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Gaston, CJ, Furutani H, Guazzotti SA, Coffee KR, Bates TS, Quinn PK, Aluwihare LI, Mitchell BG, Prather KA.  2011.  Unique ocean-derived particles serve as a proxy for changes in ocean chemistry. Journal of Geophysical Research-Atmospheres. 116   10.1029/2010jd015289   AbstractWebsite

Oceans represent a significant natural source of gases and particles to the atmosphere. Relative to gas phase compounds, less is known regarding the influence of changes in biological activity in the ocean on the chemistry of sea spray aerosols produced in marine environments. To gain insight into the influence of ocean biology and chemistry on atmospheric aerosol chemistry, simultaneous real-time measurements were made of atmospheric aerosol size and chemical mixing-state, gas phase dimethyl sulfide (DMS), as well as seawater DMS and chlorophyll a. In three different marine environments with elevated chlorophyll a and DMS, unique Mg particles were detected containing Mg(2+), Ca(2+), K(+), and organic carbon. These particles were segregated from sea salt particles highlighting that two subpopulations within the sea spray were being ejected from the ocean. Strong temporal correlations were observed between these unique ocean-derived particles and freshly emitted sea salt particles (R(2) = 0.86), particularly as wind speed increased to at least 10 m/s, and atmospheric DMS (R(2) = 0.76). Time series correlations between ocean measurements and atmospheric aerosol chemistry suggest that chlorophyll a and DMS serve as indicators of changes in the chemistry of the ocean, most likely an increase in organic material, which is directly reflected in the single particle mixing-state. This is the first time such real-time correlations are shown between ocean chemistry and atmospheric aerosol mixing-state. The reasons behind these observed changes in aerosol chemistry are critical for understanding the heterogeneous reactivity, water uptake, and cloud forming potential of sea spray aerosols.

Goldberg, SJ, Ball GI, Allen BC, Schladow SG, Simpson AJ, Masoom H, Soong R, Graven HD, Aluwihare LI.  2015.  Refractory dissolved organic nitrogen accumulation in high-elevation lakes. Nature Communications. 6   10.1038/ncomms7347   AbstractWebsite

The role of dissolved organic matter (DOM) as either a sink for inorganic nutrients or an additional nutrient source is an often-neglected component of nutrient budgets in aquatic environments. Here, we examined the role of DOM in reactive nitrogen (N) storage in Sierra Nevada (California, USA) lakes where atmospheric deposition of N has shifted the lakes toward seasonal phosphorus (P)-limitation. Nuclear magnetic resonance (NMR) spectroscopy and isotope analyses performed on DOM isolated from Lake Tahoe reveal the accumulation of refractory proteinaceous material with a 100-200-year residence time. In contrast, smaller lakes in the same watershed contain DOM with typical terrestrial characteristics, indicating that proteins in Lake Tahoe are autochthonously produced. These data support the role of DOM as a possible sink for reactive N in these lake ecosystems and identify a potential role for DOM in affecting the inorganic nutrient stoichiometry of these environments.