scholarly journals Where is Late Cenozoic climate change most likely to impact denudation?

2017 ◽  
Author(s):  
Sebastian G. Mutz ◽  
Todd A. Ehlers ◽  
Martin Werner ◽  
Gerrit Lohmann ◽  
Christian Stepanek ◽  
...  
Keyword(s):  
Climate Change ◽  
Cluster Analysis ◽  
General Circulation ◽  
Climatic Variability ◽  
Circulation Model ◽  
Northwest Pacific ◽  
Western Himalayas ◽  
Late Cenozoic ◽  
Diverse Range ◽  
The Impact

Abstract. The denudation history of active orogens is often interpreted in the context of modern climate and vegetation gradients. Here we address the validity of this approach and ask the question: what are the spatial and temporal variations in paleo-climate for a latitudinally diverse range of active orogens? We do this using high-resolution (T159, ca. 80 × 80 km at the equator) paleo-climate simulations from the ECHAM5 global Atmospheric General Circulation Model and a statistical cluster analysis of climate over different orogens (Andes, Himalaya, SE Alaska, Pacific NW USA). Time periods and boundary conditions considered include the Pliocene (PLIO, ~ 3 Ma), the Last Glacial Maximum (LGM, ~ 21 ka), Mid Holocene (MH, ~ 6 ka) and Pre-Industrial (PI, reference year 1850). The regional simulated climates of each orogen are described by means of cluster analyses based on the variability of precipitation, 2 m air temperature, the intra-annual amplitude of these values, and monsoonal wind speeds where appropriate. Results indicate the largest differences to the PI climate are observed for the LGM and PLIO climates in the form of widespread cooling and reduced precipitation in the LGM and warming and enhanced precipitation during the PLIO. The LGM climate shows the largest deviation in annual precipitation from the PI climate, and shows enhanced precipitation in the temperate Andes, and coastal regions for both SE Alaska and the US Pacific Northwest Pacific. Furthermore, LGM precipitation is reduced in the western Himalayas and enhanced in the eastern Himalayas, resulting in a shift of the wettest regional climates eastward along the orogen. The cluster-analysis results also suggest more climatic variability across latitudes east of the Andes in the PLIO climate than in other time-slice experiments conducted here. Taken together, these results highlight significant changes in Late Cenozoic regional climatology over the last ~ 3 Ma. Finally, we document regions where the largest magnitudes of Late Cenozoic changes in precipitation and temperature occur and offer the highest potential for future observational studies interested in quantifying the impact of climate change on denudation and weathering rates.

scholarly journals Estimates of late Cenozoic climate change relevant to Earth surface processes in tectonically active orogens

2018 ◽  
Vol 6 (2) ◽  
pp. 271-301 ◽  
Author(s):  
Sebastian G. Mutz ◽  
Todd A. Ehlers ◽  
Martin Werner ◽  
Gerrit Lohmann ◽  
Christian Stepanek ◽  
...  
Keyword(s):  
Climate Change ◽  
Cluster Analysis ◽  
General Circulation ◽  
Climatic Variability ◽  
Circulation Model ◽  
Temporal Variations ◽  
Western Himalayas ◽  
Late Cenozoic ◽  
Diverse Range ◽  
The Impact

