Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic
Abstract A record spanning ten years of non-methane hydrocarbon (NMHC) data from the Pico Mountain Observatory (PMO), Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central N...
| Main Authors: | , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
BioOne
2015-08-01
|
| Series: | Elementa: Science of the Anthropocene |
| Subjects: | |
| Online Access: | http://elementascience.org/article/info:doi/10.12952/journal.elementa.000054 |
| _version_ | 1819154139069808640 |
|---|---|
| author | Detlev Helmig Mauricio Muoz Jacques Hueber Claudio Mazzoleni Lynn Mazzoleni Robert C. Owen Maria Val-Martin Paulo Fialho Christian Plass-Duelmer Paul I. Palmer Alastair C. Lewis Gabriele Pfister |
| author_facet | Detlev Helmig Mauricio Muoz Jacques Hueber Claudio Mazzoleni Lynn Mazzoleni Robert C. Owen Maria Val-Martin Paulo Fialho Christian Plass-Duelmer Paul I. Palmer Alastair C. Lewis Gabriele Pfister |
| author_sort | Detlev Helmig |
| collection | DOAJ |
| description | Abstract A record spanning ten years of non-methane hydrocarbon (NMHC) data from the Pico Mountain Observatory (PMO), Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central North Atlantic, at an elevation of 2225 m asl, allows these data to be used to investigate the background conditions and pollution transport events occurring in the lower free North Atlantic troposphere. The quantity ln([propane]/[ethane]) was used as an indicator of both photochemical processing and a marker for the occurrence of pollution transport events detected at the station. The Pico data were compared with three other continuous NMHC data sets from sites bordering the North Atlantic, i.e. the Global Atmospheric Watch (GAW) stations at Summit, Greenland, Hohenpeisssenberg, Germany, and Cape Verde, using ln([propane]/[ethane]) results as an indicator for the degree of photochemical processing (aging) seen in the data. Comparisons of these three data sets showed some significant differences in the seasonal background and range of observed values. The statistical distribution of binned monthly data was determined, and individual sample events were then scaled to the monthly median observed value. Back trajectories, determined by the HYSPLIT model were used to investigate the geographic origin of the observed trace gases as a function of the degree of photochemical processing. Results show that PMO samples have been subjected to a diversity of air transport and aging, from highly processed air to freshly emitted air throughout the year, and in particular during summer months. The predominant air transport is from North America, with only occasional influence from continental areas located east and southeast (Europe and Africa). The available record was found to be too variable and still too short to allow deciphering NMHC trends from the data. Ethane and propane measurements at the PMO were compared with the MOZART-4 atmospheric chemistry and transport model at the appropriate time and location. The model was found to yield good agreement in the description of the lower range of atmospheric mole fractions observed, of the seasonal cycle, and the regional oxidation chemistry. However, ethane and propane enhancements in transport events were underestimated, indicating that after the 3 days of synoptic transport to PMO the spatial extent of plumes frequently is smaller than the 2.8x2.8 (300 km) model grid resolution. |
| first_indexed | 2024-12-22T15:16:19Z |
| format | Article |
| id | doaj.art-e139a1ea5e7d409da6a4f0adef8e30dd |
| institution | Directory Open Access Journal |
| issn | 2325-1026 |
| language | English |
| last_indexed | 2024-12-22T15:16:19Z |
| publishDate | 2015-08-01 |
| publisher | BioOne |
| record_format | Article |
| series | Elementa: Science of the Anthropocene |
| spelling | doaj.art-e139a1ea5e7d409da6a4f0adef8e30dd2022-12-21T18:21:45ZengBioOneElementa: Science of the Anthropocene2325-10262015-08-0110.12952/journal.elementa.000054ELEMENTA-D-14-00003Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North AtlanticDetlev HelmigMauricio MuozJacques HueberClaudio MazzoleniLynn MazzoleniRobert C. OwenMaria Val-MartinPaulo FialhoChristian Plass-DuelmerPaul I. PalmerAlastair C. LewisGabriele PfisterAbstract A record spanning ten years of non-methane hydrocarbon (NMHC) data from the Pico Mountain Observatory (PMO), Pico Island, Azores, Portugal, was analyzed for seasonal NMHC behavior, atmospheric processing, and trends, focusing on ethane and propane. The location of this site in the central North Atlantic, at an elevation of 2225 m asl, allows these data to be used to investigate the background conditions and pollution transport events occurring in the lower free North Atlantic troposphere. The quantity ln([propane]/[ethane]) was used as an indicator of both photochemical processing and a marker for the occurrence of pollution transport events detected at the station. The Pico data were compared with three other continuous NMHC data sets from sites bordering the North Atlantic, i.e. the Global Atmospheric Watch (GAW) stations at Summit, Greenland, Hohenpeisssenberg, Germany, and Cape Verde, using ln([propane]/[ethane]) results as an indicator for the degree of photochemical processing (aging) seen in the data. Comparisons of these three data sets showed some significant differences in the seasonal background and range of observed values. The statistical distribution of binned monthly data was determined, and individual sample events were then scaled to the monthly median observed value. Back trajectories, determined by the HYSPLIT model were used to investigate the geographic origin of the observed trace gases as a function of the degree of photochemical processing. Results show that PMO samples have been subjected to a diversity of air transport and aging, from highly processed air to freshly emitted air throughout the year, and in particular during summer months. The predominant air transport is from North America, with only occasional influence from continental areas located east and southeast (Europe and Africa). The available record was found to be too variable and still too short to allow deciphering NMHC trends from the data. Ethane and propane measurements at the PMO were compared with the MOZART-4 atmospheric chemistry and transport model at the appropriate time and location. The model was found to yield good agreement in the description of the lower range of atmospheric mole fractions observed, of the seasonal cycle, and the regional oxidation chemistry. However, ethane and propane enhancements in transport events were underestimated, indicating that after the 3 days of synoptic transport to PMO the spatial extent of plumes frequently is smaller than the 2.8x2.8 (300 km) model grid resolution.http://elementascience.org/article/info:doi/10.12952/journal.elementa.000054Atmospheric ChemistryAtmospheric TransportVolatile Organic CompoundsGlobal Atmosphere Watch |
| spellingShingle | Detlev Helmig Mauricio Muoz Jacques Hueber Claudio Mazzoleni Lynn Mazzoleni Robert C. Owen Maria Val-Martin Paulo Fialho Christian Plass-Duelmer Paul I. Palmer Alastair C. Lewis Gabriele Pfister Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic Elementa: Science of the Anthropocene Atmospheric Chemistry Atmospheric Transport Volatile Organic Compounds Global Atmosphere Watch |
| title | Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic |
| title_full | Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic |
| title_fullStr | Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic |
| title_full_unstemmed | Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic |
| title_short | Climatology and atmospheric chemistry of the non-methane hydrocarbons ethane and propane over the North Atlantic |
| title_sort | climatology and atmospheric chemistry of the non methane hydrocarbons ethane and propane over the north atlantic |
| topic | Atmospheric Chemistry Atmospheric Transport Volatile Organic Compounds Global Atmosphere Watch |
| url | http://elementascience.org/article/info:doi/10.12952/journal.elementa.000054 |
| work_keys_str_mv | AT detlevhelmig climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT mauriciomuoz climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT jacqueshueber climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT claudiomazzoleni climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT lynnmazzoleni climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT robertcowen climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT mariavalmartin climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT paulofialho climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT christianplassduelmer climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT paulipalmer climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT alastairclewis climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic AT gabrielepfister climatologyandatmosphericchemistryofthenonmethanehydrocarbonsethaneandpropaneoverthenorthatlantic |