OCEANFILMS (Organic Compounds from Ecosystems to Aerosols: Natural Films and Interfaces via Langmuir Molecular Surfactants) sea spray organic aerosol emissions – implementation in a global climate model and impacts on clouds

Journal Article · Thu Apr 21 00:00:00 EDT 2022 · Atmospheric Chemistry and Physics (Online)

DOI:https://doi.org/10.5194/acp-22-5223-2022· OSTI ID:1868881

Burrows, Susannah M.  ^[1]; Easter, Richard C.  ^[1]; Liu, Xiaohong ^[2]; Ma, Po-Lun  ^[1]; Wang, Hailong  ^[1]; Elliott, Scott M. ^[3]; Singh, Balwinder ^[1]; Zhang, Kai  ^[1]; Rasch, Philip J. ^[4]

---

1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States)
2. Texas A & M Univ., College Station, TX (United States)
3. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
4. Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Univ. of Washington, Seattle, WA (United States)

Sea spray aerosol is one of the major sources of atmospheric particulate matter globally. It has increasingly been recognized that organic matter derived from ocean biological precursors contributes significantly to the composition of submicron sea spray and may modify sea spray aerosol impacts on clouds and climate. This paper describes the implementation of the OCEANFILMS (Organic Compounds from Ecosystems to Aerosols: Natural Films and Interfaces via Langmuir Molecular Surfactants) parameterization for sea spray organic aerosol emissions in a global Earth system model, the Energy Exascale Earth System Model (E3SM). OCEANFILMS is a physically based model that links sea spray chemistry with ocean biogeochemistry using a Langmuir partitioning approach. We describe the implementation details of OCEANFILMS within E3SM, compare simulated aerosol fields with observations, and investigate impacts on simulated clouds and climate. Four sensitivity cases are tested, in which organic emissions either strictly add to or strictly replace sea salt emissions (in mass and number) and are either fully internally or fully externally mixed with sea salt. The simulation with internally mixed, added organics agrees reasonably well with observed seasonal cycles of organic matter in marine aerosol and has been selected as the default configuration of the E3SM. In this configuration, sea spray organic aerosol contributes an additional source of cloud condensation nuclei, adding up to 30 cm^-3 to Southern Ocean boundary-layer cloud condensation nuclei concentrations (supersaturation = 0.1 %). The addition of this new aerosol source strengthens shortwave radiative cooling by clouds by -0.36 W m^-2 in the global annual mean and contributes more than -3.5 W m^-2 to summertime zonal mean cloud forcing in the Southern Ocean, with maximum zonal mean impacts of about -4 W m^-2 around 50–60°S. This is consistent with a previous top-down, satellite-based empirical estimate of the radiative forcing by sea spray organic aerosol over the Southern Ocean. Through its mechanistic approach, OCEANFILMS offers a path towards improved understanding of the feedbacks between ocean biology, sea spray organic matter, and climate.

• Research Organization: Pacific Northwest National Laboratory (PNNL), Richland, WA (United States); Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
• Sponsoring Organization: USDOE Office of Science (SC); National Energy Research Scientific Computing Center (NERSC)
• Grant/Contract Number: AC05-76RL01830; SC0011611; KP1703020/65814; KP1703110/65814; AC02-05CH11231
• OSTI ID: 1868881
• Report Number(s): PNNL-SA-131643
• Journal Information: Atmospheric Chemistry and Physics (Online), Vol. 22, Issue 8; ISSN 1680-7324
• Publisher: Copernicus Publications, EGU
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY