| 1. |
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| 2. |
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| 3. |
- Alexandridis, Nikolaos, et al.
(author)
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Climate change and ecological intensification of agriculture in sub-Saharan Africa : A systems approach to predict maize yield under push-pull technology
- 2023
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In: Agriculture, Ecosystems and Environment. - 0167-8809 .- 1873-2305. ; 352
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Journal article (peer-reviewed)abstract
- Assessing effects of climate change on agricultural systems and the potential for ecological intensification to increase food security in developing countries is essential to guide management, policy-making and future research. ‘Push-pull’ technology (PPT) is a poly-cropping design developed in eastern Africa that utilizes plant chemicals to mediate plant–insect interactions. PPT application yields significant increases in crop productivity, by reducing pest load and damage caused by arthropods and parasitic weeds, while also bolstering soil fertility. As climate change effects may be species- and/or context-specific, there is need to elucidate how, in interaction with biotic factors, projected climate conditions are likely to influence future functioning of PPT. Here, we first reviewed how changes in temperature, precipitation and atmospheric CO2 concentration can influence PPT components (i.e., land use, soils, crops, weeds, diseases, pests and their natural enemies) across sub-Saharan Africa (SSA). We then imposed these anticipated responses on a landscape-scale qualitative mathematical model of maize production under PPT in eastern Africa, to predict cumulative, structure-mediated impacts of climate change on maize yield. Our review suggests variable impacts of climate change on PPT components in SSA by the end of the 21st century, including reduced soil fertility, increased weed and arthropod pest pressure and increased prevalence of crop diseases, but also increased biological control by pests’ natural enemies. Extrapolating empirical evidence of climate effects to predict responses to projected climate conditions is mainly limited by a lack of mechanistic understanding regarding single and interactive effects of climate variables on PPT components. Model predictions of maize yield responses to anticipated impacts of climate change in eastern Africa suggest predominantly negative future trends. Nevertheless, maize yields can be sustained or increased by favourable changes in system components with less certain future behaviour, including higher PPT adoption, preservation of field edge density and agricultural diversification beyond cereal crops.
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| 4. |
- Alexandridis, Nikolaos, et al.
(author)
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Climate change and ecological intensification of agriculture in sub-Saharan Africa – A systems approach to predict maize yield under push-pull technology
- 2023
-
In: Agriculture, Ecosystems & Environment. - 0167-8809 .- 1873-2305. ; 352
-
Journal article (peer-reviewed)abstract
- Assessing effects of climate change on agricultural systems and the potential for ecological intensification to increase food security in developing countries is essential to guide management, policy-making and future research. ‘Push-pull’ technology (PPT) is a poly-cropping design developed in eastern Africa that utilizes plant chemicals to mediate plant–insect interactions. PPT application yields significant increases in crop productivity, by reducing pest load and damage caused by arthropods and parasitic weeds, while also bolstering soil fertility. As climate change effects may be species- and/or context-specific, there is need to elucidate how, in interaction with biotic factors, projected climate conditions are likely to influence future functioning of PPT. Here, we first reviewed how changes in temperature, precipitation and atmospheric CO2 concentration can influence PPT components (i.e., land use, soils, crops, weeds, diseases, pests and their natural enemies) across sub-Saharan Africa (SSA). We then imposed these anticipated responses on a landscape-scale qualitative mathematical model of maize production under PPT in eastern Africa, to predict cumulative, structure-mediated impacts of climate change on maize yield. Our review suggests variable impacts of climate change on PPT components in SSA by the end of the 21st century, including reduced soil fertility, increased weed and arthropod pest pressure and increased prevalence of crop diseases, but also increased biological control by pests’ natural enemies. Extrapolating empirical evidence of climate effects to predict responses to projected climate conditions is mainly limited by a lack of mechanistic understanding regarding single and interactive effects of climate variables on PPT components. Model predictions of maize yield responses to anticipated impacts of climate change in eastern Africa suggest predominantly negative future trends. Nevertheless, maize yields can be sustained or increased by favourable changes in system components with less certain future behaviour, including higher PPT adoption, preservation of field edge density and agricultural diversification beyond cereal crops.
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| 5. |
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| 6. |
- Chen, Deliang, 1961, et al.
