scholarly journals Projected Change in Temperature and Precipitation Over Africa from CMIP6

2020 ◽  
Vol 4 (3) ◽  
pp. 455-475 ◽  
Author(s):  
Mansour Almazroui ◽  
Fahad Saeed ◽  
Sajjad Saeed ◽  
M. Nazrul Islam ◽  
Muhammad Ismail ◽  
...  
Keyword(s):  
Global Climate Models ◽  
First Century ◽  
Mean Annual Temperature ◽  
African Continent ◽  
Model Ensemble ◽  
Temperature And Precipitation ◽  
Projected Change ◽  
The Mean ◽  
Twenty First Century

Abstract We analyze data of 27 global climate models from the sixth phase of the Coupled Model Intercomparison Project (CMIP6), and examine projected changes in temperature and precipitation over the African continent during the twenty-first century. The temperature and precipitation changes are computed for two future time slices, 2030–2059 (near term) and 2070–2099 (long term), relative to the present climate (1981–2010), for the entire African continent and its eight subregions. The CMIP6 multi-model ensemble projected a continuous and significant increase in the mean annual temperature over all of Africa and its eight subregions during the twenty-first century. The mean annual temperature over Africa for the near (long)-term period is projected to increase by 1.2 °C (1.4 °C), 1.5 °C (2.3 °C), and 1.8 °C (4.4 °C) under the Shared Socioeconomic Pathways (SSPs) for weak, moderate, and strong forcing, referenced as SSP1-2.6, SSP2-4.5, and SSP5-8.5, respectively. The future warming is not uniform over Africa and varies regionally. By the end of the twenty-first century, the largest rise in mean annual temperature (5.6 °C) is projected over the Sahara, while the smallest rise (3.5 °C) is over Central East Africa, under the strong forcing SSP5-8.5 scenario. The projected boreal winter and summer temperature patterns for the twenty-first century show spatial distributions similar to the annual patterns. Uncertainty associated with projected temperature over Africa and its eight subregions increases with time and reaches a maximum by the end of the twenty-first century. On the other hand, the precipitation projections over Africa during the twenty-first century show large spatial variability and seasonal dependency. The northern and southern parts of Africa show a reduction in precipitation, while the central parts of Africa show an increase, in future climates under the three reference scenarios. For the near (long)-term periods, the area-averaged precipitation over Africa is projected to increase by 6.2 (4.8)%, 6.8 (8.5)%, and 9.5 (15.2)% under SSP1-2.6, SSP2-4.5, and SSP5-8.5, respectively. The median warming simulated by the CMIP6 model ensemble remains higher than the CMIP5 ensemble over most of Africa, reaching as high as 2.5 °C over some regions, while precipitation shows a mixed spatial pattern.

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.

scholarly journals Evaluation of the Global Climate Models in the CMIP5 over the Tibetan Plateau

2013 ◽  
Vol 26 (10) ◽  
pp. 3187-3208 ◽  
Author(s):  
Fengge Su ◽  
Xiaolan Duan ◽  
Deliang Chen ◽  
Zhenchun Hao ◽  
Lan Cuo
Keyword(s):  
Tibetan Plateau ◽  
Radiative Forcing ◽  
Climate Models ◽  
Seasonal Pattern ◽  
Global Climate Models ◽  
First Century ◽  
The Tibetan Plateau ◽  
Twenty First Century ◽  
Near Term

Abstract The performance of 24 GCMs available in the fifth phase of the Coupled Model Intercomparison Project (CMIP5) is evaluated over the eastern Tibetan Plateau (TP) by comparing the model outputs with ground observations for the period 1961–2005. The twenty-first century trends of precipitation and temperature based on the GCMs’ projections over the TP are also analyzed. The results suggest that for temperature most GCMs reasonably capture the climatological patterns and spatial variations of the observed climate. However, the majority of the models have cold biases, with a mean underestimation of 1.1°–2.5°C for the months December–May, and less than 1°C for June–October. For precipitation, the simulations of all models overestimate the observations in climatological annual means by 62.0%–183.0%, and only half of the 24 GCMs are able to reproduce the observed seasonal pattern, which demonstrates a critical need to improve precipitation-related processes in these models. All models produce a warming trend in the twenty-first century under the Representative Concentration Pathway 8.5 (rcp8.5) scenario; in contrast, the rcp2.6 scenario predicts a lower average warming rate for the near term, and a small cooling trend in the long-term period with the decreasing radiative forcing. In the near term, the projected precipitation change is about 3.2% higher than the 1961–2005 annual mean, whereas in the long term the precipitation is projected to increase 6.0% under rcp2.6 and 12.0% under the rcp8.5 scenario. Relative to the 1961–2005 mean, the annual temperature is projected to increase by 1.2°–1.3°C in the short term; the warmings under the rcp2.6 and rcp8.5 scenarios are 1.8° and 4.1°C, respectively, for the long term.

scholarly journals Selected agroclimatical characteristics of Žabčice region for period 1991–2005

