Flood and center timing in a changing world

2021 ◽  
Author(s):  
Conrad Wasko ◽  
Rory Nathan ◽  
Murray Peel
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Extreme Rainfall ◽  
Interesting Property ◽  
Quality Data ◽  
Climate Change Signal ◽  
Catchment Scale ◽  
Antecedent Moisture ◽  
Flood Magnitude ◽  
Definition Of

<p>Climate change is expected to change the pattern of rainfall resulting in changed flood magnitude. However, in large part due to interannual variability, identifying a climate change signal in flood magnitude remains difficult. As an alternative to investigating trends in flood magnitude, it has been suggested that trends in flood timing, that is, the day of annual streamflow maxima, may be a detectable trend due climate change.</p><p>Here, using high-quality data from around the world, trends in flood and center timing are investigated. We begin by standardizing the data on a local definition of water year. We find an interesting property, that after standardization, the flood and centre timing of streamflow can be approximated by a normal distribution. Moreover, we find that without the standardization on local water year the calculated trend can reverse. We proceed by analyzing trends in centre and flood timing globally using linear regression.</p><p>Results are commensurable with large-scale climatic change. But, unlike changes in extreme rainfall, trends are not spatially consistent. Flood timing is shifting to earlier in the year in the tropics, and later in the year in the extra-tropics, consistent with changes in mean rainfall and flood magnitude. There is evidence of a reversal of trends post-drought, suggesting that the mechanisms controlling flooding at a catchment scale are changing as a result of climate change. It is concluded that trends in flood timing are related to flood generating mechanisms, and largely modulated by changing antecedent moisture conditions.</p>

scholarly journals Impact of air–sea coupling on the climate change signal over the Iberian Peninsula

2021 ◽  
Author(s):  
Alba de la Vara ◽  
William Cabos ◽  
Dmitry V. Sein ◽  
Claas Teichmann ◽  
Daniela Jacob
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Mediterranean Sea ◽  
Large Scale ◽  
Regional Distribution ◽  
Coupled Model ◽  
Climate Change Signal ◽  
The North ◽  
The Mediterranean ◽  
The Impact

AbstractIn this work we use a regional atmosphere–ocean coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere–ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP climate is influenced by both the Atlantic Ocean and the Mediterranean sea. Complex interactions with the orography take place there and high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the twenty-first century (2070–2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between the coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model show that regionalization has an effect in terms of higher resolution over the land and ocean.

scholarly journals Atmospheric Climate Change Detection by Radio Occultation Data Using a Fingerprinting Method

2011 ◽  
Vol 24 (20) ◽  
pp. 5275-5291 ◽  
Author(s):  
Bettina C. Lackner ◽  
Andrea K. Steiner ◽  
Gabriele C. Hegerl ◽  
Gottfried Kirchengast
Keyword(s):  
Climate Change ◽  
Change Detection ◽  
Confidence Level ◽  
Geopotential Height ◽  
Radio Occultation ◽  
Lower Stratosphere ◽  
Quality Data ◽  
Climate Change Signal ◽  
High Quality ◽  
Climate Change Detection

Abstract The detection of climate change signals in rather short satellite datasets is a challenging task in climate research and requires high-quality data with good error characterization. Global Navigation Satellite System (GNSS) radio occultation (RO) provides a novel record of high-quality measurements of atmospheric parameters of the upper-troposphere–lower-stratosphere (UTLS) region. Because of characteristics such as long-term stability, self calibration, and a very good height resolution, RO data are well suited to investigate atmospheric climate change. This study describes the signals of ENSO and the quasi-biennial oscillation (QBO) in the data and investigates whether the data already show evidence of a forced climate change signal, using an optimal-fingerprint technique. RO refractivity, geopotential height, and temperature within two trend periods (1995–2010 intermittently and 2001–10 continuously) are investigated. The data show that an emerging climate change signal consistent with the projections of three global climate models from the Coupled Model Intercomparison Project cycle 3 (CMIP3) archive is detected for geopotential height of pressure levels at a 90% confidence level both for the intermittent and continuous period, for the latter so far in a broad 50°S–50°N band only. Such UTLS geopotential height changes reflect an overall tropospheric warming. 90% confidence is not achieved for the temperature record when only large-scale aspects of the pattern are resolved. When resolving smaller-scale aspects, RO temperature trends appear stronger than GCM-projected trends, the difference stemming mainly from the tropical lower stratosphere, allowing for climate change detection at a 95% confidence level. Overall, an emerging trend signal is thus detected in the RO climate record, which is expected to increase further in significance as the record grows over the coming years. Small natural changes during the period suggest that the detected change is mainly caused by anthropogenic influence on climate.

