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Prof. Uma Bhatt
University of Alaska Fairbanks

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0 Climate Change
0 sea ice
0 Seasonal forecasting
0 multidisciplinary research
0 Arctic and Alaska Climate Variability

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Research letter
Published: 03 July 2021 in Geophysical Research Letters
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Weather and sea ice forecasts provided in support of the U.S. Navy's Ice Exercise winter 2020 campaign in the Beaufort Sea noted frequent storms in the absence of the climatological Beaufort High which coincided with anomalous eastward drift of the region's ice cover. To place the 2020 Beaufort-Chukchi regional atmospheric conditions in historical context, we evaluated winter low sea-level pressure (SLP) extremes and storm characteristics in the region over the 1948–2020 period. March 2020 SLP in the Beaufort-Chukchi region was the lowest of the modern reanalysis era (1009.07 hPa) with record counts of passing storms and days with SLP at least two standard deviations below the climatological mean. The Beaufort High collapse in winter 2020 continued a recent pattern of Beaufort High collapses dating back to 2010. Unlike other recent collapses, such as 2017, most of the late-winter 2020 cyclones originated locally over the western Arctic Ocean.

ACS Style

Thomas J. Ballinger; John E. Walsh; Uma S. Bhatt; Peter A. Bieniek; Mark A. Tschudi; Brian Brettschneider; Hajo Eicken; Andrew R. Mahoney; Jackie Richter‐Menge; Lewis H. Shapiro. Unusual West Arctic Storm Activity During Winter 2020: Another Collapse of the Beaufort High? Geophysical Research Letters 2021, 48, 1 .

AMA Style

Thomas J. Ballinger, John E. Walsh, Uma S. Bhatt, Peter A. Bieniek, Mark A. Tschudi, Brian Brettschneider, Hajo Eicken, Andrew R. Mahoney, Jackie Richter‐Menge, Lewis H. Shapiro. Unusual West Arctic Storm Activity During Winter 2020: Another Collapse of the Beaufort High? Geophysical Research Letters. 2021; 48 (13):1.

Chicago/Turabian Style

Thomas J. Ballinger; John E. Walsh; Uma S. Bhatt; Peter A. Bieniek; Mark A. Tschudi; Brian Brettschneider; Hajo Eicken; Andrew R. Mahoney; Jackie Richter‐Menge; Lewis H. Shapiro. 2021. "Unusual West Arctic Storm Activity During Winter 2020: Another Collapse of the Beaufort High?" Geophysical Research Letters 48, no. 13: 1.

Journal article
Published: 18 May 2021 in Remote Sensing
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In recent years, there have been rapid improvements in both remote sensing methods and satellite image availability that have the potential to massively improve burn severity assessments of the Alaskan boreal forest. In this study, we utilized recent pre- and post-fire Sentinel-2 satellite imagery of the 2019 Nugget Creek and Shovel Creek burn scars located in Interior Alaska to both assess burn severity across the burn scars and test the effectiveness of several remote sensing methods for generating accurate map products: Normalized Difference Vegetation Index (NDVI), Normalized Burn Ratio (NBR), and Random Forest (RF) and Support Vector Machine (SVM) supervised classification. We used 52 Composite Burn Index (CBI) plots from the Shovel Creek burn scar and 28 from the Nugget Creek burn scar for training classifiers and product validation. For the Shovel Creek burn scar, the RF and SVM machine learning (ML) classification methods outperformed the traditional spectral indices that use linear regression to separate burn severity classes (RF and SVM accuracy, 83.33%, versus NBR accuracy, 73.08%). However, for the Nugget Creek burn scar, the NDVI product (accuracy: 96%) outperformed the other indices and ML classifiers. In this study, we demonstrated that when sufficient ground truth data is available, the ML classifiers can be very effective for reliable mapping of burn severity in the Alaskan boreal forest. Since the performance of ML classifiers are dependent on the quantity of ground truth data, when sufficient ground truth data is available, the ML classification methods would be better at assessing burn severity, whereas with limited ground truth data the traditional spectral indices would be better suited. We also looked at the relationship between burn severity, fuel type, and topography (aspect and slope) and found that the relationship is site-dependent.

ACS Style

Christopher Smith; Santosh Panda; Uma Bhatt; Franz Meyer; Anushree Badola; Jennifer Hrobak. Assessing Wildfire Burn Severity and Its Relationship with Environmental Factors: A Case Study in Interior Alaska Boreal Forest. Remote Sensing 2021, 13, 1966 .

AMA Style

Christopher Smith, Santosh Panda, Uma Bhatt, Franz Meyer, Anushree Badola, Jennifer Hrobak. Assessing Wildfire Burn Severity and Its Relationship with Environmental Factors: A Case Study in Interior Alaska Boreal Forest. Remote Sensing. 2021; 13 (10):1966.

Chicago/Turabian Style

Christopher Smith; Santosh Panda; Uma Bhatt; Franz Meyer; Anushree Badola; Jennifer Hrobak. 2021. "Assessing Wildfire Burn Severity and Its Relationship with Environmental Factors: A Case Study in Interior Alaska Boreal Forest." Remote Sensing 13, no. 10: 1966.

Journal article
Published: 27 April 2021 in Remote Sensing
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Alaska has witnessed a significant increase in wildfire events in recent decades that have been linked to drier and warmer summers. Forest fuel maps play a vital role in wildfire management and risk assessment. Freely available multispectral datasets are widely used for land use and land cover mapping, but they have limited utility for fuel mapping due to their coarse spectral resolution. Hyperspectral datasets have a high spectral resolution, ideal for detailed fuel mapping, but they are limited and expensive to acquire. This study simulates hyperspectral data from Sentinel-2 multispectral data using the spectral response function of the Airborne Visible/Infrared Imaging Spectrometer-Next Generation (AVIRIS-NG) sensor, and normalized ground spectra of gravel, birch, and spruce. We used the Uniform Pattern Decomposition Method (UPDM) for spectral unmixing, which is a sensor-independent method, where each pixel is expressed as the linear sum of standard reference spectra. The simulated hyperspectral data have spectral characteristics of AVIRIS-NG and the reflectance properties of Sentinel-2 data. We validated the simulated spectra by visually and statistically comparing it with real AVIRIS-NG data. We observed a high correlation between the spectra of tree classes collected from AVIRIS-NG and simulated hyperspectral data. Upon performing species level classification, we achieved a classification accuracy of 89% for the simulated hyperspectral data, which is better than the accuracy of Sentinel-2 data (77.8%). We generated a fuel map from the simulated hyperspectral image using the Random Forest classifier. Our study demonstrated that low-cost and high-quality hyperspectral data can be generated from Sentinel-2 data using UPDM for improved land cover and vegetation mapping in the boreal forest.

ACS Style

Anushree Badola; Santosh Panda; Dar Roberts; Christine Waigl; Uma Bhatt; Christopher Smith; Randi Jandt. Hyperspectral Data Simulation (Sentinel-2 to AVIRIS-NG) for Improved Wildfire Fuel Mapping, Boreal Alaska. Remote Sensing 2021, 13, 1693 .

AMA Style

Anushree Badola, Santosh Panda, Dar Roberts, Christine Waigl, Uma Bhatt, Christopher Smith, Randi Jandt. Hyperspectral Data Simulation (Sentinel-2 to AVIRIS-NG) for Improved Wildfire Fuel Mapping, Boreal Alaska. Remote Sensing. 2021; 13 (9):1693.

Chicago/Turabian Style

Anushree Badola; Santosh Panda; Dar Roberts; Christine Waigl; Uma Bhatt; Christopher Smith; Randi Jandt. 2021. "Hyperspectral Data Simulation (Sentinel-2 to AVIRIS-NG) for Improved Wildfire Fuel Mapping, Boreal Alaska." Remote Sensing 13, no. 9: 1693.

Journal article
Published: 27 February 2021 in Remote Sensing
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In Alaska the current wildfire fuel map products were generated from low spatial (30 m) and spectral resolution (11 bands) Landsat 8 satellite imagery which resulted in map products that not only lack the granularity but also have insufficient accuracy to be effective in fire and fuel management at a local scale. In this study we used higher spatial and spectral resolution AVIRIS-NG hyperspectral data (acquired as part of the NASA ABoVE project campaign) to generate boreal forest vegetation and fire fuel maps. Based on our field plot data, random forest classified images derived from 304 AVIRIS-NG bands at Viereck IV level (Alaska Vegetation Classification) had an 80% accuracy compared to the 33% accuracy of the LANDFIRE’s Existing Vegetation Type (EVT) product derived from Landsat 8. Not only did our product more accurately classify fire fuels but was also able to identify 20 dominant vegetation classes (percent cover >1%) while the EVT product only identified 8 dominant classes within the study area. This study demonstrated that highly detailed and accurate fire fuel maps can be created at local sites where AVIRIS-NG is available and can provide valuable decision-support information to fire managers to combat wildfires.

ACS Style

Christopher Smith; Santosh Panda; Uma Bhatt; Franz Meyer. Improved Boreal Forest Wildfire Fuel Type Mapping in Interior Alaska Using AVIRIS-NG Hyperspectral Data. Remote Sensing 2021, 13, 897 .

AMA Style

Christopher Smith, Santosh Panda, Uma Bhatt, Franz Meyer. Improved Boreal Forest Wildfire Fuel Type Mapping in Interior Alaska Using AVIRIS-NG Hyperspectral Data. Remote Sensing. 2021; 13 (5):897.

Chicago/Turabian Style

Christopher Smith; Santosh Panda; Uma Bhatt; Franz Meyer. 2021. "Improved Boreal Forest Wildfire Fuel Type Mapping in Interior Alaska Using AVIRIS-NG Hyperspectral Data." Remote Sensing 13, no. 5: 897.

Accepted manuscript
Published: 15 February 2021 in Environmental Research Letters
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This study applies an indicators framework to investigate climate drivers of tundra vegetation trends and variability over the 1982–2019 period. Previously known indicators relevant for tundra productivity (summer warmth index, coastal spring sea-ice area, coastal summer open-water) and three additional indicators (continentality, summer precipitation, and the Arctic Dipole: second mode of sea level pressure variability) are analyzed with maximum annual Normalized Difference Vegetation Index (MaxNDVI) and the sum of summer bi-weekly (time-integrated) NDVI (TI-NDVI) from the Advanced Very High Resolution Radiometer (AVHRR) time-series. Climatological mean, trends, and correlations between variables are presented. Changes in sea ice continue to drive variations in the other indicators. As spring sea ice has decreased, summer open water, summer warmth, MaxNDVI, and TI-NDVI have increased. However, the initial very strong upward trends in previous studies for MaxNDVI and TI-NDVI are weakening and becoming spatially and temporally more variable as the ice retreats from the coastal areas. TI-NDVI has declined over the last decade particularly over High Arctic regions and southwest Alaska. The Continentality Index (maximum minus minimum monthly temperatures) is decreasing across the tundra, more so over North America than Eurasia. The relationship has weakened between sea-ice and summer warmth index and TI-NDVI, as the maritime influence of open water has increased along with total precipitation. The winter Arctic Dipole is correlated in Eurasia with spring sea ice, summer open water, MaxNDVI, TI-NDVI, the continentality index and total summer precipitation. This winter connection to tundra emphasizes the role of sea ice in driving the summer indicators. The winter (DJF) Arctic Dipole drives sea ice variations which in turn shape summer open water, the atmospheric summer warmth index and NDVI anomalies. The winter and spring indicators represent potential predictors of tundra vegetation productivity a season or two in advance of the growing season.

ACS Style

Uma S. Bhatt; Donald A Walker; Martha K. Raynolds; John E. Walsh; Peter A Bieniek; Lei Cai; Josefino C Comiso; Howard E. Epstein; Gerald V Frost; Robert Gersten; Amy S Hendricks; Jorge E Pinzon; Larry V Stock; Compton J. Tucker. Climate drivers of Arctic tundra variability and change using an indicators framework. Environmental Research Letters 2021, 16, 055019 .

AMA Style

Uma S. Bhatt, Donald A Walker, Martha K. Raynolds, John E. Walsh, Peter A Bieniek, Lei Cai, Josefino C Comiso, Howard E. Epstein, Gerald V Frost, Robert Gersten, Amy S Hendricks, Jorge E Pinzon, Larry V Stock, Compton J. Tucker. Climate drivers of Arctic tundra variability and change using an indicators framework. Environmental Research Letters. 2021; 16 (5):055019.

Chicago/Turabian Style

Uma S. Bhatt; Donald A Walker; Martha K. Raynolds; John E. Walsh; Peter A Bieniek; Lei Cai; Josefino C Comiso; Howard E. Epstein; Gerald V Frost; Robert Gersten; Amy S Hendricks; Jorge E Pinzon; Larry V Stock; Compton J. Tucker. 2021. "Climate drivers of Arctic tundra variability and change using an indicators framework." Environmental Research Letters 16, no. 5: 055019.

