EOL Seminar: Marine Ice Nucleating Particles: Implications for High Latitude Aerosol-Cloud Interactions

Date: 
Tuesday, April 4, 2017 - 15:30 to 16:30
Location: 
FL2-1022 Large Auditorium
Contact Name: 
Holger Voemel
Contact Email: 
Contact Phone: 
8837

Marine Ice Nucleating Particles: Implications for High Latitude Aerosol-Cloud Interactions

Christina S. McCluskey
Department of Atmospheric Science
Colorado State University


Large energy biases and uncertainties in future climate projections have been attributed to poor representation of cloud phase (ice or liquid) properties in global climate models (GCMs). Specifically, over high latitudes, such as the Southern Ocean, GCMs tend to predict too few clouds that do not reproduce the high supercooled liquid contents observed via satellite. Several processes govern cloud phase distributions, including the presence of atmospheric ice nucleating particles (INPs), or particles that initiate heterogeneous ice nucleation (IN). Sea spray aerosol (SSA), generated from wave breaking and bubble bursting at the ocean surface, is considered a unique INP source. Typical IN activity of SSA is lower than terrestrial aerosol, but laboratory and limited field measurements indicate that marine INP emissions may vary over orders of magnitude due to increased organic aerosol arising from oceanic biological productivity (i.e., phytoplankton blooms). Quantifying the role of SSA in natural INP populations, both regionally and globally, is a key gap in the scientific understanding of aerosol-cloud interactions in remote regions, where other INP sources (e.g., mineral dust) are absent.


In this presentation, I will discuss a series of studies aimed towards investigating the abundance and characteristics of marine INPs at varied latitudes, ranging from 65°S to 60°N, over the PacificOcean and at the Mace Head Observatory (MHO, Ireland). Aerosol and IN measurements from six ship campaigns are used to explore latitudinal variability in natural marine INP number concentrations. Strong variability in INP number concentrations and INP composition are observed and linked to clean marine versus terrestrial influences at the MHO. Investigations on the role of organic-rich plumes originating from biologically active oceans on marine INP emissions at the MHO and in the Southern Ocean will also be discussed. These findings advance the scientific understanding of the link between biological activity and marine INPs in the natural environment and illuminate marine INPs as a potentially important feature in remote ocean aerosol-cloud interactions


For those unable to attend, the seminar will be webcast live at:  http://www.fin.ucar.edu/it/mms/fl-live.htm


Tuesday April 4, 2017 3:30pm

FL2-1022 Large Auditorium

3450 Mitchell Lane Boulder, CO