(author)
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Summary of a workshop on extreme weather events in a warming world organized by the Royal Swedish Academy of Sciences
- 2020
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In: Tellus Series B-Chemical and Physical Meteorology. - : Stockholm University Press. - 1600-0889 .- 0280-6509. ; 72:1
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Journal article (peer-reviewed)abstract
- Climate change is not only about changes in means of climatic variables such as temperature, precipitation and wind, but also their extreme values which are of critical importance to human society and ecosystems. To inspire the Swedish climate research community and to promote assessments of international research on past and future changes in extreme weather events against the global climate change background, the Earth Science Class of the Royal Swedish Academy of Sciences organized a workshop entitled 'Extreme weather events in a warming world' in 2019. This article summarizes and synthesizes the key points from the presentations and discussions of the workshop on changes in floods, droughts, heat waves, as well as on tropical cyclones and extratropical storms. In addition to reviewing past achievements in these research fields and identifying research gaps with a focus on Sweden, future challenges and opportunities for the Swedish climate research community are highlighted.
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| 7. |
- Droste, Nils, et al.
(author)
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Soil carbon insures arable crop production against increasing adverse weather due to climate change
- 2020
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In: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 15:12
-
Journal article (peer-reviewed)abstract
- Intensification of arable crop production degrades soil health and production potential through loss of soil organic carbon. This, potentially, reduces agriculture's resilience to climate change and thus food security. Furthermore, the expected increase in frequency of adverse and extreme weather events due to climate change are likely to affect crop yields differently, depending on when in the growing season they occur. We show that soil carbon provides farmers with a natural insurance against climate change through a gain in yield stability and more resilient production. To do this, we combined yield observations from 12 sites and 54 years of Swedish long-term agricultural experiments with historical weather data. To account for heterogenous climate effects, we partitioned the growing season into four representative phases for two major cereal crops. Thereby, we provide evidence that higher soil carbon increases yield gains from favourable conditions and reduces yield losses due to adverse weather events and how this occurs over different stages of the growing season. However, agricultural management practices that restore the soil carbon stock, thus contributing to climate change mitigation and adaptation, usually come at the cost of foregone yield for the farmer in the short term. To halt soil degradation and make arable crop production more resilient to climate change, we need agricultural policies that address the public benefits of soil conservation and restoration.
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| 8. |
- Fridén, Alexia, et al.
(author)
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Mapping two centuries of forest governance in Nordic countries : An open access database
- 2024
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In: Forest Policy and Economics. - 1389-9341. ; 160
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Journal article (peer-reviewed)abstract
- Forest ecosystems play a crucial role in the production and protection of economic, social, and environmental values. To understand current challenges and trajectories shaping future strategies within the Nordic forest sector, it is important to map and trace past and present policy and governance developments. The core contribution of this short communication is to present an open-access database that compiles key forest-related public national policies, legislative documents, and private governance initiatives in Denmark, Finland, Sweden, and Norway from the 19th century to the present day. To showcase the potential use of the database, we conducted a comparative appraisal of forest governance trends across Nordic countries, outlining differences and shared characteristics. We identify a shift from a highly regulated and rationalized forest management regime in the 19th and early 20th centuries towards more flexible forms of contemporary governance. This transformation comes with the growing importance of sectorial freedom with responsibility principles, but also increasing calls for forest multifunctionality. Demands for recreation, climate change mitigation, and biodiversity conservation have intensified pressures on forest owners to provide public goods. However, the production and processing of marketable forest resources remains important to meet circular bioeconomy strategy goals. We conclude by briefly discussing the implications for strategic multifunctional use and polycentric governance of forests.
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| 9. |
- Gröger, Matthias, et al.
