The use of general circulation models in the analysis of the ecosystem impacts of climatic change

1985 ◽  
Vol 7 (3) ◽  
pp. 267-284 ◽  
Author(s):  
W. Lawrence Gates
Keyword(s):  
Climatic Change ◽  
General Circulation ◽  
General Circulation Models ◽  
Ecosystem Impacts

scholarly journals Genetic Variation in Abies religiosa for Quantitative Traits and Delineation of Elevational and Climatic Zoning for Maintaining Monarch Butterfly Overwintering Sites in Mexico, considering Climatic Change

2017 ◽  
Vol 66 (1) ◽  
pp. 14-23 ◽  
Author(s):  
M. A. Ortiz-Bibian ◽  
A. Blanco-García ◽  
R. A. Lindig-Cisneros ◽  
M. Gómez-Romero ◽  
D. Castellanos-Acuña ◽  
...  
Keyword(s):  
Climatic Change ◽  
General Circulation ◽  
Final Height ◽  
Danaus Plexippus ◽  
Biosphere Reserve ◽  
General Circulation Models ◽  
Monarch Butterfly ◽  
Frost Damage ◽  
Seed Collection ◽  
Abies Religiosa

AbstractConservation of Abies religiosa (sacred fir) within the Monarch Butterfly Biosphere Reserve (MBBR) in Mexico requires adaptive management to cope with expected climatic change, in order to have healthy trees for Danaus plexippus overwintering sites in the future. Open pollinated seeds from fifteen A. religiosa populations were collected along an elevational gradient (2850-3550 masl; one sampled population every 50 m of elevational difference). Seedlings were evaluated in a common garden test over a period of 30 months. We found significant differences (P < 0.03) among populations in total elongation, final height, date of growth cessation, foliage, stem and total dry weight, as well as frost damage. These differences were strongly associated with the Mean Temperature of the Coldest Month (MTCM; r2= 0.6222, P = 0.0005). Seedlings originating from lower elevation populations grew more but suffered more frost damage than those from higher elevations. Populations differentiate genetically when they are separated by 364 m in elevation. Such differentiation was used to delineate three elevational/climatic zones for seed collection, with limits defined at: 2650 masl or 9.7 °C of MTCM; 3000 masl or 8.5 °C; 3350 masl or 7.3 °C; and 3700 masl or 6.1 °C. Zonification for seedling deployment aiming to match a suitable climate in year 2030 (after projections using an ensemble of 18 General Circulation Models and a Representative Concentration Pathway 6.0 watts/ m2), would have the same MTCM zone limits, but shifted 350 m upwards in elevation. This shift would exceed the highest elevations within the MBBR, necessitating the establishment of A. religiosa stands outside the MBBR, to serve as potential future overwintering sites.

The use of tracers in modelling the oceanic uptake of carbon dioxide

1988 ◽  
Vol 325 (1583) ◽  
pp. 23-42
Keyword(s):  
Carbon Dioxide ◽  
Land Use ◽  
Land Use Change ◽  
Climatic Change ◽  
Diffusion Model ◽  
General Circulation ◽  
General Circulation Models ◽  
Vertical Diffusion ◽  
Mixing Processes ◽  
Change Models

Increasing levels of atmospheric carbon dioxide from the burning of fossil fuels and changes in land use pose a threat of significant global climatic change in the 21st century. Owing to uncertainty in the pre-industrial atmospheric CO 2 concentration and in CO 2 releases from land-use change, direct estimates of the airborne fraction of this man-made CO 2 are not well established. Effort has therefore been devoted to estimating the strengths of the oceanic and biospheric sinks as an alternative route to determining the airborne fraction. This paper reviews the development of oceanic CO 2 -uptake models. One-dimensional box models, with first-order exchange kinetics or vertical diffusion to simulate CO 2 penetration into the deep ocean and calibrated against natural 14 C distributions, appear inadequate. Their uptake is too small to be consistent with the recent atmospheric record and most estimated histories of CO 2 release from land use change. Models incorporating representations of specific oceanic mixing processes important in CO 2 uptake achieve somewhat larger CO 2 uptake, especially when calibrated against ‘ short timescale ’ tracers, such as radiocarbon and tritium derived from bomb tests. Despite this general conclusion, substantial differences between such models remain. A comparison between my two-dimensional advection—diffusion model and Siegenthaler’s outcrop—diffusion model illustrates how the relative importance of air-sea gas exchange rate and rate of ocean mixing in limiting CO 2 uptake depends critically upon modelling assumptions. The failure of most models calibrated with a single oceanic tracer to reproduce well the distribution of other tracers has encouraged the development of multi-box, geographically realistic, models whose circulation and mixing patterns are determined by simultaneous inverse solution of a set of conservation equations for a range of tracers. This technique, when augmented with additional dynamical constraints, probably offers the most promise for advancing CO 2 -uptake modelling while suitable three-dimensional oceanic general circulation models are being developed. The latter, atmospherically driven, models will eventually play a key role in assessing how any future climatic change may feed back on atmospheric CO 2 levels. Feedback could arise either by alteration of the mixing processes responsible for man-made CO 2 uptake, or more fundamentally if changes in the surface-ocean productivity result from changes in circulation-mediated nutrient supply.

