Estimation of the Terrestrial Carbon Pool and Hydrological Sensitivity of the West Siberian Lowland
Funding Agency: NASA Earth & Space Science Fellowship
Funding Period: 2000-2003
West Siberia is delicately poised with respect to future climate change scenarios, such that perturbations to its unique climatological, ecological and hydrological features may amplify such change both regionally and globally through several feedback mechanisms. West Siberia contains the world’s largest stores of peat carbon, exports massive volumes of freshwater to the Arctic Ocean, currently encompasses portions of the climatically sensitive northern treeline and southern limit of permafrost, and is warming faster than the Arctic as a whole. Taken collectively, these features place West Siberia at the forefront of numerous critical global change issues. However, in order to assess potential changes in West Siberia, it is necessary to first establish certain climatological, ecological and hydrological baselines for the region. To this end, my research examines recent meteorological trends, the accuracy of current land cover classification databases, and the present-day distribution of dissolved organic carbon (DOC) and inorganic solute concentrations in streams of West Siberia. Results show that West Siberia has experienced significant warming and notable increases in precipitation over recent decades, driven in part by large-scale arctic atmospheric variability. With further warming, globally significant changes to the region’s ecology, hydrology, carbon cycling and land-atmosphere exchange may occur. However, through collection of a unique field-based database of land cover observations, I show that many of the currently available land cover databases are of insufficient quality to model such changes or even ascertain present-day conditions. Finally, my studies of stream biogeochemistry show that cold, permafrost-influenced watersheds release little DOC and inorganic solutes to streams, but considerably higher concentrations occur in warm, permafrost-free watersheds. Noting the observed recent warming trends and accuracy of land cover maps found in this research, I estimate that (i) the flux of DOC from West Siberia to the Arctic Ocean may increase ∼29–46% by 2100; and (ii) the flux of inorganic solutes from West Siberia to the Arctic Ocean may increase ∼59% should permafrost in the region completely disappear. These impacts of warming on West Siberian stream biogeochemistry could have important implications for carbon cycle dynamics in arctic Eurasian shelf waters, the Arctic Ocean and the atmosphere. Abstract: West Siberia is delicately poised with respect to future climate change scenarios, such that perturbations to its unique climatological, ecological and hydrological features may amplify such change both regionally and globally through several feedback mechanisms. West Siberia contains the world’s largest stores of peat carbon, exports massive volumes of freshwater to the Arctic Ocean, currently encompasses portions of the climatically sensitive northern treeline and southern limit of permafrost, and is warming faster than the Arctic as a whole. Taken collectively, these features place West Siberia at the forefront of numerous critical global change issues. However, in order to assess potential changes in West Siberia, it is necessary to first establish certain climatological, ecological and hydrological baselines for the region. To this end, my research examines recent meteorological trends, the accuracy of current land cover classification databases, and the present-day distribution of dissolved organic carbon (DOC) and inorganic solute concentrations in streams of West Siberia. Results show that West Siberia has experienced significant warming and notable increases in precipitation over recent decades, driven in part by large-scale arctic atmospheric variability. With further warming, globally significant changes to the region’s ecology, hydrology, carbon cycling and land-atmosphere exchange may occur. However, through collection of a unique field-based database of land cover observations, I show that many of the currently available land cover databases are of insufficient quality to model such changes or even ascertain present-day conditions. Finally, my studies of stream biogeochemistry show that cold, permafrost-influenced watersheds release little DOC and inorganic solutes to streams, but considerably higher concentrations occur in warm, permafrost-free watersheds. Noting the observed recent warming trends and accuracy of land cover maps found in this research, I estimate that (i) the flux of DOC from West Siberia to the Arctic Ocean may increase ∼29–46% by 2100; and (ii) the flux of inorganic solutes from West Siberia to the Arctic Ocean may increase ∼59% should permafrost in the region completely disappear. These impacts of warming on West Siberian stream biogeochemistry could have important implications for carbon cycle dynamics in arctic Eurasian shelf waters, the Arctic Ocean and the atmosphere.
Resulting Publications:
Frey, K. E. & J. W. McClelland (2009), Impacts of permafrost degradation on arctic river biogeochemistry. Hydrological Processes 23, 169–182. pdf copy
Frey, K. E., J. W. McClelland, R. M. Holmes & L. C. Smith (2007a), Impacts of climate warming and permafrost thaw on the riverine transport of nitrogen and phosphorus to the Kara Sea. Journal of Geophysical Research-Biogeosciences 112, G04S58, doi:10.1029/2006JG000369 (10 pp.). pdf copy
Frey, K. E., D. I. Siegel & L. C. Smith (2007b), Geochemistry of West Siberian streams and their potential response to permafrost degradation. Water Resources Research 43, W03406, doi:1029/2006WR0049022006 (15 pp.). pdf copy
Frey, K. E. & L. C. Smith (2007), How well do we know northern land cover? Comparison of four global vegetation and wetland products with a new ground-truth database for West Siberia. Global Biogeochemical Cycles 21, GB1016, doi:10.1029/2006GB002706 (15 pp.). pdf copy
Frey, K. E. & L. C. Smith (2005), Amplified carbon release from vast West Siberian peatlands by 2100. Geophysical Research Letters 32, L09401, doi:10.1029/2004GL022025 (4 pp.). pdf copy
Sheng, Y., L. C. Smith, G. M. MacDonald, K. V. Kremenetski, K. E. Frey, A. A. Velichko, M. Lee, D. W. Beilman & P. Dubinin (2004), A high resolution GIS-based inventory of the West Siberian peat carbon pool. Global Biogeochemical Cycles 18, GB3004, doi:10.1029/2003GB002190 (14 pp.). pdf copy
Smith, L. C., G. M. MacDonald, A. A. Velichko, D. W. Beilman, O. K. Borisova, K. E. Frey, K. V. Kremenetski & Y. Sheng, (2004), Siberian peatlands a net carbon sink and methane source since the early Holocene. Science 303, 353–356. pdf copy
Frey, K. E. & L. C. Smith (2003), Recent temperature and precipitation increases in West Siberia and their association with the Arctic Oscillation. Polar Research 22, 287–300. pdf copy
Kremenetski, K. V., A. A. Velichko, O. K. Borisova, G. M. MacDonald, L. C. Smith, K. E. Frey & L. A. Orlova (2003), Peatlands of the Western Siberian lowlands: Current knowledge on zonation, carbon content and Late Quaternary history. Quaternary Science Reviews 22, 703–723. pdf copy
Sheng, Y., L. C. Smith, K. E. Frey & D. E. Alsdorf (2002), A high temporal resolution data set of ERS scatterometer radar backscatter for research in Arctic and sub-Arctic regions. Polar Record 38, 115–120. pdf copy
Smith, L. C., G. M. MacDonald, K. E. Frey, A. Velichko, K. Kremenetski, O. Borisova, P. Dubinin, & R. R. Forster (2000), U.S.-Russian venture probes Siberian peatlands’ sensitivity to climate. Eos, Transactions, American Geophysical Union 81, 497, 503–504. pdf copy