Diel cycle of sea spray aerosol concentration

Abstract

Sea spray aerosol (SSA) formation have a major role in the climate system, but measurements at a global-scale of this micro-scale process are highly challenging. We measured high-resolution temporal patterns of SSA number concentration over the Atlantic Ocean, Caribbean Sea, and the Pacific Ocean covering over 42,000 km. We discovered a ubiquitous 24-hour rhythm to the SSA number concentration, with concentrations increasing after sunrise, remaining higher during the day, and returning to predawn values after sunset. The presence of dominating continental aerosol transport can mask the SSA cycle. We did not find significant links between the diel cycle of SSA number concentration and diel variations of surface winds, atmospheric physical properties, radiation, pollution, nor oceanic physical properties. However, the daily mean sea surface temperature positively correlated with the magnitude of the day-to-nighttime increase in SSA concentration. Parallel diel patterns in particle sizes were also detected in near-surface waters attributed to variations in the size of particles smaller than ~1 µm. These variations may point to microbial day-to-night modulation of bubble-bursting dynamics as a possible cause of the SSA cycle.

Identification of Sub-micrometer Ambient Sea Salt Number Size Distribution by Positive Matrix Factorization

“…The time series of this factor is negatively correlated to the organic matter, MSA and nss-sulfate, indicating its primary origin and dominance in winter. This factor also accounts for over 80% of the variance in particle number larger than 200 nm, consistent with the established understanding that sea salt dominates aerosol mass in the marine boundary layer. ,, This finding supports previous studies that have used the total particles larger than 500 nm as a proxy of sea spray aerosol. , However, the substantial number of sea salt particles below 200 nm suggests their potential contribution to marine cloud nuclei.…”

“…13,52,53 This finding supports previous studies that have used the total particles larger than 500 nm as a proxy of sea spray aerosol. 54,55 However, the substantial number of sea salt particles below 200 nm suggests their potential contribution to marine cloud nuclei.…”

Impact of airborne algicidal bacteria on marine phytoplankton blooms

“…To classify the elemental composition of the collected particles in the polycarbonate filters, we used a scanning electron microscopy with energy-disperse X-ray spectroscopy (SEM-EDS) and the method as described in Flores et al . (2021) [ 14 ] together with the particle classification scheme as described in Laskin et al . (2012) [ 15 ].…”

“…We classified each particle with a mean geometrical diameter D geo > 0.3 μm into one of five major classes of aerosols: (i) Sea salt: [Na] greater than all other elements detected (except Cl); (ii) Metals with Na: [Na] present but [Na] < [Al, Si, K, Ca, S]; (iii) Sulphate/sea salt: [Na] > [Al, Si, K, Ca] but [Na] < [S]; (iv) Sulphates: [Na] = 0 and [S] > 0; and (v) Other: all remaining particles. The SEM details and EDS spectra acquisition are as described previously [ 14 ]. A total of 7857 particles were analysed.…”

Ocean Emission Pathway and Secondary Formation Mechanism of Aminiums Over the Chinese Marginal Sea

“…Amines originated from a variety of sources, including animal husbandry, industrial emissions, vegetation emissions, marine emissions (Ge et al., 2011a; Hemmilä et al., 2018), ethanol gasoline vehicles (Feng et al., 2022), human excreta (Chang et al., 2021), and coal combustion (Liu et al., 2022). In the oceanic areas, marine emission was one of the most important contributors to amines in the marine boundary layer and tended to be closely associated with biological activities in the surface seawater (Flores et al., 2021). Marine organisms can utilize glycine betaine and trimethylamine N ‐oxides to maintain osmotic pressure under high salinity conditions (Gibb & Hatton, 2004; Kiene & Lynn, 1998; Oren et al., 2013).…”