Compare and Analyze of the Definition and Development of Distributed Generation in China and Abroad

2014 ◽  
Vol 953-954 ◽  
pp. 925-928 ◽  
Author(s):  
Bi Bin Huang
Keyword(s):  
Climate Change ◽  
Power Generation ◽  
Energy Conservation ◽  
Distributed Generation ◽  
Basic Characteristic ◽  
Large Scale ◽  
General Definition ◽  
Development Status ◽  
Incentive Policy ◽  
Definition Of

As the positive and important supplement to large-scale power generation, distributed generation (DG) will become key measure to promote energy conservation and solve the problems of climate change in China. Due to absence of universal authoritative definition of DG, this paper summarizes the basic characteristic of DG based on the definitions in typical countries (or organizations) and carried out general definition of DG considering our national conditions and power grid features. From the views of resource, incentive policy and industry, this paper analyzed the fundamental for DG development and compared the development status in typical countries.

scholarly journals A wavelet-based approach to detect climate change on the coherent and turbulent component of the atmospheric circulation

2016 ◽  
Vol 7 (2) ◽  
pp. 517-523 ◽  
Author(s):  
Davide Faranda ◽  
Dimitri Defrance
Keyword(s):  
Climate Change ◽  
Atmospheric Circulation ◽  
Coherent Structures ◽  
Large Scale ◽  
Dominant Role ◽  
Moving Average ◽  
Climate Change Signal ◽  
Complex Spectrum ◽  
Wind Fields ◽  
Turbulent Spectra

Abstract. The modifications of atmospheric circulation induced by anthropogenic effects are difficult to capture because wind fields feature a complex spectrum where the signal of large-scale coherent structures (planetary, baroclinic waves and other long-term oscillations) is mixed up with turbulence. Our purpose is to study the effects of climate changes on these two components separately by applying a wavelet analysis to the 700 hPa wind fields obtained in climate simulations for different forcing scenarios. We study the coherent component of the signal via a correlation analysis to detect the persistence of large-scale or long-lasting structures, whereas we use the theory of autoregressive moving-average stochastic processes to measure the spectral complexity of the turbulent component. Under strong anthropogenic forcing, we detect a significant climate change signal. The analysis suggests that coherent structures will play a dominant role in future climate, whereas turbulent spectra will approach a classical Kolmogorov behaviour.

scholarly journals FRONTLINE: Climate change reporting in an Australian context: Recognition, adaptation and solutions

2013 ◽  
Vol 19 (1) ◽  
pp. 203 ◽  
Author(s):  
Bridget Fitzgerald
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Environmental Reporting ◽  
Context Recognition ◽  
Advocacy Journalism ◽  
Local Impacts ◽  
Definition Of ◽  
Journalism Research ◽  
Journalistic Practice ◽  
Impacts Of Climate Change

Exegesis: This exegesis is based on the production of three features that explore local impacts of climate change. The features are part of a journalism research project that investigated the question: how can journalistic practice generate an accurate, balanced account of climate change issues in Australia? The journalist rejects an approach that positions environmental reporting—or the ‘green beat’—as a form of advocacy journalism. In contrast, the researcher positions her journalism practice within mainstream Australian journalism. The researcher sets out to produce reports, which adhere to the conventional journalism norms, including those of ‘balance’ and ‘accuracy’. She explicitly critiques and rejects the phenomenon known as ‘balance as bias’, explored by Boykoff and Boycoff (2004) which, by over accessing climate sceptic sources, obstructs the reporting of climate change as an important economic, social, political and environmental issue. This exegesis explains and defends a different approach that focuses on local reporting rather than large-scale events in distant places. Robert Entman’s definition of framing is used to explain how climate change issues were addressed in each narrative.

scholarly journals Riparian ecosystem in the alpine connectome. Terrestrial-aquatic and terrestrial-terrestrial interactions in high elevation lakes

2015 ◽  
Author(s):  
Dragos G Zaharescu ◽  
Antonio Palanca-Soler ◽  
Peter S Hooda ◽  
Catalin Tanase ◽  
Carmen I Burghelea ◽  
...  
Keyword(s):  
Climate Change ◽  
Environmental Change ◽  
Large Scale ◽  
Water Saturation ◽  
Catchment Scale ◽  
Landscape Elements ◽  
Riparian Ecosystem ◽  
Wide Range ◽  
Terrestrial Environments ◽  
Surrounding Landscape

