CMDL aerosol data file
Format Specifications [v2.79]
Last Modified modified 02/20/08
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- This document describes the file formats used to store aerosol data at CMDL. There are three basic types of files: ambient aerosol, ambient meteorology, and sampling system state.
- All data files are plain ASCII text, in comma-separated, fixed-length fields. The end of a record is denoted by a linefeed character (ASCII hex 10), which optionally may be preceded by a carriage return.
- Universal Coordinated Time (UTC) is used for all time fields. For averaged data, the time reported is the start of the averaging interval.
- Basic aerosol data file record format: (stations with minimal instrumentation may truncate the records at the point where no additional data are available). Leading plus signs are replaced with a blank. This is the common format for the basic measurements obtained at a high time resolution. Missing value codes are always positive. For stations where a particular instrument is not present, the corresponding data field may be either empty or contain the missing value code for that parameter.
- Separate data and header files are used for each type of data. The data fields for ambient data are identical for all stations (although truncated records may be used for stations with limited instrumentation), while different data fields may be used in the sampling system state files from the various stations. There may even be several different types of sampling system state files for some sites.
- A flags field is used in ambient aerosol data files to indicate sampling conditions and data processing status.
- Aerosol light scattering and light absorption coefficients are reported relative to a particular temperature and pressure, either ambient or standard temperature (273.15K) and pressure. An STP correction bit in the flags field is used to denote which reference case is used.
Naming Convention
File names consist of content, status, time codes, and station identifiers. The general format is:
<FC><s><timecode>.<STN>
<FC> is a two character (with the exception of "volumes") File Code that indicates the general content.
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General content |
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aerosol data (Old CP format) |
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ad_ & fd_ |
aerosol and filter digital data (ad_ is Old CP format) |
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af _& ff_ |
aerosol filter data (af_ is old CP format) |
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Averaged data segments |
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aerosol and GPS merged data |
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aerosol monitor data |
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aethelometer data -- old format |
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UPS data |
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UPS monitor records |
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One minute averaged CN data |
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CN monitor data |
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One minute averaged CCN data |
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The results of running a model to calculate the supersaturation of a given average |
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filter monitor records |
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fitted f(RH) info for specific wavelength"w" (e.g., fr, fb or fg) |
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Filter sample time records |
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GPS data |
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"humidograph" data; A merging of several instruments at a one minute averaging frequency |
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1 sec edited IAP data with GPS merged in |
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segment averaged IAP data with GPS merged in |
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Humidograph set point channel changes |
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aethalometer data |
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one minute averaged data for the CLAP or PSAP |
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segment averaged lae data file with GPS data merged in |
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CLAP monitor records |
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lw_ |
3-wavelength PSAP data |
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general monitor info |
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ambient meteorological data; not produced by CPD; primarily exist with Older CP formated data |
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One minute averages of Nephelometer data |
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zero-corrected na_ data file |
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segment averaged naNe data file with GPS data merged in (see nb_ file type) |
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neph calibration results |
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neph state errors |
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nk_ |
neph span check report |
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neph monitor data |
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neph state data |
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na_ zero data file |
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oa, oc, oe, om, |
wet neph filenames else the same as the na,nc, ... |
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Present Weather Detector |
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LovePID data |
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si__ |
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output from scheduled tasks |
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sr_ |
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seconds and samples per sample period |
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umac digital state changes |
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ua_& um_ |
umac monitor records |
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vol & volumes |
Weekly cumulative filter volume records |
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Wind Speed and Wind Direction file |
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Watlow monitor data |
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Weather Data |
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Averaged data |
<s> is a one or
two character Status Code indicating the processing state of the file
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Status-Code |
Data form |
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_ |
as high-resolution (usually minute) data |
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b,g,r |
blue,green or red wavelength for f(RH) data |
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e |
high resolution, edited data |
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edited data for time segments. |
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h, H |
as hourly averages |
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d, D |
as daily averages |
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m, M |
as monthly averages |
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A |
"generic" average-formatted file |
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t |
as 2-hour averages |
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w |
as weekly averages |
<timecode> is a
string indicating time interval of contents
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Timecode |
Data Time Interval |
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X |
the most recently processed data (usually one day) |
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cum |
"cumulative", variable interval |
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Head |
no time interval - this is a header file |
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<yr>w<wk> |
one week of year <yr> beginning with week <wk> |
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<yr>Q<q> |
one quarter of year <yr> beginning with quarter <q> |
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<yr> |
year <yr> |
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<yr>d<doy> |
one day of year <yr> beginning with DOY <doy> |
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<yr>m<mn> |
one month of year <yr> beginning with month <mn> |
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YYYY_DDD_X |
Data from year YYYY, day of year DDD, sequential label X varies from A-Z to allow multiple files per day. |
<STN> is the three character station identifier (source of the data).
