Sea spray fluxes from the southwest coast of the United Kingdom – dependence on wind speed and wave height
<p>Fluxes of sea spray aerosols were measured with the eddy covariance technique from the Penlee Point Atmospheric Observatory (PPAO) on the southwest coast of the United Kingdom over several months from 2015 to 2017. Two different fast-responding aerosol instruments were employed: an ultra-fi...
| Main Authors: | , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2019-12-01
|
| Series: | Atmospheric Chemistry and Physics |
| Online Access: | https://www.atmos-chem-phys.net/19/15271/2019/acp-19-15271-2019.pdf |
| Summary: | <p>Fluxes of sea spray aerosols were measured with the eddy
covariance technique from the Penlee Point Atmospheric Observatory (PPAO) on
the southwest coast of the United Kingdom over several months from 2015 to
2017. Two different fast-responding aerosol instruments were employed: an
ultra-fine condensation particle counter (CPC) that detects aerosols with
a radius above ca. 1.5 nm and a compact lightweight aerosol spectrometer
probe (CLASP) that provides a size distribution between ca. 0.1 and 6 <span class="inline-formula">µ</span>m. The measured sea spray emission fluxes essentially all originated from
the shallow waters upwind, rather than from the surf zone/shore break.
Fluxes from the CPC and from the CLASP (integrated over all sizes) were
generally comparable, implying a reasonable closure in the aerosol number
flux. Compared to most previous observations over the open ocean, at the
same wind speed the mean sea spray number fluxes at PPAO are much greater.
Significant wave height and wave Reynolds numbers explain more variability in
sea spray fluxes than wind speed does, implying that enhanced wave breaking
resulting from shoaling in shallow coastal waters is a dominant control on
sea spray emission. Comparisons between two different wind sectors (open
water vs. fetch-limited Plymouth Sound) and between two sets of sea states
(growing vs. falling seas) further confirm the importance of wave
characteristics on sea spray fluxes. These results suggest that spatial
variability in wave characteristics need to be taken into account in
predictions of coastal sea spray productions and also aerosol loading.</p> |
|---|---|
| ISSN: | 1680-7316 1680-7324 |