scholarly journals Ondas de calor nas capitais do Sul do Brasil e Montevidéu - Uruguai (Heat waves in the capitals of southern Brazil and Montevideo - Uruguay)

2019 ◽  
Vol 12 (4) ◽  
pp. 1259
Author(s):  
Rafael Brito Silveira ◽  
Maikon Passos Amilton Alves ◽  
Marcelo Barreiro ◽  
Daniel Pires Bitencourt
Keyword(s):  
Heat Wave ◽  
Air Temperature ◽  
Heat Waves ◽  
Kendall Test ◽  
Temperature Data ◽  
Extreme Weather Events ◽  
Southern Brazil ◽  
Porto Alegre ◽  
Significance Level ◽  
Weather Events

Múltiplas partes do globo, possivelmente, passarão a ter dias e noites mais quentes e, com a elevação das temperaturas globais, há tendências de acréscimo do risco de eventos atmosféricos extremos, tais como as ondas de calor. O objetivo principal desse estudo foi verificar as características gerais das ondas de calor nas três capitais da região Sul do Brasil (Curitiba, Florianópolis e Porto Alegre) e também em Montevidéu, capital do Uruguai. Esta análise baseou-se nos parâmetros: frequência, intensidade, duração e suas respectivas tendências. As ondas de calor foram identificadas em uma série de 30 anos de dados diários de temperatura média do ar. As análises de tendência foram averiguadas por meio do teste de Mann-Kendall a um nível de significância de α = 5%. Os resultados mostraram que todos os parâmetros nas quatro cidades apresentam tendências estatisticamente significativas e, com exceção da duração em Montevidéu, todas as demais são positivas. Para além do âmbito das tendências, analisando os parâmetros, comparativamente, conclui-se que Porto Alegre apresenta maior destaque nas médias. Além disto, afirma-se que o inverno é a estação com maior frequência de ondas de calor para todas as cidades.  A B S T R A C TMultiple parts of the globe are likely to have warmer days and nights, and with rising global temperatures, there is a tendency to increase the risk of extreme weather events, such as heat waves. The main objective of this study was to verify the general characteristics of heat waves in the three capitals of southern Brazil (Curitiba, Florianópolis and Porto Alegre) and also in Montevideo, capital of Uruguay. This analysis was based on the parameters: frequency, intensity, duration and their respective trends. Heat waves were identified in a series of 30 years of daily average air temperature data. Trend analyzes were performed using the Mann-Kendall test at a significance level of α = 5%. The results showed that all the parameters in the four cities present statistically significant trends and, except for the duration in Montevideo, all the others are positive. In addition to the scope of the trends, analyzing the parameters, comparatively, it is concluded that Porto Alegre presents greater prominence in the averages. In addition, it is claimed that winter is the season with the highest frequency of heat waves for all cities.Keywords: heat wave, subtropical, capitals, trends, parameters.

scholarly journals Extreme Weather Impacts on Inland Waterways Transport of Yangtze River

Atmosphere ◽  
2019 ◽  
Vol 10 (3) ◽  
pp. 133 ◽  
Author(s):  
Lijun Liu ◽  
Yuanqiao Wen ◽  
Youjia Liang ◽  
Fan Zhang ◽  
Tiantian Yang
Keyword(s):  
Heat Wave ◽  
Yangtze River ◽  
Heat Waves ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
The Yangtze River ◽  
Climate Zone ◽  
Inland Waterways ◽  
Weather Events ◽  
The Impact

