Earth System Dynamics Discussions最新文献_第8页

The response of small and shallow lakes to climate change: new insights from hindcast modelling 小湖和浅湖对气候变化的响应:来自后预测模型的新见解

Earth System Dynamics Discussions Pub Date : 2020-07-24 DOI: 10.5194/esd-2020-51

Francesco Piccioni, C. Casenave, B. Lemaire, P. Moigne, P. Dubois, B. Vinçon-Leite

{"title":"The response of small and shallow lakes to climate change: new insights from hindcast modelling","authors":"Francesco Piccioni, C. Casenave, B. Lemaire, P. Moigne, P. Dubois, B. Vinçon-Leite","doi":"10.5194/esd-2020-51","DOIUrl":"https://doi.org/10.5194/esd-2020-51","url":null,"abstract":"Abstract. Small and shallow water bodies are a dominant portion of inland freshwaters. However, the effects of climate change on such ecosystems have rarely been quantitatively adressed. We propose a methodology to evaluate the thermal response of a small and shallow lake to long-term changes in the meteorological conditions, through model simulations. To do so, a 3D hydrodynamic model is forced with meteorological data and used to hindcast the evolution of a urban lake in the Paris region between 1960 and 2017. Its thermal response is analyzed through the definition of a series of indices describing its thermal regime in terms of water temperature, thermal stratification and tendency to biomass production. Model results and meteorological forcing are analyzed over time to test the presence of monotonic trends and 3D simulations are exploited to highlight spatial patterns in the dynamics of stratification. The thermal regime of the study site underwent significant changes. Its response was highly correlated with three meteorological variables: air temperature, solar radiation and wind speed. Mean annual water temperature showed a considerable warming trend of 0.6 °C/dec, accompanied by longer stratification and by an increase of thermal energy available for biomass production. Water warming was significant during all four seasons, with maxima in Spring and Summer, while stratification and energy for phytoplankton growth increased especially during Spring and Autumn. Stratification only established in the deeper areas of the water body, possibly inducing heterogeneity in the release of nutrient from the sediment and in the development of harmful algal blooms. Numerous similar ecosystems might be experiencing analogous changes, and appropriate management policies are needed to preserve their ecological value.","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"16 1","pages":"1-22"},"PeriodicalIF":0.0,"publicationDate":"2020-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88281377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Agricultural management effects on mean and extreme temperaturetrends 农业管理对平均和极端温度趋势的影响

Earth System Dynamics Discussions Pub Date : 2020-07-20 DOI: 10.5194/esd-2020-35

Aine M. Gormley-Gallagher, S. Sterl, A. Hirsch, S. Seneviratne, E. Davin, W. Thiery

{"title":"Agricultural management effects on mean and extreme temperature\u0000trends","authors":"Aine M. Gormley-Gallagher, S. Sterl, A. Hirsch, S. Seneviratne, E. Davin, W. Thiery","doi":"10.5194/esd-2020-35","DOIUrl":"https://doi.org/10.5194/esd-2020-35","url":null,"abstract":"Abstract. Regression-based trend analysis is applied to observations and present-day ensemble simulations with the Community Earth System Model to assess if climate models overestimate warming trends because theoretical constant levels of irrigation and conservation agriculture (CA) are excluded. At the regional scale, an irrigation- and CA-induced acceleration of the annual mean near-surface air temperature (T2m) warming trends and the annual maximum daytime temperature (TXx) warming trends were evident. Estimation of the impact of irrigation and CA on the spatial average of the warming trends indicated that irrigation and CA have a pulse cooling effect on T2m and TXx, after which the warming trends increase at a greater rate than the control simulations. This differed at the local (subgrid) scale under irrigation where surface temperature cooling and the dampening of warming trends were both evident. As the local surface warming trends, in contrast to regional trends, do not account for atmospheric (water vapour) feedbacks, their dampening confirms the importance of atmospheric feedbacks (water vapour forcing) in explaining the enhanced regional trends. At the land surface, the positive radiative forcing signal is too weak to offset the local cooling from the irrigation-induced increase in the evaporative fraction. Our results underline that agricultural management has complex and nonnegligible impacts on the local climate and highlights the need to account for land management in climate projections.\u0000","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"284 1","pages":"1-27"},"PeriodicalIF":0.0,"publicationDate":"2020-07-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76843127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 6

Simulating Lake Tanganyika's hydrodynamics under a changing climate 模拟坦噶尼喀湖在气候变化下的水动力学