(author)
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Coupled regional Earth system modeling in the Baltic Sea region
- 2021
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In: Earth System Dynamics. - : Copernicus GmbH. - 2190-4979 .- 2190-4987. ; 12:3, s. 939-973
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Research review (peer-reviewed)abstract
- Nonlinear responses to externally forced climate change are known to dampen or amplify the local climate impact due to complex cross-compartmental feedback loops in the Earth system. These feedbacks are less well represented in the traditional stand-alone atmosphere and ocean models on which many of today's regional climate assessments rely (e.g., EURO-CORDEX, NOSCCA and BACC II). This has promoted the development of regional climate models for the Baltic Sea region by coupling different compartments of the Earth system into more comprehensive models. Coupled models more realistically represent feedback loops than the information imposed on the region by prescribed boundary conditions and, thus, permit more degrees of freedom. In the past, several coupled model systems have been developed for Europe and the Baltic Sea region. This article reviews recent progress on model systems that allow two-way communication between atmosphere and ocean models; models for the land surface, including the terrestrial biosphere; and wave models at the air-sea interface and hydrology models for water cycle closure. However, several processes that have mostly been realized by one-way coupling to date, such as marine biogeochemistry, nutrient cycling and atmospheric chemistry (e.g., aerosols), are not considered here. In contrast to uncoupled stand-alone models, coupled Earth system models can modify mean near-surface air temperatures locally by up to several degrees compared with their stand-alone atmospheric counterparts using prescribed surface boundary conditions. The representation of small-scale oceanic processes, such as vertical mixing and sea-ice dynamics, appears essential to accurately resolve the air-sea heat exchange over the Baltic Sea, and these parameters can only be provided by online coupled high-resolution ocean models. In addition, the coupling of wave models at the ocean-atmosphere interface allows for a more explicit formulation of small-scale to microphysical processes with local feedbacks to water temperature and large-scale processes such as oceanic upwelling. Over land, important climate feedbacks arise from dynamical terrestrial vegetation changes as well as the implementation of land-use scenarios and afforestation/deforestation that further alter surface albedo, roughness length and evapotranspiration. Furthermore, a good representation of surface temperatures and roughness length over open sea and land areas is critical for the representation of climatic extremes such as heavy precipitation, storms, or tropical nights (defined as nights where the daily minimum temperature does not fall below 20gC), and these parameters appear to be sensitive to coupling. For the present-day climate, many coupled atmosphere-ocean and atmosphere-land surface models have demonstrated the added value of single climate variables, in particular when low-quality boundary data were used in the respective stand-alone model. This makes coupled models a prospective tool for downscaling climate change scenarios from global climate models because these models often have large biases on the regional scale. However, the coupling of hydrology models to close the water cycle remains problematic, as the accuracy of precipitation provided by atmosphere models is, in most cases, insufficient to realistically simulate the runoff to the Baltic Sea without bias adjustments. Many regional stand-alone ocean and atmosphere models are tuned to suitably represent present-day climatologies rather than to accurately simulate climate change. Therefore, more research is required into how the regional climate sensitivity (e.g., the models' response to a given change in global mean temperature) is affected by coupling and how the spread is altered in multi-model and multi-scenario ensembles of coupled models compared with uncoupled ones.
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| 10. |
- Hiensch, Anouk E, et al.
(author)
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Design of a multinational randomized controlled trial to assess the effects of structured and individualized exercise in patients with metastatic breast cancer on fatigue and quality of life : the EFFECT study.
- 2022
-
In: Trials. - : Springer Science and Business Media LLC. - 1745-6215. ; 23:1, s. 610-
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Journal article (peer-reviewed)abstract
- BACKGROUND: Many patients with metastatic breast cancer experience cancer- and treatment-related side effects that impair activities of daily living and negatively affect the quality of life. There is a need for interventions that improve quality of life by alleviating fatigue and other side effects during palliative cancer treatment. Beneficial effects of exercise have been observed in the curative setting, but, to date, comparable evidence in patients with metastatic breast cancer is lacking. The aim of this study is to assess the effects of a structured and individualized 9-month exercise intervention in patients with metastatic breast cancer on quality of life, fatigue, and other cancer- and treatment-related side effects.METHODS: The EFFECT study is a multinational, randomized controlled trial including 350 patients with metastatic breast cancer. Participants are randomly allocated (1:1) to an exercise or control group. The exercise group participates in a 9-month multimodal exercise program, starting with a 6-month period where participants exercise twice a week under the supervision of an exercise professional. After completing this 6-month period, one supervised session is replaced by one unsupervised session for 3 months. In addition, participants are instructed to be physically active for ≥30 min/day on all remaining days of the week, while being supported by an activity tracker and exercise app. Participants allocated to the control group receive standard medical care, general written physical activity advice, and an activity tracker, but no structured exercise program. The primary outcomes are quality of life (EORTC QLQ-C30, summary score) and fatigue (EORTC QLQ-FA12), assessed at baseline, 3, 6 (primary endpoint), and 9 months post-baseline. Secondary outcomes include physical fitness, physical performance, physical activity, anxiety, depression, pain, sleep problems, anthropometric data, body composition, and blood markers. Exploratory outcomes include quality of working life, muscle thickness, urinary incontinence, disease progression, and survival. Additionally, the cost-effectiveness of the exercise program is assessed. Adherence and safety are monitored throughout the intervention period.DISCUSSION: This large randomized controlled trial will provide evidence regarding the (cost-) effectiveness of exercise during treatment of metastatic breast cancer. If proven (cost-)effective, exercise should be offered to patients with metastatic breast cancer as part of standard care.TRIAL REGISTRATION: ClinicalTrials.gov NCT04120298 . Registered on October 9, 2019.