The impact of extreme weather events on the navigation environment in the inland waterways of the Yangtze River is an interdisciplinary hotspot in subjects of maritime traffic safety and maritime meteorology, and it is also a difficult point for the implementation of decision-making and management by maritime and meteorological departments in China. The objective of this study is to review the variation trends and distribution patterns in the periods of adverse and extreme weather events that are expected to impact on inland waterways transport (IWT) on the Yangtze River. The frequency of severe weather events, together with the changes in their spatial extension and intensity, is analyzed based on the ERA-Interim datasets (1979–2017) and the GHCNDEX dataset (1979–2017), as well as the research progresses and important events (2004–2016) affecting the navigation environment. The impacts of extreme weather events on IWT accidents and phenomena of extreme weather (e.g., thunderstorms, lightning, hail, and tornadoes) that affect the navigation environment are also analyzed and discussed. The results show that: (1) the sections located in the plain climate zone is affected by extreme weather in every season, especially strong winds and heat waves; (2) the sections located in the hilly mountain climate zone is affected particularly by spring extreme phenomena, especially heat waves; (3) the sections located in the Sichuan Basin climate zone is dominated by the extreme weather phenomena in autumn, except cold waves; (4) the occurrence frequency of potential flood risk events is relatively high under rainstorm conditions and wind gusts almost affect the navigation environment of the Jiangsu and Shanghai sections in every year; (5) the heat wave indices (TXx, TR, and WSDI) tend to increase and the temperature of the coldest day of the year gradually increases; (6) the high occurrences of IWT accidents need to be emphasized by relevant departments, caused by extreme weather during the dry season; and (7) the trends and the degree of attention of extreme weather events affecting IWT are ranked as: heat wave > heavy rainfall > wind gust > cold spell > storm. Understanding the seasonal and annual frequency of occurrence of extreme weather events has reference significance for regional management of the Yangtze River.

scholarly journals Reliability Framework for Characterizing Heat Wave and Cold Spell Events

2021 ◽  
Author(s):  
Sanaz Moghim ◽  
Mohammad Sina Jahangir
Keyword(s):  
Heat Wave ◽  
Heat Waves ◽  
Probability Distributions ◽  
Extreme Temperature ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Average Intensity ◽  
Cold Spell ◽  
Weather Events ◽  
Two Cities

Abstract Extreme weather events such as heat waves and cold spells affect people’s lives. This study uses a probabilistic framework to evaluate heat waves and cold spells in different regions (Tehran in Iran and Vancouver in Canada). Average daily temperatures of meteorological stations of the two cities from 1995 to 2016 are used to identify four main indicators including intensity, average intensity, duration, and the rate of the occurrence. In addition, average intensities of the events are obtained from the MODIS Land Surface Temperature (LST) in each pixel of the two cities. To include possible uncertainties, the predictive probability distributions of the intensity and duration are derived using a Bayesian scheme and Monte-Carlo Markov Chain (MCMC) method. The probability distributions of the indicators show that the most extreme temperature (lowest temperature) occurs during the cold spell. Results indicate that although Tehran is more probable to experience heat waves than Vancouver, both cities are more likely to be affected by the cold spell than the heat wave. The developed approach can be used to characterize other extreme weather events in any location.

scholarly journals Heat wave effects on the behavior and life-history traits of sedentary antlions

2020 ◽  
Vol 31 (6) ◽  
pp. 1326-1333 ◽  
Author(s):  
Krzysztof Miler ◽  
Daniel Stec ◽  
Marcin Czarnoleski
Keyword(s):  
Heat Wave ◽  
Heat Waves ◽  
The Body ◽  
Extreme Weather Events ◽  
Closely Related Species ◽  
Hunting Activity ◽  
Weather Events ◽  
Wave Effects ◽  
Microhabitat Preferences

Abstract Research on the behavioral responses of animals to extreme weather events, such as heat wave, is lacking even though their frequency and intensity in nature are increasing. Here, we investigated the behavioral response to a simulated heat wave in two species of antlions (Neuroptera: Myrmeleontidae). These insects spend the majority of their lives as larvae and live in sandy areas suitable for a trap-building hunting strategy. We used larvae of Myrmeleon bore and Euroleon nostras, which are characterized by different microhabitat preferences—sunlit in the case of M. bore and shaded in the case of E. nostras. Larvae were exposed to fluctuating temperatures (40 °C for 10 h daily and 25 °C for the remaining time) or a constant temperature (25 °C) for an entire week. We found increased mortality of larvae under heat. We detected a reduction in the hunting activity of larvae under heat, which corresponded to changes in the body mass of individuals. Furthermore, we found long-term consequences of the simulated heat wave, as it prolonged the time larvae needed to molt. These effects were pronounced in the case of E. nostras but did not occur or were less pronounced in the case of M. bore, suggesting that microhabitat-specific selective pressures dictate how well antlions handle heat waves. We, thus, present results demonstrating the connection between behavior and the subsequent changes to fitness-relevant traits in the context of a simulated heat wave. These results illustrate how even closely related species may react differently to the same event.

