scholarly journals Toward Assessing NARCCAP Regional Climate Model Credibility for the North American Monsoon: Future Climate Simulations*

2015 ◽  
Vol 28 (17) ◽  
pp. 6707-6728 ◽  
Author(s):  
Melissa S. Bukovsky ◽  
Carlos M. Carrillo ◽  
David J. Gochis ◽  
Dorit M. Hammerling ◽  
Rachel R. McCrary ◽  
...  
Keyword(s):  
Climate Change ◽  
North American ◽  
Southern Oscillation ◽  
Monsoon Season ◽  
Regional Climate ◽  
Global Climate Models ◽  
North American Monsoon ◽  
The North ◽  
Climate Simulations ◽  
Projected Changes

Abstract This study presents climate change results from the North American Regional Climate Change Assessment Program (NARCCAP) suite of dynamically downscaled simulations for the North American monsoon system in the southwestern United States and northwestern Mexico. The focus is on changes in precipitation and the processes driving the projected changes from the regional climate simulations and their driving coupled atmosphere–ocean global climate models. The effect of known biases on the projections is also examined. Overall, there is strong ensemble agreement for a large decrease in precipitation during the monsoon season; however, this agreement and the magnitude of the ensemble-mean change is likely deceiving, as the greatest decreases are produced by the simulations that are the most biased in the baseline/current climate. Furthermore, some of the greatest decreases in precipitation are being driven by changes in processes/phenomena that are less credible (e.g., changes in El Niño–Southern Oscillation, when it is initially not simulated well). In other simulations, the processes driving the precipitation change may be plausible, but other biases (e.g., biases in low-level moisture or precipitation intensity) appear to be affecting the magnitude of the projected changes. The most and least credible simulations are clearly identified, while the other simulations are mixed in their abilities to produce projections of value.

scholarly journals On the competition among aerosol number, size and composition in predicting CCN variability: a multi-annual field study in an urbanized desert

2015 ◽  
Vol 15 (12) ◽  
pp. 6943-6958 ◽  
Author(s):  
E. Crosbie ◽  
J.-S. Youn ◽  
B. Balch ◽  
A. Wonaschütz ◽  
T. Shingler ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Size Distribution ◽  
North American ◽  
Monsoon Season ◽  
Aerosol Size Distribution ◽  
North American Monsoon ◽  
Aerosol Composition ◽  
Data Set ◽  
The North ◽  
Concentration Changes

Abstract. A 2-year data set of measured CCN (cloud condensation nuclei) concentrations at 0.2 % supersaturation is combined with aerosol size distribution and aerosol composition data to probe the effects of aerosol number concentrations, size distribution and composition on CCN patterns. Data were collected over a period of 2 years (2012–2014) in central Tucson, Arizona: a significant urban area surrounded by a sparsely populated desert. Average CCN concentrations are typically lowest in spring (233 cm−3), highest in winter (430 cm−3) and have a secondary peak during the North American monsoon season (July to September; 372 cm−3). There is significant variability outside of seasonal patterns, with extreme concentrations (1 and 99 % levels) ranging from 56 to 1945 cm−3 as measured during the winter, the season with highest variability. Modeled CCN concentrations based on fixed chemical composition achieve better closure in winter, with size and number alone able to predict 82 % of the variance in CCN concentration. Changes in aerosol chemical composition are typically aligned with changes in size and aerosol number, such that hygroscopicity can be parameterized even though it is still variable. In summer, models based on fixed chemical composition explain at best only 41 % (pre-monsoon) and 36 % (monsoon) of the variance. This is attributed to the effects of secondary organic aerosol (SOA) production, the competition between new particle formation and condensational growth, the complex interaction of meteorology, regional and local emissions and multi-phase chemistry during the North American monsoon. Chemical composition is found to be an important factor for improving predictability in spring and on longer timescales in winter. Parameterized models typically exhibit improved predictive skill when there are strong relationships between CCN concentrations and the prevailing meteorology and dominant aerosol physicochemical processes, suggesting that similar findings could be possible in other locations with comparable climates and geography.

scholarly journals Projected Changes of Precipitation IDF Curves for Short Duration under Climate Change in Central Vietnam

Hydrology ◽  
2018 ◽  
Vol 5 (3) ◽  
pp. 33 ◽  
Author(s):  
Nguyen Tien Thanh ◽  
Luca Dutto Aldo Remo
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Southern Oscillation ◽  
Regional Climate ◽  
Extreme Weather Events ◽  
Climate Data ◽  
Rcp Scenarios ◽  
Central Vietnam ◽  
Idf Curves ◽  
Projected Changes