2006 ◽  
Vol 54 (4) ◽  
pp. 81-90
Author(s):  
Jan Svoboda ◽  
Jan Brotan
Keyword(s):  
Absolute Maximum ◽  
Mean Annual Temperature ◽  
Measured Temperature ◽  
Absolute Minimum ◽  
Monthly Temperature ◽  
Temperature And Precipitation ◽  
Time Period ◽  
Normal Period ◽  
The Mean

Presented work is continuation of the first comprehensive agroclimatological study of Žabcice area (Rožnovský, Svoboda, 1995) and focuses on the time period 1991 to 2005. The work contains some of the agroclimatological data, which are used by number of experts at our university working within area of the MZLU Agricultural Farm in Žabčice especially on project no. J08/984321001. Results are based on data measured by the special agrometeorological station of Institute of Agrosystems and Bioclimatology at MZLU in Brno that is situated within trial area “Obora“ (altitude: 179 m; latitude: N 49°01´; longitude: E 16°16´). Measurements at Žabčice station follow methodology of Czech Hydrometeorological Institute (Slabá, 1972; Fišák, 1994).Climatic diagram according Walter and Leith is usually based on normal period (Rožnovský, Svoboda, 1995) but it is possible to prepare it for shorter period (in this case 1991–2005) and make a comparison. If the ratio of the temperature and precipitation axis is 10:30 (which is the most suitable according our experience) it may be stated that:• During period 1961–1990 the curve of precipitation sums is under the curve of mean monthly temperature from the middle of July till beginning of October. This period is the period of drought for Žabčice.• For the period from 1991 to 2005 the curve of precipitation sums is under the curve of temperature from mid April to mid June (just a slightly, but it can explain spring droughts appearances) and at the begining of August till the end of the first decade of September. In comparison with the normal pe- riod 1961–1990 and the long term mean 1901–1950 for station Židlochovice the probability of possible drought has increased.• Mean annual temperature changed from 9.2 °C to 10.0 °C and precipitation changed from 480.0 mm to 483.0 mm however with different distribution as can be seen at the fig. 4.• The mean monthly temperature of the coldest month increased from – 5.4 °C to – 3.9 °C and lowest measured temperature within this period was – 22.3 °C in comparison with 1961–1990 when the value was – 29.0 °C.• Mean monthly temperature of the warmest month increased from 25.2 °C to 27.2 °C and absolute maximum increased from 36.6 °C to 38.47 °C.• Months with the mean minimum monthly temperature below 0.0 °C and months with absolute minimum below 0.0 °C have also changed. All measured data and calculated values are shown in tables and figures.

The New Baloch Militancy: Drivers and Dynamics

2021 ◽  
pp. 097492842110272
Author(s):  
Shakoor Ahmad Wani
Keyword(s):  
Resource Sharing ◽  
First Century ◽  
Structural Factors ◽  
Distinctive Character ◽  
Armed Struggle ◽  
Twenty First Century

Since the early 2000, Balochistan is yet again embroiled in a cobweb of violence after a hiatus of more than two decades. The Baloch nationalist militancy began to reinvigorate after the seizure of power by General Pervez Musharraf in 1999. Musharraf marginalised the moderate Baloch nationalists and repressed dissident voices. The differences over power and resource sharing escalated quickly into a full-blown armed struggle once Musharraf used indiscriminate force to subdue opposition against his regime. This article examines the proximate and long-term structural factors that led to the resurgence of armed militancy at the turn of the twenty-first century. It analyses the new drivers and dynamics of the present conflict that make it more virulent and lend it a distinctive character.

scholarly journals Projections of Twenty-First-Century Climate Extremes for Alaska via Dynamical Downscaling and Quantile Mapping

2017 ◽  
Vol 56 (9) ◽  
pp. 2393-2409 ◽  
Author(s):  
Rick Lader ◽  
John E. Walsh ◽  
Uma S. Bhatt ◽  
Peter A. Bieniek
Keyword(s):  
Climate Change ◽  
Dynamical Downscaling ◽  
Climate Extremes ◽  
First Century ◽  
The Arctic ◽  
Maximum Temperature ◽  
Daily Maximum Temperature ◽  
Quantile Mapping ◽  
Temperature And Precipitation ◽  
Twenty First Century

AbstractClimate change is expected to alter the frequencies and intensities of at least some types of extreme events. Although Alaska is already experiencing an amplified response to climate change, studies of extreme event occurrences have lagged those for other regions. Forced migration due to coastal erosion, failing infrastructure on thawing permafrost, more severe wildfire seasons, altered ocean chemistry, and an ever-shrinking season for snow and ice are among the most devastating effects, many of which are related to extreme climate events. This study uses regional dynamical downscaling with the Weather Research and Forecasting (WRF) Model to investigate projected twenty-first-century changes of daily maximum temperature, minimum temperature, and precipitation over Alaska. The forcing data used for the downscaling simulations include the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-Interim; 1981–2010), Geophysical Fluid Dynamics Laboratory Climate Model, version 3 (GFDL CM3), historical (1976–2005), and GFDL CM3 representative concentration pathway 8.5 (RCP8.5; 2006–2100). Observed trends of temperature and sea ice coverage in the Arctic are large, and the present trajectory of global emissions makes a continuation of these trends plausible. The future scenario is bias adjusted using a quantile-mapping procedure. Results indicate an asymmetric warming of climate extremes; namely, cold extremes rise fastest, and the greatest changes occur in winter. Maximum 1- and 5-day precipitation amounts are projected to increase by 53% and 50%, which is larger than the corresponding increases for the contiguous United States. When compared with the historical period, the shifts in temperature and precipitation indicate unprecedented heat and rainfall across Alaska during this century.

