Change in thunderstorm activity in a projected warmer future climate over Bangladesh

2021 ◽  
Author(s):  
Shahana Akter Esha ◽  
Nasreen Jahan
Keyword(s):  
Climate Model ◽  
Convective Available Potential Energy ◽  
Thunderstorm Activity ◽  
Future Climate ◽  
Convective Precipitation ◽  
Severe Thunderstorms ◽  
Wide Range ◽  
The Future ◽  
Rcp 8.5 ◽  
Increasing Risk

<p>Thunderstorms can have a wide range of impacts on modern societies and their assets. Severe thunderstorms associated with thunder squall, hail, tornado, and lightning cause extensive damage and losses to lives, especially in the densely populated sub-tropical countries like Bangladesh. In this study the future changes in thunderstorm conducive environments, in terms convective available potential energy (CAPE), have been assessed under the RCP 8.5 scenario for the selected major cities of Bangladesh. Results show an increase in CAPE for all the selected cities and in the range of 44%–106%. Later, a statistical thunderstorm frequency prediction model has been developed based on CAPE and convective precipitation and the probable scenario of thunderstorm frequency in the 21st century under future climate has been projected. The simulations were carried out for three different time slices (Early, Mid and Late 21<sup>st</sup> century) with CMCC-CM (Centro Euro-Mediterraneo per Cambiamenti Climatici Climate Model) model data. The future projection of thunderstorm shows an increase in thunderstorm frequency for all the season in a warmer future climate. But pre-monsoon and monsoon are found to be the most thunderstorm frequent season. Given the substantial damage from severe thunderstorms in the current climate, such increases imply an increasing risk of thunderstorm-related damage in this disaster-prone region of the world.</p>

scholarly journals Regionalization of Climate Change Simulations over the Eastern Mediterranean

2009 ◽  
Vol 22 (8) ◽  
pp. 1944-1961 ◽  
Author(s):  
Bariş Önol ◽  
Fredrick H. M. Semazzi
Keyword(s):  
Climate Change ◽  
Regional Climate Model ◽  
Temperature Increase ◽  
Climate Model ◽  
Eastern Mediterranean ◽  
Regional Climate ◽  
Future Climate ◽  
Climate Change Projections ◽  
Model Simulations ◽  
The Future

Abstract In this study, the potential role of global warming in modulating the future climate over the eastern Mediterranean (EM) region has been investigated. The primary vehicle of this investigation is the Abdus Salam International Centre for Theoretical Physics Regional Climate Model version 3 (ICTP-RegCM3), which was used to downscale the present and future climate scenario simulations generated by the NASA’s finite-volume GCM (fvGCM). The present-day (1961–90; RF) simulations and the future climate change projections (2071–2100; A2) are based on the Intergovernmental Panel on Climate Change (IPCC) greenhouse gas (GHG) emissions. During the Northern Hemispheric winter season, the general increase in precipitation over the northern sector of the EM region is present both in the fvGCM and RegCM3 model simulations. The regional model simulations reveal a significant increase (10%–50%) in winter precipitation over the Carpathian Mountains and along the east coast of the Black Sea, over the Kackar Mountains, and over the Caucasus Mountains. The large decrease in precipitation over the southeastern Turkey region that recharges the Euphrates and Tigris River basins could become a major source of concern for the countries downstream of this region. The model results also indicate that the autumn rains, which are primarily confined over Turkey for the current climate, will expand into Syria and Iraq in the future, which is consistent with the corresponding changes in the circulation pattern. The climate change over EM tends to manifest itself in terms of the modulation of North Atlantic Oscillation. During summer, temperature increase is as large as 7°C over the Balkan countries while changes for the rest of the region are in the range of 3°–4°C. Overall the temperature increase in summer is much greater than the corresponding changes during winter. Presentation of the climate change projections in terms of individual country averages is highly advantageous for the practical interpretation of the results. The consistence of the country averages for the RF RegCM3 projections with the corresponding averaged station data is compelling evidence of the added value of regional climate model downscaling.