Abstract. The denudation history of active orogens is often interpreted in the context of modern climate gradients. Here we address the validity of this approach and ask what are the spatial and temporal variations in palaeoclimate for a latitudinally diverse range of active orogens? We do this using high-resolution (T159, ca. 80 × 80 km at the Equator) palaeoclimate simulations from the ECHAM5 global atmospheric general circulation model and a statistical cluster analysis of climate over different orogens (Andes, Himalayas, SE Alaska, Pacific NW USA). Time periods and boundary conditions considered include the Pliocene (PLIO, ∼ 3 Ma), the Last Glacial Maximum (LGM, ∼ 21 ka), mid-Holocene (MH, ∼ 6 ka), and pre-industrial (PI, reference year 1850). The regional simulated climates of each orogen are described by means of cluster analyses based on the variability in precipitation, 2 m air temperature, the intra-annual amplitude of these values, and monsoonal wind speeds where appropriate. Results indicate the largest differences in the PI climate existed for the LGM and PLIO climates in the form of widespread cooling and reduced precipitation in the LGM and warming and enhanced precipitation during the PLIO. The LGM climate shows the largest deviation in annual precipitation from the PI climate and shows enhanced precipitation in the temperate Andes and coastal regions for both SE Alaska and the US Pacific Northwest. Furthermore, LGM precipitation is reduced in the western Himalayas and enhanced in the eastern Himalayas, resulting in a shift of the wettest regional climates eastward along the orogen. The cluster-analysis results also suggest more climatic variability across latitudes east of the Andes in the PLIO climate than in other time slice experiments conducted here. Taken together, these results highlight significant changes in late Cenozoic regional climatology over the last ∼ 3 Myr. Comparison of simulated climate with proxy-based reconstructions for the MH and LGM reveal satisfactory to good performance of the model in reproducing precipitation changes, although in some cases discrepancies between neighbouring proxy observations highlight contradictions between proxy observations themselves. Finally, we document regions where the largest magnitudes of late Cenozoic changes in precipitation and temperature occur and offer the highest potential for future observational studies that quantify the impact of climate change on denudation and weathering rates.

scholarly journals Impact of climate change on sediment yield in the Mekong River basin: a case study of the Nam Ou basin, Lao PDR

2013 ◽  
Vol 17 (1) ◽  
pp. 1-20 ◽  
Author(s):  
B. Shrestha ◽  
M. S. Babel ◽  
S. Maskey ◽  
A. van Griensven ◽  
S. Uhlenbrook ◽  
...  
Keyword(s):  
Climate Change ◽  
Sediment Yield ◽  
General Circulation ◽  
Climate Models ◽  
Greenhouse Gas Emission ◽  
Circulation Model ◽  
Sediment Flux ◽  
Seasonal Temperature ◽  
Impact Of Climate Change ◽  
The Impact

Abstract. This paper evaluates the impact of climate change on sediment yield in the Nam Ou basin located in northern Laos. Future climate (temperature and precipitation) from four general circulation models (GCMs) that are found to perform well in the Mekong region and a regional circulation model (PRECIS) are downscaled using a delta change approach. The Soil and Water Assessment Tool (SWAT) is used to assess future changes in sediment flux attributable to climate change. Results indicate up to 3.0 °C shift in seasonal temperature and 27% (decrease) to 41% (increase) in seasonal precipitation. The largest increase in temperature is observed in the dry season while the largest change in precipitation is observed in the wet season. In general, temperature shows increasing trends but changes in precipitation are not unidirectional and vary depending on the greenhouse gas emission scenarios (GHGES), climate models, prediction period and season. The simulation results show that the changes in annual stream discharges are likely to range from a 17% decrease to 66% increase in the future, which will lead to predicted changes in annual sediment yield ranging from a 27% decrease to about 160% increase. Changes in intra-annual (monthly) discharge as well as sediment yield are even greater (−62 to 105% in discharge and −88 to 243% in sediment yield). A higher discharge and sediment flux are expected during the wet seasons, although the highest relative changes are observed during the dry months. The results indicate high uncertainties in the direction and magnitude of changes of discharge as well as sediment yields due to climate change. As the projected climate change impact on sediment varies remarkably between the different climate models, the uncertainty should be taken into account in both sediment management and climate change adaptation.

scholarly journals Impact of GCM structure uncertainty on hydrological processes in an arid area of China

2017 ◽  
Vol 49 (3) ◽  
pp. 893-907 ◽  
Author(s):  
Gonghuan Fang ◽  
Jing Yang ◽  
Yaning Chen ◽  
Zhi Li ◽  
Philippe De Maeyer
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Assessment Tool ◽  
Circulation Model ◽  
Hydrological Processes ◽  
Future Climate Change ◽  
Management Decision ◽  
Structural Uncertainty ◽  
Rcp Scenarios ◽  
The Impact

