CALIFORNIA APPLICATIONS PROGRAM (CAP)

Daniel R. Cayan (SIO)

Link to NOAA Strategic Plan: NOAA’s Mission Goal 2: Understand Climate Variability and Change to Enhance Society’s Ability to Plan and Respond

RESEARCH OBJECTIVES AND SPECIFIC PLANS TO ACHIEVE THEM

The California Applications Program (CAP) and the California Climate Change Center (CCCC) aim to develop and provide better climate information and forecasts for decision makers in California and the surrounding region. Applications addressed include problems involving water resources, wildfire, and human health. Time scales of interest range from seasonal to secular changes associated with natural and anthropogenic influences. By working directly with users and practitioners, CAP and CCCC are working to evaluate climate information needs and utility from the user perspective.

RESEARCH ACCOMPLISHMENTS

Working with scientists from the NOAA Earth Systems Research Laboratory, Dettinger continues to investigate the impact of atmospheric rivers (ARs) of water vapor on western flooding. AR flood events have occurred throughout the whole west coast region.

Satellite and ground-based data sets were examined by Iacobellis to determine the spatial variability and coherence of cloud properties over California and the Western United States. The spatial coherence of cloudiness over California varies considerably by season, with the coherence generally largest during winter. There is also a strong topographic influence on clouds that is strongest in summer when there exists significant spatial coherence of cloudiness over large horizontal spans (on the order of 100s of km) of the California coastal region, especially concentrated to the west of the first major coastal mountain front at elevations less than about 600 meters.

Gershunov is investigating the structure, mechanisms, and temporal changes in California heat waves. Episodes that are most strongly expressed at night have shown a marked tendency to increase during the last few decades. The July 2006 heat wave in the California region was particularly strong, especially in having exceptionally hot nighttime temperatures.

The Climate, Ecosystem and Fire Applications (CEFA) co-organized the National Seasonal Assessment Workshop: Western States and Alaska with Climate Assessment for the Southwest (CLIMAS) RISA and the National Interagency Coordination Center (NICC). The workshop was held during April 2006 in Boulder, Colorado at the NOAA-CIRES Climate Diagnostics Center. The purpose of this workshop was to bring together fire managers, fire meteorologists, fire and fuel specialists, and climatologists to develop an assessment of recent past and current conditions, and prepare an outlook for the 2006 season that combined climate, fuels, fire management information. CEFA organized a climate training workshop at the request of Predictive Services. Topics included climate change, drought, medium-range forecasting and ENSO. A workshop report is available online at CLIMAS.

The "Western Energy Project,” formerly the California Energy Security project, is an effort that Westerling is now managing. WEP has additional funding from NOAA’s CDEP program and the California Energy Commission, and will explore the use of climatic and hydrologic forecasts in managing hydropower production and western energy markets. Part of this project involves forecasting temperatures using a methodology adapted by Eric Alfaro et al. (2005) for the CalEnergy project. This methodology was previously used by Alexander Gershunov to forecast precipitation and Tony Westerling to forecast fire area burned. Now, by incorporating these temperature forecasts into wildfire activity (area burned, suppression costs, number of fires) forecasts, we have improved the skill of forecasts for wildfire in forested ecosystems.

Westerling and collaborators have adapted area burned forecasts for use by the forest service to produce suppression cost forecasts. We are working with Forest Service research personnel at the USDA Forest Services' Rocky Mountain, Pacific Southwest, and Southern Research Stations to further develop these suppression cost forecasts. These forecasts have been used to guide the allocation of suppression resources within the Forest Service budget for the last two years. We expect this project to continue for the next year.

During this last year, Georgakakos and HRC staff continued their project to improve efficiency of operational water management in the region. The INFORM project, funded by a consortium of Federal and State Agencies, provides the forecast and management numerical tools that form the basis of a common language for the meetings.

Georgakakos and colleagues at HRC produced a hydrologic model for the water balance computations of the San Diego water supply and its conveyance through the city reservoir system to the consumers. Simulation uncertainty is explicitly modeled in a Monte Carlo framework. Tests with historical period data produced acceptable results on a monthly basis. During this project period they focused on the formulation of a capacity expansion model and the use of climate model output to examine the financial impacts of a projected climatic change for the city of San Diego under projected population and demand growth. In particular, they conducted reliability analysis for the purposes of answering the following question: Given historical operating policy, is the existing reservoir capacity sufficient for the city to both meet urban water demand, and to maintain emergency storage requirements? The simulations conducted for the climate scenarios and for the years 2006-2030 are identical to the historical simulations, except that they are using GCM data from the Canadian, German and British GCM models. Throughout the project tenure, collaboration with San Diego Water Department Officials and staff was maintained.

Graduate student S. Taylor investigated spatio-temporal variability of northwesterly surface wind along the U.S. west coast using observational records from satellite scatterometer winds and coastal buoy observations. The strongest and most persistent winds in the northeastern Pacific Ocean are concentrated along the California coast from Cape Mendocino to just south of Point Conception and extending west from the coast about 800 km, where more than 50% of all winds exceed 7.5 m/s from the northwest from March-September. Taylor completed his Ph.D. thesis on this topic this last winter.

Hanson has continued an effort to build a new, comprehensive groundwater modeling system for the California Central Valley including an extensive set of meteorological input and irrigation demand and supply via a “farm package,” and a large collection of water level observations from groundwater well logs. This modeling utility will provide crucial information to water managers and users in this critical agricultural region of the state where, historically, groundwater usage has not been monitored.

Redmond is working with CEC to improve California climate monitoring. They have initiated a California Climate Tracker to follow the state climate conditions, to be routinely updated. This is intended for usage by the general public, by agency managers, politicians, and the news media, as well as the research community. Input will be solicited to improve the readability, ease of use and access, and the understandability of the information presented to general audiences. They also would like to integrate this function with other monitoring efforts, and with the California Climate Data Archives (CalClim) web pages.

Cayan continues to work to organize and prepare the second climate change scenarios assessment for the California governor and legislature. Cayan is also contributing to projects involving water resources and hazards, human health (climate and mosquitoes), regional wind and weather and wildfire and also working to improve climate observations in California watersheds.