In future years, extreme weather events are expected to frequently increase due to climate change, especially in the combination of climate change and events of El Niño–Southern Oscillation. This pays special attention to the construction of intensity–duration–frequency (IDF) curves at a tempo-spatial scale of sub-daily and sub-grid under a context of climate change. The reason for this is that IDF curves represent essential means to study effects on the performance of drainage systems, damps, dikes and reservoirs. Therefore, the objective of this study is to present an approach to construct future IDF curves with high temporo-spatial resolutions under climate change in central Vietnam, using the case of VuGia-ThuBon. The climate data of historical and future from a regional climate model RegCM4 forced by three global models MPI-ESM-MR, IPSL-CM5A-LR and ICHEC-EC-EARTH are used to re-grid the resolution of 10 km × 10 km grid spacing from 25 km × 25 km on the base of bilinear interpolation. A bias correction method is then applied to the finest resolution of a hydrostatic climate model for an ensemble of simulations. Furthermore, the IDF curves for short durations of precipitation are constructed for the historical climate and future climates under two representative concentration pathway (RCP) scenarios, RCP4.5 and RCP8.5, based on terms of correlation factors. The major findings show that the projected precipitation changes are expected to significantly increase by about 10 to 30% under the scenarios of RCP4.5 and RCP8.5. The projected changes of a maximum of 1-, 2-, and 3-days precipitation are expected to increase by about 30–300 mm/day. More importantly, for all return periods (i.e., 10, 20, 50, 100, and 200 years), IDF curves completely constructed for short durations of precipitation at sub-daily show an increase in intensities for the RCP4.5 and RCP8.5 scenarios.

scholarly journals Late Paleogene emergence of a North American loess plateau

Geology ◽  
2020 ◽  
Vol 48 (3) ◽  
pp. 273-277 ◽  
Author(s):  
Majie Fan ◽  
Ran Feng ◽  
John W. Geissman ◽  
Christopher J. Poulsen
Keyword(s):  
Great Plains ◽  
North American ◽  
Global Climate ◽  
North American Monsoon ◽  
Spatiotemporal Pattern ◽  
The North ◽  
Data Compilation ◽  
Climate Simulations ◽  
Central Rocky Mountains ◽  
Latest Eocene

Abstract The relative roles of tectonics and global climate in forming the hydroclimate for widespread eolian deposition remain controversial. Oligocene loess has been previously documented in the interior of western United States, but its spatiotemporal pattern and causes remain undetermined. Through new stratigraphic record documentation and data compilation, we reveal the time transgressive occurrence of loess beginning in the latest Eocene in the central Rocky Mountains, that expands eastward to the Great Plains across the Eocene-Oligocene transition (EOT). Our climate simulations show that moderate uplift of the southern North America Cordillera initiated drying in the Cordilleran hinterland and immediate foreland, forming a potential dust source and sink, and global cooling at the EOT expanded the drying and eolian deposition eastward by causing retreat of the North American Monsoon. Therefore, the eolian deposition reflects continental aridification induced both by regional tectonism and global climate change during the late Paleogene.

scholarly journals Climate change projections of the North American Regional Climate Change Assessment Program (NARCCAP)

2013 ◽  
Vol 120 (4) ◽  
pp. 965-975 ◽  
Author(s):  
L. O. Mearns ◽  
S. Sain ◽  
L. R. Leung ◽  
M. S. Bukovsky ◽  
S. McGinnis ◽  
...  
Keyword(s):  
Climate Change ◽  
North American ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Climate Change Projections ◽  
Change Assessment ◽  
Assessment Program ◽  
The North ◽  
Climate Change Assessment

scholarly journals North American Climate in CMIP5 Experiments. Part I: Evaluation of Historical Simulations of Continental and Regional Climatology

2013 ◽  
Vol 26 (23) ◽  
pp. 9209-9245 ◽  
Author(s):  
Justin Sheffield ◽  
Andrew P. Barrett ◽  
Brian Colle ◽  
D. Nelun Fernando ◽  
Rong Fu ◽  
...  
Keyword(s):  
North American ◽  
Regional Climate ◽  
Arctic Sea Ice ◽  
North American Monsoon ◽  
Multimodel Ensemble ◽  
Western Atlantic ◽  
Large Variability ◽  
The North ◽  
North American Climate ◽  
Hydrological Variables