Journal article
Published: 17 January 2021 in Land
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The late-season extreme fire activity in Southcentral Alaska during 2019 was highly unusual and consequential. Firefighting operations had to be extended by a month in 2019 due to the extreme conditions of hot summer temperature and prolonged drought. The ongoing fires created poor air quality in the region containing most of Alaska’s population, leading to substantial impacts to public health. Suppression costs totaled over $70 million for Southcentral Alaska. This study’s main goals are to place the 2019 season into historical context, provide an attribution analysis, and assess future changes in wildfire risk in the region. The primary tools are meteorological observations and climate model simulations from the NCAR CESM Large Ensemble (LENS). The 2019 fire season in Southcentral Alaska included the hottest and driest June–August season over the 1979–2019 period. The LENS simulation analysis suggests that the anthropogenic signal of increased fire risk had not yet emerged in 2019 because of the CESM’s internal variability, but that the anthropogenic signal will emerge by the 2040–80 period. The effect of warming temperatures dominates the effect of enhanced precipitation in the trend towards increased fire risk.

ACS Style

Uma S. Bhatt; Rick T. Lader; John E. Walsh; Peter A. Bieniek; Richard Thoman; Matthew Berman; Cecilia Borries-Strigle; Kristi Bulock; Jonathan Chriest; Micah Hahn; Amy S. Hendricks; Randi Jandt; Joseph Little; Daniel McEvoy; Chris Moore; T. Scott Rupp; Jennifer Schmidt; Eric Stevens; Heidi Strader; Christine Waigl; James White; Alison York; Robert Ziel. Emerging Anthropogenic Influences on the Southcentral Alaska Temperature and Precipitation Extremes and Related Fires in 2019. Land 2021, 10, 82 .

AMA Style

Uma S. Bhatt, Rick T. Lader, John E. Walsh, Peter A. Bieniek, Richard Thoman, Matthew Berman, Cecilia Borries-Strigle, Kristi Bulock, Jonathan Chriest, Micah Hahn, Amy S. Hendricks, Randi Jandt, Joseph Little, Daniel McEvoy, Chris Moore, T. Scott Rupp, Jennifer Schmidt, Eric Stevens, Heidi Strader, Christine Waigl, James White, Alison York, Robert Ziel. Emerging Anthropogenic Influences on the Southcentral Alaska Temperature and Precipitation Extremes and Related Fires in 2019. Land. 2021; 10 (1):82.

Chicago/Turabian Style

Uma S. Bhatt; Rick T. Lader; John E. Walsh; Peter A. Bieniek; Richard Thoman; Matthew Berman; Cecilia Borries-Strigle; Kristi Bulock; Jonathan Chriest; Micah Hahn; Amy S. Hendricks; Randi Jandt; Joseph Little; Daniel McEvoy; Chris Moore; T. Scott Rupp; Jennifer Schmidt; Eric Stevens; Heidi Strader; Christine Waigl; James White; Alison York; Robert Ziel. 2021. "Emerging Anthropogenic Influences on the Southcentral Alaska Temperature and Precipitation Extremes and Related Fires in 2019." Land 10, no. 1: 82.

Accepted manuscript
Published: 12 November 2020 in Environmental Research Letters
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Vegetation properties of arctic tundra vary dramatically across its full latitudinal extent, yet few studies have quantified tundra ecosystem properties across latitudinal gradients with field-based observations that can be related to remotely sensed proxies. Here we present data from field sampling of six locations along the Eurasia Arctic Transect in northwestern Siberia. We collected data on the aboveground vegetation biomass, the Normalized Difference Vegetation Index (NDVI), and the Leaf Area Index (LAI) for both sandy and loamy soil types, and analyzed their spatial patterns. Aboveground biomass, NDVI, and LAI all increased with increasing Summer Warmth Index (SWI – sum of monthly mean temperatures > 0˚C), although functions differed, as did sandy vs. loamy sites. Shrub biomass increased non-linearly with SWI, although shrub type biomass diverged with soil texture in the southernmost locations, with greater evergreen shrub biomass on sandy sites, and greater deciduous shrub biomass on loamy sites. Moss biomass peaked in the center of the gradient, whereas lichen biomass generally increased with SWI. Total aboveground biomass varied by two orders of magnitude, and shrubs increased from 0 g m-2 at the northernmost sites to >500 g m-2 at the forest-tundra ecotone. Current observations and estimates of increases in total aboveground and shrub biomass with climate warming in the Arctic fall short of what would represent a "subzonal shift" based on our spatial data. Non-vascular (moss and lichen) biomass is a dominant component (>90% of the photosynthetic biomass) of the vegetation across the full extent of arctic tundra, and should continue to be recognized as crucial for Earth system modeling. This study is one of only a few that present data on tundra vegetation across the temperature extent of the biome, providing 1) key links to satellite-based vegetation indices, 2) baseline field-data for ecosystem change studies, and 3) context for the ongoing changes in arctic tundra vegetation.

ACS Style

Howard E. Epstein; Donald A Walker; Gerald V Frost; Martha K. Raynolds; Uma Bhatt; Ronald Daanen; Bruce C Forbes; Jozsef Geml; Elina Kaärlejarvi; Olga Khitun; Artem Khomutov; Patrick Kuss; Marina Leibman; Georgiy Matyshak; Nataliya Moskalenko; Pavel Orekhov; Vladimir E. Romanovsky; Ina Timling. Spatial patterns of arctic tundra vegetation properties on different soils along the Eurasia Arctic Transect, and insights for a changing Arctic. Environmental Research Letters 2020, 16, 014008 .

AMA Style

Howard E. Epstein, Donald A Walker, Gerald V Frost, Martha K. Raynolds, Uma Bhatt, Ronald Daanen, Bruce C Forbes, Jozsef Geml, Elina Kaärlejarvi, Olga Khitun, Artem Khomutov, Patrick Kuss, Marina Leibman, Georgiy Matyshak, Nataliya Moskalenko, Pavel Orekhov, Vladimir E. Romanovsky, Ina Timling. Spatial patterns of arctic tundra vegetation properties on different soils along the Eurasia Arctic Transect, and insights for a changing Arctic. Environmental Research Letters. 2020; 16 (1):014008.

Chicago/Turabian Style

Howard E. Epstein; Donald A Walker; Gerald V Frost; Martha K. Raynolds; Uma Bhatt; Ronald Daanen; Bruce C Forbes; Jozsef Geml; Elina Kaärlejarvi; Olga Khitun; Artem Khomutov; Patrick Kuss; Marina Leibman; Georgiy Matyshak; Nataliya Moskalenko; Pavel Orekhov; Vladimir E. Romanovsky; Ina Timling. 2020. "Spatial patterns of arctic tundra vegetation properties on different soils along the Eurasia Arctic Transect, and insights for a changing Arctic." Environmental Research Letters 16, no. 1: 014008.

