Evaluations of high-resolution dynamically downscaled ensembles over the contiguous United States

Zobel, Zachary; Wang, Jiali; Wuebbles, Donald J.; Kotamarthi, V. R.

doi:10.1007/s00382-017-3645-6

Cited by 40 publications

(39 citation statements)

References 84 publications

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“…Future climate scenarios were first generated by a 12‐km regional climate model (WRF versions 3.3.1) and then linearly interpolated into 10‐km resolution. The initial and boundary conditions for WRF were collected from three different global climate models (GCMs) from the fifth phase of the Coupled Model Intercomparison Project (CMIP5) archive (Wang & Kotamarthi, ; Zobel et al ., under review). These are Community Climate System Model, version 4 (CCSM4), Geophysical Fluid Dynamics Laboratory Earth System Model with Generalized Ocean Layer Dynamics component (GFDL‐ESG2G) and the Hadley Centre Global Environment Model, version 2‐Earth System (HadGEM2‐ES).…”

Section: Methodsmentioning

confidence: 99%

The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO₂

Jin

Zhuang

Wang

et al. 2017

Global Change Biology

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Heat and drought are two emerging climatic threats to the US maize and soybean production, yet their impacts on yields are collectively determined by the magnitude of climate change and rising atmospheric CO concentrations. This study quantifies the combined and separate impacts of high temperature, heat and drought stresses on the current and future US rainfed maize and soybean production and for the first time characterizes spatial shifts in the relative importance of individual stress. Crop yields are simulated using the Agricultural Production Systems Simulator (APSIM), driven by high-resolution (12 km) dynamically downscaled climate projections for 1995-2004 and 2085-2094. Results show that maize and soybean yield losses are prominent in the US Midwest by the late 21st century under both Representative Concentration Pathway (RCP) 4.5 and RCP8.5 scenarios, and the magnitude of loss highly depends on the current vulnerability and changes in climate extremes. Elevated atmospheric CO partially but not completely offsets the yield gaps caused by climate extremes, and the effect is greater in soybean than in maize. Our simulations suggest that drought will continue to be the largest threat to US rainfed maize production under RCP4.5 and soybean production under both RCP scenarios, whereas high temperature and heat stress take over the dominant stress of drought on maize under RCP8.5. We also reveal that shifts in the geographic distributions of dominant stresses are characterized by the increase in concurrent stresses, especially for the US Midwest. These findings imply the importance of considering heat and drought stresses simultaneously for future agronomic adaptation and mitigation strategies, particularly for breeding programs and crop management. The modeling framework of partitioning the total effects of climate change into individual stress impacts can be applied to the study of other crops and agriculture systems.

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Section: Methodsmentioning

confidence: 99%

The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO₂

Jin

Zhuang

Wang

et al. 2017

Global Change Biology

Self Cite

150

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“…In order to understand the uncertainties in future projections, it is important to also carefully evaluate the biases in historical periods (Bukovsky, ; Christensen et al, ; Loikith et al, ; Lorenz & Jacob, ; Wang & Kotamarthi, ; Zobel et al, ). Zobel et al () have conducted a historical evaluation of this ensemble used in this study, using several metrics to evaluate the biases present in both the climatological mean as well as the temperature extremes from 1995 to 2004. In addition to this research, prior downscaling studies have used ensembles to enhance understanding of future climatology and extreme value uncertainties.…”

Section: Introductionmentioning

confidence: 99%

High‐Resolution Dynamical Downscaling Ensemble Projections of Future Extreme Temperature Distributions for the United States