Current and future flood risk assessment in the Danube region

2020 ◽  
Author(s):  
Kai Schröter ◽  
Michel Wortmann ◽  
Stefan Lüdtke ◽  
Ben Hayes ◽  
Martin Drews ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Flood Risk ◽  
Climate Model ◽  
Risk Model ◽  
Future Climate ◽  
Exceedance Probability ◽  
Flood Risk Assessment ◽  
Danube Catchment ◽  
The Future ◽  
Danube Region

<p>Severe hydro-meteorological hazards have been increasing during recent decades and, as a consequence of global change, more frequent and intense events are expected in the future. Climate informed planning of adaptation actions needs both consistent and reliable information about future risks and associated uncertainties, and appropriate tools to support comprehensive risk assessment and management. <br>The Future Danube Model (FDM) is a multi-hazard and risk model suite for the Danube region which provides climate information related to perils such as heavy precipitation, heatwaves, floods and droughts under recent and future climate conditions. FDM has a modular structure with exchangeable components for climate input, hydrology, inundation, risk, adaptation and visualisation. FDM is implemented within the open-source OASIS Loss Modelling Framework, which defines a standard for estimating ground-up loss and financial damage of disaster events or event scenarios. <br>The OASIS lmf implementation of the FDM is showcased for the current and future fluvial flood risk assessment in the Danube catchment. We generate stochastic inundation event sets for current and future climate in the Danube region using the output of several EURO-CORDEX models as climate input. One event set represents 10,000 years of daily climate data for a given climate model, period and representative concentration pathway. With this input, we conduct long term continuous simulations of flood processes using a coupled semi-distributed hydrological and a 1.5D hydraulic model for fluvial floods. Flood losses to residential building are estimated using a probabilistic multi-variable vulnerability model. Effects of adaptation actions are exemplified by scenarios of private precaution. Changes in risk are illustrated with exceedance probability curves for different event sets representing current and future climate on different spatial aggregation levels which are of interest for adaptation planning.</p>

scholarly journals Role of the Convection Scheme in Modeling Initiation and Intensification of Tropical Depressions over the North Atlantic

2017 ◽  
Vol 145 (4) ◽  
pp. 1495-1509 ◽  
Author(s):  
J.-P. Duvel ◽  
S. J. Camargo ◽  
A. H. Sobel
Keyword(s):  
Relative Humidity ◽  
Climate Model ◽  
Early Stage ◽  
Global Climate ◽  
Global Climate Model ◽  
Convective Available Potential Energy ◽  
Convective Precipitation ◽  
Cloud Base ◽  
Entrainment Rate ◽  
Convection Scheme

Abstract The authors analyze how modifications of the convective scheme modify the initiation of tropical depression vortices (TDVs) and their intensification into stronger warm-cored tropical cyclone–like vortices (TCs) in global climate model (GCM) simulations. The model’s original convection scheme has entrainment and cloud-base mass flux closures based on moisture convergence. Two modifications are considered: one in which entrainment is dependent on relative humidity and another in which the closure is based on the convective available potential energy (CAPE). Compared to reanalysis, TDVs are more numerous and intense in all three simulations, probably as a result of excessive parameterized deep convection at the expense of convection detraining at midlevel. The relative humidity–dependent entrainment rate increases both TDV initiation and intensification relative to the control. This is because this entrainment rate is reduced in the moist center of the TDVs, giving more intense convective precipitation, and also because it generates a moister environment that may favor the development of early stage TDVs. The CAPE closure inhibits the parameterized convection in strong TDVs, thus limiting their development despite a slight increase in the resolved convection. However, the maximum intensity reached by TC-like TDVs is similar in the three simulations, showing the statistical character of these tendencies. The simulated TCs develop from TDVs with different dynamical origins than those observed. For instance, too many TDVs and TCs initiate near or over southern West Africa in the GCM, collocated with the maximum in easterly wave activity, whose characteristics are also dependent on the convection scheme considered.

scholarly journals Climate Data to Undertake Hygrothermal and Whole Building Simulations Under Projected Climate Change Influences for 11 Canadian Cities