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| 11. |
- Luo, Fei, et al.
(author)
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Summertime Rossby waves in climate models : Substantial biases in surface imprint associated with small biases in upper-level circulation
- 2022
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In: Weather and Climate Dynamics. - : Copernicus GmbH. - 2698-4016. ; 3:3, s. 905-935
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Journal article (peer-reviewed)abstract
- In boreal summer, circumglobal Rossby waves can promote stagnating weather systems that favor extreme events like heat waves or droughts. Recent work showed that amplified Rossby wavenumber 5 and 7 show phase-locking behavior which can trigger simultaneous warm anomalies in different breadbasket regions in the Northern Hemisphere. These types of wave patterns thus pose a potential threat to human health and ecosystems. The representation of such persistent wave events in summer and their surface anomalies in general circulation models (GCMs) has not been systematically analyzed. Here we validate the representation of wavenumbers 1-10 in three state-of-The-Art global climate models (EC-Earth, CESM, and MIROC), quantify their biases, and provide insights into the underlying physical reasons for the biases. To do so, the ExtremeX experiments output data were used, consisting of (1) historic simulations with a freely running atmosphere with prescribed ocean and experiments that additionally (2) nudge towards the observed upper-level horizontal winds, (3) prescribe soil moisture conditions, or (4) do both. The experiments are used to trace the sources of the model biases to either the large-scale atmospheric circulation or surface feedback processes. Focusing on wave 5 and wave 7, we show that while the wave's position and magnitude are generally well represented during high-Amplitude (>g 1.5 SD) episodes, the associated surface anomalies are substantially underestimated. Near-surface temperature, precipitation and mean sea level pressure are typically underestimated by a factor of 1.5 in terms of normalized standard deviations. The correlations and normalized standard deviations for surface anomalies do not improve if the soil moisture is prescribed. However, the surface biases are almost entirely removed when the upper-level atmospheric circulation is nudged. When both prescribing soil moisture and nudging the upper-level atmosphere, then the surface biases remain quite similar to the experiment with a nudged atmosphere only. We conclude that the near-surface biases in temperature and precipitation are in the first place related to biases in the upper-level circulation. Thus, relatively small biases in the models' representation of the upper-level waves can strongly affect associated temperature and precipitation anomalies.
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| 12. |
- May, Wilhelm, et al.