et al. 2017

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The aim of this study is to examine projections of extreme temperatures over the continental United States (CONUS) for the 21st century using an ensemble of high spatial resolution dynamically downscaled model simulations with different boundary conditions. The downscaling uses the Weather Research and Forecast model at a spatial resolution of 12 km along with outputs from three different Coupled Model Intercomparison Project Phase 5 global climate models that provide boundary conditions under two different future greenhouse gas (GHG) concentration trajectories. The results from two decadal‐length time slices (2045–2054 and 2085–2094) are compared with a historical decade (1995–2004). Probability density functions of daily maximum/minimum temperatures are analyzed over seven climatologically cohesive regions of the CONUS. The impacts of different boundary conditions as well as future GHG concentrations on extreme events such as heat waves and days with temperature higher than 95°F are also investigated. The results show that the intensity of extreme warm temperature in future summer is significantly increased, while the frequency of extreme cold temperature in future winter decreases. The distribution of summer daily maximum temperature experiences a significant warm‐side shift and increased variability, while the distribution of winter daily minimum temperature is projected to have a less significant warm‐side shift with decreased variability. Using “business‐as‐usual” scenario, 5‐day heat waves are projected to occur at least 5–10 times per year in most CONUS and ≥95°F days will increase by 1–2 months by the end of the century.

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“…Precipitation data from these gauges are gridded to

\frac{true}{1} °

resolution using a mapping algorithm from Shepard (). Widmann and Bretherton () were the first to implement this technique (see Zobel et al, , for more details). After this, we regridded the original ESM data to match the spatial resolution of the observations and RCM simulations for comparison.…”

Section: Model and Validation Datamentioning

confidence: 99%

“…ESMs do well at representing large‐scale precipitation patterns on a seasonal and yearly timescale (e.g., IPCC, ; Hayhoe et al, ; Sheffield, Barrett, et al, ; Sheffield, Camargo, et al, ). However, current models have spatial resolutions that are too coarse to adequately capture extreme precipitation events in local areas or seasonal precipitation patterns in areas of complex terrain (Hayhoe et al, ; Liang et al, ; Racherla et al, ; Wang et al, ; Zobel et al, ). For example, mesoscale convective systems result in as much as 60% of seasonal rainfall in the central United States during the spring and summer, but existing ESM results lack the high spatial resolution needed to simulate these events accurately.…”

Section: Introductionmentioning

confidence: 99%

Analyses for High‐Resolution Projections Through the End of the 21st Century for Precipitation Extremes Over the United States

et al. 2018

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This study compares an ensemble of dynamically downscaled projections of extreme daily precipitation over the contiguous United States (CONUS). With a grid spacing of 12 km and a domain that encompasses most of North America, we use the Weather Research and Forecast model as a regional climate model. We incorporate initial and boundary conditions from three different Coupled Model Intercomparison Project Phase 5 Earth system models (ESMs). We focus on precipitation extremes in the future climate (2045–2054 and 2085–2094) by comparing a business‐as‐usual high‐emissions scenario to emissions from a historical period (1995–2004). In the historical period, the Weather Research and Forecasting‐downscaled simulations result in significant improvements over the ESMs for precipitation extremes. In the analyses of future climate, there is a large increase in the projected frequency of extreme precipitation events over the entire CONUS and a decrease in median precipitation days. Moreover, most regions show an increase in the number of dry days in the future scenarios. The magnitude of extreme precipitation events is projected to increase in the CONUS at all temperatures above freezing. The strongest precipitation events will increase in intensity, primarily because of a shift in precipitation distribution due to the increase in near‐surface air temperatures (Clausius‐Claperyon relationship). However, these events are also affected by changes in some atmospheric dynamical factors, such as stronger low level jet, especially over the Midwestern United States. In addition, compared to those calculated by the ESMs, the downscaled projections show important regional differences in the frequency and magnitude of extreme precipitation events.

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Evaluations of high-resolution dynamically downscaled ensembles over the contiguous United States

Cited by 40 publications

References 84 publications

The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO₂

The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO₂

High‐Resolution Dynamical Downscaling Ensemble Projections of Future Extreme Temperature Distributions for the United States

Analyses for High‐Resolution Projections Through the End of the 21st Century for Precipitation Extremes Over the United States

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Evaluations of high-resolution dynamically downscaled ensembles over the contiguous United States

Cited by 40 publications

References 84 publications

The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO2

The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO2

High‐Resolution Dynamical Downscaling Ensemble Projections of Future Extreme Temperature Distributions for the United States

Analyses for High‐Resolution Projections Through the End of the 21st Century for Precipitation Extremes Over the United States

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Product

Resources

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The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO₂

The combined and separate impacts of climate extremes on the current and future US rainfed maize and soybean production under elevated CO₂