HOCl and Cl<sub>2</sub> observations in marine air
Cl atoms in the marine atmosphere may significantly impact the lifetimes of methane and other hydrocarbons. However, the existing estimates of Cl atom levels in marine air are based on indirect evidence. Here we present measurements of the Cl precursors HOCl and Cl<sub>2</sub> in the mar...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2011-08-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | http://www.atmos-chem-phys.net/11/7617/2011/acp-11-7617-2011.pdf |
| _version_ | 1811216808316764160 |
|---|---|
| author | R. Sommariva R. von Glasow J. D. Lee L. J. Carpenter R. Sander M. J. Lawler E. S. Saltzman |
| author_facet | R. Sommariva R. von Glasow J. D. Lee L. J. Carpenter R. Sander M. J. Lawler E. S. Saltzman |
| author_sort | R. Sommariva |
| collection | DOAJ |
| description | Cl atoms in the marine atmosphere may significantly impact the lifetimes of methane and other hydrocarbons. However, the existing estimates of Cl atom levels in marine air are based on indirect evidence. Here we present measurements of the Cl precursors HOCl and Cl<sub>2</sub> in the marine boundary layer during June of 2009 at the Cape Verde Atmospheric Observatory in the eastern tropical Atlantic. These are the first measurements of tropospheric HOCl. HOCl and Cl<sub>2</sub> levels were low in air with open ocean back trajectories, with maximum levels always below 60 and 10 ppt (pmol/mol), respectively. In air with trajectories originating over Europe, HOCl and Cl<sub>2</sub> levels were higher, with HOCl maxima exceeding 100 ppt each day and Cl<sub>2</sub> reaching up to 35 ppt. The increased Cl cycling associated with long distance pollutant transport over the oceans likely impacts a wide geographic area and represents a mechanism by which human activities have increased the reactivity of the marine atmosphere. Data-constrained model simulations indicate that Cl atoms account for approximately 15 % of methane destruction on days when aged polluted air arrives at the site. A photochemical model does not adequately simulate the observed abundances of HOCl and Cl<sub>2</sub>, raising the possibility of an unknown HOCl source. |
| first_indexed | 2024-04-12T06:44:27Z |
| format | Article |
| id | doaj.art-1c4b5d55afbc4088864ae094e0fd701c |
| institution | Directory Open Access Journal |
| issn | 1680-7316 1680-7324 |
| language | English |
| last_indexed | 2024-04-12T06:44:27Z |
| publishDate | 2011-08-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Chemistry and Physics |
| spelling | doaj.art-1c4b5d55afbc4088864ae094e0fd701c2022-12-22T03:43:35ZengCopernicus PublicationsAtmospheric Chemistry and Physics1680-73161680-73242011-08-0111157617762810.5194/acp-11-7617-2011HOCl and Cl<sub>2</sub> observations in marine airR. SommarivaR. von GlasowJ. D. LeeL. J. CarpenterR. SanderM. J. LawlerE. S. SaltzmanCl atoms in the marine atmosphere may significantly impact the lifetimes of methane and other hydrocarbons. However, the existing estimates of Cl atom levels in marine air are based on indirect evidence. Here we present measurements of the Cl precursors HOCl and Cl<sub>2</sub> in the marine boundary layer during June of 2009 at the Cape Verde Atmospheric Observatory in the eastern tropical Atlantic. These are the first measurements of tropospheric HOCl. HOCl and Cl<sub>2</sub> levels were low in air with open ocean back trajectories, with maximum levels always below 60 and 10 ppt (pmol/mol), respectively. In air with trajectories originating over Europe, HOCl and Cl<sub>2</sub> levels were higher, with HOCl maxima exceeding 100 ppt each day and Cl<sub>2</sub> reaching up to 35 ppt. The increased Cl cycling associated with long distance pollutant transport over the oceans likely impacts a wide geographic area and represents a mechanism by which human activities have increased the reactivity of the marine atmosphere. Data-constrained model simulations indicate that Cl atoms account for approximately 15 % of methane destruction on days when aged polluted air arrives at the site. A photochemical model does not adequately simulate the observed abundances of HOCl and Cl<sub>2</sub>, raising the possibility of an unknown HOCl source.http://www.atmos-chem-phys.net/11/7617/2011/acp-11-7617-2011.pdf |
| spellingShingle | R. Sommariva R. von Glasow J. D. Lee L. J. Carpenter R. Sander M. J. Lawler E. S. Saltzman HOCl and Cl<sub>2</sub> observations in marine air Atmospheric Chemistry and Physics |
| title | HOCl and Cl<sub>2</sub> observations in marine air |
| title_full | HOCl and Cl<sub>2</sub> observations in marine air |
| title_fullStr | HOCl and Cl<sub>2</sub> observations in marine air |
| title_full_unstemmed | HOCl and Cl<sub>2</sub> observations in marine air |
| title_short | HOCl and Cl<sub>2</sub> observations in marine air |
| title_sort | hocl and cl sub 2 sub observations in marine air |
| url | http://www.atmos-chem-phys.net/11/7617/2011/acp-11-7617-2011.pdf |
| work_keys_str_mv | AT rsommariva hoclandclsub2subobservationsinmarineair AT rvonglasow hoclandclsub2subobservationsinmarineair AT jdlee hoclandclsub2subobservationsinmarineair AT ljcarpenter hoclandclsub2subobservationsinmarineair AT rsander hoclandclsub2subobservationsinmarineair AT mjlawler hoclandclsub2subobservationsinmarineair AT essaltzman hoclandclsub2subobservationsinmarineair |