Articles
Published: 12 June 2020 in Polar Geography
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Profound changes in Arctic sea-ice, a growing desire to utilize the Arctic’s abundant natural resources, and the potential competitiveness of Arctic shipping routes, all provide for increased industry marine activity throughout the Arctic Ocean. This is anticipated to result in further challenges for maritime safety. Those operating in ice-infested waters require various types of information for sea-ice and iceberg hazards. Ice information requirements depend on regional needs and whether the stakeholder wants to avoid ice all together, operate near or in the Marginal Ice Zone, or areas within the ice pack. An insight into user needs demonstrates how multiple spatial and temporal resolutions for sea-ice information and forecasts are necessary to provide information to the marine operating community for safety, planning, and situational awareness. Although ship-operators depend on sea-ice information for tactical navigation, stakeholders working in route and capacity planning can benefit from climatological and long-range forecast information at lower spatial and temporal resolutions where the interest is focused on open-water season. The advent of the Polar Code has brought with it additional information requirements, and exposed gaps in capacity and knowledge. Thus, future satellite data sources should be at resolutions that support both tactical and planning activities.

ACS Style

Penelope Mae Wagner; Nick Hughes; Pascale Bourbonnais; Julienne Stroeve; Lasse Rabenstein; Uma Bhatt; Joe Little; Helen Wiggins; Andrew Fleming. Sea-ice information and forecast needs for industry maritime stakeholders. Polar Geography 2020, 43, 160 -187.

AMA Style

Penelope Mae Wagner, Nick Hughes, Pascale Bourbonnais, Julienne Stroeve, Lasse Rabenstein, Uma Bhatt, Joe Little, Helen Wiggins, Andrew Fleming. Sea-ice information and forecast needs for industry maritime stakeholders. Polar Geography. 2020; 43 (2-3):160-187.

Chicago/Turabian Style

Penelope Mae Wagner; Nick Hughes; Pascale Bourbonnais; Julienne Stroeve; Lasse Rabenstein; Uma Bhatt; Joe Little; Helen Wiggins; Andrew Fleming. 2020. "Sea-ice information and forecast needs for industry maritime stakeholders." Polar Geography 43, no. 2-3: 160-187.

Journal article
Published: 03 May 2020 in Forests
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Research Highlights: Flammability of wildland fuels is a key factor influencing risk-based decisions related to preparedness, response, and safety in Alaska. However, without effective measures of current and expected flammability, the expected likelihood of active and problematic wildfires in the future is difficult to assess and prepare for. This study evaluates the effectiveness of diverse indices to capture high-risk fires. Indicators of drought and atmospheric drivers are assessed along with the operational Canadian Forest Fire Danger Rating System (CFFDRS). Background and Objectives: In this study, 13 different indicators of atmospheric conditions, fuel moisture, and flammability are compared to determine how effective each is at identifying thresholds and trends for significant wildfire activity. Materials and Methods: Flammability indices are compared with remote sensing characterizations that identify where and when fire activity has occurred. Results: Among these flammability indicators, conventional tools calibrated to wildfire thresholds (Duff Moisture Code (DMC) and Buildup Index (BUI)), as well as measures of atmospheric forcing (Vapor Pressure Deficit (VPD)), performed best at representing the conditions favoring initiation and size of significant wildfire events. Conventional assessments of seasonal severity and overall landscape flammability using DMC and BUI can be continued with confidence. Fire models that incorporate BUI in overall fire potential and fire behavior assessments are likely to produce effective results throughout boreal landscapes in Alaska. One novel result is the effectiveness of VPD throughout the state, making it a potential alternative to FFMC among the short-lag/1-day indices. Conclusions: This study demonstrates the societal value of research that joins new academic research results with operational needs. Developing the framework to do this more effectively will bring science to action with a shorter lag time, which is critical as we face growing challenges from a changing climate.

ACS Style

Robert H. Ziel; Peter A. Bieniek; Uma S. Bhatt; Heidi Strader; T. Scott Rupp; Alison York. A Comparison of Fire Weather Indices with MODIS Fire Days for the Natural Regions of Alaska. Forests 2020, 11, 516 .

AMA Style

Robert H. Ziel, Peter A. Bieniek, Uma S. Bhatt, Heidi Strader, T. Scott Rupp, Alison York. A Comparison of Fire Weather Indices with MODIS Fire Days for the Natural Regions of Alaska. Forests. 2020; 11 (5):516.

Chicago/Turabian Style

Robert H. Ziel; Peter A. Bieniek; Uma S. Bhatt; Heidi Strader; T. Scott Rupp; Alison York. 2020. "A Comparison of Fire Weather Indices with MODIS Fire Days for the Natural Regions of Alaska." Forests 11, no. 5: 516.

Perspective
Published: 31 January 2020 in Nature Climate Change
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As the Arctic warms, vegetation is responding, and satellite measures indicate widespread greening at high latitudes. This ‘greening of the Arctic’ is among the world’s most important large-scale ecological responses to global climate change. However, a consensus is emerging that the underlying causes and future dynamics of so-called Arctic greening and browning trends are more complex, variable and inherently scale-dependent than previously thought. Here we summarize the complexities of observing and interpreting high-latitude greening to identify priorities for future research. Incorporating satellite and proximal remote sensing with in-situ data, while accounting for uncertainties and scale issues, will advance the study of past, present and future Arctic vegetation change.

ACS Style

Isla H. Myers-Smith; Jeffrey T. Kerby; Gareth K. Phoenix; Jarle W. Bjerke; Howard E. Epstein; Jakob J. Assmann; Christian John; Laia Andreu-Hayles; Sandra Angers-Blondin; Pieter S. A. Beck; Logan T. Berner; Uma S. Bhatt; Anne D. Bjorkman; Daan Blok; Anders Bryn; Casper T. Christiansen; J. Hans C. Cornelissen; Andrew M. Cunliffe; Sarah C. Elmendorf; Bruce C. Forbes; Scott J. Goetz; Robert D. Hollister; Rogier de Jong; Michael M. Loranty; Marc Macias-Fauria; Kadmiel Maseyk; Signe Normand; Johan Olofsson; Thomas C. Parker; Frans-Jan W. Parmentier; Eric Post; Gabriela Schaepman-Strub; Frode Stordal; Patrick F. Sullivan; Haydn J. D. Thomas; Hans Tømmervik; Rachael Treharne; Craig E. Tweedie; Donald A. Walker; Martin Wilmking; Sonja Wipf. Complexity revealed in the greening of the Arctic. Nature Climate Change 2020, 10, 106 -117.

AMA Style

Isla H. Myers-Smith, Jeffrey T. Kerby, Gareth K. Phoenix, Jarle W. Bjerke, Howard E. Epstein, Jakob J. Assmann, Christian John, Laia Andreu-Hayles, Sandra Angers-Blondin, Pieter S. A. Beck, Logan T. Berner, Uma S. Bhatt, Anne D. Bjorkman, Daan Blok, Anders Bryn, Casper T. Christiansen, J. Hans C. Cornelissen, Andrew M. Cunliffe, Sarah C. Elmendorf, Bruce C. Forbes, Scott J. Goetz, Robert D. Hollister, Rogier de Jong, Michael M. Loranty, Marc Macias-Fauria, Kadmiel Maseyk, Signe Normand, Johan Olofsson, Thomas C. Parker, Frans-Jan W. Parmentier, Eric Post, Gabriela Schaepman-Strub, Frode Stordal, Patrick F. Sullivan, Haydn J. D. Thomas, Hans Tømmervik, Rachael Treharne, Craig E. Tweedie, Donald A. Walker, Martin Wilmking, Sonja Wipf. Complexity revealed in the greening of the Arctic. Nature Climate Change. 2020; 10 (2):106-117.

Chicago/Turabian Style

Isla H. Myers-Smith; Jeffrey T. Kerby; Gareth K. Phoenix; Jarle W. Bjerke; Howard E. Epstein; Jakob J. Assmann; Christian John; Laia Andreu-Hayles; Sandra Angers-Blondin; Pieter S. A. Beck; Logan T. Berner; Uma S. Bhatt; Anne D. Bjorkman; Daan Blok; Anders Bryn; Casper T. Christiansen; J. Hans C. Cornelissen; Andrew M. Cunliffe; Sarah C. Elmendorf; Bruce C. Forbes; Scott J. Goetz; Robert D. Hollister; Rogier de Jong; Michael M. Loranty; Marc Macias-Fauria; Kadmiel Maseyk; Signe Normand; Johan Olofsson; Thomas C. Parker; Frans-Jan W. Parmentier; Eric Post; Gabriela Schaepman-Strub; Frode Stordal; Patrick F. Sullivan; Haydn J. D. Thomas; Hans Tømmervik; Rachael Treharne; Craig E. Tweedie; Donald A. Walker; Martin Wilmking; Sonja Wipf. 2020. "Complexity revealed in the greening of the Arctic." Nature Climate Change 10, no. 2: 106-117.

Research article
Published: 17 June 2019 in International Journal of Climatology
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Snowfall and snow season length across Alaska control the surface hydrology and underlying soil properties and also influence near‐surface air temperature by changing the energy balance. Current projections of warming suggest that considerable change will occur to key snow parameters, possibly contributing to extensive infrastructure damage from thawing permafrost, an increased frequency of rain‐on‐snow events and reduced soil recharge in the spring due to shallow end‐of‐winter snowpack. This study investigates projected changes to mean annual snowfall, dates of snow onset and snowmelt and extreme snowfall for Alaska, using dynamically downscaled reanalysis and climate model simulations. These include the ERA‐Interim reanalysis from 1981 to 2010, and two Coupled Model Intercomparison Project Phase 5 models: Community Climate System Model version 4 (CCSM4) and Geophysical Fluid Dynamics Laboratory Climate Model version 3 (GFDL‐CM3) from 1981 to 2100. The analysis is presented in 30‐year periods (i.e., 1981–2010, 2011–2040, 2041–2070 and 2071–2100) with the future scenarios from Representative Concentration Pathway 8.5. Late‐century projections of average annual snowfall at low elevations (0–1,000 m) show decreases of 41.3 and 40.6% for CCSM4 and GFDL‐CM3, respectively. At high elevations (1,000–2,000 m), the reductions are smaller at 13.5 and 14.2%, respectively. End‐of‐winter snow‐water equivalent displays reductions at all elevations in the future periods. Snow season length is shortened due to later snow onset and earlier snowmelt; many locations in southwest Alaska no longer experience continuous winter snowpack by the late‐century period. Maximum 2‐day snowfall amounts are projected to decrease near Anchorage and Nome, while Fairbanks and Utqiaġvik (Barrow) show no significant trend.

ACS Style

Rick Lader; John Walsh; Uma S. Bhatt; Peter A. Bieniek. Anticipated changes to the snow season in Alaska: Elevation dependency, timing and extremes. International Journal of Climatology 2019, 40, 169 -187.

AMA Style

Rick Lader, John Walsh, Uma S. Bhatt, Peter A. Bieniek. Anticipated changes to the snow season in Alaska: Elevation dependency, timing and extremes. International Journal of Climatology. 2019; 40 (1):169-187.

Chicago/Turabian Style

Rick Lader; John Walsh; Uma S. Bhatt; Peter A. Bieniek. 2019. "Anticipated changes to the snow season in Alaska: Elevation dependency, timing and extremes." International Journal of Climatology 40, no. 1: 169-187.

Primary research articles
Published: 03 April 2019 in Global Change Biology
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Seasonality in photosynthetic activity is a critical component of seasonal carbon, water and energy cycles in the Earth system. This characteristic is a consequence of plant's adaptive evolutionary processes to a given set of environmental conditions. Changing climate in northern lands (>30°N) alters the state of climatic constraints on plant growth, and therefore, changes in the seasonality and carbon accumulation are anticipated. However, how photosynthetic seasonality evolved to its current state, and what role climatic constraints and their variability played in this process and ultimately in carbon cycle is still poorly understood due to its complexity. Here, we take the ‘laws of minimum’ as a basis and introduce a new framework where the timing (Day of Year) of peak photosynthetic activity (DOYPmax) acts as a proxy for plant's adaptive state to climatic constraints on its growth. Our analyses confirm that spatial variations in DOYPmax reflect spatial gradients in climatic constraints as well as seasonal maximum and total productivity. We find a widespread warming‐induced advance in DOYPmax (−1.66 ± 0.30 days decade−1, P < 0.001) across northern lands, indicating a spatio‐temporal dynamism of climatic constraints to plant growth. We show that the observed changes in DOYPmax are associated with an increase in total gross primary productivity through enhanced carbon assimilation early in the growing season, which leads to an earlier phase shift in land‐atmosphere carbon fluxes and an increase in their amplitude. Such changes are expected to continue in the future based on our analysis of Earth System Model (ESM) projections. Our study provides a simplified, yet realistic framework based on first principles for the complex mechanisms by which various climatic factors constrain plant growth in northern ecosystems. This article is protected by copyright. All rights reserved.

ACS Style

Taejin Park; Chi Chen; Marc Macias‐Fauria; Hans Tømmervik; Sungho Choi; Alexander J. Winkler; Uma Bhatt; Donald A. Walker; Shilong Piao; Victor Brovkin; Ramakrishna R. Nemani; Ranga B. Myneni. Changes in timing of seasonal peak photosynthetic activity in northern ecosystems. Global Change Biology 2019, 25, 2382 -2395.

AMA Style

Taejin Park, Chi Chen, Marc Macias‐Fauria, Hans Tømmervik, Sungho Choi, Alexander J. Winkler, Uma Bhatt, Donald A. Walker, Shilong Piao, Victor Brovkin, Ramakrishna R. Nemani, Ranga B. Myneni. Changes in timing of seasonal peak photosynthetic activity in northern ecosystems. Global Change Biology. 2019; 25 (7):2382-2395.

