Dr. Stephen Gray is the Director of the Alaska Climate Adaptation Science Center (AK CASC), one of the nine regional centers that form the National and Regional Climate Adaptation Science Center network.
Dr. Gray previously served as the director of the University of Wyoming Water Resources Data System, a climatologist for the state of Wyoming, and an associate research scientist in the University of Wyoming Department of Civil and Architectural Engineering. In addition, he held adjunct faculty appointments in the University of Wyoming Program in Ecology and the Laboratory of Tree-Ring Research at the University of Arizona.
Among other duties, Dr. Gray was a senior advisor to the University of Wyoming Environment and Natural Resource Program and the Wyoming Water Association. His work explored the interplay between climate variability, climatic change, and natural resource management. Much of his research focused on drought and climate change impacts in the western United States. His studies included a detailed examination of snowpack variability in the North American mountain ranges and a review of how changes in ocean circulation patterns affect precipitation in the West.
Dr. Gray received the American Water Resources Association’s Henry R. Boggess Award in 2005, and he is a former National Research Council Research Associate with the USGS. He received his Ph.D. from the University of Wyoming.
Education and Certifications
Ph.D., University of Wyoming
Science and Products
Webinar: Ridge-to-Reef and Icefield-to-Ocean: Collaborative Research in Extreme Environments
Alaska Native Tribes, Regional Tribal Consortia, and ANCSA Corporations
Webinar: Aquatic Ecosystem Vulnerability to Fire and Climate Change in Alaskan Boreal Forests
Anticipating Future Impacts of Temperature on Streamflow in the Colorado River Basin
Understanding Extreme Climate Events in the North Central U.S.
A network of 31 Upper Missouri River Basin naturalized water-year (Oct-Sep) streamflow reconstructions spanning years 800 - 1998 CE
Increased drought severity tracks warming in the United States’ largest river basin
Basinwide hydroclimatic drought in the Colorado River basin
1200 years of Upper Missouri River streamflow reconstructed from tree rings
Changing station coverage impacts temperature trends in the Upper Colorado River Basin
Downscaling of climate model output for Alaskan stakeholders
Reconstructions of Columbia River streamflow from tree-ring chronologies in the Pacific Northwest, USA
Updated streamflow reconstructions for the Upper Colorado River Basin
Science and Products
Webinar: Ridge-to-Reef and Icefield-to-Ocean: Collaborative Research in Extreme EnvironmentsThis webinar discussed how Alaska and Pacific Islands CASC scientists are responding to climate change challenges through cross-regional research, cultural engagement, and synthesis.
Alaska Native Tribes, Regional Tribal Consortia, and ANCSA CorporationsSince time immemorial, the Indigenous peoples of Alaska have taken care of the land, water, fish, birds, and wildlife that sustains their livelihood, traditions, and communities. This close relationship with the land, water, and natural world puts these communities at the forefront of climate change impacts. Drawing upon a strong history of adaptation and innovation, Native Alaskans are key...
Webinar: Aquatic Ecosystem Vulnerability to Fire and Climate Change in Alaskan Boreal ForestsView this webinar for more information about conservation efforts surrounding aquatic habitats in boreal Alaska.
Anticipating Future Impacts of Temperature on Streamflow in the Colorado River BasinThe Colorado River is a crucial water source for millions of people in the Southwest. Warming temperatures, clearly documented in climate records for the Colorado River basin, are having an impact on the amount of annual streamflow yielded from rain and snow. Recent work has revealed that warming temperatures have played an increasingly important role over the past decades, both exacerbating droug
Understanding Extreme Climate Events in the North Central U.S.The climate of the North Central U.S. is driven by a combination of factors, including atmospheric circulation patterns, the region’s complex topography which extends from the High Rockies to the Great Plains, and variations in hydrology. Together, these factors determine the sustainability of the region’s ecosystems and the services that they provide communities. In order to understand the vuln
A network of 31 Upper Missouri River Basin naturalized water-year (Oct-Sep) streamflow reconstructions spanning years 800 - 1998 CEPaleohydrologic records provide a valuable perspective on the variability of streamflow and hydroclimate that is critical for water resource planning and placing present day and future conditions into a long-term context. Until now, key insights gained from streamflow reconstructions in the other river basins across the Western U.S. been lacking in the Upper Missouri River Basin due to a lack of e
Increased drought severity tracks warming in the United States’ largest river basinAcross the Upper Missouri River Basin, the recent drought of 2000 to 2010, known as the “turn-of-the-century drought,” was likely more severe than any in the instrumental record including the Dust Bowl drought. However, until now, adequate proxy records needed to better understand this event with regard to long-term variability have been lacking. Here we examine 1,200 y of streamflow from a networ
Basinwide hydroclimatic drought in the Colorado River basinThe Colorado River basin (CRB) supplies water to approximately 40 million people and is essential to hydropower generation, agriculture, and industry. In this study, a monthly water balance model is used to compute hydroclimatic water balance components (i.e., potential evapotranspiration, actual evapotranspiration, and runoff) for the period 1901–2014 across the entire CRB. The time series of mon
1200 years of Upper Missouri River streamflow reconstructed from tree ringsPaleohydrologic records can provide unique, long-term perspectives on streamflow variability and hydroclimate for use in water resource planning. Such long-term records can also play a key role in placing both present day events and projected future conditions into a broader context than that offered by instrumental observations. However, relative to other major river basins across the western U
AlaskaAlaska is the largest state in the Nation, almost one-fifth the size of the combined lower 48 United States, and is rich in natural capital resources. Alaska is often identified as being on the front lines of climate change since it is warming faster than any other state and faces a myriad of issues associated with a changing climate. The cost of infrastructure damage from a warming climate is pro
Changing station coverage impacts temperature trends in the Upper Colorado River BasinOver the Upper Colorado River Basin (UCRB), temperatures in widely used gridded data products do not warm as much as mean temperatures from a stable set of U.S. Historical Climatology Network (USHCN) stations, located at generally lower elevations, in most months of the year. This is contrary to expectations of elevation-dependent warming, which suggests that warming increases with elevation. Thes
Downscaling of climate model output for Alaskan stakeholdersThe 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 t
Reconstructions of Columbia River streamflow from tree-ring chronologies in the Pacific Northwest, USAWe developed Columbia River streamflow reconstructions using a network of existing, new, and updated tree-ring records sensitive to the main climatic factors governing discharge. Reconstruction quality is enhanced by incorporating tree-ring chronologies where high snowpack limits growth, which better represent the contribution of cool-season precipitation to flow than chronologies from trees posit
Updated streamflow reconstructions for the Upper Colorado River BasinUpdated proxy reconstructions of water year (October–September) streamflow for four key gauges in the Upper Colorado River Basin were generated using an expanded tree ring network and longer calibration records than in previous efforts. Reconstructed gauges include the Green River at Green River, Utah; Colorado near Cisco, Utah; San Juan near Bluff, Utah; and Colorado at Lees Ferry, Arizona. The r