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New Gridded Hydrometeorological Dataset and Downscaling Application
The accompanying slides were shown during a June 14, 2015, webinar hosted by SW CSC scientists and partners from the Bureau of Reclamation and Army Corps of Engineers that provided a briefing on a new gridded hydrometeorological dataset and downscaling application. The dataset includes 1/16 degree (~6.5 km) grids of station-based daily precipitation, temperature (min and max), as well as derived hydrologic quantities related to surface moisture and energy states and fluxes. The downscaling application is the Localized Constructed Analogs (LOCA) being tested on the western United States.
Climate Change and Fire Regimes in the Southwest
In the Sierra Nevada, the position of the North Pacific Jet (NPJ) strongly modulates winter hydroclimatology and, therefore, affects both tree growth and fire activity. However, there is some evidence that greater greenhouse gas-driven warming at high northern latitudes weakens the equator-to-pole temperature gradient, yielding so-called Arctic amplification and more extreme weather by altering the orientation of the NPJ. Over the last decade, the polar jet stream – the fast-flowing, high-altitude westerly air current that flows over mid and high latitudes - has experienced more north-south oriented trajectories and slower progressions, consistent with Arctic amplification. In this webinar, Dr. Julio Betancourt discussed recent research, which uses tree-ring data from 1409 – 1990 to reconstruct how the NPJ influences tree growth and fire activity in the Sierra Nevada. Dr. Betancourt has elected not to post slides from this talk, due to the preliminary nature of the research. However, he is happy to answer questions if you contact him directly at
California heat waves in the present and future and implications for human health
The flavor of California heat waves is changing: they are becoming more humid and therefore expressed with disproportionate intensity in nighttime rather than daytime temperatures. Moreover, coastal heat waves are becoming more intense even relative to the background warming and climate models project this trend to intensify. This has the potential for severe impacts on health, ecosystems, agriculture, water resources, energy demand and infrastructure, all with economic consequences.
Colorado River Myths and Realities: The Coming Conflict
The Colorado River is currently in the midst of a 14-year drought nearly unrivaled in over 1250 years. The river’s two massive reservoirs, Lakes Mead and Powell, are now less than half full. Due to the drought, the Department of Interior’s Bureau of Reclamation projects that the first delivery shortages are likely to occur in two years. Further, scientists believe that climate change will reduce Colorado River runoff by 2050. Water managers also believe that water demand will increase because of increased population and warmer temperatures. The current legal system for operating this critical system is not tenable in the face of these pressures. Given that the entire American Southwest including all of its major population centers are dependent on the reliable supply of Colorado River water, what solutions in basin are likely in the near and distant future?
Drought conditions and outlook for the Southwest
Parts of the Southwest have experienced drought conditions almost continuously since the turn of the century. Areas affected have included the Colorado River Basin, more recently the Sierra Nevada, and yet more recently the Cascades. The current winter and the past 30 months have been the driest on record in the Sierra Nevada. Kelly Redmond, SW CSC Investigator, discusses possible contributory factors to the drought and prospects for the remainder of this winter and beyond.
Storms, floods and climate change in the Southwest
Storms and floods are among the most destructive natural hazards in the Southwest, but also play key and beneficial roles in the operation of its landscapes and ecosystems. In this webinar, Dr. Mike Dettinger reviews some of the primary mechanisms and processes that cause storms and floods in the region and some of their impacts. He also discusses the most recent projections of how they are likely to change in the future as greenhouse warming changes the world’s and region’s climate.
Projecting and Detecting Species-Level Responses to Variations in Weather and Changes in Climate
Erica Fleishman, from UC Davis, discusses the challenges of projecting how individual species might respond to climate-related changes in their current habitats.
Modeling Southwestern Forest Vulnerability
The second in the SW CSC webinar series; Mark Schwartz - SW CSC Principal Investigator/UC Davis
Sea Level Rise and Impacts to Coastal Habitats
The third webinar in the SW CSC series; Glen MacDonald, SW CSC Principal Investigator/UCLA.
SW CSC Webinar Series: IPCC Working Group 1 Report and Implications for the Southwest
In the first webinar of the SW CSC series, Jonathan Overpeck discusses the recent IPCC Working Group 1 report on the physical science basis of climate change and the implications for the climate of the Southwest.