Forecast-Informed Reservoir Operations: A Concept Supporting Water Supply and Flood Control

Transcription

1 16 inches of rain in 1 day in Central California Forecast-Informed Reservoir Operations: A Concept Supporting Water Supply and Flood Control Developed by the Center for Western Weather and Water Extremes CW3E at UC San Diego/Scripps Institution of Oceanography Dr. F. Martin Ralph (mralph@ucsd.edu) 6 May 2014; UCDC Water Research Briefing; Washington, DC

2 The Challenge

3 A Major Result from 10-years of Research Atmospheric rivers what they are, how they work, and their crucial role in both water supply and flooding across much of the U.S. West Coast Figure from an article in Scientific American by Dettinger and Ingram (January 2013)

4 35-45% of annual precipitation in California fell in association with Atmospheric Rivers, Floods and the Water Resources of California by Mike Dettinger, Marty Ralph,, Tapash Das, Paul Neiman, Dan Cayan Water, % of annual precipitation in the Pacific Northwest fell in association with atmospheric river events An average AR transports the equivalent of 7.5 times the average discharge of the Mississippi River, or ~10 M acre feet/day

5 ARkStorm: An emergency preparedness scenario for California USGS organized a large team of experts. A meteorology team was formed and built a plausible physical scenario. Back-to-back extreme AR events (mostly based on actual 1969 and 1986 storms) struck over about 3 weeks. Considers the 1861/82 floods as an example. Dettinger et al (Natural Hazards) Projected damage and economic losses exceed $500 Billion The meteorological scenario was then given to follow-on groups of experts in damage assessment and economic disruption estimation and has become the basis for emergency preparedness exercises.

6 Water year 2012 precipitation total was 46.2 inches Atmospheric Rivers Contribute to Annual Precipitation in Northern California s Key Region Providing much of the State s Water Supply One major AR event in Dec 2012 over 3-5 days provided about 1/3 of the entire Water Year s precipitation (i.e., 15 inches out of 46 inches)

7 California s Department of Water Resources (DWR) Program Applications of Atmospheric Rivers Network Data Flood Preparedness and Response Flood Planning Reservoir Coordinated Operations Water Supply Forecasting Courtesy of Mike Anderson - CA Dept. Water Resources - CA State climatologist

8 Atmospheric Rivers A UCSD/CW3E Vision Supporting California Water Management A Path Toward Solutions Concept Demonstrate that better monitoring and prediction of atmospheric river storms can enable increased water storage while maintaining flood control capabilities Strategies Develop, deploy and demonstrate new atmospheric-river-focused monitoring and prediction methods targeting extreme events and their roles in flooding and drought. This is done by advancing the science, observing systems, forecast models, decision support tools and communication methods. Expertise and Partnerships Needed: University, Local, State, Federal.

9 Atmospheric Rivers A UCSD/CW3E There is no Vision Silver Supporting bullet for California this complex Water problem. Management There is no silver bullet Requires an Integrated, Multi-disciplinary Strategy BENEFITS: Water Supply, Flood Control Decision Support Ecosystems, Tools + Forecast-Informed Hydropower, etc Reservoir Operations 21st Century Observations 21st Century Modeling Science F.M. Ralph Scripps/CW3E

10 Conceptual Observation Network and Forecast Lead Time for Atmospheric Rivers Recommendation from an interagency team presented in Ralph et al., 2014 Landfall Amplifying Jet Stream - RWD G-IV MJO 7-10 days UAVs Profilers Frontal wave stalls AR over CA - AROs Ensemble MJO Fcst Recurving West Pacific Tropicals 5-7 days Tropical Tap?