Abstract Quantifying the uncertainty sources in assessment of climate change impacts on hydrological processes is helpful for local water management decision-making. This paper investigated the impact of the general circulation model (GCM) structural uncertainty on hydrological processes in the Kaidu River Basin. Outputs of 21 GCMs from the Coupled Model Intercomparison Project Phase 5 (CMIP5) under two representative concentration pathway (RCP) scenarios (i.e., RCP4.5 and RCP8.5), representing future climate change under uncertainty, were first bias-corrected using four precipitation and three temperature methods and then used to force a well-calibrated hydrological model (the Soil and Water Assessment Tool, SWAT) in the study area. Results show that the precipitation will increase by 3.1%–18% and 7.0%–22.5%, the temperature will increase by 2.0 °C–3.3 °C and 4.2 °C–5.5 °C and the streamflow will change by −26% to 3.4% and −38% to −7% under RCP4.5 and RCP8.5, respectively. Timing of snowmelt will shift forward by approximately 1–2 months for both scenarios. Compared to RCPs and bias correction methods, GCM structural uncertainty contributes most to streamflow uncertainty based on the standard deviation method (55.3%) while it is dominant based on the analysis of variance approach (94.1%).

An Examination of Climate Change on Extreme Heat Events and Climate–Mortality Relationships in Large U.S. Cities

2011 ◽  
Vol 3 (4) ◽  
pp. 281-292 ◽  
Author(s):  
Scott Greene ◽  
Laurence S. Kalkstein ◽  
David M. Mills ◽  
Jason Samenow
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
The United States ◽  
Attributable Mortality ◽  
Climate Projections ◽  
Synoptic Classification ◽  
The Impact ◽  
Related Mortality

Abstract This study examines the impact of a changing climate on heat-related mortality in 40 large cities in the United States. A synoptic climatological procedure, the spatial synoptic classification, is used to evaluate present climate–mortality relationships and project how potential climate changes might affect these values. Specifically, the synoptic classification is combined with downscaled future climate projections for the decadal periods of 2020–29, 2045–55, and 2090–99 from a coupled atmospheric–oceanic general circulation model. The results show an increase in excessive heat event (EHE) days and increased heat-attributable mortality across the study cities with the most pronounced increases projected to occur in the Southeast and Northeast. This increase becomes more dramatic toward the end of the twenty-first century as the anticipated impact of climate change intensifies. The health impact associated with different emissions scenarios is also examined. These results suggest that a “business as usual” approach to greenhouse gas emissions mitigation could result in twice as many heat-related deaths by the end of the century than a lower emissions scenario. Finally, a comparison of future estimates of heat-related mortality during EHEs is presented using algorithms developed during two different, although overlapping, time periods, one that includes some recent large-scale significant EHE intervention strategies (1975–2004), and one without (1975–95). The results suggest these public health responses can significantly decrease heat-related mortality.

scholarly journals Investigating the Impact of Climate Change on Future Runoff of River Satluj

2016 ◽  
Vol 8 (1) ◽  
pp. 10-21
Author(s):  
Narayan P Gautam ◽  
Manohar Arora ◽  
N.K. Goel ◽  
A.R.S. Kumar
Keyword(s):  
Climate Change ◽  
Water Resources ◽  
General Circulation ◽  
Circulation Model ◽  
Climate Change Scenarios ◽  
Impact Of Climate Change ◽  
Basin Scale ◽  
The Future ◽  
Future Climatic Condition ◽  
The Impact