Chicago/Turabian Style

Taejin Park; Chi Chen; Marc Macias‐Fauria; Hans Tømmervik; Sungho Choi; Alexander J. Winkler; Uma Bhatt; Donald A. Walker; Shilong Piao; Victor Brovkin; Ramakrishna R. Nemani; Ranga B. Myneni. 2019. "Changes in timing of seasonal peak photosynthetic activity in northern ecosystems." Global Change Biology 25, no. 7: 2382-2395.

Letter
Published: 01 April 2019 in Environmental Research Letters
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Key observational indicators of climate change in the Arctic, most spanning a 47 year period (1971–2017) demonstrate fundamental changes among nine key elements of the Arctic system. We find that, coherent with increasing air temperature, there is an intensification of the hydrological cycle, evident from increases in humidity, precipitation, river discharge, glacier equilibrium line altitude and land ice wastage. Downward trends continue in sea ice thickness (and extent) and spring snow cover extent and duration, while near-surface permafrost continues to warm. Several of the climate indicators exhibit a significant statistical correlation with air temperature or precipitation, reinforcing the notion that increasing air temperatures and precipitation are drivers of major changes in various components of the Arctic system. To progress beyond a presentation of the Arctic physical climate changes, we find a correspondence between air temperature and biophysical indicators such as tundra biomass and identify numerous biophysical disruptions with cascading effects throughout the trophic levels. These include: increased delivery of organic matter and nutrients to Arctic near‐coastal zones; condensed flowering and pollination plant species periods; timing mismatch between plant flowering and pollinators; increased plant vulnerability to insect disturbance; increased shrub biomass; increased ignition of wildfires; increased growing season CO2 uptake, with counterbalancing increases in shoulder season and winter CO2 emissions; increased carbon cycling, regulated by local hydrology and permafrost thaw; conversion between terrestrial and aquatic ecosystems; and shifting animal distribution and demographics. The Arctic biophysical system is now clearly trending away from its 20th Century state and into an unprecedented state, with implications not only within but beyond the Arctic. The indicator time series of this study are freely downloadable at AMAP.no.

ACS Style

Jason E Box; William T Colgan; Torben Røjle Christensen; Niels Martin Schmidt; Magnus Lund; Frans-Jan W Parmentier; Ross Brown; Uma S Bhatt; Eugénie S Euskirchen; Vladimir E Romanovsky; John Walsh; James E Overland; Muyin Wang; Robert W Corell; Walter N Meier; Bert Wouters; Sebastian Mernild; Johanna Mård; Janet Pawlak; Morten Skovgård Olsen. Key indicators of Arctic climate change: 1971–2017. Environmental Research Letters 2019, 14, 045010 .

AMA Style

Jason E Box, William T Colgan, Torben Røjle Christensen, Niels Martin Schmidt, Magnus Lund, Frans-Jan W Parmentier, Ross Brown, Uma S Bhatt, Eugénie S Euskirchen, Vladimir E Romanovsky, John Walsh, James E Overland, Muyin Wang, Robert W Corell, Walter N Meier, Bert Wouters, Sebastian Mernild, Johanna Mård, Janet Pawlak, Morten Skovgård Olsen. Key indicators of Arctic climate change: 1971–2017. Environmental Research Letters. 2019; 14 (4):045010.

Chicago/Turabian Style

Jason E Box; William T Colgan; Torben Røjle Christensen; Niels Martin Schmidt; Magnus Lund; Frans-Jan W Parmentier; Ross Brown; Uma S Bhatt; Eugénie S Euskirchen; Vladimir E Romanovsky; John Walsh; James E Overland; Muyin Wang; Robert W Corell; Walter N Meier; Bert Wouters; Sebastian Mernild; Johanna Mård; Janet Pawlak; Morten Skovgård Olsen. 2019. "Key indicators of Arctic climate change: 1971–2017." Environmental Research Letters 14, no. 4: 045010.

Research article
Published: 17 January 2019 in International Journal of Climatology
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Continuous high quality data are critical for weather and climate investigations. Numerous data gaps exist particularly over mountainous regions which limits the ability to construct climatologies and perform trend analysis. This study addresses the issue of sparse precipitation data over Northwest Himalaya (NWH) and fills data voids by applying the quantile mapping (QM) method. QM is applied to observed winter precipitation for a period of 25 years (1991–1992 to 2015–2016) to construct a continuous reliable data set. The first 20 years (1991–1992 to 2010–2011) are used for training and the remaining 5 years (2011–2012 to 2015–2016) are used for validation. In total, 10 stations are available for this study and each one is considered serially as a reference to generate daily precipitation values at the other stations. The mean precipitation of NWH region is constructed by considering the mean of all the stations. Standard statistical measures like root mean square errors, standard deviation, skill score and its decompositions are applied to evaluate the generated datasets. Based on statistical analysis, the Kanzalwan station, located in Great Himalaya range, is one of the best performing reference stations for generating precipitation values over NWH. The statistical measures of this station show the highest skill scores, lowest root mean square error and lowest standard mean errors for all winter months except January. This study provides a successful application of QM to generate precipitation data for climate analysis over the complex terrain of the Himalaya region.

ACS Style

Usha Devi; Manorama S. Shekhar; Gyan P. Singh; Nalamasu N. Rao; Uma S. Bhatt. Methodological application of quantile mapping to generate precipitation data over Northwest Himalaya. International Journal of Climatology 2019, 39, 3160 -3170.

AMA Style

Usha Devi, Manorama S. Shekhar, Gyan P. Singh, Nalamasu N. Rao, Uma S. Bhatt. Methodological application of quantile mapping to generate precipitation data over Northwest Himalaya. International Journal of Climatology. 2019; 39 (7):3160-3170.

Chicago/Turabian Style

Usha Devi; Manorama S. Shekhar; Gyan P. Singh; Nalamasu N. Rao; Uma S. Bhatt. 2019. "Methodological application of quantile mapping to generate precipitation data over Northwest Himalaya." International Journal of Climatology 39, no. 7: 3160-3170.

Journal article
Published: 01 October 2018 in Earth Interactions
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Climate warming is expected to disproportionately affect crop yields in the southern United States due to excessive heat stress, while presenting new farming opportunities through a longer growing season farther north. Few studies have investigated the impact of this warming on agro-climate indices that link meteorological data with important field dates in northern regions. This study employs regional dynamical downscaling using the Weather Research and Forecasting (WRF) Model to assess changes in growing season length (GSL), spring planting dates, and occurrences of plant heat stress (PHS) for five regions in Alaska. Differences between future representative concentration pathway 8.5 (RCP8.5; 2011–40, 2041–70, 2071–2100) and historical (1981–2010) periods are obtained using boundary forcing from the Geophysical Fluid Dynamics Laboratory Climate Model, version 3, and the NCAR Community Climate System Model, version 4. The model output is bias corrected using ERA-Interim. Median GSL shows increases of 48–87 days by 2071–2100, with the largest changes in northern Alaska. Similarly, by 2071–2100, planting dates advance 2–4 weeks, and PHS days increase from near 0 to 5–10 instances per summer in the hottest areas. The largest GSL changes occur in the mid- (2041–70) and late century (2071–2100), when a warming signal emerges from the historical interannual variability. These periods coincide with the greatest divergence of the RCPs, suggesting that near-term decision-making may affect substantial future changes. Early-century (2011–40) projections show median GSL increases of 8–27 days, which is close to the historical standard deviation of GSL. Thus, internal variability will remain an important source of uncertainty into the midcentury, despite a trend for longer growing seasons.