This is the first part of a three-part paper on North American climate in phase 5 of the Coupled Model Intercomparison Project (CMIP5) that evaluates the historical simulations of continental and regional climatology with a focus on a core set of 17 models. The authors evaluate the models for a set of basic surface climate and hydrological variables and their extremes for the continent. This is supplemented by evaluations for selected regional climate processes relevant to North American climate, including cool season western Atlantic cyclones, the North American monsoon, the U.S. Great Plains low-level jet, and Arctic sea ice. In general, the multimodel ensemble mean represents the observed spatial patterns of basic climate and hydrological variables but with large variability across models and regions in the magnitude and sign of errors. No single model stands out as being particularly better or worse across all analyses, although some models consistently outperform the others for certain variables across most regions and seasons and higher-resolution models tend to perform better for regional processes. The CMIP5 multimodel ensemble shows a slight improvement relative to CMIP3 models in representing basic climate variables, in terms of the mean and spread, although performance has decreased for some models. Improvements in CMIP5 model performance are noticeable for some regional climate processes analyzed, such as the timing of the North American monsoon. The results of this paper have implications for the robustness of future projections of climate and its associated impacts, which are examined in the third part of the paper.

Reply to “Comments on ‘The North American Regional Climate Change Assessment Program: Overview of Phase I Results'”

2013 ◽  
Vol 94 (7) ◽  
pp. 1077-1078 ◽  
Author(s):  
Linda O. Mearns ◽  
Melissa S. Bukovsky ◽  
Ruby Leung ◽  
Yun Qian ◽  
Ray Arritt ◽  
...  
Keyword(s):  
Climate Change ◽  
Phase I ◽  
North American ◽  
Regional Climate ◽  
Regional Climate Change ◽  
Change Assessment ◽  
Assessment Program ◽  
The North ◽  
Climate Change Assessment

Regional Governance of Global Climate Change: The North American Commission for Environmental Cooperation

2007 ◽  
Vol 7 (2) ◽  
pp. 11-27 ◽  
Author(s):  
Michele M. Betsill
Keyword(s):  
Climate Change ◽  
Global Climate Change ◽  
North American ◽  
Global Climate ◽  
Regional Climate ◽  
Regional Governance ◽  
Governance System ◽  
Environmental Cooperation ◽  
Climate Governance ◽  
The North

Over the past decade the governance of global climate change has evolved into a complex, multi-level process involving actors and initiatives at multiple levels of social organization from the global to the local in both the public and private spheres. This article analyzes the North American Commission for Environmental Cooperation (CEC) as one component of this multilevel governance system. Specifically, it evaluates the CEC as a site of regional climate governance based on three potential advantages of governance through regional organizations: a small number of actors, opportunities for issue linkage, and linkage between national and global governance systems. On each count I find that the benefits of a CEC-based climate governance system are limited and argue for greater consideration of how such a system would interact with other forms of climate governance in North America.

scholarly journals The effects of ENSO and the North American monsoon on mast seeding in two Rocky Mountain conifer species

2021 ◽  
Vol 376 (1839) ◽  
Author(s):  
Andreas P. Wion ◽  
Ian S. Pearse ◽  
Kyle C. Rodman ◽  
Thomas T. Veblen ◽  
Miranda D. Redmond
Keyword(s):  
Pinus Ponderosa ◽  
North American ◽  
Large Scale ◽  
Southern Oscillation ◽  
Mast Seeding ◽  
North American Monsoon ◽  
Climate Indices ◽  
Conifer Species ◽  
Cone Production ◽  
The North

We aimed to disentangle the patterns of synchronous and variable cone production (i.e. masting) and its relationship to climate in two conifer species native to dry forests of western North America. We used cone abscission scars to reconstruct ca 15 years of recent cone production in Pinus edulis and Pinus ponderosa , and used redundancy analysis to relate time series of annual cone production to climate indices describing the North American monsoon and the El Niño Southern Oscillation (ENSO). We show that the sensitivity to climate and resulting synchrony in cone production varies substantially between species. Cone production among populations of P. edulis was much more spatially synchronous and more closely related to large-scale modes of climate variability than among populations of P. ponderosa . Large-scale synchrony in P. edulis cone production was associated with the North American monsoon and we identified a dipole pattern of regional cone production associated with ENSO phase. In P. ponderosa , these climate indices were not strongly associated with cone production, resulting in asynchronous masting patterns among populations. This study helps frame our understanding of mast seeding as a life-history strategy and has implications for our ability to forecast mast years in these species. This article is part of the theme issue ‘The ecology and evolution of synchronized seed production in plants’.

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