62°S Witnesses the Transition of Boundary Layer Marine Aerosol Pattern Over the Southern Ocean (50°S–68°S, 63°E–150°E) During the Spring and Summer: Results From MARCUS (I)
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- University of Oklahoma, Norman, OK (United States); Cooperative Institute for Severe and High Impact Weather Research and Operations, Norman, OK (United States)
- University of Washington, Seattle, WA (United States)
- Argonne National Laboratory (ANL), Argonne, IL (United States)
- University of Oklahoma, Norman, OK (United States)
- Colorado State University, Fort Collins, CO (United States)
- National Center for Atmospheric Research (NCAR), Boulder, CO (United States). Climate Global Dynamics Laboratory
- Commonwealth Scientific and Industrial Research Organisation (CSIRO), Melbourne (Australia); University of Tasmania, Hobart, TAS (Australia)
We report the Atmospheric Radiation Measurement Mobile Facility-2 was installed onboard the research vessel Aurora Australis to measure aerosol properties during the 2017–2018 Measurement of Aerosols, Radiation, and CloUds over the pristine Southern ocean (MARCUS) Experiment, providing unique data on aerosols latitudinal and seasonal variation, including south of 60°S where previous observations are scarce. Data from a Cloud Condensation Nuclei (CCN) counter and Ultra-High-Sensitivity Aerosol Spectrometer show that both the number concentration (NCCN) and size distribution of CCN-active aerosols, with diameters (D) between 60 nm < D < 1,000 nm are different over the North Southern Ocean (NSO) (50°S–60°S) and the South Southern Ocean (SSO) (62°S–68°S). The average NSO NCCN at 0.2% and 0.5% supersaturation were 28% and 49% less than that over the SSO. This increase of CCN over the SSO is caused by the increase of aerosols with 60 nm < D < 200 nm, consistent with calculations of Aerosol Scattering Angstrom Exponents derived from a nephelometer. Aerosol hygroscopicity growth factor measured by the Hygroscopic Tandem Differential Mobility Analyzer stayed close to 1.41 for aerosols with 50 nm < D < 250 nm over the SSO, but increased from 1.30 to 1.67 over the NSO, indicating different chemical compositions. Both CCN and Ice Nucleating Particles (INPs) showed a stronger variation with season than with latitude. The variation of heat-labile and presumably proteinacous INPs suggests an increase of ice nucleating-active microbes in summer.
- Research Organization:
- Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Atmospheric Radiation Measurement (ARM) Data Center; Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Science (SC), Biological and Environmental Research (BER); Australian Government; National Science Foundation (NSF)
- Contributing Organization:
- Pacific Northwest National Laboratory (PNNL); Brookhaven National Laboratory (BNL)
- Grant/Contract Number:
- SC0021116; SC0018626; SC0016225; SC0020098; SC0021159; SC0018995; SC0021116
- OSTI ID:
- 2345873
- Alternate ID(s):
- OSTI ID: 2349406; OSTI ID: 2545800
- Journal Information:
- Journal of Geophysical Research. Atmospheres, Journal Name: Journal of Geophysical Research. Atmospheres Journal Issue: 9 Vol. 129; ISSN 2169-897X
- Publisher:
- American Geophysical UnionCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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