ACS Style

Rick Lader; John E. Walsh; Uma S. Bhatt; Peter A. Bieniek. Agro-Climate Projections for a Warming Alaska. Earth Interactions 2018, 22, 1 -24.

AMA Style

Rick Lader, John E. Walsh, Uma S. Bhatt, Peter A. Bieniek. Agro-Climate Projections for a Warming Alaska. Earth Interactions. 2018; 22 (18):1-24.

Chicago/Turabian Style

Rick Lader; John E. Walsh; Uma S. Bhatt; Peter A. Bieniek. 2018. "Agro-Climate Projections for a Warming Alaska." Earth Interactions 22, no. 18: 1-24.

Journal article
Published: 12 September 2018 in Geophysical Research Letters
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Arctic tundra vegetation has largely been “greening” in recent decades, resulting in major changes to terrestrial ecosystems, with implications for surface energy balance, permafrost, carbon and water cycling, herbivore populations, and human land use. While general greening trends have been well‐studied, more specific vegetation‐temperature dynamics are spatially and temporally heterogeneous and currently not well understood. This study uses Normalized Difference Vegetation Index (NDVI) and Summer Warmth Index (SWI) data to investigate patterns of arctic tundra vegetation and temperature dynamics over North American and Eurasian continents and by Arctic bioclimate subzones (essentially latitudinal‐based). Relative vegetation increases in northern subzones were muted compared to temperature increases, whereas relative vegetation increases in southern subzones were consistent with, or greater than, relative temperature changes. Detrended, interannual NDVI variances were greatest in middle and southern subzones, whereas interannual SWI variances were greatest in southern subzones. Annual SWI and NDVI relationships were strongest in midlatitude subzones.

ACS Style

L. M. Reichle; H. E. Epstein; U. S. Bhatt; M. K. Raynolds; D. A. Walker. Spatial Heterogeneity of the Temporal Dynamics of Arctic Tundra Vegetation. Geophysical Research Letters 2018, 45, 9206 -9215.

AMA Style

L. M. Reichle, H. E. Epstein, U. S. Bhatt, M. K. Raynolds, D. A. Walker. Spatial Heterogeneity of the Temporal Dynamics of Arctic Tundra Vegetation. Geophysical Research Letters. 2018; 45 (17):9206-9215.

Chicago/Turabian Style

L. M. Reichle; H. E. Epstein; U. S. Bhatt; M. K. Raynolds; D. A. Walker. 2018. "Spatial Heterogeneity of the Temporal Dynamics of Arctic Tundra Vegetation." Geophysical Research Letters 45, no. 17: 9206-9215.

Synthesis
Published: 08 September 2018 in Applied Vegetation Science
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Questions How do plant communities on zonal loamy vs. sandy soils vary across the full maritime Arctic bioclimate gradient? How are plant communities of these areas related to existing vegetation units of the European Vegetation Classification? What are the main environmental factors controlling transitions of vegetation along the bioclimate gradient? Location 1700‐km Eurasia Arctic Transect (EAT), Yamal Peninsula and Franz Josef Land (FJL), Russia. Methods The Braun‐Blanquet approach was used to sample mesic loamy and sandy plots on 14 total study sites at six locations, one in each of the five Arctic bioclimate subzones and the forest–tundra transition. Trends in soil factors, cover of plant growth forms (PGFs) and species diversity were examined along the summer warmth index (SWI) gradient and on loamy and sandy soils. Classification and ordination were used to group the plots and to test relationships between vegetation and environmental factors. Results Clear, mostly non‐linear, trends occurred for soil factors, vegetation structure and species diversity along the climate gradient. Cluster analysis revealed seven groups with clear relationships to subzone and soil texture. Clusters at the ends of the bioclimate gradient (forest–tundra and polar desert) had many highly diagnostic taxa, whereas clusters from the Yamal Peninsula had only a few. Axis 1 of a DCA was strongly correlated with latitude and summer warmth; Axis 2 was strongly correlated with soil moisture, percentage sand and landscape age. Conclusions Summer temperature and soil texture have clear effects on tundra canopy structure and species composition, with consequences for ecosystem properties. Each layer of the plant canopy has a distinct region of peak abundance along the bioclimate gradient. The major vegetation types are weakly aligned with described classes of the European Vegetation Checklist, indicating a continuous floristic gradient rather than distinct subzone regions. The study provides ground‐based vegetation data for satellite‐based interpretations of the western maritime Eurasian Arctic, and the first vegetation data from Hayes Island, Franz Josef Land, which is strongly separated geographically and floristically from the rest of the gradient and most susceptible to on‐going climate change.

ACS Style

Donald A. Walker; Howard E. Epstein; Jozef Šibík; Uma Bhatt; Vladimir E. Romanovsky; Amy L. Breen; Silvia Chasníková; Ronald Daanen; Lisa A. Druckenmiller; Ksenia Ermokhina; Bruce C. Forbes; Gerald V. Frost; Jozsef Geml; Elina Kaärlejarvi; Olga Khitun; Artem Khomutov; Timo Kumpula; Patrick Kuss; Georgy Matyshak; Natalya Moskalenko; Pavel Orekhov; Jana Peirce; Martha K. Raynolds; Ina Timling. Vegetation on mesic loamy and sandy soils along a 1700‐km maritime Eurasia Arctic Transect. Applied Vegetation Science 2018, 22, 150 -167.

AMA Style

Donald A. Walker, Howard E. Epstein, Jozef Šibík, Uma Bhatt, Vladimir E. Romanovsky, Amy L. Breen, Silvia Chasníková, Ronald Daanen, Lisa A. Druckenmiller, Ksenia Ermokhina, Bruce C. Forbes, Gerald V. Frost, Jozsef Geml, Elina Kaärlejarvi, Olga Khitun, Artem Khomutov, Timo Kumpula, Patrick Kuss, Georgy Matyshak, Natalya Moskalenko, Pavel Orekhov, Jana Peirce, Martha K. Raynolds, Ina Timling. Vegetation on mesic loamy and sandy soils along a 1700‐km maritime Eurasia Arctic Transect. Applied Vegetation Science. 2018; 22 (1):150-167.

