing ratios were reported. From 2013 
forward, zero and negative hourly-average mixing ratios were reported and flagged as below 
the measurement detection limit (flag = V1). These zero or negative values resulted from 
the application of NIST-referenced calibration curves to very low mixing ratio values. 
Values of -999.0 represent missing or invalid data. 