Alpine regions are under increased attention worldwide do their role in storing freshwater of high quality and their high sensitivity to climate change - comparable only to the poles. Riparian ecosystems in such regions, integrating water and nutrient fluxes from aquatic and terrestrial environments, host a disproportionally rich biodiversity, despite experiencing severe climate and nutrient restrictions. With climate change rapidly encroaching in the alpine biome, it is important to fully understand how the lake and its surrounding landscape elements sustain such rich ecosystems, before their functional connectivity could be seriously severed. A total of 189 glacial origin lakes in the Central Pyrenees were surveyed to test how key elements of lake and terrestrial environments work together at different scales to shape the riparian plant composition. Secondly, we evaluated how these ecotope features drive the formation of riparian communities potentially sensitive to environmental change, and assessed their habitat distribution. At each lake plant taxonomic composition was assessed together with elemental composition of water and sediment and ecosystem-relevant geographical factors. At macroscale vegetation composition responded to pan-climatic gradients altitude and latitude, which captured, in a narrow geographic area the transition between large European climatic zones. Hydrodynamics was the main catchment-scale factor connecting riparian vegetation with large-scale water fluxes, followed by topography and geomorphology. Lake sediment Mg and Pb, and water Mn and Fe contents reflected local connections with nutrient availability, and water saturation of the substrate. Community analysis identified four keystone plant communities of large niche breadths, present in a wide range of habitats, from (i) damp environments, (ii) snow bed-silicate bedrock, (iii) wet heath, and (iv) limestone bedrock. With environmental change advancing in the alpine biome, this study provides critical information on fundamental linkages between riparian ecosystem and surrounding landscape elements, which could prove invaluable in assessing future biomic impacts.

scholarly journals Detecting range shifts among Australian fishes in response to climate change

2011 ◽  
Vol 62 (9) ◽  
pp. 1027 ◽  
Author(s):  
David J. Booth ◽  
Nick Bond ◽  
Peter Macreadie
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Environmental Changes ◽  
Meta Analysis ◽  
Economic Consequences ◽  
Range Shifts ◽  
Definitive Evidence ◽  
Key Drivers ◽  
Definition Of ◽  
Impacts Of Climate Change

One of the most obvious and expected impacts of climate change is a shift in the distributional range of organisms, which could have considerable ecological and economic consequences. Australian waters are hotspots for climate-induced environmental changes; here, we review these potential changes and their apparent and potential implications for freshwater, estuarine and marine fish. Our meta-analysis detected <300 papers globally on ‘fish’ and ‘range shifts’, with ~7% being from Australia. Of the Australian papers, only one study exhibited definitive evidence of climate-induced range shifts, with most studies focussing instead on future predictions. There was little consensus in the literature regarding the definition of ‘range’, largely because of populations having distributions that fluctuate regularly. For example, many marine populations have broad dispersal of offspring (causing vagrancy). Similarly, in freshwater and estuarine systems, regular environmental changes (e.g. seasonal, ENSO cycles – not related to climate change) cause expansion and contraction of populations, which confounds efforts to detect range ‘shifts’. We found that increases in water temperature, reduced freshwater flows and changes in ocean currents are likely to be the key drivers of climate-induced range shifts in Australian fishes. Although large-scale frequent and rigorous direct surveys of fishes across their entire distributional ranges, especially at range edges, will be essential to detect range shifts of fishes in response to climate change, we suggest careful co-opting of fisheries, museum and other regional databases as a potential, but imperfect alternative.

scholarly journals CECILIA Regional Climate Simulations for Future Climate: Analysis of Climate Change Signal

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Michal Belda ◽  
Petr Skalák ◽  
Aleš Farda ◽  
Tomáš Halenka ◽  
Michel Déqué ◽  
...  
Keyword(s):  
Climate Change ◽  
Large Scale ◽  
Climate Models ◽  
Regional Climate ◽  
Regional Climate Models ◽  
Global Scale ◽  
Climate Change Signal ◽  
Northwestern Part ◽  
Climate Simulations ◽  
Climate Analysis

Regional climate models (RCMs) are important tools used for downscaling climate simulations from global scale models. In project CECILIA, two RCMs were used to provide climate change information for regions of Central and Eastern Europe. Models RegCM and ALADIN-Climate were employed in downscaling global simulations from ECHAM5 and ARPEGE-CLIMAT under IPCC A1B emission scenario in periods 2021–2050 and 2071–2100. Climate change signal present in these simulations is consistent with respective driving data, showing similar large-scale features: warming between 0 and 3°C in the first period and 2 and 5°C in the second period with the least warming in northwestern part of the domain increasing in the southeastern direction and small precipitation changes within range of +1 to −1 mm/day. Regional features are amplified by the RCMs, more so in case of the ALADIN family of models.

