1. Marine Ice Nucleating Particles and the Need for Southern Ocean Measurements Paul J DeMott 1, Thomas Christopher James Hill 1, Matthew J Ruppel 2, Kimberly A Prather 2,3, Douglas B Collins 2, Jessica l Axson 2, Taehyoung Lee 4, Chung Yeon Hwang 5, Ryan C Sullivan 6, Gavin R McMeeking 7, Ryan Mason 8, Allan K Bertram 8, Olga L Mayol-Bracero 9, Ernie R Lewis 10 1 Colorado State University, Fort Collins, CO, USA 2 University of California, San Diego, CA, USA 3 Scripps Institution of Oceanography, San Diego, CA, USA 4 Hankuk University of Foreign Studies, Seoul, Korea 5 Korea Polar Research Institute, Incheon, Korea 6 Carnegie Mellon University, Pittsburgh, PA, USA 7 Droplet Measurement Technologies, Boulder, CO, USA 8 University of British Columbia, Vancouver, BC, Canada 9 University of Puerto Rico, San Juan, Puerto Rico Brookhaven National Laboratory, Upton, NY, USA March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

2. Research questions and significance of ice nucleating particle (INP) measurement of marine aerosols To what extent are oceans sources of the nuclei for ice cloud formation? What are sea spray produced ice nucleating particles (INP)? Do INP emissions play any role in affecting cloud differences (frequency and phase) over oceans, especially SH? – Poor prediction of SH radiation budget by climate models (Trenberth and Fasullo, 2010), too few and too short-lived clouds – Prevalence of supercooled cloud tops down to -20˚C via MODIS and Calipso (Huang et al. 2012) – Low ice crystal concentration ( >-20˚C), only isolated secondary ice (Grosvenor et al. 2012; Chubb et al. 2013) March 10, 2014 DOE-ASR CAPI Ice Nucleation Breakout (Potomac, MD) Trenberth and Fasullo (2010) Kanitz et al. (2011) NH land SH ocean Ship-based lidar assessment of cloud ice fraction

3. Some historical ice nuclei data March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle) Burrows et al. (2013) Bigg (1973)

4. Real-time and offline INP measurements Inertial impactor at ~2.4  m Continuous flow diffusion chamber (CFDC): Inertial impactor  EM PCVI  single particle devices > ~4  m Bioanalyses: pyrosequencing Ambient aerosol Collection for offline analysis (onto filter or into liquid, frozen) Immersion freezing of few to few tens microliter samples Vali (1971):n IN per ml = qPCR) identification of INA bacteria; heat treatment for selective removal of biological organisms Concentrator March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

5. CAICE (Center for Aerosol Impacts on Climate and the Environment) Lab Studies Glass Wave Channel Marine Aerosol Reference Tank (MART) March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

6. CAICE fresh seawater (Scripps pier) wave- breaking experiments (Prather et al., PNAS, 2013) Basic INP-T spectrum with overlap of methods Modest dependence on n>0.5  m (mimics airborne inorganic INP) Methods correspond (robust for other inter-comparisons)  time dependence is a minor factor in assessing the activity spectrum of marine INP.  methods have no obvious flaws March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

7. Two types of laboratory studies performed thus far Wave ChannelPlunging tanks March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

8. Bacteria can mediate INP produced by spray However, a major common INP type is SS-OC (sea salt coated with organic carbon, with Mg, sometimes K, P) decay Feed bacteria March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

9. Ice nuclei from sea spray particles peak with chl-a in “spiked” phytoplankton blooms (January 2013) Same SS-OC particles inclusions ATOFMS SSOC cluster March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

10. “Natural” phytoplankton blooms (January 2014) No change or degradation during bloom but post-bloom INP enhancement at warmer T Note: INP in filter collections were insensitive to 24 hr. dry in clean air Seawater INP units < 200 nm, apparently organic March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

11. Two distinctly different ocean transects (MAGIC LA- Honolulu versus SHIPPO Incheon to Nome) POC Chl-a MODIS – Aqua data (Giovanni) SHIPPO (July 2012) MAGIC-IN (July-Sept 2013) March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

12. Ice nucleating particles and aerosol biodiversity measured from ambient marine boundary layer filter collections Korea Polar Research Institute’s (KOPRI) Summer 2012 SHIPPO (SHIp-borne Pole-to-Pole Observations) DeMott et al. (in preparation) INP Conc. (L -1 ) 100 C heat March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

13. MAGIC-IN: Relatively low INP concentrations over oligotrophic oceans March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle) SHIPPO

14. Comparison of all studies to remote continental INP data  weaker marine INP sources 22 19 March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

15. Comparison of all studies to remote continental INP data  weaker marine INP sources 22 19 March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

16. Comparison of all studies to remote continental INP data  weaker marine INP sources 19 March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

17. March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

18. Summary Ice nuclei measurements from sea spray directly in lab and from near-surface marine aerosols – Reasonable consistency with previous measurements over oceans – Typically INP 0cean < INP land – Varied labile fraction of IN > -20˚C, but clear dominance of organic INP – Complex interplay between biological activity, nutrients, and bubble drop emissions impact IN numbers released in sea spray – Need further compositional data isolating INP units (underway) Next steps: More lab studies, MAGIC analyses,, numerical modeling collaborations, new oceanic studies (e.g., SHIPPO2014, MNF?, SOCRATES) March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)

19. Acknowledgments U.S. National Science Foundation, NSF-CHE-1305427 Center for Aerosol Impacts on Climate and the Environment, also grants ATM-0841602 and AGS-1036028 Department of Energy, Atmospheric Radiation Measurements program Ice in Clouds – Tropical Science Team and NSF/NCAR C-130 staff and crew Dr. Bruce Moffett, JCM Labs, UK March18, 2014 Workshop on Clouds, Aerosols and the Air-Sea Interface of the Southern Oceans (Seattle)