Earth System Dynamics Discussions Pub Date : 2020-07-08 DOI: 10.5194/esd-2020-36

Kevin Sterckx, Philippe Delandmeter, J. Lambrechts, É. Deleersnijder, W. Thiery

{"title":"Simulating Lake Tanganyika's hydrodynamics under a changing climate","authors":"Kevin Sterckx, Philippe Delandmeter, J. Lambrechts, É. Deleersnijder, W. Thiery","doi":"10.5194/esd-2020-36","DOIUrl":"https://doi.org/10.5194/esd-2020-36","url":null,"abstract":"Abstract. Lake Tanganyika is the second oldest (oldest basin of the lake is 9–12 million years old), second deepest (1470 m) lake in the world. It holds 16 % of the world's liquid freshwater. Approximately 100 000 people are directly involved in the fisheries operating from almost 800 sites along its shores. Despite the vital importance of Lake Tanganyika and other African inland waters for local communities, very little is known about the impacts of future climate change on the functioning of these lacustrine systems. This is remarkable, as projected future changes in climate and associated weather conditions are likely to influence the hydrodynamics of African water bodies, with impacts cascading into ecosystem functioning, fish availability and water quality. Here we project the future changes in the hydrodynamics of Lake Tanganyika under a high-end emission scenario using the 3D version of the Second-generation Louvain-la-Neuve Ice-ocean Model (SLIM 3D) forced by a highresolution regional climate model. We first show the added value of 3D simulations compared to previously obtained 1D model results. The simulated interseasonal variability of the lake with this 3D model explains how the current mixing system works. A short-term present-day simulation (10 years) shows that the 75 m deep thermocline moves upward in the south of the lake until the lower layer reaches the lake surface during August and September. Two 30-year simulations have been performed (one with present day and one with future conditions), such that a comparison can be made between the current situation and the situation at the end of the 21st century. The results show that the surface water temperature increases on average by 3 ± 0.5 K. The latter influences the hydrodynamics in the top 150 m of the lake, namely the bottom of the thermocline does not longer surface. This temperature-induced stratification fully shuts down the earlier explained mixing mechanism.","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"4 1","pages":"1-33"},"PeriodicalIF":0.0,"publicationDate":"2020-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80775925","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Collapse of the Atlantic Meridional Overturning described by Langevin dynamics 朗格万动力学描述的大西洋经向翻转的崩塌

Earth System Dynamics Discussions Pub Date : 2020-06-30 DOI: 10.5194/esd-2020-43

J. van den Berk, S. Drijfhout, W. Hazeleger

引用次数: 0

The role of prior assumptions in carbon budget calculations 先前假设在碳预算计算中的作用

Earth System Dynamics Discussions Pub Date : 2020-06-25 DOI: 10.5194/esd-11-563-2020

B. Sanderson

{"title":"The role of prior assumptions in carbon budget calculations","authors":"B. Sanderson","doi":"10.5194/esd-11-563-2020","DOIUrl":"https://doi.org/10.5194/esd-11-563-2020","url":null,"abstract":"Abstract. Cumulative emissions budgets and net-zero emission target dates are often used to frame climate negotiations ( Frame et al. , 2014 ; Millar et al. , 2016 ; Van Vuuren et al. , 2016 ; Rogelj et al. , 2015 b ; Matthews et al. , 2012 ) . However, their utility for near-term policy decisions is confounded by uncertainties in future negative emissions capacity ( Fuss et al. , 2014 ; Smith et al. , 2016 ; Larkin et al. , 2018 ; Anderson and Peters , 2016 ) , in the role of non- CO2 forcers ( MacDougall et al. , 2015 ) and in the long-term Earth system response to forcing ( Rugenstein et al. , 2019 ; Knutti et al. , 2017 ; Armour , 2017 ) . Such uncertainties may impact the utility of an absolute carbon budget if peak temperatures occur significantly after net-zero emissions are achieved, the likelihood of which is shown here to be conditional on prior assumptions about the long-term dynamics of the Earth system. In the context of these uncertainties, we show that the necessity and scope for negative emissions deployment later in the century can be conditioned on near-term emissions, providing support for a scenario framework which focuses on emissions reductions rather than absolute budgets ( Rogelj et al. , 2019 b ) .","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"28 1","pages":"563-577"},"PeriodicalIF":0.0,"publicationDate":"2020-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82331694","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Long-term variance of heavy precipitation across central Europe using a large ensemble of regional climate model simulations 使用大量区域气候模式模拟的中欧强降水的长期变化

Earth System Dynamics Discussions Pub Date : 2020-05-26 DOI: 10.5194/ESD-11-469-2020

