Measurements of Aerosols, Radiation, and Clouds over the Southern Oceans (MARCUS) Science Plan

The Southern Ocean (SO) is the stormiest place on earth, buffeted by winds and waves that circle the ice of Antarctica, and sheathed in clouds that mantle a dynamic ocean with rich ecosystems. The remote and usually pristine environment, typically removed from anthropogenic and natural continental a...

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Bibliographic Details
Main Author: McFarquhar, Greg
Language:unknown
Published: 2018
Subjects:
Online Access:http://www.osti.gov/servlets/purl/1253914
https://www.osti.gov/biblio/1253914
https://doi.org/10.2172/1253914
Description
Summary:The Southern Ocean (SO) is the stormiest place on earth, buffeted by winds and waves that circle the ice of Antarctica, and sheathed in clouds that mantle a dynamic ocean with rich ecosystems. The remote and usually pristine environment, typically removed from anthropogenic and natural continental aerosol sources, makes the SO unique for examining cloud-aerosol interactions for liquid and ice clouds, and the role of primary and secondary marine biogenic aerosols and sea salt. There is strong seasonality in aerosol sources and sinks over the SO that are poorly understood. Weather and climate models are challenged by uncertainties and biases in the simulation of SO clouds, aerosols, and air-sea exchanges that trace to poor physical understanding of these processes, and by cloud feedbacks (e.g., phase changes) in response to warming. Models almost universally underestimate sunlight reflected by near surface cloud, particularly in the cold sector of cyclonic storm systems, and this may be due to difficulties in representing pervasive supercooled and mixed-phase boundary-layer (BL) clouds. Motivated by these issues, a large international multi-agency effort called the Southern Ocean Clouds Radiation Transport Aerosol Transport Experimental Study (SOCRATES) has been proposed to improve our understanding of clouds, aerosols, air-sea exchanges and their interactions over the SO. Coincident with SOCRATES, the Measurements of Aerosols, Radiation and CloUds over the Southern Oceans (MARCUS) experiment will be conducted where the second U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility’s Mobile Facility (AMF2) will be installed on the Australian Antarctic supply vessel Aurora Australis (AA) as it makes routine transits between Hobart, Australia and the Antarctic, visiting the Australian Antarctic stations Mawson, Davis, and Casey, as well as Macquarie Island. During MARCUS, the AMF-2 will acquire comprehensive observations of aerosols (including cloud condensation nuclei [CCN] ...