Seasonality of Circumpolar Tundra: Ocean and Atmosphere Controls and Effects on Energy and Carbon Budgets
Summary:
The goals of this project are:
- to characterize the spatial and temporal seasonality of tundra vegetation of the circumpolar Arctic in relation to ice-ocean, atmospheric, and land characteristics
- to understand the seasonal linkages between the marine environment, the atmosphere, and the terrestrial ecosystems of the Arctic, and
- to examine the effects of seasonality changes in terrestrial vegetation on Arctic carbon dynamics.
The project is divided into the three broad components:
Component 1: Circumpolar seasonality characterization. Our earlier work examined interannual trends of vegetation greenness, land-surface temperatures, and sea-ice concentrations. In the proposed work, we will focus on the seasonal variability of these same factors plus several other land and sea variables along east-west and north-south gradients within the Arctic.
Component 2: Atmosphere and ocean controls of terrestrial seasonality. Our research will focus on analyzing the seasonal NDVI patterns in relation to characteristics of the near-shore ocean and sea-ice environment, atmospheric circulation, regional winds, and land characteristics. We will devote particular attention to the climate mechanisms behind the striking contrast between the vegetation response to declining sea ice in Berengia and west-central Eurasia by examining the seasonality of the atmosphere and marine systems in the 50-km coastal zone in these regions.
Component 3: Land energy and carbon linkages. One method for assessing the effects of changing vegetation seasonality on carbon budgets is to use phenomenological relationships that exist between remotely-sensed indices of vegetation and field observations of aboveground biomass.
Published relationships exist between the normalized difference vegetation index (NDVI) and the biomass of aboveground vegetation (or some components of aboveground vegetation) for arctic tundra ecosystems (Hope et al. 1993, Boelman et al 2003, 2005, Reidel et al. 2005). Epstein additionally has an extensive dataset of NDVI and aboveground vegetation biomass (manuscript in prep.) collected from sites throughout the Arctic of both North America (Epstein et al. 2008) and Russia, including data from all five of the arctic bioclimate subzones (Subzones A-E; sensu Walker et al. 2005). Growing season curves of the NDVI generated from satellite data (Component I) could thus be translated into growing season aboveground biomass curves, and the accumulation of carbon in aboveground tissue could be estimated. For an additional whole-season approach, the temporally-integrated (within a growing season) NDVI (TI-NDVI) has been related to the peak season aboveground biomass (Jia et al. 2006), and these relationships could be used to assess interannual changes in the stocks of aboveground carbon.
The seasonal progression of arctic terrestrial biomass, and the timing and magnitude of peak biomass are changing. This change is not consistent across all tundra ecosystems, for reasons that are still unclear. Preliminary research indicates a potential link with the seasonality of nearby marine surface conditions, i.e., sea ice and upper ocean properties. We propose to perform both statistical and model-based analyses to better understand these important linkages. We follow this with a modeling analysis of the effects of changing vegetation seasonality on plant functional type composition and arctic terrestrial carbon accumulation (or loss). The results will be a synthetic view of changing seasonality across the land/ocean boundary of the Arctic Ocean.
Project Duration:
1 September 2009 - 31 August 2012Short Description of education and/or outreach components of project:
We are working with the University of Alaska Fairbanks Museum to provide data and graphics of sea ice concentration, NDVI (over Arctic tundra), surface temperatures (over Arctic Tundra) for a visualization to appear at the museum on a Magic Planet Display. This display is about 30 inches in diameter and project onto a sphere to provide an Arctic view. The museum project was funded by NASA and partners with the Imaginarium Discover Center at the Anchorage Museum and the Challenger Learning Center in Kenai. There is also a traveling device, so our tundra greening story will be presented throughout Alaska in outreach and educational venues.
"Skip Walker on satellite observations of Arctic Greening", Program #5733 of the Earth & Sky Radio Series, aired 05-March-2009.
Keywords:
Programs:
Arctic System Science ProgramRegion:
Funding 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
Bhatt, U.S., D.A. Walker, M.K. Raynolds, J.C. Comiso, H.E. Epstein, G. Jia, R. Gens, J.E. Pinzon, C.J. Tucker, C.E. Tweedie & P.J. Webber (2010), "Circumpolar Arctic Tundra Vegetation Change is linked to Sea Ice Decline", Earth Interactions, 14, doi:10.1175/2010EI315.1. Download PDF (5.7 MB)
Walker, D.A., U.S. Bhatt, J.C. Comiso, H.E. Epstein, W.A. Gould, G.H.R. Henry, G.J. Jia, S.V. Kokelj, T.C. Lantz, J.A. Mercado-Díaz, J.E. Pinzon, M.K. Raynolds, G.R. Shaver, C.J. Tucker, C.E. Tweedie, P.J. Webber, "Arctic: Land: Vegetation" [in "State of the Climate in 2009"], Bull. Amer. Meteor. Soc., 91(6), S79-S82 (2010). Download PDF (1.2 MB)
