The example template given below contains the metadata fields that are commonly included when reporting
data related to this specific template. Some of these metadata elements may not be relevant for your data reporting, like AIRS station
ID for stations outside North America or the various QA measure data when there is no QA measure for the data. Such metadata elements could
be let out. If you want to include additional metadata elements that are not given in the example template, there is a complete list
here. In case of any doubt about such additional metadata, please consult the EBAS team!
Template for submission of coarse mode particle size distribution data
Points to note:
Common template for APS and OPS:
This template is a first step towards collecting in situ coarse mode particle size distribution data
collected at ground stations.
It therefore covers both instrument types commonly used for this purpose, aerodynamic and optical
particle size spectrometers, even though the differences in measurement principle cause a
systematic deviation and a higher uncertainty as compared to other particle size spectrometers.
The metadata included allows to distinguish instrument type and measurement principle.
Development of Standard Operating Procedures (SOPs) for these instruments may result in a separation
into different templates in the future.
Definition of "particle_number_size_distribution"
In WDCA templates, "particle_number_size_distribution" is defined as particle number concentration
normalised by the logarithmic particle diameter interval (decadal logarithm) for which the
concentration was measured, i.e. dN / d log Dp.
Reference pressure and temperature for flows:
A regular submission or level 2 file contains the data referenced to standard conditions of
temperature and pressure (273.15 K, 1013.25 hPa).
Number of size bins reported:
If necessary, please adapt the template to the number of size bins
your instrument reports data for.
This will involve changes in header lines 1, 10, 11, 12, 19ff, and 266.
Size bin diameters:
The diameters stated for each size bin are the geometric mean of lower and upper bin limit.
Spacing and position of size bins:
There are currently no SOPs for OPS and APS.
In the absence of a detailed instrument calibration by the user, the calibration, i.e. number
of size bins and their lower and upper limits, provided by the instrument manufacturer should be
In case an independent calibration is available, it should be used instead.
Assumptions on particle refractive index or particle density:
In converting their primary measurements to particle size, OPSs make an assumption on particle
effective refractive index, while APSs make an assumption on effective particle density.
In the absence of an SOP, the refractive index or density of the particles used during
calibration should be documented in the "Comment" metadata item.
Percentiles quantifying atmospheric variability:
In order to quantify the atmospheric variability over the hourly averaging period,
regularly reported data usually contain the 15.87 and 84.13 percentiles for the averaging
period in addition to the arithmetic mean.
Please use interpolation if these percentiles are not matched exactly by any
data points in the averaging period.
For in situ observations of the coarse mode particle number size distribution, there are 2 possible instrument types that could be given in the metadata (aerodynamic particle sizer and optical particle sizer):
When calculating average values, e.g. hourly, from measurements with higher time resolution, please disregard any invalid measurements. Any informative flags, e.g. local contamination, occuring at any time during the average period need to be copied to the average value.
Downloading template as nasaames file
Please download the .nas file and edit, and remember to keep the .nas file-extension when you
create your datafile:
V (valid measurement): indicate a special condition at the station, but instrument has operated correctly, the data are therefore considered valid.
I (invalid measurement): showing that data are not available (not measured, deleted or if it is no precipitation)
M (missing measurement): mainly used for level 0 data to be able to exclude these data when being reprocessed to level 1 and level 2
For data harmonization across the network, the following short list of the flags should be used with this template. It is possible to use several flags at the same time to give detailed information about the data.
Group 0: Valid data
valid data, no flag
Group 1: Exception flags for accepted, irregular data
Episode data checked and accepted by data originator. Valid measurement
Possible local contamination indicated by wind direction or velocity
Possible local contamination indicated by single scattering albedo (auto)
Possible local contamination indicated by occurrence of new particles (auto)
Possible local contamination indicated by low wind speed (auto)
Possible local contamination indicated by wind from contaminated sector (auto)
Group 3: Flags for aggregated datasets
Data completeness less than 50%
Data completeness less than 75%
Data completeness less than 90%
Group 4: Extreme or inconsistent values
Sahara dust event
Extreme value, unspecified error
Inconsistent with another unspecified measurement
Group 5: Chemical problem
Unspecified contamination or local influence, but considered valid
This service has been funded or supported by the Norwegian Institute for Air Research (NILU), the EU research
infrastructure ACTRIS (Aerosols, Clouds, and Trace gases Research InfraStructure), the European Monitoring and
Evaluation Programme (EMEP).