scholarly journals Projected Twenty-First-Century Changes in Temperature, Precipitation, and Snow Cover over North America in CCSM4

2012 ◽  
Vol 25 (13) ◽  
pp. 4405-4429 ◽  
Author(s):  
Synte Peacock
Keyword(s):  
North America ◽  
Snow Cover ◽  
First Century ◽  
Climate Projections ◽  
Model Bias ◽  
Regional Patterns ◽  
Climate System Model ◽  
Projected Change ◽  
Emissions Scenarios ◽  
Twenty First Century

Abstract Results from a suite of ensembles of twenty-first-century climate projections made using the Community Climate System Model, version 4 (CCSM4) are analyzed to document model bias and to explore possible future changes in air temperature, precipitation, and snow cover over North America. Large biases still exist in all analyzed fields in this version of the model, and the necessary assumption in future climate projections is therefore that the bias persists into the future, such that the differences in a field between two time periods are meaningful indications of potential changes. Projected temperature increases show strong regional patterns with spatial similarities for all the emissions scenarios considered, although there are considerable differences in the magnitude of the projected change. Projections indicate an increase in total precipitation over much of North America for all emissions scenarios, with the exception of the Southwest United States. All of North America except parts of northern Canada shows a projected decrease in snow cover over the twenty-first century.

Attribution of Seasonal and Regional Changes in Arctic Moisture Convergence

2009 ◽  
Vol 22 (19) ◽  
pp. 5115-5134 ◽  
Author(s):  
Natasa Skific ◽  
Jennifer A. Francis ◽  
John J. Cassano
Keyword(s):  
First Century ◽  
Moisture Convergence ◽  
Specific Humidity ◽  
Self Organizing Map ◽  
Sea Level Pressure ◽  
Climate System Model ◽  
Emissions Scenarios ◽  
Western Arctic ◽  
Twenty First Century ◽  
Area North

Abstract Spatial and temporal changes in high-latitude moisture convergence simulated by the National Center for Atmospheric Research Community Climate System Model, version 3 (CCSM3) are investigated. Moisture convergence is calculated using the aerological method with model fields of specific humidity and winds spanning the periods from 1960 to 1999 and 2070 to 2089. The twenty-first century incorporates the A2 scenario from the Special Report on Emissions Scenarios. The model’s realism in reproducing the twentieth-century moisture convergence is evaluated by comparison with values derived from the 40-yr ECMWF Re-Analysis (ERA-40). In the area north of 75°N, the simulated moisture convergence is similar to observations during summer, but it is larger in winter, spring, and autumn. The model also underestimates (overestimates) the mean annual moisture convergence in the eastern (western) Arctic. Late twenty-first century annual, seasonal, and regional changes are determined by applying a self-organizing map technique to the model’s sea level pressure fields to identify dominant atmospheric circulation regimes and their corresponding moisture convergence fields. Changes in moisture convergence from the twentieth to the twenty-first century result primarily from thermodynamic effects (∼70%), albeit shifts in the frequency of dominant circulation patterns exert a relatively large influence on future changes in the eastern Arctic. Increased moisture convergence in the central Arctic (North Atlantic) stems mainly from thermodynamic changes in summer (winter). Changes in the strength and location of poleward moisture gradients are most likely responsible for projected variations in moisture transport, which are in turn a consequence of increasing anthropogenic greenhouse gas emissions as prescribed by the A2 scenario.

scholarly journals Projected Changes in Climate Extremes Using CMIP6 Simulations Over SREX Regions

2021 ◽  
Vol 5 (3) ◽  
pp. 481-497
Author(s):  
Mansour Almazroui ◽  
Fahad Saeed ◽  
Sajjad Saeed ◽  
Muhammad Ismail ◽  
Muhammad Azhar Ehsan ◽  
...  
Keyword(s):  
Spatial Variability ◽  
Extreme Events ◽  
First Century ◽  
Maximum Temperature ◽  
Annual Maximum ◽  
Temperature And Precipitation ◽  
Projected Change ◽  
Twenty First Century ◽  
Projected Changes ◽  
The Tropics

AbstractThis paper presents projected changes in extreme temperature and precipitation events by using Coupled Model Intercomparison Project phase 6 (CMIP6) data for mid-century (2036–2065) and end-century (2070–2099) periods with respect to the reference period (1985–2014). Four indices namely, Annual maximum of maximum temperature (TXx), Extreme heat wave days frequency (HWFI), Annual maximum consecutive 5-day precipitation (RX5day), and Consecutive Dry Days (CDD) were investigated under four socioeconomic scenarios (SSP1-2.6; SSP2-4.5; SSP3-7.0; SSP5-8.5) over the entire globe and its 26 Special Report on Managing the Risks of Extreme Events and Disasters to Advance Climate Change Adaptation (SREX) regions. The projections show an increase in intensity and frequency of hot temperature and precipitation extremes over land. The intensity of the hottest days (as measured by TXx) is projected to increase more in extratropical regions than in the tropics, while the frequency of extremely hot days (as measured by HWFI) is projected to increase more in the tropics. Drought frequency (as measured by CDD) is projected to increase more over Brazil, the Mediterranean, South Africa, and Australia. Meanwhile, the Asian monsoon regions (i.e., South Asia, East Asia, and Southeast Asia) become more prone to extreme flash flooding events later in the twenty-first century as shown by the higher RX5day index projections. The projected changes in extremes reveal large spatial variability within each SREX region. The spatial variability of the studied extreme events increases with increasing greenhouse gas concentration (GHG) and is higher at the end of the twenty-first century. The projected change in the extremes and the pattern of their spatial variability is minimum under the low-emission scenario SSP1-2.6. Our results indicate that an increased concentration of GHG leads to substantial increases in the extremes and their intensities. Hence, limiting CO2 emissions could substantially limit the risks associated with increases in extreme events in the twenty-first century.

