Ice Nucleation Properties of Authentic Atmospheric Marine Particles
EMSL Project ID
47949
Abstract
The effect that aerosol particles have on climate is highly uncertain and has garnered much attention in recent years. Specifically, the effect that aerosol particles have on cloud formation is one of the largest sources of uncertainty hindering the accurate prediction of future climate. Marine aerosols constitute one of the largest sources of aerosol particles globally. Recent studies have suggested that marine aerosols may be active ice nuclei with the potential to initiate clouds that impact climate and affect the hydrological cycle. We propose to examine particles collected from marine air masses that are pristine as well as ones influenced by anthropogenic activities. Our previous studies have demonstrated the ability to identify active ice nuclei and determine their chemical composition using state-of-the-art chemical imaging techniques available at EMSL. Samples from laboratory and field experiments provide a foundation of observations to guide the current proposal. For example, we have found that specific types of marine organisms cause heterogeneous nucleation of ice. Furthermore, we have observed significant chemical changes in marine aerosol when exposed to a highly oxidizing urban plume, presumably due to alteration of the physicochemical properties of the particles. Our goal in this proposal is to identify the number fractions of marine particles in the atmosphere and to determine their ability to nucleate ice. A process level of understanding will be obtained by taking into account the physical and chemical particle properties that control microphysical cloud formation processes, resulting in the derivation of ice nucleation rates. Using the calculated ice nucleation rates for the samples of different aerosols obtained in the laboratory and the field, modeling studies using single particle process models will be carried out in order to determine the influence of particle chemistry and mixing state on absolute ice nuclei number concentrations. This study will allow for a process-level understanding of ice nucleation enabling the validation of parameters for cloud models and global climate models.
Project Details
Project type
Large-Scale EMSL Research
Start Date
2013-10-01
End Date
2015-09-30
Status
Closed
Released Data Link
Team
Principal Investigator
Co-Investigator(s)
Team Members