Pan-Arctic Climate and Ecosystem Response to Historical and Projected Changes in the Seasonality of Sea Ice Melt and Growth
Website:
http://www.arcus.org/Summary:
The primary goal of this work is to explore the causes and effects of ongoing seasonal changes in the annual cycle of sea ice. This includes a quantitative assessment of the drivers and effects of the seasonal timing of sea ice melt onset, freezing initiation, and snowfall within the observational record and coupled climate model simulations of historical and future climate. We are examining this from both energy budget and ecosystem perspectives and are explicitly considering feedbacks to the Arctic and global systems. In particular, we are investigating the interactions between seasonal changes in the surface marine state and shortwave radiation and assessing the implications of those interactions for changes in climate and marine ecosystem behavior. In turn, we plan to assess and ultimately improve the capabilities of GCMs by improving the physics associated with the parameterization of solar radiation incident on ice covered seas. Within this primary goal, three focused questions will be used to direct the specific course of research.
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How do variations in the timing of seasonal triggers, including melt onset, melt pond evolution, freeze-up initiation, and snow accumulation affect the timing and partitioning of solar energy over the historical record?
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How do relationships among seasonal triggers and solar energy partitioning evolve in a warming climate with a transition to seasonal ice cover? What are the consequent implications for sea ice mass budgets, amplified Arctic warming, and marine ecosystem behavior?
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How well do climate models simulate the relationships between seasonal triggers and the partitioning of solar radiation? What processes are missing or inadequately represented in terms of these relationships?
Project Duration:
1 August 2009 - 31 July 2012Short Description of education and/or outreach components of project:
Outreach Activities
Results from research on this project were incorporated in lectures given by Bonnie Light for ESS 431 Principles of Glaciology, Fall Semester 2009-2010.
Bonnie Light developed and presented an exhibit for Polar Science Weekend 2010 at the Pacific Science Center in Seattle. It featured hands-on demonstrations of the spectral reflectance properties of a variety of natural materials, including sea ice. During the course of the activity, guests were invited to create their own "Designer Arctic” with its own unique reflective properties, and have its reflectivity tested. Hands-on demonstrations were used to illustrate the mechanism of the ice-albedo feedback and its role in climate. This annual four-day event has typically drawn 7,000-10,000 individuals to view exhibits, lectures, and demonstrations on polar science.
As a result of its success at Polar Science Weekend, this activity was selected by museum staff to become a permanent exhibit on the Pacific Science Center floor. Bonnie Light worked with museum staff throughout 2010 to harden the design and evaluate prototypes. The exhibit now stands for museum visitors to enjoy at their leisure and learn about the ice- albedo feedback.
During summer, 2010, Marika Holland mentored an undergraduate SOARS (Significant Opportunities in Atmospheric Research and Science) protege (Daniel Pollak) on a project entitled: "Understanding Changes in the Arctic Basin Sea Ice Mass Budget as simulated by CCSM4: Implications from melt season characteristics and the surface albedo feedback".
Perovich, D.K., "A frozen ocean in a warming climate", Science on Tap: Montshire Museum, 2011.
Perovich, D.K., Lecture to high school on sea ice and climate change, 2011.
Perovich, D.K., Lecture to adult education group on sea ice and climate change, 2011.
Perovich, D.K., Participated in USA Science and Engineering Festival, 2010.
Keywords:
Programs:
Arctic System Science ProgramRegion:
Pan-ArcticFunding Agency:
National Science FoundationFunding Solicitation/Announcement:
Changing Seasonality in the Arctic System (CSAS): NSF 08-567Unique Project Identifier (Grant #, Project #, Other):
Grant/Project Funding Amount:
Journal Publications
Flanner, M.G., K.M. Shell, M. Barlage, D.K. Perovich, and M.A. Tschudi (2011), "Radiative forcing and albedo feedback from the Northern Hemisphere cryosphere between 1979 and 2008", Nature Geosciences, 4, doi:10.1038/ngeo1062.
Perovich, D.K., B. Light, K.F. Jones, H. Eicken, J. Stroeve, and T. Markus (2011), "Solar partitioning in a changing Arctic sea ice cover", Ann. Glaciol., 52 (57).
Perovich, D.K., J.A. Richter-Menge, K.F. Jones, B. Light, B.C. Elder, C.M. Polashenski, D. LaRoche, T. Markus, and R. Lindsay (2011), "Arctic sea-ice melt in 2008 and the role of solar heating", Ann. Glaciol., 52.
Nicolaus, M. S. Gerland, S. Hudson, S. Hanson, J. Haapala, and D. Perovich (2010), "Seasonality of spectral albedo and transmittance as observed in the Arctic Transpolar Drift in 2007", J. Geophys. Res., 115, C11011, doi:10.1029/2009JC006074.
Papers Submitted
Jahn, A., D.A. Bailey, C.M. Bitz, M.M. Holland, E.C. Hunke, J.E. Kay, W.H. Lipscomb, J.A. Maslanik, D. Pollak, K. Sterling, and J. Stroeve, "Late 20th century simulation of Arctic sea ice and ocean properties in CCSM", J. Climate (2011) (submitted).
Holland, M.M., D.A. Bailey, B.P. Briegleb, B. Light, and E. Hunke, "Improved sea ice shortwave radiation physics in CCSM4: The impact of melt ponds and black carbon", J. Climate, (2011) (submitted).