Florian Ehmele, Lisa‐Ann Kautz, H. Feldmann, J. Pinto

{"title":"Long-term variance of heavy precipitation across central Europe using a large ensemble of regional climate model simulations","authors":"Florian Ehmele, Lisa‐Ann Kautz, H. Feldmann, J. Pinto","doi":"10.5194/ESD-11-469-2020","DOIUrl":"https://doi.org/10.5194/ESD-11-469-2020","url":null,"abstract":"Abstract. Widespread flooding events are among the major natural hazards in central Europe. Such events are usually related to intensive, long-lasting precipitation over larger areas. Despite some prominent floods during the last three decades (e.g., 1997, 1999, 2002, and 2013), extreme floods are rare and associated with estimated long return periods of more than 100 years. To assess the associated risks of such extreme events, reliable statistics of precipitation and discharge are required. Comprehensive observations, however, are mainly available for the last 50–60 years or less. This shortcoming can be reduced using stochastic data sets. One possibility towards this aim is to consider climate model data or extended reanalyses. This study presents and discusses a validation of different century-long data sets, decadal hindcasts, and also predictions for the upcoming decade combined to a new large ensemble. Global reanalyses for the 20th century with a horizontal resolution of more than 100 km have been dynamically downscaled with a regional climate model (Consortium for Small-scale Modeling – CLimate Mode; COSMO-CLM) towards a higher resolution of 25 km. The new data sets are first filtered using a dry-day adjustment. Evaluation focuses on intensive widespread precipitation events and related temporal variabilities and trends. The presented ensemble data are within the range of observations for both statistical distributions and time series. The temporal evolution during the past 60 years is captured. The results reveal some long-term variability with phases of increased and decreased precipitation rates. The overall trend varies between the investigation areas but is mostly significant. The predictions for the upcoming decade show ongoing tendencies with increased areal precipitation. The presented regional climate model (RCM) ensemble not only allows for more robust statistics in general, it is also suitable for a better estimation of extreme values.","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"55 1","pages":"469-490"},"PeriodicalIF":0.0,"publicationDate":"2020-05-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78556663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Comparing internal variabilities in three regional single model initial-condition large ensembles (SMILE) over Europe 比较欧洲三个区域单模式初始条件大组合(SMILE)的内部变率

Earth System Dynamics Discussions Pub Date : 2020-05-01 DOI: 10.5194/esd-2019-67

Fabian von Trentini, E. Aalbers, E. Fischer, R. Ludwig

{"title":"Comparing internal variabilities in three regional single model initial-condition large ensembles (SMILE) over Europe","authors":"Fabian von Trentini, E. Aalbers, E. Fischer, R. Ludwig","doi":"10.5194/esd-2019-67","DOIUrl":"https://doi.org/10.5194/esd-2019-67","url":null,"abstract":"Abstract. Single model large ensembles are widely used model experiments to estimate internal climate variability. The underlying assumption is that the internal variability (here: inter-annual variability) of the chosen model is a good approximation of the observed natural (inter-annual) variability. In this study, we test this assumption based on three regional climate model large ensembles (16 members of an EC-EARTH-RACMO ensemble, 21 members of a CESM-CCLM ensemble, 50 members of a CanESM-CRCM ensemble) for four European domains (British Isles, France, Mid-Europe, Alps). Simulated inter-annual variability is evaluated against E-OBS and the inter-annunal variability and its future change are compared across the ensembles. To the knowledge of the authors, this is the first comparison of regional large ensembles over Europe. Analysis comprises seasonal temperature and precipitation, as well as indicators for dry periods and heat waves. Results show a large consistency of all three ensembles with E-OBS data for most indicators and regions, validating the abilities of these ensembles to represent natural variability on the annual scale. EC-EARTH-RACMO shows the highest inter-annual variability for winter temperature and precipitation, whereas CESM-CCLM shows the highest variability for summer temperature and precipitation, as well as for heatwaves and dry periods. Despite these model differences, the sign of the future changes in internal variability is largely the same in all models: for summer temperature, summer precipitation and the number of heat waves, the internal variability increases, while it decreases for winter temperature. Changes of winter precipitation and dry periods are a bit unclear, with a tendency to increase for dry periods. The overall consistency across single model large ensembles and observations strengthens the concept of large ensembles, and underlines their great potential for understanding and quantifying the role of internal climate variability.","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"1 1","pages":"1-27"},"PeriodicalIF":0.0,"publicationDate":"2020-05-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74859754","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Compound Hot-Dry and Cold-Wet Dynamical Extremes Over the Mediterranean 地中海上空干热冷湿复合动力极端现象

