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NO and NOy Abundance Data from Thermo Model 42i-Y NOY Analyzer Instrument at the Manchester Air Quality Site, 2019 onwards

Update Frequency: Monthly
Latest Data Update: 2023-06-06
Status: Ongoing
Online Status: ONLINE
Publication State: Published
Publication Date: 2023-01-25
Download Stats: last 12 months
Dataset Size: 186 Files | 450MB


Oxides of nitrogen (NO and NOy) rates measured at 7 metres above ground level by a Thermo Model 42i-Y NOY Analyzer Instrument at the Manchester Air Quality Site (MAQS) for the Integrated Research Observation System for Clean Air (OSCA) project.

Citable as:  Watson, N. (2023): NO and NOy Abundance Data from Thermo Model 42i-Y NOY Analyzer Instrument at the Manchester Air Quality Site, 2019 onwards. NERC EDS Centre for Environmental Data Analysis, date of citation.
Abbreviation: Not defined
Keywords: OSCA, air quality, supersite, maqs, OSCA-AQ


Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Access to these data is available to any registered CEDA user. Please Login or Register for an account to gain access.
Use of these data is covered by the following licence: When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

Data are collected by the project team and transfered directly from the instrument to the computer database, before being transferred to the general database, where it is processed, averaged over minute time intervals and flagged where data is suspect. Once complete, data are uploaded to CEDA for archiving.
Data processing software found in:

Data Quality:
The baseline zero level and the response factor analyser NO2 cylinder, and this technique is verified every 6 month audit. If the zero-corrected NO or NOy level falls below 0 or above 300 ppb it is flagged. Also if the NO level exceeds the NOy data, it has been flagged
File Format:
NetCDF and CSV format

Related Documents

 OSCA Project Webpage

Process overview

This dataset was generated by instruments deployed on platforms as listed below.
Output Description


  • units: 1
  • var_id: qc_flag_no
  • long_name: Data Quality flag: NO
  • units: 1
  • var_id: qc_flag_noy
  • long_name: Data Quality flag: NOy
  • long_name: Day
  • var_id: day
  • standard_name:
  • units: 1
  • long_name: Day of Year
  • var_id: day_of_year
  • standard_name:
  • long_name: Hour
  • var_id: hour
  • standard_name:
  • var_id: mass_fraction_of_noy_expressed_as_nitrogen_in_air
  • standard_name: mass_fraction_of_noy_expressed_as_nitrogen_in_air
  • long_name: Mass Fraction of NOy expressed as nitrogen in air
  • var_id: mass_fraction_of_nitric_oxide_in_air
  • standard_name: mass_fraction_of_nitric_oxide_in_air
  • long_name: Mass Fraction of Nitric Oxide in air
  • long_name: Month
  • var_id: month
  • standard_name:
  • var_id: time
  • units: seconds
  • long_name: Time (seconds since 1970-01-01 00:00:00)
  • long_name: Year
  • var_id: year
  • standard_name:
  • var_id: minute
  • standard_name:
  • long_name: minute
  • var_id: second
  • standard_name:
  • long_name: second

Co-ordinate Variables

  • units: degree_north
  • standard_name: latitude
  • var_id: latitude
  • long_name: Latitude
  • units: degree_east
  • standard_name: longitude
  • var_id: longitude
  • long_name: Longitude
Temporal Range
Start time:
End time:
Geographic Extent