Chicago/Turabian Style

Donald A. Walker; Howard E. Epstein; Jozef Šibík; Uma Bhatt; Vladimir E. Romanovsky; Amy L. Breen; Silvia Chasníková; Ronald Daanen; Lisa A. Druckenmiller; Ksenia Ermokhina; Bruce C. Forbes; Gerald V. Frost; Jozsef Geml; Elina Kaärlejarvi; Olga Khitun; Artem Khomutov; Timo Kumpula; Patrick Kuss; Georgy Matyshak; Natalya Moskalenko; Pavel Orekhov; Jana Peirce; Martha K. Raynolds; Ina Timling. 2018. "Vegetation on mesic loamy and sandy soils along a 1700‐km maritime Eurasia Arctic Transect." Applied Vegetation Science 22, no. 1: 150-167.

Journal article
Published: 01 August 2018 in Journal of Applied Meteorology and Climatology
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The ice formed by cold-season rainfall or rain on snow (ROS) has striking impacts on the economy and ecology of Alaska. An understanding of the atmospheric drivers of ROS events is required to better predict them and plan for environmental change. The spatially/temporally sparse network of stations in Alaska makes studying such events challenging, and gridded reanalysis or remote sensing products are necessary to fill the gaps. Recently developed dynamically downscaled climate data provide a new suite of high-resolution variables for investigating historical and projected ROS events across all of Alaska from 1979 to 2100. The dynamically downscaled reanalysis data of ERA-Interim replicated the seasonal patterns of ROS events but tended to produce more rain events than in station observations. However, dynamical downscaling reduced the bias toward more rain events in the coarse reanalysis. ROS occurred most frequently over southwestern and southern coastal regions. Extreme events with the heaviest rainfall generally coincided with anomalous high pressure centered to the south/southeast of the locations receiving the event and warm-air advection from the resulting southwesterly wind flow. ROS events were projected to increase in frequency overall and for extremes across most of the region but were expected to decline over southwestern/southern Alaska. Increases in frequency were projected as a result of more frequent winter rainfall, but the number of ROS events may ultimately decline in some areas as a result of temperatures rising above the freezing threshold. These projected changes in ROS can significantly affect wildlife, vegetation, and human activities across the Alaska landscape.

ACS Style

Peter A. Bieniek; Uma S. Bhatt; John E. Walsh; Rick Lader; Brad Griffith; Jennifer K. Roach; Richard L. Thoman. Assessment of Alaska Rain-on-Snow Events Using Dynamical Downscaling. Journal of Applied Meteorology and Climatology 2018, 57, 1847 -1863.

AMA Style

Peter A. Bieniek, Uma S. Bhatt, John E. Walsh, Rick Lader, Brad Griffith, Jennifer K. Roach, Richard L. Thoman. Assessment of Alaska Rain-on-Snow Events Using Dynamical Downscaling. Journal of Applied Meteorology and Climatology. 2018; 57 (8):1847-1863.

Chicago/Turabian Style

Peter A. Bieniek; Uma S. Bhatt; John E. Walsh; Rick Lader; Brad Griffith; Jennifer K. Roach; Richard L. Thoman. 2018. "Assessment of Alaska Rain-on-Snow Events Using Dynamical Downscaling." Journal of Applied Meteorology and Climatology 57, no. 8: 1847-1863.

Journal article
Published: 30 April 2018 in Environmental Modelling & Software
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The paper summarizes an end-to-end activity connecting the global climate modeling enterprise with users of climate information in Alaska. The effort included retrieval of the requisite observational datasets and model output, a model evaluation and selection procedure, the actual downscaling by the delta method with its inherent bias-adjustment, and the provision of products to a range of users through visualization software that empowers users to explore the downscaled output and its sensitivities. An additional software tool enables users to examine skill metrics and relative rankings of 21 global models for Alaska and six other domains in the Northern Hemisphere. The downscaled temperatures and precipitation are made available as calendar-month decadal means under three different greenhouse forcing scenarios through 2100 for more than 4000 communities in Alaska and western Canada. The visualization package displays the uncertainties inherent in the multi-model ensemble projections. These uncertainties are often larger than the projected changes.

ACS Style

John Walsh; Uma Bhatt; Jeremy S. Littell; Matthew Leonawicz; Michael Lindgren; Thomas A. Kurkowski; Peter A. Bieniek; Richard Thoman; Stephen Gray; T. Scott Rupp. Downscaling of climate model output for Alaskan stakeholders. Environmental Modelling & Software 2018, 110, 38 -51.

AMA Style

John Walsh, Uma Bhatt, Jeremy S. Littell, Matthew Leonawicz, Michael Lindgren, Thomas A. Kurkowski, Peter A. Bieniek, Richard Thoman, Stephen Gray, T. Scott Rupp. Downscaling of climate model output for Alaskan stakeholders. Environmental Modelling & Software. 2018; 110 ():38-51.

Chicago/Turabian Style

John Walsh; Uma Bhatt; Jeremy S. Littell; Matthew Leonawicz; Michael Lindgren; Thomas A. Kurkowski; Peter A. Bieniek; Richard Thoman; Stephen Gray; T. Scott Rupp. 2018. "Downscaling of climate model output for Alaskan stakeholders." Environmental Modelling & Software 110, no. : 38-51.

Journal article
Published: 01 January 2018 in Bulletin of the American Meteorological Society
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ACS Style

John E. Walsh; Richard L. Thoman; Uma S. Bhatt; Peter A. Bieniek; Brian Brettschneider; Michael Brubaker; Seth Danielson; Rick Lader; Florence Fetterer; Kris Holderied; Katrin Iken; Andy Mahoney; Molly McCammon; James Partain. The High Latitude Marine Heat Wave of 2016 and Its Impacts on Alaska. Bulletin of the American Meteorological Society 2018, 99, S39 -S43.

AMA Style

John E. Walsh, Richard L. Thoman, Uma S. Bhatt, Peter A. Bieniek, Brian Brettschneider, Michael Brubaker, Seth Danielson, Rick Lader, Florence Fetterer, Kris Holderied, Katrin Iken, Andy Mahoney, Molly McCammon, James Partain. The High Latitude Marine Heat Wave of 2016 and Its Impacts on Alaska. Bulletin of the American Meteorological Society. 2018; 99 (1):S39-S43.

Chicago/Turabian Style

John E. Walsh; Richard L. Thoman; Uma S. Bhatt; Peter A. Bieniek; Brian Brettschneider; Michael Brubaker; Seth Danielson; Rick Lader; Florence Fetterer; Kris Holderied; Katrin Iken; Andy Mahoney; Molly McCammon; James Partain. 2018. "The High Latitude Marine Heat Wave of 2016 and Its Impacts on Alaska." Bulletin of the American Meteorological Society 99, no. 1: S39-S43.