Greg McFarquhar

University of Illinois, Urbana, IL, USA

Greg McFarquhar

University of Illinois, Urbana, IL, USA

Workshop on Clouds, Aerosols, Radiation and Air-Sea Interface of Southern Ocean: Establishing Directions for

Future Research,18-19 March 2014, Seattle, WA

Introduction and Goals of Workshop, and Relationship to SOCRATES proposal

Chris Bretherton, University of Washington, Seattle, WA

Christian Jakob, Monash University, Melbourne, VIC

Roj Marchand, University of Washington, Seattle, WA

Greg McFarquhar, University of Illinois, Urbana, IL

Alain Protat, Australian Bureau of Meteorology,

Melbourne, Steven Siems, Monash University, Melbourne,

VIC

Bob Weller, Woods Hole, Woods Hole, MA

Rob Wood, University of Washington, Seattle, WA

Steering Committee

Workshop Goals

1. Identify state of knowledge of clouds, aerosols & air-sea interaction over Southern Ocean

2. Identify strategies for reducing uncertainties in their representation in global and regional models

3. Ultimate goal: better determining the role of clouds, aerosols & air-sea interaction in climate system.

Workshop Deliverable• Steering committee expects to develop a

whitepaper “Southern Ocean challenges and objectives” that will detail1. Main challenges about Southern Oceans2. General science objectives for Southern Oceans3. More specific science questions4. Strategy for addressing science questions

• Strategy for addressing objectives will likely include a field experiment, SOCRATES, as well as satellite analysis & model simulations

Why the Southern Ocean?

• Southern Ocean plays critical role in global climate system & is unique pristine environment

• But, there have been sparse observations of clouds, aerosols, radiation & air-sea interface in this region.

• Consequently, much unknown about atmospheric and oceanographic processes and their linkage in this region.

Challenges of Southern Ocean1. Large SW radiation & SST biases in GCMs2. Contribution of pre-industrial aerosols to indirect

forcing3. Why mixed-phase clouds frequently occur4. Why is there seasonal cycle in Ncloud

5. Influence of sea spray on cloud formation6. Influence of DMS on aerosols/clouds7. Why observed mid-level clouds not produced in

GCMs8. Understanding of frontal cloud systems in SO9. Evaluation of satellite products over SO

General Objectivesi. Characterize properties of cloud systems over SO,

& processes involved in life cycles of cold frontsii. Characterize aerosol microphysical & chemical

properties (including DMS), their role in regulating CCN, and impact on cloud formation/maintenance

iii. Evaluate satellite cloud, aerosol, precipitation and ocean products

iv. Evaluate/improve skill of models at multiple scales for reproducing aerosol/cloud/radiation/ precipitation interactions

• Rob Wood’s talk will go into more detail

SOCRATES (Southern Ocean Cloud Rain/Radiation, Aerosol Transport

Experimental Study• We ultimately hope to conduct a field campaign

over Southern Oceans• Possible proposals to come out of this meeting:– EOD/SOD to NSF for use of G-V/C-130?– Proposal to deploy ARM Mobile Facility?– Proposal to use NASA Global Hawk/ER-2 as high-

altitude facility?– Proposal to use Australian R/V Investigator?– Others?

Organization of Workshop

• Tuesday: Review past modeling & observational research efforts in the Southern Ocean region

• Tuesday AM: Overview talks on the Southern Ocean

• Tuesday PM: Concurrent sessions on Clouds and Meteorology, and on Aerosols and their interactions with Clouds

Organization of Workshop• Wednesday: Prioritize remaining scientific

issues to be resolved & identify strategy for addressing key aerosol-cloud-climate questions.

• Wednesday AM: Breakout #1: Formulate key questions on role of aerosols/clouds/air sea ‐interactions in Southern Oceans

• Wednesday PM: Breakout #2: What are needed measurements/retrievals/simulations needed to address hypotheses?

General Info

• We will divide into 3 breakout groups on Wednesday: division/organization of groups discussed Wednesday morning

• Provide session moderator with copy of slides– Let us know if you do NOT wish them displayed on

website

• Summaries of all breakout sessions will be presented in plenary

Acknowledgments

• Special thanks to Department of Energy Atmospheric Systems and Research Program (DOE ASR) for providing funding to partially support this workshop