Data ◽  
2019 ◽  
Vol 4 (2) ◽  
pp. 72 ◽  
Author(s):  
Abhishek Gaur ◽  
Michael Lacasse ◽  
Marianne Armstrong
Keyword(s):  
Climate Change ◽  
Snow Cover ◽  
Climate Model ◽  
Global Climate ◽  
Global Climate Model ◽  
Internal Variability ◽  
Climatic Conditions ◽  
Climate Data ◽  
Wide Range ◽  
The Future

Buildings and homes in Canada will be exposed to unprecedented climatic conditions in the future as a consequence of global climate change. To improve the climate resiliency of existing and new buildings, it is important to evaluate their performance over current and projected future climates. Hygrothermal and whole building simulation models, which are important tools for assessing performance, require continuous climate records at high temporal frequencies of a wide range of climate variables for input into the kinds of models that relate to solar radiation, cloud-cover, wind, humidity, rainfall, temperature, and snow-cover. In this study, climate data that can be used to assess the performance of building envelopes under current and projected future climates, concurrent with 2 °C and 3.5 °C increases in global temperatures, are generated for 11 major Canadian cities. The datasets capture the internal variability of the climate as they are comprised of 15 realizations of the future climate generated by dynamically downscaling future projections from the CanESM2 global climate model and thereafter bias-corrected with reference to observations. An assessment of the bias-corrected projections suggests, as a consequence of global warming, future increases in the temperatures and precipitation, and decreases in the snow-cover and wind-speed for all cities.

Different approaches of finding European climate analogue regions for the Steigerwald forest (Germany) in the future

2021 ◽  
Author(s):  
Katrin Ziegler ◽  
Felix Pohl ◽  
Felix Pollinger ◽  
Heiko Paeth
Keyword(s):  
Tree Species ◽  
Climate Model ◽  
Regional Climate ◽  
Future Climate ◽  
Specific Reference ◽  
Data Set ◽  
Preparation Methods ◽  
European Climate ◽  
Forest Region ◽  
The Future

<p>Adapting the impacts of climate change is a great challenge. To facilitate forest adaptation long-term and forward-looking decisions must be made today since they have to be valid for several decades. Therefore, fundamental knowledge of the future climate and of tree species which are more resilient to the future climate than trees growing in the forests today is necessary.</p><p>To give local foresters a basis for their decisions, we use the so-called analogue region method. With this method we aim to find regions in Europe which currently have the same climate as it is projected in a specific reference region for different future scenarios. For the projections, the model runs of the regional climate model REMO are used. As an example of finding analogue regions, we selected the forest region Steigerwald in North Bavaria. We use different climatic and forest specific indices and data preparation methods to test the influence of varying indices and methods on the resulting regions. After identifying the respective analogue regions, we analyze which tree species are growing currently in these regions by using the EU-Forest data set.</p>

scholarly journals A method to encapsulate model structural uncertainty in ensemble projections of future climate: EPIC v1.0

2017 ◽  
Vol 10 (12) ◽  
pp. 4563-4575 ◽  
Author(s):  
Jared Lewis ◽  
Greg E. Bodeker ◽  
Stefanie Kremser ◽  
Andrew Tait
Keyword(s):  
Climate Models ◽  
Climate Model ◽  
Weather Generator ◽  
Future Climate ◽  
Daily Maximum ◽  
Training Phase ◽  
Large Ensemble ◽  
Stochastic Weather Generator ◽  
Wide Range ◽  
Ensemble Projections