(author)
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Contributions of soil moisture interactions to climate change in the tropics in the GLACE–CMIP5 experiment
- 2015
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In: Climate Dynamics. - : Springer Science and Business Media LLC. - 1432-0894 .- 0930-7575. ; 45:11-12, s. 3275-3297
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Journal article (peer-reviewed)abstract
- Contributions of changes in soil moisture to the projected climate change in the tropics at the end of the twenty first century are quantified using the simulations from five different global climate models, which contributed to the GLACE–CMIP5 experiment. “GLACE” refers to the Global Land Atmosphere Coupling Experiment and “CMIP5” to the fifth phase of the Coupled Model Intercomparison Project. This is done by relating the overall projected changes in climate to those changes in climate that are related to the projected changes in soil moisture. The study focusses on two particular aspects of the interactions of the soil moisture with climate, the soil moisture–temperature coupling and the soil moisture–precipitation coupling. The simulations show distinct future changes in soil moisture content in the tropics, with a general tendency of increases in the central parts of the tropics and decreases in the subtropics. These changes are associated with corresponding changes in precipitation, with an overall tendency of an approximate 5 % change in soil moisture in response to a precipitation change of 1 mm/day. All five individual models are characterized by the same qualitative behaviour, despite differences in the strength and in the robustness of the coupling between soil moisture and precipitation. The changes in soil moisture content are found to give important contributions to the overall climate change in the tropics. This is in particularly the case for latent and sensible heat flux, for which about 80 % of the overall changes are related to soil moisture changes. Similarly, about 80 % of the overall near-surface temperature changes (with the mean temperature changes in the tropics removed) are associated with soil moisture changes. For precipitation, on the other hand, about 30–40 % of the overall change can be attributed to soil moisture changes. The robustness of the contributions of the soil moisture changes to the overall climate change varies between the different meteorological variables, with a high degree of robustness for the surface energy fluxes, a fair degree for near-surface temperature and a low degree for precipitation. Similar to the coupling between soil moisture and precipitation, the five individual models are characterized by the same qualitative behaviour, albeit differences in the strength and the robustness of the contributions of the soil moisture change. This suggests that despite the regional differences in the projected climate changes between the individual models, the basic physical mechanisms governing the soil moisture–temperature coupling and the soil moisture–precipitation coupling work similarly in these models. The experiment confirms the conceptual models of the soil moisture–temperature coupling and the soil moisture–precipitation coupling described Seneviratne et al. (Earth-Sci Rev 99:125–161, 2010). For the soil moisture–temperature coupling, decreases (increases) in soil moisture lead to increasing (decreasing) sensible heat fluxes and near-surface temperatures. The soil moisture–precipitation coupling is part of a positive feedback loop, where increases (decreases) in precipitation cause increases (decreases) in soil moisture content, which, in turn, lead to increasing (decreasing) latent heat fluxes and precipitation.
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| 13. |
- May, Wilhelm, et al.
(author)
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Contributions of soil moisture interactions to future precipitation changes in the GLACE-CMIP5 experiment
- 2017
-
In: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 49:5-6, s. 1681-1704
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Journal article (peer-reviewed)abstract
- Changes in soil moisture are likely to contribute to future changes in latent heat flux and various characteristics of daily precipitation. Such contributions during the second half of the twenty-first century are assessed using the simulations from the GLACE-CMIP5 experiment, applying a linear regression analysis to determine the magnitude of these contributions. As characteristics of daily precipitation, mean daily precipitation, the frequency of wet days and the intensity of precipitation on wet days are considered. Also, the frequency and length of extended wet and dry spells are studied. Particular focus is on the regional (for nine selected regions) as well as seasonal variations in the magnitude of the contributions of the projected differences in soil moisture to the future changes in latent heat flux and in the characteristics of daily precipitation. The results reveal the overall tendency that the projected differences in soil moisture contribute to the future changes in response to the anthropogenic climate forcing for all the meteorological variables considered here. These contributions are stronger and more robust (i.e., there are smaller deviations between individual climate models) for the latent heat flux than for the characteristics of daily precipitation. It is also found that the contributions of the differences in soil moisture to the future changes are generally stronger and more robust for the frequency of wet days than for the intensity of daily precipitation. Consistent with the contributions of the projected differences in soil moisture to the future changes in the frequency of wet days, soil moisture generally contributes to the future changes in the characteristics of wet and dry spells. The magnitude of these contributions does not differ systematically between the frequency and the length of such extended spells, but the contributions are generally slightly stronger for dry spells than for wet spells. Distinguishing between the nine selected regions and between the different seasons, it is found that the strength of the contributions of the differences in soil moisture to the future changes in the various meteorological variables varies by region and, in particular, by season. Similarly, the robustness of these contributions varies between the regions and in the course of the year. The importance of soil moisture changes for the future changes in various aspects of daily precipitation and other aspects of the hydrological cycle illustrates the need for a comprehensive and realistic representation of land surface processes and of land surface conditions in climate models.
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| 14. |
- May, Wilhelm, et al.
(author)
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Projected change - Atmosphere
- 2016
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In: North Sea Region Climate Change Assessment. - Cham : Springer International Publishing. - 9783319397436 - 9783319397450 ; , s. 149-173
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Book chapter (peer-reviewed)abstract
- Several aspects describing the state of the atmosphere in the North Sea region are considered in this chapter. These include large-scale circulation, means and extremes in temperature and precipitation, cyclones and winds, and radiation and clouds. The climate projections reveal several pronounced future changes in the state of the atmosphere in the North Sea region, both in the free atmosphere and near the surface: amplification and an eastward shift in the pattern of NAO variability in autumn and winter; changes in the storm track with increased cyclone density over western Europe in winter and reduced cyclone density on the southern flank in summer; more frequent strong winds from westerly directions and less frequent strong winds from south-easterly directions; marked mean warming of 1.7–3.2 °C for different scenarios, with stronger warming in winter than in summer and a relatively strong warming over southern Norway; more intense extremes in daily maximum temperature and reduced extremes in daily minimum temperature, both in strength and frequency; an increase n mean precipitation during the cold season and a reduction during the warm season; a ronounced increase in the intensity of heavy daily precipitation events, particularly in winter; a considerable increase in the intensity of extreme hourly precipitation in summer; an increase (decrease) in cloud cover in the northern (southern) part of the North Sea region, resulting in a decrease (increase) in net solar radiation at the surface.
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| 15. |
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| 16. |
- Schmith, Torben, et al.
(author)
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Limited predictability of extreme decadal changes in the Arctic Ocean freshwater content
- 2018
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In: Climate Dynamics. - : Springer Science and Business Media LLC. - 0930-7575 .- 1432-0894. ; 51:9-10, s. 3927-3942
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Journal article (peer-reviewed)abstract
- Predictability of extreme changes in the Arctic Ocean freshwater content and the associated release into the subpolar North Atlantic up to one decade ahead is investigated using a CMIP5-type global climate model. The perfect-model setup consists of a 500 year control run, from which selected 10 year long segments are predicted by initialized, perturbed ensemble predictions. Initial conditions for these are selected from the control run to represent large positive or negative decadal changes in the total freshwater content in the Arctic Ocean. Two different classes of ensemble predictions are performed, one initialized with the ‘observed’ ocean globally, and one initialized with the model climatology in the Arctic Ocean and with the observed ocean elsewhere. Analysis reveals that the former yields superior predictions 1 year ahead as regards both liquid freshwater content and sea ice volume in the Arctic Ocean. For prediction years two and above there is no overall gain in predictability from knowing the initial state in the Arctic Ocean and damped persistence predictions perform just as well as the ensemble predictions. Areas can be identified, mainly in the proper Canadian and Eurasian basins, where knowledge of the initial conditions gives a gain in predictability of liquid freshwater content beyond year two. Total freshwater export events from the Arctic Ocean into the subpolar North Atlantic have no predictability even 1 year ahead. This is a result of the sea ice component not being predictable and LFW being on the edge of being predictable for prediction time 1 year.
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| 17. |
- Wehrli, Kathrin, et al.
(author)
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The ExtremeX global climate model experiment : investigating thermodynamic and dynamic processes contributing to weather and climate extremes
- 2022
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In: Earth System Dynamics. - : Copernicus GmbH. - 2190-4979 .- 2190-4987. ; 13:3, s. 1167-1196
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Journal article (peer-reviewed)abstract
- The mechanisms leading to the occurrence of extreme weather and climate events are varied and complex. They generally encompass a combination of dynamic and thermodynamic processes, as well as drivers external to the climate system, such as anthropogenic greenhouse gas emissions and land use change. Here we present the ExtremeX multi-model intercomparison experiment, which was designed to investigate the contribution of dynamic and thermodynamic processes to recent weather and climate extremes. The numerical experiments are performed with three Earth system models: CESM, MIROC, and EC-Earth. They include control experiments with interactive atmosphere and land surface conditions, as well as experiments wherein the atmospheric circulation, soil moisture, or both are constrained using observation-based data. The temporal evolution and magnitude of temperature anomalies during heatwaves are well represented in the experiments with a constrained atmosphere. However, the magnitude of mean climatological biases in temperature and precipitation are not greatly reduced in any of the constrained experiments due to persistent or newly introduced biases. This highlights the importance of error compensations and tuning in the standard model versions. To show one possible application, ExtremeX is used to identify the main drivers of heatwaves and warm spells. The results reveal that both atmospheric circulation patterns and soil moisture conditions substantially contribute to the occurrence of these events. Soil moisture effects are particularly important in the tropics, the monsoon areas, and the Great Plains of the United States, whereas atmospheric circulation effects are major drivers in other midlatitude and high-latitude regions.
