A5027819008- Climate variability and models
- Meteorological Phenomena and Simulations
- Cryospheric studies and observations
- Climate change and permafrost
- Tropical and Extratropical Cyclones Research
- Advanced Mathematical Identities
- Insurance and Financial Risk Management
- Mathematical functions and polynomials
- Atmospheric and Environmental Gas Dynamics
- Landslides and related hazards
- Hydrology and Watershed Management Studies
- Economic and Environmental Valuation
- Advanced Combinatorial Mathematics
- Insurance, Mortality, Demography, Risk Management
- Precipitation Measurement and Analysis
- Arctic and Antarctic ice dynamics
- Oceanographic and Atmospheric Processes
- Advanced Mathematical Theories and Applications
- Efficiency Analysis Using DEA
- Water resources management and optimization
- Islamic Finance and Banking Studies
- Neural Networks and Applications
- Decision-Making and Behavioral Economics
- Financial Literacy, Pension, Retirement Analysis
- Science and Climate Studies
Stanford University
2019-2021
National Bureau of Economic Research
2021
International Paper (United States)
2021
Consolidated Safety Services-Dynamac (United States)
2021
University of California, Los Angeles
2009-2020
Brigham Young University
2017
UCLA Health
2013
Williams College
2007
Abstract. The Atmospheric River Tracking Method Intercomparison Project (ARTMIP) is an international collaborative effort to understand and quantify the uncertainties in atmospheric river (AR) science based on detection algorithm alone. Currently, there are many AR identification tracking algorithms literature with a wide range of techniques conclusions. ARTMIP strives provide community information different methodologies guidance most appropriate for given question or region interest. All...
Abstract Atmospheric rivers (ARs) are now widely known for their association with high‐impact weather events and long‐term water supply in many regions. Researchers within the scientific community have developed numerous methods to identify track of ARs—a necessary step analyses on gridded data sets, objective attribution impacts ARs. These different been answer specific research questions hence use criteria (e.g., geometry, threshold values key variables, time dependence). Furthermore,...
Abstract In this study (Part I), the mid-twenty-first-century surface air temperature increase in entire CMIP5 ensemble is downscaled to very high resolution (2 km) over Los Angeles region, using a new hybrid dynamical–statistical technique. This technique combines ability of dynamical downscaling capture finescale dynamics with computational savings statistical model downscale multiple GCMs. First, applied five Guided by an understanding underlying local dynamics, simple built relating GCM...
Abstract California’s Sierra Nevada is a high-elevation mountain range with significant seasonal snow cover. Under anthropogenic climate change, amplification of the warming expected to occur at elevations near margins due albedo feedback. However, change projections for made by global models (GCMs) and statistical downscaling methods miss this key process. Dynamical simulates additional Ideally, dynamical would be applied large ensemble 30 or more GCMs project ensemble-mean outcomes...
Abstract Using the hybrid downscaling technique developed in part I of this study, temperature changes relative to a baseline period (1981–2000) greater Los Angeles region are downscaled for two future time slices: midcentury (2041–60) and end century (2081–2100). Two representative concentration pathways (RCPs) considered, corresponding greenhouse gas emission reductions over coming decades (RCP2.6) continued twenty-first-century emissions increases (RCP8.5). All available global climate...
Abstract This study uses dynamical and statistical methods to understand end‐of‐century mean changes Sierra Nevada snowpack. Dynamical results reveal that middle‐elevation watersheds experience considerably more rain than snow during winter, leading substantial snowpack declines by spring. Despite some high‐elevation receiving slightly in January February, the warming signal still dominates across wet season leads notable springtime. A model is created mimic for 1 April snowpack, allowing an...
Abstract High-resolution gridded datasets are in high demand because they spatially complete and include important finescale details. Previous assessments have been limited to two three or analyzed the only at station locations. Here, eight high-resolution temperature assessed ways: stations, by comparing with Global Historical Climatology Network–Daily data; away from using physical principles. This assessment includes six station-based datasets, one interpolated reanalysis, dynamically...
Abstract Future snowfall and snowpack changes over the mountains of Southern California are projected using a new hybrid dynamical–statistical framework. Output from all general circulation models (GCMs) in phase 5 Coupled Model Intercomparison Project archive is downscaled to 2-km resolution region. Variables pertaining snow analyzed for middle (2041–60) end (2081–2100) twenty-first century under two representative concentration pathway (RCP) scenarios: RCP8.5 (business as usual) RCP2.6...
Abstract Atmospheric rivers (ARs) are responsible for a majority of extreme precipitation and flood events along the U.S. West Coast. To better understand present‐day characteristics AR‐related extremes, selection nine most intense historical AR during 1980–2017 is simulated using dynamical downscaling modeling framework based on Weather Research Forecasting Model. We find that chosen Model configuration reproduces both large‐scale atmospheric features—including parent synoptic‐scale...
Abstract A new hybrid statistical–dynamical downscaling technique is described to project mid- and end-of-twenty-first-century local precipitation changes associated with 36 global climate models (GCMs) in phase 5 of the Coupled Model Intercomparison Project archive over greater Los Angeles region. Land-averaged changes, ensemble-mean spread those for both time slices are presented. It demonstrated that results similar what would be produced if expensive dynamical techniques were instead...
Abstract We compare historical and end‐of‐century temperature precipitation patterns over California from one dynamically downscaled simulation using the Weather Research Forecast (WRF) model two simulations statistically Localized Constructed Analogs (LOCA). uniquely separate causes of differences between based future climate projections into in (gridded observations versus regional output) how these downscaling techniques explicitly handle changes (numerical modeling analogs). In methods,...
Abstract Using hybrid dynamical–statistical downscaling, 3-km-resolution end-of-twenty-first-century runoff timing changes over California’s Sierra Nevada for all available global climate models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) are projected. All four representative concentration pathways (RCPs) adopted by Intergovernmental Panel on Climate Change’s Fifth Assessment Report examined. These multimodel, multiscenario projections allow quantification...
where Tn is the Chebyshev polynomial of first kind, defined by T0(x) = 1, Tx(x) x, and for n > 2, Tn(x) 2xTn.x{x) - Tn_2(x). (2) For example, T2(x) 2x2 T3(x) 4x3 3x, T4(x) 8x4 8x2 + 1. This gen erates familiar trigonometric identity eos(20) 2 cos2 9 ? less cos(36>) 4 cos3 3 cos cos(4#) 8 cos4 If we change initial conditions to be Uo(x) 1 Ux(x) 2x, but keep same recurrence Un(x) 2xUn-i(x) Un-2(x), get polynomials second kind. instance, U2(x) Ax1 U3(x) Sx3 Ax, U4(x) 16x4 I2x2 The generate many...
This article presents a thorough evaluation of target date funds (TDFs) for the period 2010–2020. TDFs have grown enormously in assets, reaching $1.4 trillion at end 2019, and account approximately 24% all assets 401(k) accounts. We report on results style analysis that determines their effective asset allocation. It examines both constant regressions resulting Sharpe ratios, which reflect over- or under-performance relative to passive benchmark with same Lower cost tend match returns, while...
This paper presents a thorough evaluation of target date funds for the period 2010-2020. These have grown enormously in assets, reaching $1.4 trillion by end 2019. They account approximately 24 percent all assets 401(k) accounts. The reports on results style analysis TDFs which their effective asset allocation. It examines constant regressions reflects over- or under-performance relative to passive benchmark with same Lower cost tend match benchmark, whereas higher deviate considerably from...