scholarly journals The Impact of Climate Change on the Water Balance of Oil Sands Reclamation Covers and Natural Soil Profiles

2018 ◽  
Vol 19 (11) ◽  
pp. 1731-1752 ◽  
Author(s):  
Md. Shahabul Alam ◽  
S. Lee Barbour ◽  
Amin Elshorbagy ◽  
Mingbin Huang
Keyword(s):  
Oil Sands ◽  
Weather Generator ◽  
First Century ◽  
Soil Profiles ◽  
Percentage Increase ◽  
Climate Data ◽  
Historical Climate ◽  
Twenty First Century ◽  
The Impact

Abstract The design of reclamation soil covers at oil sands mines in northern Alberta, Canada, has been conventionally based on the calibration of soil–vegetation–atmosphere transfer (SVAT) models against field monitoring observations collected over several years, followed by simulations of long-term performance using historical climate data. This paper evaluates the long-term water balances for reclamation covers on two oil sands landforms and three natural coarse-textured forest soil profiles using both historical climate data and future climate projections. Twenty-first century daily precipitation and temperature data from CanESM2 were downscaled based on three representative concentration pathways (RCPs) employing a stochastic weather generator [Long Ashton Research Station Weather Generator (LARS-WG)]. Relative humidity, wind speed, and net radiation were downscaled using the delta change method. Downscaled precipitation and estimated potential evapotranspiration were used as inputs to simulate soil water dynamics using physically based models. Probability distributions of growing season (April–October) actual evapotranspiration (AET) and net percolation (NP) for the baseline and future periods show that AET and NP at all sites are expected to increase throughout the twenty-first century regardless of RCP, time period, and soil profile. Greater increases in AET and NP are projected toward the end of the twenty-first century. The increases in future NP at the two reclamation covers are larger (as a percentage increase) than at most of the natural sites. Increases in NP will result in greater water yield to surface water and may accelerate the rate at which chemical constituents contained within mine waste are released to downstream receptors, suggesting these potential changes need to be considered in mine closure designs.

Drivers of Twenty-First Century U.S. Winter Precipitation Trends in CMIP6 Models: A Storyline-Based Approach

2021 ◽  
pp. 1-48
Author(s):  
Daniel F. Schmidt ◽  
Kevin M. Grise
Keyword(s):  
Climate Models ◽  
Southern Oscillation ◽  
Global Climate ◽  
The United States ◽  
Winter Precipitation ◽  
Global Climate Models ◽  
First Century ◽  
Precipitation Trend ◽  
Twenty First Century ◽  
Precipitation Trends

AbstractClimate change during the twenty-first century has the potential to substantially alter geographic patterns of precipitation. However, regional precipitation changes can be very difficult to project, and in some regions, global climate models do not even agree on the sign of the precipitation trend. Since some of this uncertainty is due to internal variability rather than model bias, models cannot be used to narrow the possibilities to a single outcome, but they can usefully quantify the range of plausible outcomes and identify the combination of dynamical drivers that would be likely to produce each.This study uses a storylines approach—a type of regression-based analysis—to identify some of the key dynamical drivers that explain the variance in 21st century U.S. winter precipitation trends across CMIP6 models under the SSP3-7.0 emissions scenario. This analysis shows that the spread in precipitation trends is not primarily driven by differences in modeled climate sensitivity. Key drivers include global-mean surface temperature, but also tropical upper-troposphere temperature, the El Niño-Southern Oscillation (ENSO), the Pacific-North America (PNA) pattern, and the East Pacific (EP) dipole (a dipole pattern in geopotential heights over North America’s Pacific coast). Combinations of these drivers can reinforce or cancel to produce various high- or low-impact scenarios for winter precipitation trends in various regions of the United States. For example, the most extreme winter precipitation trends in the southwestern U.S. result from opposite trends in ENSO and EP, whereas the wettest winter precipitation trends in the midwestern U.S. result from a combination of strong global warming and a negative PNA trend.

The Future of Order

2020 ◽  
pp. 228-244
Author(s):  
Kyle M. Lascurettes
Keyword(s):  
United States ◽  
International Relations ◽  
The United States ◽  
International Order ◽  
First Century ◽  
Relative Power ◽  
The Future ◽  
Twenty First Century ◽  
Near Term

Chapter 9 (“The Future of Order”) reviews the empirical findings of the book and discusses their implications for the study of international relations. It then leverages these findings to address the two most important questions for international order in the twenty-first century: In the near term, what changes to the existing liberal order will the United States advocate as it continues to decline in relative power? And in the long term, what is its projected hegemonic successor, China, likely to do with the existing order when it finds itself in a position to fundamentally recast its underlying principles?

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