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| 18. |
- Wu, Minchao, et al.
(author)
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Impacts of land use on climate and ecosystem productivity over the Amazon and the South American continent
- 2017
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In: Environmental Research Letters. - : IOP Publishing. - 1748-9326. ; 12:5
-
Journal article (peer-reviewed)abstract
- The Amazon basin is characterized by a strong interplay between the atmosphere and vegetation. Anthropogenic land use and land cover change (LULCC) affects vegetation and the exchange of energy and water with the atmosphere. Here we have assessed potential LULCC impacts on climate and natural vegetation dynamics over South America with a regional Earth system model that also accounts for vegetation dynamics. The biophysical and biogeochemical impacts from LULCC were addressed with two simulations over the CORDEX-South America domain. The results show that LULCC imposes local and remote influences on South American climate. These include significant local warming over the LULCC-affected area, changes in circulation patterns over the Amazon basin during the dry season, and an intensified hydrological cycle over much of the LULCC-affected area during the wet season. These changes affect the natural vegetation productivity which shows contrasting and significant changes between northwestern (around 10% increase) and southeastern (up to 10% decrease) parts of the Amazon basin caused by mesoscale circulation changes during the dry season, and increased productivity in parts of the LULCC-affected areas. We conclude that ongoing deforestation around the fringes of the Amazon could impact pristine forest by changing mesoscale circulation patterns, amplifying the degradation of natural vegetation caused by direct, local impacts of land use activities.
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| 19. |
- Wu, Minchao, et al.
(author)
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Vegetation-climate feedbacks modulate rainfall patterns in Africa under future climate change
- 2016
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In: Earth System Dynamics. - : Copernicus GmbH. - 2190-4979 .- 2190-4987. ; 7:3, s. 627-647
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Journal article (peer-reviewed)abstract
- Africa has been undergoing significant changes in climate and vegetation in recent decades, and continued changes may be expected over this century. Vegetation cover and composition impose important influences on the regional climate in Africa. Climate-driven changes in vegetation structure and the distribution of forests versus savannah and grassland may feed back to climate via shifts in the surface energy balance, hydrological cycle and resultant effects on surface pressure and larger-scale atmospheric circulation. We used a regional Earth system model incorporating interactive vegetation-atmosphere coupling to investigate the potential role of vegetation-mediated biophysical feedbacks on climate dynamics in Africa in an RCP8.5-based future climate scenario. The model was applied at high resolution (0.44 × 0.44°) for the CORDEX-Africa domain with boundary conditions from the CanESM2 general circulation model. We found that increased tree cover and leaf-area index (LAI) associated with a CO2 and climate-driven increase in net primary productivity, particularly over subtropical savannah areas, not only imposed important local effect on the regional climate by altering surface energy fluxes but also resulted in remote effects over central Africa by modulating the land-ocean temperature contrast, Atlantic Walker circulation and moisture inflow feeding the central African tropical rainforest region with precipitation. The vegetation-mediated feedbacks were in general negative with respect to temperature, dampening the warming trend simulated in the absence of feedbacks, and positive with respect to precipitation, enhancing rainfall reduction over the rainforest areas. Our results highlight the importance of accounting for vegetation-atmosphere interactions in climate projections for tropical and subtropical Africa.
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| 20. |
- Aad, G., et al.
(author)
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- 2011
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swepub:Mat__t (peer-reviewed)
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| 21. |
- Aad, G., et al.
(author)
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- 2011
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Journal article (peer-reviewed)
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| 22. |
- Aad, G., et al.
(author)
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- 2012
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swepub:Mat__t (peer-reviewed)
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| 23. |
- Aad, G., et al.
(author)
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- 2012
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swepub:Mat__t (peer-reviewed)
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| 24. |
- Aad, G., et al.
(author)
-
- 2011
-
swepub:Mat__t (peer-reviewed)
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| 25. |
- Aad, G., et al.
(author)
-
- 2013
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swepub:Mat__t (peer-reviewed)
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