skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Measurements of Aerosols, Radiation, and Clouds over the Southern Ocean (MARCUS) Ice Nucleating Particle Measurements Field Campaign Report

Program Document ·
OSTI ID:1489372
 [1];  [1];  [2]
  1. Colorado State Univ., Fort Collins, CO (United States)
  2. University of Oklahoma

Evidence exists that sea-spray-sourced ice nucleating particles (INPs) are organic in origin, resulting from biological and biochemical processes in seawater and the sea surface microlayer, and represent a distinctly different and variable, but oftentimes much less effective, INP population in comparison to long-range transported desert dust (DeMott et al. 2016; McCluskey et al. 2018a). Over the Southern Ocean (SO), far from land sources, these INPs may dominate in the marine boundary layer (McCluskey et al. 2018b). Thereby, marine INPs may affect cloud phase and lifetime in this region where pervasive supercooled and mixed-phase boundary-layer clouds appear underrepresented in climate models. This motivated collection of ice nucleating particle concentration measurements during the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) user facility Measurements of Aerosols, Radiation and Clouds over the Southern Ocean (MARCUS) deployment of the second ARM Mobile Facility (AMF2) on the Aurora Australis vessel from early November, 2017 (Austral spring) to late March, 2018 (Austral fall). During this period, four voyages were made from Hobart, Tasmania to the Australian Antarctic Division bases at Casey, Davis, and Mawson, as well as a final resupply cruise to Macquarie Island, the sight of the related Macquarie Island Cloud and Radiation Experiment (MICRE) campaign. Aerosol filter collections of alternating 24- and 48-hour duration were made during all voyages. These filters were returned frozen for subsequent processing to determine variability in the temperature spectrum of the concentrations of INPs active via the immersion freezing mechanism and to conduct additional analyses to indicate the chemical and biological nature of INPs over the SO. The MARCUS data set provides the first spatial and seasonal picture of INP concentrations over the SO in more than four decades, complementing the full annual cycle of INP data we collected for a point location in MICRE.

Research Organization:
DOE Office of Science Atmospheric Radiation Measurement (ARM) Program (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Biological and Environmental Research (BER)
Contributing Organization:
Colorado State University, University of Oklahoma
DOE Contract Number:
DE-ACO5-7601830
OSTI ID:
1489372
Report Number(s):
DOE/SC-ARM-18-031
Country of Publication:
United States
Language:
English