34
BAMOS
Dec 2018
Science summary
Southern Ocean voyage creates
insights into cloud formation and
future research opportunities
Christina McCluskey 1 , Peter G. Strutton 2 , Paul J. DeMott 3 , Sebastien Moreau 4
1
UCAR; 2 University of Tasmania; 3 Colorado State University; 4 Norwegian Polar Institute
Note from the Editor: This science summary provides a synthesis of the research published in Geophysical Research
Letters. For more information, read the full journal article ‘Observations of Ice Nucleating Particles Over Southern
Ocean Waters’ by McCluskey et al., 2018.
Climate models have large shortwave radiation biases in the
Southern Ocean, and this impacts climate sensitivity estimates.
The shortwave biases are likely due to poor representation of
clouds, because aerosol cloud interactions over the Southern
Ocean are unique, with a high prevalence of supercooled
liquid clouds and a lack of terrestrial aerosol sources. Ice
nucleating particles (INPs), rare atmospheric particles required
for heterogeneous ice formation, are a likely important and
uncertain component for estimating cloud phase, lifetime, and
radiative properties. There are many source of INPs globally,
but models indicate that INPs over the Southern Ocean likely
originate from sea spray aerosol production at the ocean
surface via bubble bursting.
In early 2016, the Marine National Facility Research Vessel
Investigator conducted a month-long voyage to the Southern
Ocean that combined three major research projects:
1. the recovery and deployment of the Integrated Marine
Observing System (IMOS) moorings at the Southern
Ocean Time Series site, about 700km southwest of Hobart,
Tasmania;
2. the Clouds, Aerosols, Precipitation, Radiation, and
atmospherIc Composition Over the southeRN ocean
(CAPRICORN) program and
3. an Australian Research Council funded project to map
mesoscale eddies south of Tasmania.
Launching the balloon on the RV Investigator. Image: Grace Salgado