Multimodal Imaging and chemical analysis of Sea Spray Aerosols
EMSL Project ID
48592
Abstract
The marine environment is a highly diverse and complex system, playing an important role in biogeochemical cycling of the world carbon stock. Sea spray aerosols (SSA) make significant contributions to these cycles by ejecting carbon from the sea surface microlayer (SSML). However, despite the fact that aerosol particles play an important role in cloud microphysical properties and are known to either warm or cool the atmosphere via the direct absorption and scattering of incoming solar radiation, the vast majority of the existing constraints for climate models do not include aerosol particles. This is largely due to the uncertainty in aerosol structure, composition, aging and chemistry. The analysis of sea spray aerosols (SSA) is a complex multiscale problem due to their wide size distribution (a few nm to several microns) and heterogeneous composition (organic, inorganic and biological material). While bulk measurements on SSA can provide information about their size distribution and chemical content, individual particle imaging and chemical analysis is required to fully categorize SSA types, physiochemical properties, origin and their aging mechanisms. We have recently developed a new technique to capture individual hydrated aerosol particles on substrates and image them using graphene oxide (GO) supported cryo-TEM, this represents a significant departure from previous analysis and not only allows us to study hydrated particle structure but also particle aging. This will provide an important insight in SSAs as, in comparison to other land based aerosols, they have a large water component. Using this technique combined with state of the art multimodal imaging at EMSL we propose the elucidation of the morphology and chemical composition of SSA will lead to a clear understanding of their role in the environment. Particles will be analyzed by cryo-TEM/STEM, cryo-SEM, helium ion microscopy, nano-SIMS and dynamic-TEM. The complementary imaging techniques will allow us to image the full range of SSA sizes, from a few nm to several microns, asses particle morphology, internal structure and map elemental composition. Once the various SSA types have been identified their reactivity and dynamics in time can be studied using the Hummingbird gas/liquid stage holder and DTEM. Combining the cryo- and liquid- TEM approach will allow us to study particle dynamics, reactivity and aging for individual particles over short (micro seconds / seconds) and long (minutes/ hours) time frames. We predict the understanding gained from this study will greatly improve the current knowledge of how SSAs affect climate and the environment.
Project Details
Project type
Special Science
Start Date
2014-09-22
End Date
2015-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members