Seasonality of Circumpolar Tundra: Ocean and Atmosphere Controls and Effects on Energy and Carbon Budgets

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Overview

The goals of this project are:

  1. to characterize the spatial and temporal seasonality of tundra vegetation of the circumpolar Arctic in relation to ice-ocean, atmospheric, and land characteristics
  2. to understand the seasonal linkages between the marine environment, the atmosphere, and the terrestrial ecosystems of the Arctic, and
  3. 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.

Members

Lead Principal Investigator

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Howard Epstein

University of Virginia

Epstein - link to SAM contact for fixing fields.

Principal Investigator

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Uma Bhatt

University of Alaska Fairbanks

Bhatt - link to SAM contact for fixing fields.

Principal Investigator

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Donald (Skip) Walker

University of Alaska Fairbanks

Walker - link to SAM contact for fixing fields.

Principal Investigator

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Michael Steele

University of Washington

Steele - link to SAM contact for fixing fields.

Co-Principal Investigator

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Martha Raynolds

University of Alaska Fairbanks

Raynolds - link to SAM contact for fixing fields.

Co-Principal Investigator

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Peter Bieniek

University of Alaska Fairbanks

Bieniek - link to SAM contact for fixing fields.
Resources

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).

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)

Dates

1 September 2009 to 31 August 2013

Program