Abstract. A method, based on climate pattern scaling, has been developed to expand a small number of projections of fields of a selected climate variable (X) into an ensemble that encapsulates a wide range of indicative model structural uncertainties. The method described in this paper is referred to as the Ensemble Projections Incorporating Climate model uncertainty (EPIC) method. Each ensemble member is constructed by adding contributions from (1) a climatology derived from observations that represents the time-invariant part of the signal; (2) a contribution from forced changes in X, where those changes can be statistically related to changes in global mean surface temperature (Tglobal); and (3) a contribution from unforced variability that is generated by a stochastic weather generator. The patterns of unforced variability are also allowed to respond to changes in Tglobal. The statistical relationships between changes in X (and its patterns of variability) and Tglobal are obtained in a training phase. Then, in an implementation phase, 190 simulations of Tglobal are generated using a simple climate model tuned to emulate 19 different global climate models (GCMs) and 10 different carbon cycle models. Using the generated Tglobal time series and the correlation between the forced changes in X and Tglobal, obtained in the training phase, the forced change in the X field can be generated many times using Monte Carlo analysis. A stochastic weather generator is used to generate realistic representations of weather which include spatial coherence. Because GCMs and regional climate models (RCMs) are less likely to correctly represent unforced variability compared to observations, the stochastic weather generator takes as input measures of variability derived from observations, but also responds to forced changes in climate in a way that is consistent with the RCM projections. This approach to generating a large ensemble of projections is many orders of magnitude more computationally efficient than running multiple GCM or RCM simulations. Such a large ensemble of projections permits a description of a probability density function (PDF) of future climate states rather than a small number of individual story lines within that PDF, which may not be representative of the PDF as a whole; the EPIC method largely corrects for such potential sampling biases. The method is useful for providing projections of changes in climate to users wishing to investigate the impacts and implications of climate change in a probabilistic way. A web-based tool, using the EPIC method to provide probabilistic projections of changes in daily maximum and minimum temperatures for New Zealand, has been developed and is described in this paper.

scholarly journals Future Changes in Surface Runoff over Korea Projected by a Regional Climate Model under A1B Scenario

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Ji-Woo Lee ◽  
Suryun Ham ◽  
Song-You Hong ◽  
Kei Yoshimura ◽  
Minsu Joh
Keyword(s):  
Climate Change ◽  
Regional Climate Model ◽  
Surface Runoff ◽  
Climate Model ◽  
Hydrological Cycle ◽  
Regional Climate ◽  
Future Climate ◽  
Climate Simulation ◽  
Intergovernmental Panel ◽  
The Future

This study assesses future change of surface runoff due to climate change over Korea using a regional climate model (RCM), namely, the Global/Regional Integrated Model System (GRIMs), Regional Model Program (RMP). The RMP is forced by future climate scenario, namely, A1B of Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment Report (AR4). The RMP satisfactorily reproduces the observed seasonal mean and variation of surface runoff for the current climate simulation. The distribution of monsoonal precipitation-related runoff is adequately captured by the RMP. In the future (2040–2070) simulation, it is shown that the increasing trend of temperature has significant impacts on the intra-annual runoff variation. The variability of runoff is increased in summer; moreover, the strengthened possibility of extreme occurrence is detected in the future climate. This study indicates that future climate projection, including surface runoff and its variability over Korea, can be adequately addressed on the RMP testbed. Furthermore, this study reflects that global warming affects local hydrological cycle by changing major water budget components. This study adduces that the importance of runoff should not be overlooked in regional climate studies, and more elaborate presentation of fresh-water cycle is needed to close hydrological circulation in RCMs.

scholarly journals Increasing potential for intense tropical and subtropical thunderstorms under global warming

2017 ◽  
Vol 114 (44) ◽  
pp. 11657-11662 ◽  
Author(s):  
Martin S. Singh ◽  
Zhiming Kuang ◽  
Eric D. Maloney ◽  
Walter M. Hannah ◽  
Brandon O. Wolding
Keyword(s):  
Global Warming ◽  
Theoretical Model ◽  
Climate Models ◽  
Climate Model ◽  
Convective Available Potential Energy ◽  
Thunderstorm Activity ◽  
Lapse Rate ◽  
Climate Projections ◽  
Entrainment Rate ◽  
The Tropics