scholarly journals Extremal dependence as given by the tail pairwise dependence matrix inprecipitation and temperature data

2021 ◽  
Author(s):  
Svenja Szemkus ◽  
Petra Friederichs
Keyword(s):  
Principal Component Analysis ◽  
Spatial Patterns ◽  
Heat Waves ◽  
Principal Component ◽  
Component Analysis ◽  
Extreme Weather ◽  
Temperature Data ◽  
Extreme Weather Events ◽  
Weather Events ◽  
Pairwise Dependence

<p>A better understanding of the dynamics and impacts of extreme weather events and their changes due to climate change is the subject of the ClimXtreme project (climxtreme.net) funded by the German Federal Ministry of Education and Research. <br>The CoDEx project is investigating how data compression techniques can contribute to a better description and understanding of extremes. Various unsupervised learning approaches, such as clustering or principal component analysis, focusing on extremes have been developed recently and will be investigated and compared within the project. <br>We use principal component analysis to study the spatial (co-)occurrence during extreme weather events such as heavy precipitation, heat waves or droughts. The focus on extreme events is done by using the tail pairwise dependence matrix (TPDM), proposed by Cooley and Thibaud (2019) as an analogue to the covariance matrix for extremes. Since the simultaneous occurrence of precipitation deficits and high temperature played an important role, especially in heat waves, we explore how Cooley and Thibaud's concept can be used in this regard. We propose an estimation of the TPDM based on pairwise dependencies of two variables. A singular value decomposition gives us insight into the spatial co-occurrence of extreme spatial patterns, which contributes to the understanding of so-called compound events. <br>We use daily precipitation and temperature data, including observational stations and regional reanalyses in Germany and Europe. Using this method, we extract spatial patterns over Germany and Europe based on extreme dependencies. In addition, we identify historical events, and examine them in more detail in this context.</p>

scholarly journals An updated review on recent trends in observational surface atmospheric variables and their extremes over Spain

2017 ◽  
Vol 43 (1) ◽  
pp. 209 ◽  
Author(s):  
S.M. Vicente-Serrano ◽  
E. Rodríguez-Camino ◽  
F. Domínguez-Castro ◽  
A. El Kenawy ◽  
C. Azorín-Molina
Keyword(s):  
Wind Speed ◽  
Solar Radiation ◽  
Air Temperature ◽  
Heat Waves ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Weather Events ◽  
Recent Trends ◽  
The Mean ◽  
Atmospheric Variables

This article reviewed state-of-the-art findings on recent trends in observed atmospheric variables and their extremes in Spain. Our study screened peer-reviewed articles, published within the last decade, on recent climate variability in Spain, with a particular focus on a range of the essential atmospheric variables. The review focusses on the recent evolution of precipitation and air temperature, but also on other meteorological variables such as solar radiation, wind speed, surface humidity and evapotranspiration. While this review highlights results on changes in the mean state of climate in Spain, it also gives equal attention to findings on extreme weather events (e.g. rainstorms, heat waves and droughts). This paper also reviews trends of the most extreme events, like rainstorms, heat waves and droughts. A detailed review of studies focusing on recent changes in the surface climate of Spain revealed some key findings. Studies demonstrate an overall increase of solar radiation since the 1980s. A similar behaviour was observed for surface air temperature since the 1960s, on the order of +0.3ºC decade-1, with rapid warming rates during summer. Different seasonal trend patterns of wind speed were noted over Spain, with declines in winter-spring and increases in summer-autumn. A remarkable decrease (-5%) in relative humidity was observed from 1961 to 2011. For precipitation, studies suggested a strong variability over both space and time, with a moderate decrease of the annual total precipitation. In accordance with changes in the mean conditions of climate, studies of extreme weather events stressed a notable warming in warm extremes, while changes in cold extremes were generally insignificant.