Climate change has been emerging as one of the challenges in the global environment. Information of predicted climatic changes in basin scale is highly useful to know the future climatic condition in the basin that ultimately becomes helpful to carry out planning and management of the water resources available in the basin. Climatic scenario is a plausible and often simplified representation of the future climate, based on an internally consistent set of climatological relationships that has been constructed for explicit use in investigating the potential consequences of anthropogenic climate change. This study based on statistical downscaling, provide good example focusing on predicting the rainfall and runoff patterns, using the coarse general circulation model (GCM) outputs. The outputs of the GCMs are utilized to study the impact of climate change on water resources. The present study has been taken up to identify the climate change scenarios for Satluj river basin, India.Journal of Hydrology and Meteorology, Vol. 8(1) p.10-21

scholarly journals Impact of climate change on drought in the Daklak province

2014 ◽  
Vol 17 (3) ◽  
pp. 5-11
Author(s):  
Khoi Nguyen Dao ◽  
Quang Nguyen Xuan Chau
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Standardized Precipitation Index ◽  
Circulation Model ◽  
Meteorological Drought ◽  
Impact Of Climate Change ◽  
The Future ◽  
Delta Change ◽  
The Standardized Precipitation Index ◽  
The Impact

The main objective of this study was to evaluate the impact of climate change on the meteorological drought in the Daklak province. In this study, the meteorological drought was calculated using the Standardized Precipitation Index (SPI).From this result, two scensrios fot the precipitation VA1B and B1 were downscaled, from the outputs of 4 GCMs (General Circulation Model): CGCM3.1 (T63), CM2.0, CM2.1, and HadCM3 using the simple downscaling method (delta change method). The impacts of climate change on the droughts were assessed by comparing the present (1980- 2009) and the future droughts (2010-2039, 2040-2069, and 2070-2099).Results of the study suggested that the future temperature would increase by 0.9-2.8ºC and the future precipitation would decrease by 0.4-4.7% for both A1B and B1 scenarios. Under the future climate scenarios, the frequency and severity of extreme drought would increase. The results obtained in this study could be useful for planning and managing water resources at this region.

Persistent Anomaly Changes in High-Resolution Climate Simulations

2021 ◽  
pp. 1-46
Author(s):  
Gary M. Lackmann ◽  
Rebecca L. Miller ◽  
Walter A. Robinson ◽  
Allison C. Michaelis
Keyword(s):  
Climate Change ◽  
High Resolution ◽  
General Circulation ◽  
Circulation Model ◽  
Circulation Index ◽  
Weather Extremes ◽  
The North ◽  
Climate Simulations ◽  
Persistent Anomalies ◽  
The Impact

AbstractPersistent anomalies (PAs) are associated with a variety of impactful weather extremes, prompting research into how their characteristics will respond to climate change. Previous studies, however, have not provided conclusive results, owing to the complexity of the phenomenon and to difficulties in general circulation model (GCM) representations of PAs. Here, we diagnose PA activity in ten years of current and projected future output from global, high-resolution (15-km mesh) time-slice simulations performed with the Model for Prediction Across Scales-Atmosphere (MPAS-A). These time slices span a range of ENSO states. They include high-resolution representations of sea-surface temperatures and GCM-based sea ice for present and future climates. Future projections, based on the RCP8.5 scenario, exhibit strong Arctic amplification and tropical upper warming, providing a valuable experiment with which to assess the impact of climate change on PA frequency. The MPAS-A present-climate simulations reproduce the main centers of observed PA activity, but with an eastward shift in the North Pacific and reduced amplitude in the North Atlantic. The overall frequency of positive PAs in the future simulations is similar to that in the present-day simulations, while negative PAs become less frequent. Although some regional changes emerge, the small, generally negative changes in PA frequency and meridional circulation index indicate that climate change does not lead to increased persistence of midlatitude flow anomalies or increased waviness in these simulations.

scholarly journals Model-based scenarios of Mediterranean droughts

2007 ◽  
Vol 12 ◽  
pp. 145-151 ◽  
Author(s):  
M. Weiß ◽  
M. Flörke ◽  
L. Menzel ◽  
J. Alcamo
Keyword(s):  
Climate Change ◽  
General Circulation Model ◽  
North Africa ◽  
General Circulation ◽  
Climate Changes ◽  
Circulation Model ◽  
Hydrological Drought ◽  
Minor Role ◽  
A Minor ◽  
The Impact

Abstract. This study examines the change in current 100-year hydrological drought frequencies in the Mediterranean in comparison to the 2070s as simulated by the global model WaterGAP. The analysis considers socio-economic and climate changes as indicated by the IPCC scenarios A2 and B2 and the global general circulation model ECHAM4. Under these conditions today's 100-year drought is estimated to occur 10 times more frequently in the future over a large part of the Northern Mediterranean while in North Africa, today's 100-year drought will occur less frequently. Water abstractions are shown to play a minor role in comparison to the impact of climate change, but can intensify the situation.