11 California has begun implementation of key land-based sensors An Atmospheric River-focused longterm observing network is being installed in CA as part of a 5-year project between CA Dept. of Water Resources (DWR), NOAA and Scripps Inst. Of Oceanography - Installed >100 field sites 11

12 CalWater-2* Early Start field campaign 3-25 February 2014 Summary Courtesy of Marty Ralph UCSD/Scripps/Center for Western Weather and Water Extremes This AR increased precipitation-todate from 16% to 40% of normal in < 4 days in key Northern California watersheds, but runoff was muted due to dry soils. Up to > 12 inches of rain some drought relief Flight area for NOAA s G-IV aircraft on 8 Feb 2014 Goal: developing AR flight method to sample a frontal wave that can cause an AR to stall over one area at landfall (G-IV PI: Chris Fairall NOAA; Mission Scientists: Marty Ralph Scripps, Ryan Spackman STC) Russian River s highest flow in > 1 year Hawaii *CalWater-2 is a 5-year program (from ) proposed to focus on West Coast precipitation processes and how a changing climate will affect them. It is led by UCSD/Scripps with partners from DWR, CEC, NOAA, NASA, SSM/I satellite observations of water DOE vapor and on others. 8 Feb 2014 (Courtesy G. Wick, NOAA)

13 50 N 40 N CalWater 2 / ACAPEX Observational Strategy Jan Mar N 40N 12 December 2010 Ship - DOE AMF2 - Small UAS - Air-sea fluxes - Precipitation estimates NOAA HMT Network Wind Profilers, Radars, GPS Met DOE G-1 - Aerosols - Microphysics Sierra Nevada and Coastal Ranges (white bars) 30N 30 N 20 N Remote aerosol plume (schematic) Hawaii 20N 40N 30N 160W 150W 140W 130W 18 December Dropsondes SSM/I satellite observations of IWV showing - Precipitation a strong atmospheric & Cloud Radar river on 12 Dec 2010 (from Ralph and Dettinger BAMS 2012) 20N 160W 150W 140W 130W 120W NOAA WP-3D - Aerosols & Trace Gas Instruments - Cloud Probes - Dropsondes - Precipitation & Cloud Radar NASA Global Hawk & NOAA G- IV 160 W 150 W 140 W 130 W IWV (g cm -2 ) Courtesy of F. M. Ralph, NOAA Earth System Research Laboratory

14 Atmospheric River Experiment AREX Proposal to NASA s EV AO Marty Ralph (PI) Duane Waliser (Deputy PI), Ryan Spackman (Deputy PI) Scripps Institution of Oceanography NASA JPL Science and Technology Corporation NOAA Earth System Research Laboratory Water vapor budget of ARs offshore and their impacts on landfall - NASA Global Hawk (3 winters) - NASA DC-8 (2 winters) EFREP AR Obs network onshore

15 Droughts, on average, end with a bang (and begin with a whimper) all over the U.S. Atmospheric rivers provide the bang in a large fraction of the west coast drought breaks, especially in winters Dettinger, Michael D., 2013: Atmospheric Rivers as Drought Busters on the U.S. West Coast. J. Hydrometeor, 14,

16 Atmospheric Rivers (fall and winter) Great Plains Deep Convection (spring and summer) Spring Front Range Upslope (rain/snow) Scripps Institution of Oceanography Center for Western Weather and Water Extremes Southwest Monsoon (summer & fall) Where: UCSD/Scripps Inst. Oceanography La Jolla, California When: Start Who: Dr. F. M. Ralph (Director) Dr. Dan Cayan Dr. Mike Dettinger Dr. Ryan Spackman Mission Provide 21 st Century water cycle science, technology and outreach to support effective policies and practices that address the impacts of extreme weather and water events on the environment, people and the economy of Western North America Goal Revolutionize the physical understanding, observations, weather predictions and climate projections of extreme events in Western North America, including atmospheric rivers and the North American summer monsoon as well as their impacts on floods, droughts, hydropower, ecosystems and the economy

17 The Challenge Using modern science and engineering, and a collaborative approach to developing a small scale demonstration, the answer is likely YES A NEXT STEP IS UNDERWAY: A planning team has been formed to develop a detailed roadmap forward, including relevant local, state and federal entities, brought together by UCSD/Scripps/Center for Western Weather and Water Extremes. Information needs will be defined, potential solutions developed, to be carried out as a demonstration on Lake Mendocino in northern California.

18 Region for which atmospheric river events are a dominant cause of extreme precipitation, flooding and contribute to water supply in the Western U.S. (Ralph et al. 2014) Region of major atmospheric river influence Lake Mendocino - Pilot study Contact: F. Martin Ralph (mralph@ucsd.edu) Website: