NAC 2 H: The North American Climate Change and Hydroclimatology Data Set

2020 ◽  
Vol 56 (8) ◽  
Author(s):  
Richard Arsenault ◽  
François Brissette ◽  
Jie Chen ◽  
Qiang Guo ◽  
Gabrielle Dallaire
Keyword(s):  
Climate Change ◽  
North American ◽  
Data Set ◽  
The North ◽  
North American Climate

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.

Climate Change in the North American Arctic: A One Health Perspective

EcoHealth ◽  
2015 ◽  
Vol 12 (4) ◽  
pp. 713-725 ◽  
Author(s):  
Joseph P. Dudley ◽  
Eric P. Hoberg ◽  
Emily J. Jenkins ◽  
Alan J. Parkinson
Keyword(s):  
Climate Change ◽  
North American ◽  
One Health ◽  
The North ◽  
North American Arctic

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 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.

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.

Evolutionary relationships in Oxytropis species, as estimated from the nuclear ribosomal internal transcribed spacer (ITS) sequences point to multiple expansions into the Arctic

Botany ◽  
2012 ◽  
Vol 90 (8) ◽  
pp. 770-779 ◽  
Author(s):  
Annie Archambault ◽  
Martina V. Strömvik
Keyword(s):  
North American ◽  
Internal Transcribed Spacer ◽  
Phylogenetic Trees ◽  
Its Region ◽  
Its Sequences ◽  
The Arctic ◽  
Evolutionary Relationships ◽  
Data Set ◽  
The North ◽  
North American Arctic

Species of the genus Oxytropis are distributed in the northern hemisphere, especially in alpine and arctic areas. Although comprehensive taxonomic treatments exist for local floras, an understanding of the evolutionary relationships is lacking for the genus as a whole. To determine if different ancestral Oxytropis species colonized the North American Arctic separately, as suggested by taxonomy, we sequenced the nuclear ribosomal internal transcribed spacer (ITS) region from 16 Oxytropis specimens, including four species that were used in a previous transcriptome study. In addition, 81 other Oxytropis ITS sequences were retrieved from public sequence databases and included in the analysis. The whole data set was analyzed using phylogenetic trees and statistical parsimony networks. Results show that all Oxytropis ITS sequences are very similar. Furthermore, at least six lineages evolved from different temperate ancestors to colonize the North American Arctic. This pattern is believed to be typical of the arctic flora. Additionally, the sequence relationship analyses confirm that the subgenus Phacoxytropis may be ancestral in Oxytropis.

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