scholarly journals Towards advancing scientific knowledge of climate change impacts on short-duration rainfall extremes

2021 ◽  
Vol 379 (2195) ◽  
pp. 20190542 ◽  
Author(s):  
Hayley J. Fowler ◽  
Haider Ali ◽  
Richard P. Allan ◽  
Nikolina Ban ◽  
Renaud Barbero ◽  
...  
Keyword(s):  
Climate Change ◽  
Short Duration ◽  
Large Scale ◽  
Flash Flood ◽  
Extreme Rainfall ◽  
Heavy Precipitation ◽  
Climate Modelling ◽  
Large Scale Circulation ◽  
Rainfall Extremes ◽  
International Coordination

A large number of recent studies have aimed at understanding short-duration rainfall extremes, due to their impacts on flash floods, landslides and debris flows and potential for these to worsen with global warming. This has been led in a concerted international effort by the INTENSE Crosscutting Project of the GEWEX (Global Energy and Water Exchanges) Hydroclimatology Panel. Here, we summarize the main findings so far and suggest future directions for research, including: the benefits of convection-permitting climate modelling; towards understanding mechanisms of change; the usefulness of temperature-scaling relations; towards detecting and attributing extreme rainfall change; and the need for international coordination and collaboration. Evidence suggests that the intensity of long-duration (1 day+) heavy precipitation increases with climate warming close to the Clausius–Clapeyron (CC) rate (6–7% K −1 ), although large-scale circulation changes affect this response regionally. However, rare events can scale at higher rates, and localized heavy short-duration (hourly and sub-hourly) intensities can respond more strongly (e.g. 2 × CC instead of CC). Day-to-day scaling of short-duration intensities supports a higher scaling, with mechanisms proposed for this related to local-scale dynamics of convective storms, but its relevance to climate change is not clear. Uncertainty in changes to precipitation extremes remains and is influenced by many factors, including large-scale circulation, convective storm dynamics andstratification. Despite this, recent research has increased confidence in both the detectability and understanding of changes in various aspects of intense short-duration rainfall. To make further progress, the international coordination of datasets, model experiments and evaluations will be required, with consistent and standardized comparison methods and metrics, and recommendations are made for these frameworks. This article is part of a discussion meeting issue ‘Intensification of short-duration rainfall extremes and implications for flash flood risks’.

scholarly journals Impact of Air-Sea Coupling on the Climate Change Signal Over The Iberian Peninsula

2021 ◽  
Author(s):  
ALBA DE LA VARA ◽  
William Cabos ◽  
Dmitry V. Sein ◽  
Claas Teichmann ◽  
Daniela Jacob
Keyword(s):  
Climate Change ◽  
Iberian Peninsula ◽  
Large Scale ◽  
Regional Distribution ◽  
Coupled Model ◽  
Added Value ◽  
Climate Change Signal ◽  
The North ◽  
Projected Changes ◽  
The Impact

Abstract In this work we use a regional ocean-atmosphere coupled model (RAOCM) and its stand-alone atmospheric component to gain insight into the impact of atmosphere-ocean coupling on the climate change signal over the Iberian Peninsula (IP). The IP is a well suited location for this study as high-resolution models are required to realistically reproduce its current and future climate. We find that under the RCP8.5 scenario, the generalized 2-m air temperature (T2M) increase by the end of the 21st century (2070-2099) in the atmospheric-only simulation is tempered by the coupling. The impact of coupling is specially seen in summer, when the warming is stronger. Precipitation shows regionally-dependent changes in winter, whilst a drier climate is found in summer. The coupling generally reduces the magnitude of the changes. Differences in T2M and precipitation between coupled and uncoupled simulations are caused by changes in the Atlantic large-scale circulation and in the Mediterranean Sea. Additionally, the differences in projected changes of T2M and precipitation with the RAOCM under the RCP8.5 and RCP4.5 scenarios are tackled. Results show that in winter and summer T2M increases less and precipitation changes are of a smaller magnitude with the RCP4.5. Whilst in summer changes present a similar regional distribution in both runs, in winter there are some differences in the NW of the IP due to differences in the North Atlantic circulation. The differences in the climate change signal from the RAOCM and the driving Global Coupled Model shows the added value of regionalization in terms of higher resolution over the land and ocean.

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