Defining the Center—Finding the Boundaries: The Challenge of Re-Visioning the Church in North America for the Twenty-First Century

1994 ◽  
Vol 22 (3) ◽  
pp. 317-337
Author(s):  
Craig Van Gelder
Keyword(s):  
North America ◽  
North American ◽  
American Culture ◽  
First Century ◽  
New Paradigm ◽  
Twenty First Century ◽  
Mission Field ◽  
The Church

It is becoming increasingly clear that we are experiencing a shift in North American culture that requires the church to think of North America as mission field. The thesis of this article is that the church will need to develop a new paradigm of mission to accomplish this. This article identifies 18 issues which such a paradigm of mission will need to address. These issues are discussed in terms of three aspects: (1) the context in which we live, (2) the gospel we seek to proclaim, and (3) the church which seeks to proclaim this gospel.

Conflicts, battlefields, indigenous peoples and tourism: addressing dissonant heritage in warfare tourism in Australia and North America in the twenty‐first century

2013 ◽  
Vol 7 (3) ◽  
pp. 257-271 ◽  
Author(s):  
Raynald Harvey Lemelin ◽  
Kyle Powys Whyte ◽  
Kelsey Johansen ◽  
Freya Higgins Desbiolles ◽  
Christopher Wilson ◽  
...  
Keyword(s):  
North America ◽  
Indigenous Peoples ◽  
First Century ◽  
Twenty First Century

Mid-twenty-first century global wave climate projections: Results from a dynamic CMIP5 based ensemble

2019 ◽  
Vol 172 ◽  
pp. 69-87 ◽  
Author(s):  
Gil Lemos ◽  
Alvaro Semedo ◽  
Mikhail Dobrynin ◽  
Arno Behrens ◽  
Joanna Staneva ◽  
...  
Keyword(s):  
Wave Climate ◽  
First Century ◽  
Climate Projections ◽  
Twenty First Century

Reduced frequency and size of late-twenty-first-century snowstorms over North America

2020 ◽  
Vol 10 (6) ◽  
pp. 539-544 ◽  
Author(s):  
Walker S. Ashley ◽  
Alex M. Haberlie ◽  
Vittorio A. Gensini
Keyword(s):  
North America ◽  
First Century ◽  
Reduced Frequency ◽  
Twenty First Century

Twenty-First-Century Workers’ Education in North America

2016 ◽  
Vol 41 (1) ◽  
pp. 89-113 ◽  
Author(s):  
Corey Dolgon ◽  
Reuben Roth
Keyword(s):  
North America ◽  
First Century ◽  
Twenty First Century

scholarly journals Climate System Response to External Forcings and Climate Change Projections in CCSM4

2012 ◽  
Vol 25 (11) ◽  
pp. 3661-3683 ◽  
Author(s):  
Gerald A. Meehl ◽  
Warren M. Washington ◽  
Julie M. Arblaster ◽  
Aixue Hu ◽  
Haiyan Teng ◽  
...  
Keyword(s):  
Twentieth Century ◽  
Sea Ice ◽  
Meridional Overturning Circulation ◽  
Climate System ◽  
First Century ◽  
The Arctic ◽  
System Response ◽  
Transient Climate Response ◽  
Climate System Model ◽  
Twenty First Century

Results are presented from experiments performed with the Community Climate System Model, version 4 (CCSM4) for the Coupled Model Intercomparison Project phase 5 (CMIP5). These include multiple ensemble members of twentieth-century climate with anthropogenic and natural forcings as well as single-forcing runs, sensitivity experiments with sulfate aerosol forcing, twenty-first-century representative concentration pathway (RCP) mitigation scenarios, and extensions for those scenarios beyond 2100–2300. Equilibrium climate sensitivity of CCSM4 is 3.20°C, and the transient climate response is 1.73°C. Global surface temperatures averaged for the last 20 years of the twenty-first century compared to the 1986–2005 reference period for six-member ensembles from CCSM4 are +0.85°, +1.64°, +2.09°, and +3.53°C for RCP2.6, RCP4.5, RCP6.0, and RCP8.5, respectively. The ocean meridional overturning circulation (MOC) in the Atlantic, which weakens during the twentieth century in the model, nearly recovers to early twentieth-century values in RCP2.6, partially recovers in RCP4.5 and RCP6, and does not recover by 2100 in RCP8.5. Heat wave intensity is projected to increase almost everywhere in CCSM4 in a future warmer climate, with the magnitude of the increase proportional to the forcing. Precipitation intensity is also projected to increase, with dry days increasing in most subtropical areas. For future climate, there is almost no summer sea ice left in the Arctic in the high RCP8.5 scenario by 2100, but in the low RCP2.6 scenario there is substantial sea ice remaining in summer at the end of the century.

Sign in / Sign up

Export Citation Format

Share Document