QUANTITATIVE ESTIMATION OF THE IMPACT OF CLIMATE CHANGE ON CROP EVAPOTRANSPIRATION AND YIELD IN THE CENTRAL REGION OF INDIA

2021 ◽  
pp. 83-89
Author(s):  
A. BALVANSHI ◽  
◽  
H. L. TIWARI ◽  
Keyword(s):  
Climate Change ◽  
General Circulation ◽  
Quantitative Estimation ◽  
Circulation Model ◽  
Future Climate Change ◽  
Crop Evapotranspiration ◽  
Yield Data ◽  
Aquacrop Model ◽  
The Future ◽  
The Impact

The present work focuses on estimation of future evapotranspiration of paddy, maize, soybean and assessment of yields of these crops under RCP scenarios 2.6, 4.5, and 8.5 for years 1997-2099 using FAO Cropwat and AquaCrop yield simulating models for the Sehore district, in central state of India. Statistically downscaled General Circulation Model CanESM2 data were used as input to Cropwat and AquaCrop tools for generation of future crop evapotranspiration and crop yield data. The AquaCrop yield model was first checked for its suitability and accuracy in prediction of yield for years 1997-2010. The future scenario RCP 8.5 shows the highest reduction in the yield of paddy (-8.5%), maize (-4.52%), and soybean (-3.93%) during the future period. It was concluded that the FAO AquaCrop model can be applied to many other crops as well as in the other regions to formulate proper cropping strategies that will help to decrease the risks due to future climate change.

Impacts and uncertainties of climate change on streamflow of the Johor River Basin, Malaysia using a CMIP5 General Circulation Model ensemble

2014 ◽  
Vol 5 (4) ◽  
pp. 676-695 ◽  
Author(s):  
Mou Leong Tan ◽  
Darren L. Ficklin ◽  
Ab Latif Ibrahim ◽  
Zulkifli Yusop
Keyword(s):  
Climate Change ◽  
River Basin ◽  
General Circulation ◽  
Swat Model ◽  
Circulation Model ◽  
Climate Projections ◽  
Climate Change Scenarios ◽  
Efficiency Coefficient ◽  
Monthly Streamflow ◽  
The Impact

The impact of climate change and uncertainty of climate projections from general circulation models (GCMs) from phase 5 of the Coupled Model Intercomparison Project (CMIP5) on streamflow in the Johor River Basin, Malaysia was assessed. Eighteen GCMs were evaluated, and the six that adequately simulated historical climate were selected for an ensemble of GCMs under three Representative Concentration Pathways (RCPs; 2.6 (low emissions), 4.5 (moderate emissions) and 8.5 (high emissions)) for three future time periods (2020s, 2050s and 2080s) as inputs into the Soil and Water Assessment Tool (SWAT) hydrological model. We also quantified the uncertainties associated with GCM structure, greenhouse gas concentration pathways (RCP 2.6, 4.5 and 8.5), and prescribed increases of global temperature (1–6 °C) through streamflow changes. The SWAT model simulated historical monthly streamflow well, with a Nash–Sutcliffe efficiency coefficient of 0.66 for calibration and 0.62 for validation. Under RCPs 2.6, 4.5, and 8.5, the results indicate that annual precipitation changes of 1.01 to 8.88% and annual temperature of 0.60–3.21 °C will lead to a projected annual streamflow ranging from 0.91 to 12.95% compared to the historical period. The study indicates multiple climate change scenarios are important for a robust hydrological impact assessment.

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