Sources of aerosol number near the southwest coast of the United Kingdom - quantification of sea spray and ship emission fluxes
Abstract
We present 2015-2017 measurements of total aerosol number concentration (>3 nm), sea spray number fluxes by eddy covariance, and ship emissions of aerosol number from the Penlee Point Atmospheric Observatory on the southwest coast of the United Kingdom. Aerosol number concentration in southwesterly winds (off the North Atlantic) shows clear diurnal and seasonal variability. Sea spray flux strongly increases with wind speed as well as significant wave height. Aerosol number concentration in southeasterly winds (across the English Channel) is significantly affected by ship emissions. We find that ships contribute significantly to the aerosol number budget, with a mean emission factor of 500 aerosols/s/cm2 of water. This is on the lower end of previous estimates, possibly because the English Channel has been subject to ship sulfur emission control since 2015. Sea spray number flux becomes comparable to ship emission flux only at very high wind speeds. Generally sea spray is more important towards the aerosol mass budget.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.A11L2410B
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0320 Cloud physics and chemistry;
- ATMOSPHERIC COMPOSITION AND STRUCTUREDE: 0426 Biosphere/atmosphere interactions;
- BIOGEOSCIENCESDE: 4504 Air/sea interactions;
- OCEANOGRAPHY: PHYSICAL