Successive Modulation of ENSO to the Future Greenhouse Warming

2008 ◽  
Vol 21 (1) ◽  
pp. 3-21 ◽  
Author(s):  
Soon-Il An ◽  
Jong-Seong Kug ◽  
Yoo-Geun Ham ◽  
In-Sik Kang
Keyword(s):  
General Circulation ◽  
Southern Oscillation ◽  
General Circulation Models ◽  
Tropical Pacific ◽  
Greenhouse Warming ◽  
Delayed Response ◽  
Subsurface Temperature ◽  
Climate System Model ◽  
The Mean ◽  
The Tropical Pacific

Abstract The multidecadal modulation of the El Niño–Southern Oscillation (ENSO) due to greenhouse warming has been analyzed herein by means of diagnostics of Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4) coupled general circulation models (CGCMs) and the eigenanalysis of a simplified version of an intermediate ENSO model. The response of the global-mean troposphere temperature to increasing greenhouse gases is more likely linear, while the amplitude and period of ENSO fluctuates in a multidecadal time scale. The climate system model outputs suggest that the multidecadal modulation of ENSO is related to the delayed response of the subsurface temperature in the tropical Pacific compared to the response time of the sea surface temperature (SST), which would lead a modulation of the vertical temperature gradient. Furthermore, an eigenanalysis considering only two parameters, the changes in the zonal contrast of the mean background SST and the changes in the vertical contrast between the mean surface and subsurface temperatures in the tropical Pacific, exhibits a good agreement with the CGCM outputs in terms of the multidecadal modulations of the ENSO amplitude and period. In particular, the change in the vertical contrast, that is, change in difference between the subsurface temperature and SST, turns out to be more influential on the ENSO modulation than changes in the mean SST itself.

scholarly journals Contributors to linkage between Arctic warming and East Asian winter climate

2021 ◽  
Author(s):  
Xinping Xu ◽  
Shengping He ◽  
Yongqi Gao ◽  
Botao Zhou ◽  
Huijun Wang
Keyword(s):  
Sea Ice ◽  
General Circulation ◽  
Initial Conditions ◽  
Wave Train ◽  
East Asian ◽  
Surface Air Temperature ◽  
General Circulation Models ◽  
The Arctic ◽  
Winter Climate ◽  
Arctic Warming

AbstractPrevious modelling and observational studies have shown discrepancies in the interannual relationship of winter surface air temperature (SAT) between Arctic and East Asia, stimulating the debate about whether Arctic change can influence midlatitude climate. This study uses two sets of coordinated experiments (EXP1 and EXP2) from six different atmospheric general circulation models. Both EXP1 and EXP2 consist of 130 ensemble members, each of which in EXP1 (EXP2) was forced by the same observed daily varying sea ice and daily varying (daily climatological) sea surface temperature (SST) for 1982–2014 but with different atmospheric initial conditions. Large spread exists among ensemble members in simulating the Arctic–East Asian SAT relationship. Only a fraction of ensemble members can reproduce the observed deep Arctic warming–cold continent pattern which extends from surface to upper troposphere, implying the important role of atmospheric internal variability. The mechanisms of deep Arctic warming and shallow Arctic warming are further distinguished. Arctic warming aloft is caused primarily by poleward moisture transport, which in conjunction with the surface warming coupled with sea ice melting constitutes the surface-amplified deep Arctic warming throughout the troposphere. These processes associated with the deep Arctic warming may be related to the forcing of remote SST when there is favorable atmospheric circulation such as Rossby wave train propagating from the North Atlantic into the Arctic.

scholarly journals Simulation of Extreme Precipitation in Four Climate Regions in China by General Circulation Models (GCMs): Performance and Projections

Water ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1509
Author(s):  
Mengru Zhang ◽  
Xiaoli Yang ◽  
Liliang Ren ◽  
Ming Pan ◽  
Shanhu Jiang ◽  
...  
Keyword(s):  
Extreme Precipitation ◽  
General Circulation ◽  
Global Climate ◽  
Summer Precipitation ◽  
General Circulation Models ◽  
Cumulative Distribution ◽  
Extreme Precipitation Events ◽  
Increasing Trend ◽  
The Future ◽  
Semi Arid

In the context of global climate change, it is important to monitor abnormal changes in extreme precipitation events that lead to frequent floods. This research used precipitation indices to describe variations in extreme precipitation and analyzed the characteristics of extreme precipitation in four climatic (arid, semi-arid, semi-humid and humid) regions across China. The equidistant cumulative distribution function (EDCDF) method was used to downscale and bias-correct daily precipitation in eight Coupled Model Intercomparison Project Phase 5 (CMIP5) general circulation models (GCMs). From 1961 to 2005, the humid region had stronger and longer extreme precipitation compared with the other regions. In the future, the projected extreme precipitation is mainly concentrated in summer, and there will be large areas with substantial changes in maximum consecutive 5-day precipitation (Rx5) and precipitation intensity (SDII). The greatest differences between two scenarios (RCP4.5 and RCP8.5) are in semi-arid and semi-humid areas for summer precipitation anomalies. However, the area of the four regions with an increasing trend of extreme precipitation is larger under the RCP8.5 scenario than that under the RCP4.5 scenario. The increasing trend of extreme precipitation in the future is relatively pronounced, especially in humid areas, implying a potential heightened flood risk in these areas.

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