Earth System Dynamics Discussions Pub Date : 2020-04-22 DOI: 10.5194/esd-2020-21

P. De Luca, G. Messori, D. Faranda, P. Ward, D. Coumou

{"title":"Compound Hot-Dry and Cold-Wet Dynamical Extremes Over the Mediterranean","authors":"P. De Luca, G. Messori, D. Faranda, P. Ward, D. Coumou","doi":"10.5194/esd-2020-21","DOIUrl":"https://doi.org/10.5194/esd-2020-21","url":null,"abstract":"Abstract. The Mediterranean (MED) basin is a climate change hot-spot that has seen drying and a pronounced increase in heatwaves over the last century. At the same time, it is experiencing increasing heavy precipitation during wintertime cold spells. Understanding and quantifying the risks from compound events over the MED is paramount for present and future disaster risk reduction measures. Here, we apply a novel method to study compound events based on dynamical systems theory and analyse compound temperature and precipitation anomalies over the MED from 1979 to 2018. The dynamical systems analysis measures the strength of the coupling between different atmospheric variables over the MED. Further, we consider compound hot-dry days in summer and cold-wet days in winter. Our results show that these hot-dry and cold-wet compound days are associated with maxima in the temperature–precipitation coupling parameter of the dynamical systems analysis. This indicates that there is a strong interaction between temperature and precipitation during compound events. In summer, we find a significant upward trend in the coupling between temperature and precipitation over 1979–2018, which is likely driven by a stronger coupling during hot and dry days. Thermodynamic processes associated with long-term MED warming can best explain the trend. No such trend is found for wintertime cold-wet compound events. Our findings suggest that long-term warming strengthens the coupling of temperature and precipitation which intensifies hot-dry compound events.","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"39 1","pages":"1-24"},"PeriodicalIF":0.0,"publicationDate":"2020-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85732894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

ESD Reviews: mechanisms, evidence, and impacts of climate tipping elements 可持续发展战略综述:气候引爆要素的机制、证据和影响

Earth System Dynamics Discussions Pub Date : 2020-04-21 DOI: 10.5194/esd-2020-16

Seaver Wang, Z. Hausfather

{"title":"ESD Reviews: mechanisms, evidence, and impacts of climate tipping elements","authors":"Seaver Wang, Z. Hausfather","doi":"10.5194/esd-2020-16","DOIUrl":"https://doi.org/10.5194/esd-2020-16","url":null,"abstract":"Abstract. Increasing attention is focusing upon climate tipping elements – large-scale earth systems anticipated to respond through positive feedbacks to anthropogenic climate change by shifting towards new long-term states. In some but not all cases, such changes could produce additional greenhouse gas emissions or radiative forcing that could compound global warming. Developing greater understanding of tipping elements is important for predicting future climate risks. Here we review mechanisms, predictions, impacts, and knowledge gaps associated with ten notable climate tipping elements. We also evaluate which tipping elements are more imminent and whether shifts will likely manifest rapidly or over longer timescales. Some tipping elements are significant to future global climate and will likely affect major ecosystems, climate patterns, and/or carbon cycling within the current century. However, assessments under different emissions scenarios indicate a strong potential to reduce or avoid impacts associated with many tipping elements through climate change mitigation. Most tipping elements do not possess the potential for abrupt future change within years, and some tipping elements are perhaps more accurately termed climate feedbacks. Nevertheless, significant uncertainties remain associated with many tipping elements, highlighting an acute need for further research and modeling to better constrain risks.","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"32 1","pages":"1-93"},"PeriodicalIF":0.0,"publicationDate":"2020-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78214826","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5

Bayesian deconstruction of climate sensitivity estimates using simple models: implicit priors and the confusion of the inverse 使用简单模型的气候敏感性估计的贝叶斯解构:隐含先验和逆的混淆

Earth System Dynamics Discussions Pub Date : 2020-04-21 DOI: 10.5194/ESD-11-347-2020

J. Annan, J. Hargreaves

{"title":"Bayesian deconstruction of climate sensitivity estimates using simple models: implicit priors and the confusion of the inverse","authors":"J. Annan, J. Hargreaves","doi":"10.5194/ESD-11-347-2020","DOIUrl":"https://doi.org/10.5194/ESD-11-347-2020","url":null,"abstract":"Abstract. Observational constraints on the equilibrium climate sensitivity have been generated in a variety of ways, but a number of results have been calculated which appear to be based on somewhat informal heuristics. In this paper we demonstrate that many of these estimates can be reinterpreted within the standard subjective Bayesian framework in which a prior over the uncertain parameters is updated through a likelihood arising from observational evidence. We consider cases drawn from paleoclimate research, analyses of the historical warming record, and feedback analysis based on the regression of annual radiation balance observations for temperature. In each of these cases, the prior which was (under this new interpretation) implicitly used exhibits some unconventional and possibly undesirable properties. We present alternative calculations which use the same observational information to update a range of explicitly presented priors. Our calculations suggest that heuristic methods often generate reasonable results in that they agree fairly well with the explicitly Bayesian approach using a reasonable prior. However, we also find some significant differences and argue that the explicitly Bayesian approach is preferred, as it both clarifies the role of the prior and allows researchers to transparently test the sensitivity of their results to it.","PeriodicalId":11466,"journal":{"name":"Earth System Dynamics Discussions","volume":"29 1","pages":"347-356"},"PeriodicalIF":0.0,"publicationDate":"2020-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85001414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2