Characterization of sea spray aerosol under future ocean conditions with implications for cloud formation processes
EMSL Project ID
49402
Abstract
Oceans cover 71% of the Earth's surface, contain nearly half the global primary productivity, and are a major source of atmospheric Sea Spray Aerosol (SSA) representing one of the most uncertain components of the aerosol-radiation-climate problem. SSA particles consist of inorganic salts and organic material with smaller particles mainly organic in nature. In the coming decades, ocean acidification and increasing water temperatures resulting from continuous CO2 emissions will impact the metabolic activities of planktonic microorganisms. This in turn will lead to changing biochemical seawater properties including the concentrations and types of macromolecular and polymeric subclasses of dissolved organic matter released from cells. The production flux of submicron organic-rich particles, amount and type of organic macromolecules, and how chemical species are compositionally distributed amongst the population of SSA particles impact their potential to act as cloud condensation nuclei (CCN) and ice nuclei (IN). Our goal is to understand how the internal compositional heterogeneity and morphology of discrete SSA particles being CCN and IN active change in warmer and more acidic ocean waters? Will the ability of SSA produced from a future ocean to act as CCN and IN be impacted and thereby influence cloud formation and climate? These questions will be addressed using a range of single particle micro-spectroscopic analytical and high resolution mass spectrometer techniques available at EMSL to examine aerosol particles generated during a series of experiments with seawater and bacterio-phytoplankton in laboratory mesocosms simulating e water pH and temperature of a future climate. SSAs generated by bubble bursting at the seawater surface will be captured size-resolved by impaction onto substrates for micro-spectroscopic examination and CCN and ice nucleation measurements. Relevant EMSL instruments to examine the microstructure and chemical characteristics of particles in the nm-to-um size range, the most influential size class for climatic processes include CCSEM/EDX, IN-ESEM, FT-Raman spectrometer, TEM, TOF-SIMS, and nano-DESI. The combination of these instrumentation will allow to examine in detail the nature of the biogenic material crucial to i) improve hygroscopicity parameterizations for CCN activation in models and to identify and characterize the ice nucleating particle features resulting in improved ice nucleation parameterizations.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2016-10-01
End Date
2019-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members