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Station ID |
Station location |
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air |
Aircraft Field Campaigns |
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alt |
Alert, Canada |
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amf |
Arm Mobile Facility |
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bnd |
Bondville, IL |
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bld |
Boulder, CO |
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brw |
Barrow, AK |
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cpo |
Cheeka Peak, WA |
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cpt |
Cape Point, South Africa |
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csj |
Cape San Juan, Puerto Rico |
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cvi |
Counterflow Virtual Impactor |
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iap |
In-situ Aircraft Profiles |
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kco |
Kaashidoo, Maldives |
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kos |
Kosan, Cheju, South Korea |
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kpo |
Kpuszta, Hungary |
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lab |
Lab, Boulder, CO |
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lar |
Laramie, WY |
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mln |
Mauna Loa, HI [New] |
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mlo |
Mauna Loa, HI |
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nsa |
North Slope (Barrow), AK |
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nwr |
Niwot Ridge, CO |
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p-3 |
p-3 flight |
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sfa |
Surface Field Campaigns A |
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sfb |
Surface Field Campaigns B |
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sfc |
Surface Field Campaigns |
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sgp |
So. Great Plains |
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smo |
American Samoa |
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spo |
South Pole |
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thd |
Trinidad Head, CA |
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wlg |
Mt. Waliguan, China |
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wsa |
Sable Island, Canada |
Field Separator
All files currently have a comma as the field separator.
Field definition
Each File Code, Status Code combination has a specific format, as described below:
File: a__<timecode>.<STN>
Return to File-Code
|
Col # |
Name |
Format and Missing Value Code (mvc) |
Description |
Scanf info. |
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1 |
Station_ID STN |
WSA |
3-character ID code |
%3s |
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2 |
Year |
1993 |
Year |
%4d |
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3 |
StartTime_UTC DOY |
012.12345 |
DOY and FRACTIONAL_DOY (January 1 = 1) |
%09.5f |
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4 |
0011 |
4-character code representing system status. |
%4s |
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5 |
±9.999e-99 |
Aerosol number concentration (cm-3) measured with CNC on "control" inlet |
%10.3e |
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6 |
CN_ambient |
±9.999e-99 |
Aerosol number concentration (cm-3) measured with CNC on "ambient" inlet |
%10.3e |
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7 |
Bap_G |
±9.999e-99 |
Aerosol light absorption coefficient (m-1), green channel. |
%10.3e |
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8 |
RefBsp_B |
±9.999e-99 |
Aerosol total light scattering coefficient (m-1), blue channel. |
%10.3e |
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9 |
RefBsp_G |
±9.999e-99 |
Aerosol total light scattering coefficient (m-1), green channel. |
%10.3e |
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10 |
RefBsp_R |
±9.999e-99 |
Aerosol total light scattering coefficient (m-1), red channel. |
%10.3e |
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11 |
RefBbsp_B |
±9.999e-99 |
Aerosol backwards-hemispheric light scattering coefficient (m-1), blue channel. For stations equipped with 4-wavelength nephelometers, this field is aerosol total light scattering coefficient (m-1), near infrared channel. |
%10.3e |
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12 |
RefBbsp_G |
±9.999e-99 |
Aerosol backwards-hemispheric light scattering coefficient (m-1), green channel. |
%10.3e |
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13 |
RefBbsp_R |
±9.999e-99 |
Aerosol backwards-hemispheric light scattering coefficient (m-1), red channel. |
%10.3e |
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14 |
RH_refNeph |
±999 |
Relative Humidity (percent) inside nephelometer |
%4d |
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15 |
T_refNeph |
±999.9 |
Temperature (K) inside nephelometer |
%5.1f |
|
16 |
P_refNeph |
±9999.9 |
Pressure (hPa) inside nephelometer |
%7.1f |
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17 |
WS |
±99.9 |
Local wind speed (m s-1) |
%5.1f |
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18 |
WD |
±999 |
Local wind direction (degrees True) |
%4d |
File: ad_<timecode>.<STN>,
fd_<timecode>.<STN>
Return to File-Code
|
Col # |
Name |
Format and Missing Value Code (mvc) |
Description |
Scanf info |
|
1 |
Station_ID |
WSA |
3-character ID code |
%3s |
|
2 |
Year |
1993 |
Year |
%4d |
|
3 |
Time_UTC |
012.12345 |
DOY and FRACTIONAL_DOY (January 1 = 1) |
%09.5f |
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4 |
0011 |
4-character code representing system status. |
%4s |
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5 |
Analyzers_ON |
0 |
1=analyzers ON, 0 = analyzers OFF |
%1d |
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6 |
Active_Filter |
9 |
Valid filters are 1-8. If more than one filter is active at any one time, or if no filters are active, this field is set to zero. |
%1d |
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7 |
Filter_Error |
999 |
0=no filter error Otherwise, this field contains the decimal value of a byte composed of the status of each filter. Each filter is a bit (1=filter on, 0=filter off), and are organized such that position 0 (LSB) = filter 1, position 1 = filter 2, up to position 7 respectively. |
%03d |
|
8 |
Unused1 |
0 |
unused digital input |
%1d |
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9 |
Unused2 |
0 |
unused digital input |
%1d |
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10 |
Unused3 |
0 |
unused digital input |
%1d |
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11 |
Unused4 |
0 |
unused digital input |
%1d |
File: af_<timecode>.<STN>,
ff_<timecode>.<STN>
Return to File-Code
|
Col # |
Name |
Format and Missing Value Code (mvc) |
Description |
Scanf info |
|
1 |
Station_ID |
WSA |
3-character ID code |
%3s |
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2 |
Year |
1993 |
Year |
%4d |
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3 |
StartTime_UTC |
012.12345 |
DOY and FRACTIONAL_DOY (January 1 = 1) |
%09.5f |
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4 |
Empty String |
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Exists due to historical formatting |
%s |
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5 |
Filter |
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Exists due to historical formatting |
%s |
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6 |
Text |
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Exists due to historical formatting |
%s |
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7 |
vol0_blank |
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volume of air/gas through the blank |
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8 |
vol1 |
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total volume of air/gas through filter1 |
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9 |