Intense thunderstorms produce rapid cloud updrafts and may be associated with a range of destructive weather events. An important ingredient in measures of the potential for intense thunderstorms is the convective available potential energy (CAPE). Climate models project increases in summertime mean CAPE in the tropics and subtropics in response to global warming, but the physical mechanisms responsible for such increases and the implications for future thunderstorm activity remain uncertain. Here, we show that high percentiles of the CAPE distribution (CAPE extremes) also increase robustly with warming across the tropics and subtropics in an ensemble of state-of-the-art climate models, implying strong increases in the frequency of occurrence of environments conducive to intense thunderstorms in future climate projections. The increase in CAPE extremes is consistent with a recently proposed theoretical model in which CAPE depends on the influence of convective entrainment on the tropospheric lapse rate, and we demonstrate the importance of this influence for simulated CAPE extremes using a climate model in which the convective entrainment rate is varied. We further show that the theoretical model is able to account for the climatological relationship between CAPE and a measure of lower-tropospheric humidity in simulations and in observations. Our results provide a physical basis on which to understand projected future increases in intense thunderstorm potential, and they suggest that an important mechanism that contributes to such increases may be present in Earth’s atmosphere.

Temperature scaling of convective cells in present and future conditions

2020 ◽  
Author(s):  
Christopher Purr ◽  
Erwan Brisson ◽  
Bodo Ahrens
Keyword(s):  
High Temperatures ◽  
Extreme Precipitation ◽  
Climate Models ◽  
Climate Model ◽  
Maximum Intensity ◽  
Convective Precipitation ◽  
Slight Reduction ◽  
The Future ◽  
Temperature Scaling ◽  
Convective Cells

<p>Convection permitting climate models (CPMs) agree on an increase in short-term, extreme precipitation in the future. However, different studies using CPM simulations found regionally varying temperature scaling rates of hourly extreme precipitation either close to or above the Clausius-Clapeyron-rate (CC-rate) of 7%/K. These variations suggest that the dynamics of convective events strongly regulate the local scaling rates. In order to understand how the characteristics of convective events change in the future, we apply a tracking algorithm to precipitation data with 5-min temporal resolution from a regional climate model (COSMO-CLM) simulation. The model is run over central Europe at a grid size of 0.025° for an evaluation period (1981-2015) driven by ERA-Interim reanalysis data, as well as a present-day (1976-2005) and a future (2071-2100) period driven by the EC-Earth global model. We investigate the temperature scaling of convective cell characteristics like total precipitation per cell, mean area, lifetime and maximum intensity, as well as changes in the diurnal cycle of convective cells which might explain the overall scaling rates. The cell characteristics precipitation sum, mean area and maximum intensity show an exponential increase with temperature across most of the temperature range with a drop-off at high temperatures very similar to fixed location scaling curves. While the maximum intensity and area scale at rates close to the CC-rate, the precipitation sum scales at a rate close to twice the CC-rate. In contrast to this, the lifetime of convective cells does not increase with temperature but stays constant with a drop-off at high temperatures. The future simulation shows a shift of the scaling curves towards higher peak values at higher temperatures. Convective activity is projected to decrease during daytime and increase during nighttime. While the mean intensity of convective cells increases throughout the whole day, the number of cells is reduced during the afternoon peak and increased during nighttime. This leads to a slight reduction of convective precipitation during daytime and almost a doubling of convective precipitation during nighttime.</p>

Heavy rainfall and flood risk assessment method considering the future climate change

2020 ◽  
Author(s):  
Tomohito Yamada ◽  
Tsuyoshi Hoshino
Keyword(s):  
Heavy Rainfall ◽  
Flood Control ◽  
Climate Model ◽  
Model Simulation ◽  
Assessment Method ◽  
Future Climate ◽  
Future Climate Change ◽  
Observation Data ◽  
Risk Assessment Method ◽  
The Future

<p>Existing flood control plans have been implemented based on rainfall estimated from observation data. However, we have data from the past several decades. Thus, it is not enough to project future extreme events from existing observation data. Therefore, Japan has been created huge ensemble of high-resolution climate model simulation based on the laws of physics. The data consist of past and future climate situations (past climate: total 3,000 years, 4 K warmer climate: total 5,400 years). It has enabled to quantitatively evaluate the probability of heavy rainfall and flooding on the future 4K-warmed earth.</p><p>Moreover, we apply the statistical theory of extreme value to evaluate the probability of heavy rainfall and flooding in the future. The results from statistical method is equivalent to the results from the huge ensemble data from climate model. It supports Japanese governments in formulating and carrying out their adaptation plans.</p>

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