Conference Abstracts
Bhatt, U.S., D.A. Walker, M.K. Raynolds, P.A. Bieniek, H.E. Epstein, J.C. Comiso, J.E. Pinzon, C.J. Tucker, I.V. Polyakov, Y. Liu, R. Gens, C.E. Tweedie, P.J. Webber, M. Steele, G.J. Jia, "Understanding drivers of recent Arctic tundra vegetation changes", Abstract GC43B-08, AGU Fall Meeting, San Francisco, CA (2010). Download PDF (12 MB)
Walker, D.A., "Arctic vegetation along two long bioclimatic transects in North America and Russia", Fulbright Lecture, Botany Department, Masarysk University Brno, Czech Republic (2011). Download PDF (19.5 MB)
Walker, D.A., "Greening of the Arctic: Climate change and circumpolar Arctic vegetation", Fulbright Lecture, Cesko Budovice University Cesko Budovice, Czech Republic (2011). Download PDF (15.8 MB)
Walker, D.A., "Socio-ecological effects of oil and gas development in the Arctic: Comparison of the Prudhoe Bay, Alaska and Bovanenkova, Russia regions", Earth Day, 20th Celebration of the Czech Fulbright Commission American Center, Prague, Czech Republic (2011). Download PDF (52.8 MB)
Walker, D.A., H.P. Kuss, M. Kopecky, G.V. Frost, F.J.A. Daniëls, A.N. Kade, C.M. Vonlanthen, M.K. Raynolds, H.E. Epstein, "The North American and Eurasia Arctic transects: Using phytosociology and remote sensing to detect vegetation pattern and change", European Vegetation Survey 20th Workshop, Rome, Italy (2011). Download PDF (10.5 MB)
Bhatt, U.S., D.A. Walker, M.K. Raynolds, et al., "Circumpolar Arctic tundra vegetation change is linked to sea-ice decline", State of the Arctic, Miami, FL (2010). Download PDF (1.9 MB)
Bhatt, U.S., D.A. Walker, M.K. Raynolds, et al., “Climatology and Seasonality of the ice-ocean-atmosphere-terrestrial system on the Yamal”, Yamal Land-Cover Land-Use Change Workshop, Rovaniemi, Finland (2010). Download PDF (685 KB)
Comiso, J.C., “State of the Cryosphere in the Arctic”, Second Yamal Land-Cover Land-Use Change Workshop, Rovaniemi, Finland (2010). Download PDF (22.7 MB)
Epstein, H.E., D.A. Walker, M.K. Raynolds, et al., “Vegetation biomass, leaf area index, and NDVI patterns and relationships along two latitudinal transects in arctic tundra”, Second Yamal Land-Cover Land-Use Change Workshop, Rovaniemi, Finland (2010). Download PDF (3.5 MB)
Pinzon, J.E., C.J. Tucker, “GIMMS 3g NDVI set and global NDVI trends”, Second Yamal Land-Cover Land-Use Change Workshop, Rovaniemi, Finland (2010). Download PDF (802 KB)
Raynolds, M.K., D.A, Walker, U.S. Bhatt, et al., “NDVI trends 1981-2008 in the circumpolar Arctic and Yamal”, Yamal Land-Cover land-Use Change Workshop, Rovaniemi, Finland (2010). Download PDF (863 KB)
Walker, D.A., H.E. Epstein, U.S. Bhatt, et al., “Greening of the Arctic: A planet-to-plant analysis of Arctic vegetation change”, IPY Oslo Science Conference, Oslo, Norway (2010). Download PDF (69.9 MB)
Bhatt, U.S., D.A. Walker, M.K. Raynolds, et. al., “Panarctic linkages between greening of Arctic tundra, sea ice decline, and summer land temperatures”, NEESPI Workshop CITIES-2009, Krasnoyarsk, Russia (2009). Download PDF (8.4 MB)
Bhatt, U.S., D.A. Walker, M.K. Raynolds, et al., “Seasonality of the air-sea-ice-land environment of Arctic tundra in Northern Eurasia and North America”, Department of Atmospheric Sciences, Informal Seminar, Fairbanks, AK (2009).
Posters
Bhatt, U.S., D.A. Walker, M.K. Raynolds, H.E. Epstein, G.J. Jia, J.C. Comiso, J. Pinzon, "Seasonality of the atmosphere-ocean-ice-terrestrial environment of Arctic tundra", State of the Arctic Meeting, Miami, FL (2010). Download PDF (3.8 MB)
Bhatt, U.S., D.A. Walker, M.K. Raynolds, H.E. Epstein, G.J. Jia, J.C. Comiso, J.E. Pinzon, C.J. Tucker, "Circumpolar arctic tundra vegetation change is linked to sea-ice decline", Yamal Land-Cover Land-Use Change Workshop, Rovaniemi, Finland (2010). Download PDF (5.2 MB)
Bhatt, U.S., D.A. Walker, M.K. Raynolds, H.E. Epstein, G.J. Jia, J.C. Comiso, J.E. Pinzon, C.J. Tucker, "Climatology and variability of the ice-ocean-atmosphere-terrestrial system on the Yamal", Land Cover, Land Use Change Spring Science Team Meeting, Bethesda, MD (2010). Download PDF (3.9 MB)
Bieniek, P.A., U.S. Bhatt, D.A. Walker, M.K. Raynolds, J.C. Comiso, H.E. Epstein, R. Gens, J.E. Pinzon, C.J. Tucker, M. Steele, C. Ozimek, "Alaska tundra vegetation trends and their links to the large-scale climate", Abstract GC43B-0976, AGU Fall Meeting, San Francisco, CA (2010). Download PDF (615 KB)
Epstein, H.E., D.A. Walker, M.K. Raynolds, A.M. Kelley, G.J. Jia, C.L. Ping, G.J. Michaelson, M.O. Leibman, E. Kaarlejärvi, A.V. Khomutov, H.P. Kuss, N.G. Moskalenko, P. Orechov, G. Matyshak, B.C. Forbes, "Vegetation biomass, leaf area index, and NDVI patterns and relationships along two latitudinal transects in arctic tundra", Second Yamal Land-Cover Land-Use Change Workshop Rovaniemi, Finland (2010). Download PDF (3.5 MB)
Raynolds, M.K., D.A. Walker, D. Verbyla, C.A. Munger, "Changes in tundra vegetation over 25 years as measured by Landsat NDVI in the Upper Kuparuk River Basin, North Slope Alaska, 1985-2009", Abstract GC43B-0984, AGU Fall Meeting, San Francisco, CA (2010). Download PDF (5 MB)
