{"ob_id":14135,"uuid":"61e6e242d5334cf0949e2c3e969b96d1","title":"Centre for Ecology and Hydrology: Long-term monitoring of PAN (peroxyacetyl nitrate) in eastern Scotland 1993-1999","abstract":"Hourly measurement data for PAN (peroxyacetyl nitrate) mixing ratios in the atmosphere at a rural site at Bush Estate, Penicuik EH26 0QB (CEH Edinburgh), 15 km south of Edinburgh, from 1993 to 1999 in ppt (parts per trillion). Measurements were made using a gas chromatograph with electron capture detector. \r\n\r\nAnnual average concentrations were between 0.1 and 0.15 nl l-1, with episodes up to 3 nl l-1 in long-range transported polluted air. PAN concentrations were approximately log-normally distributed. The concentrations measured are the result of a balance between photochemical production rates and removal by thermal decomposition and dry deposition. \r\n\r\nThere was a pronounced seasonal maximum in PAN concentrations in late spring, and a strong diurnal cycle only in April-June, with a maximum at 1700 h. Individual episodes, with concentrations up to 3 nl l-1, could be traced over distances of ca. 1000 km, with rapid changes in concentration as the prevailing winds advected polluted air masses across the site.","keywords":"CEH, PAN, Chemistry","discoveryKeywords":[1138],"publicationState":"published","dataPublishedTime":"2016-02-22T15:55:47","doiPublishedTime":null,"member":["https://catalogue.ceda.ac.uk/api/v2/observations/14136/?format=json"],"identifier_set":[],"responsiblepartyinfo_set":["https://catalogue.ceda.ac.uk/api/v2/rpis/54211/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54219/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54225/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54213/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54214/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54212/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54221/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54220/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54215/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54222/?format=json","https://catalogue.ceda.ac.uk/api/v2/rpis/54218/?format=json"]}