Conference Abstracts
Perovich, D.K., "Sunlight and sea ice in a changing Arctic", Gordon Conference on Polar Marine Science, Ventura, CA (2011).
Pollak, D., M. Holland, and D. Bailey, "Understanding changes in the Arctic basin sea ice mass budget as simulated by CCSM4: Implications from melt season characteristics and the surface albedo feedback", AMS 11th Conference on Polar Meteorology and Oceanography, Boston, MA (2011).
Pollak, D., M. Holland, and D. Bailey, "Understanding changes in the Arctic basin sea ice mass budget as simulated by CCSM4: Implications from melt season characteristics and the surface albedo feedback", AMS 11th Conference on Polar Meteorology and Oceanography, Boston, MA (2011).
Holland, M., "Radiative Forcing of Ponds and Aerosols in CCSM4", CESM Workshop, Breckenridge, CO (2010).
Perovich, D.K., B. Light, C. Polashenski, and S.V. Nghiem, "A Changing Arctic Sea Ice Cover and the Partitioning of Solar Radiation", AGU Fall Meeting, San Francisco, CA (2010).
Perovich, D.K., "The ice albedo feedback in a changing Arctic", Rapid Change in Arctic Sea Ice: Assessing Drivers and Future Trajectories, Fairbanks, AK (2010).
Perovich, D.K., "Impacts of Arctic sea ice change on ice – albedo feedback", IGARSS 2010 - 2010 IEEE International Geoscience and Remote Sensing Symposium, Honolulu, HI (2010).
Perovich, D.K., "Sunshine, ice, and feedbacks: The heat and mass budget of Arctic sea ice", Institute for Pure and Applied Mathematics Workshop on the Mathematics of Sea Ice in the Climate System, Los Angeles, CA (2010).
Perovich, D.K., "Sea ice and sunlight: Climate change and the Arctic sea ice cover", Jones Seminar, Dartmouth College, Hanover, NH (2010).
Perovich, D.K., "Sunlight, Sea Ice, Ponds, and Ocean: What is Driving the Ice – Albedo Feedback?", Annual Meeting of the American Association for the Advancement of Science, San Diego, CA (2010).
Pollak, D., M. Holland, and D. Bailey, "Understanding changes in the Arctic basin sea ice mass budget as simulated by CCSM4: Implications from melt season characteristics and the surface albedo feedback", AGU Fall Meeting, San Francisco, CA (2010).
Light, B., D. Perovich, T. Grenfell, K. Runciman, K. Jones, and M. Wyant, "Transmission of Sunlight through melting Arctic Sea Ice", AGU Fall Meeting, San Francisco, CA (2009).
Research Efforts to Date
Our efforts have focused on two areas, evaluating and improving the ecosystem model performance in the arctic region, and modifying the model code to allow for iron accumulation in, and transport by sea ice. We have looked at the ecosystem/biogeochemical module performance in the Arctic region in a one degree coupled model simulation, focusing on comparisons with observed chlorophyll (satellite) and nutrient distributions (World Ocean Atlas climatologies). The model does a reasonable job in the Arctic region, but we are exploring ways to improve the performance, using the coarser resolution (3 degree) version of the ocean model, including modifications to a few key parameters that govern grazing rates, and the remineralization of sinking organic matter. Graduate student Shanlin Wang has been modifying the ocean model code to allow for passing dissolved iron between the sea ice and ocean models. This will permit transport of iron by sea ice, which we hypothesize influences productivity in some regions of the both Arctic and Antarctic. We are also in the process of modifying the sea ice model code in this regard in collaboration with Marika Holland and Dave Bailey at NCAR. These efforts are progressing and we anticipate our first simulations designed to look at sea ice iron-transport influences on ocean biogeochemistry will be conducted this summer.
Research Findings
The new Community Climate System Model, version 4 (CCSM4) has improved sea ice shortwave radiative transfer and new capabilities, including a melt pond parameterization and aerosol deposition and cycling. These have implications for the timing of seasonal triggers (such as melt onset, pond formation, freezeup) that can influence the shortwave absorption and albedo feedback. These improvements have been documented in a submitted manuscript (Holland et al., submitted) that assess the role of melt pond formation and aerosol (including black carbon) deposition on the sea ice and how this changes with a changing mean climate state. While the direct radiative forcing of the melt ponds and aerosol deposition is modest (about 1 W/m2), the surface albedo feedback amplifies the sea ice response and lead to a considerably different sea ice state.
An initial analysis of Arctic sea ice seasonal triggers (melt onset/freezeup) from Community Climate System, 4 (CCSM4) integrations has been performed. This includes a comparison of the timing of melt onset and freezeup in the model integrations to satellite derived observations (Markus et al., 2009). The simulated last 20th century CCSM4 climatology agrees well to the observations with the regionally averaged melt onset dates differing by only a few days (Jahn et al., submitted). The discrepancy in freeze-up dates is somewhat larger but still within the model-data comparison uncertainty. Given the good agreement in the timing of seasonal triggers simulated by CCSM4, we have started to analyze the changes in the timing of these triggers over the late 20th-early 21st century and their implications for the surface albedo feedback.
References cited:
Markus, T., J.C. Stroeve, and J. Miller, 2009: Recent changes in arctic sea ice melt onset, freezeup, and melt season length. J. Geophys. Res., 114, doi:10.1029/2009JC005436.
