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W. Robert Bolton

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Annual summer, early winter, and total winter seasonal precipitation metrics, in millimeters, for Alaska and Northwest Canada. Seasonal metrics were calculated from monthly data with season lengths calculated from the piecewise cubic hermite interpolating polynomial calculated from monthly temperature data used to calculate our degree-day dataset. Input monthly data from the Scenarios Network for Alaska + Arctic Planing, consisting of downscaled CRU TS 4.0 historic estimates of monthly temperature were used for the period from 1901-2020, and downscaled CMIP5/AR5 projected estimates of monthly temperature were used from the period from 2006-2100. Summer precipitation and early winter precipitation were calculated...
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Raster Climate Priming Index and supporting data for Alaska and Northwest Canada 1901-2100
The datasets presented here include the Climate Priming Index, degree-day, and seasonal precipitation data used as inputs to the index for the state of Alaska. The data is presented for two time periods: a historic period from 1901-2020, and a projected period from 2000-2100 using 3 climate scenarios. The climate priming index was developed to identify years where the climatic conditions support the initiation of thermokarst processes in areas of ice-rich permafrost. The Climate Priming Index is comprised of 6 components calculated from cumulative distribution functions based on 5 unique variables: freezing degree-days, thawing degree-days, summer precipitation, early winter precipitation, and total winter precipitation....
Abstract (from http://onlinelibrary.wiley.com/doi/10.1111/gcb.12757/abstract): The landscape of the Barrow Peninsula in northern Alaska is thought to have formed over centuries to millennia, and is now dominated by ice-wedge polygonal tundra that spans drained thaw-lake basins and interstitial tundra. In nearby tundra regions, studies have identified a rapid increase in thermokarst formation (i.e., pits) over recent decades in response to climate warming, facilitating changes in polygonal tundra geomorphology. We assessed the future impact of 100 years of tundra geomorphic change on peak growing season carbon exchange in response to: (i) landscape succession associated with the thaw-lake cycle; and (ii) low, moderate,...
This report describes the progress made by the Integrated Ecosystem Model (IEM) for Alaska and Northwest Canada Project for the full duration of the project (September 1, 2011 through August 31, 2016).This primary goal in this project was to develop the IEM modeling framework to integrate the driving components for and the interactions among disturbance regimes, permafrost dynamics, hydrology, and vegetation succession/migration for Alaska and Northwest Canada. The major activities of the project include (1) development and delivery of input data sets, (2) model coupling, (3) evaluation and applications of fire and vegetation dynamics, (4) evaluation and application of ecosystem carbon and energy balance, (5) evaluation...
Abstract (from Remote Sensing): Root-zone soil moisture exerts a fundamental control on vegetation, energy balance, and the carbon cycle in Arctic ecosystems, but it is still not well understood in vast, remote, and understudied regions of discontinuous permafrost. The root-zone soil moisture product (30 m resolution) used in this analysis was retrieved from a time-series P-Band (420–440 MHz) synthetic aperture radar (SAR) backscatter observations (August 2017 & October 2017). While similar approaches have been taken to retrieve surface (0 cm to 5 cm) soil moisture from L-Band (1.2 GHz) SAR backscatter, this is one of the first known attempts at reaching the root-zone in permafrost regions. Here, we analyze secondary...
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