scholarly journals Impacts of compound extreme weather events on ozone in the present and future

2018 ◽  
Author(s):  
Junxi Zhang ◽  
Yang Gao ◽  
Kun Luo ◽  
L. Ruby Leung ◽  
Yang Zhang ◽  
...  
Keyword(s):  
Extreme Events ◽  
Heat Waves ◽  
Extreme Weather ◽  
Extreme Weather Events ◽  
Low Wind Speed ◽  
Weather Events ◽  
The Us ◽  
The Future ◽  
Compound Events ◽  
Ozone Episodes

Abstract. The Weather Research and Forecasting model with Chemistry (WRF/Chem) was used to study the effect of extreme weather events on ozone in US for historical (2001–2010) and future (2046–2055) periods under RCP8.5 scenario. During extreme weather events, including heat waves, atmospheric stagnation, and their compound events, ozone concentration is much higher compared to non-extreme events period. A striking enhancement of effect during compound events is revealed when heat wave and stagnation occur simultaneously and both high temperature and low wind speed promote the production of high ozone concentrations. In regions with high emissions, compound extreme events can shift the high-end tails of the probability density functions (PDFs) of ozone to even higher values to generate extreme ozone episodes. In regions with low emissions, extreme events can still increase high ozone frequency but the high-end tails of the PDFs are constrained by the low emissions. Despite large anthropogenic emission reduction projected for the future, compound events increase ozone more than the single events by 10 % to 13 %, comparable to the present, and high ozone episodes are not eliminated. Using the CMIP5 multi-model ensemble, the frequency of compound events is found to increase more dominantly compared to the increased frequency of single events in the future over the US, Europe, and China. High ozone episodes will likely continue in the future due to increases in both frequency and intensity of extreme events, despite reductions in anthropogenic emissions of its precursors. However, the latter could reduce or eliminate extreme ozone episodes, so improving projections of compound events and their impacts on extreme ozone may better constrain future projections of extreme ozone episodes that have detrimental effects on human health.

scholarly journals Affrontare il cambiamento climatico è una ‘missione possibile’

2020 ◽  
Vol 32 (1) ◽  
pp. 154-160
Author(s):  
Roberto Buizza
Keyword(s):  
Climate Change ◽  
Greenhouse Gases ◽  
Heat Waves ◽  
Extreme Weather Events ◽  
Health Issues ◽  
Ice Melting ◽  
Greenhouse Gases Emissions ◽  
The Earth ◽  
Weather Events ◽  
Change Impact

Climate change is real, and we, humans, are responsible for it. Its impact is already evident, both on the Earth system (global warming, sea-level rise, sea-ice melting, more intense and frequent extreme weather events such as heat waves and fires) and on people (famines, health issues, migrations, political tensions and conflicts). We need immediate and concrete mitigation actions aiming to reduce greenhouse gases emissions, and adaptation actions to be able to cope with the increasing changing climate. We have to reach zero-net greenhouse gases emissions as soon as possible, by reducing emissions by at least 5% a year, starting from now. Otherwise the climate change impact will become more and more severe: it will induce more injustice, and it will have a major impact on people health. We have the resources and the technologies to deal with it: we must have the courage to change and transform and deal with it. Addressing climate change is not impossible: to the contrary, it is a ‘possible mission’.

scholarly journals If They Like You, They Learn from You: How a Brief Weathercaster-Delivered Climate Education Segment Is Moderated by Viewer Evaluations of the Weathercaster

2013 ◽  
Vol 5 (4) ◽  
pp. 367-377 ◽  
Author(s):  
Ashley A. Anderson ◽  
Teresa A. Myers ◽  
Edward W. Maibach ◽  
Heidi Cullen ◽  
Jim Gandy ◽  
...  
Keyword(s):  
Global Warming ◽  
South Carolina ◽  
Heat Wave ◽  
Risk Perceptions ◽  
Extreme Weather Events ◽  
Tv Viewing ◽  
Significant Interaction Effect ◽  
Weather Events ◽  
Local Manifestation ◽  
Promising Source

Abstract Local television (TV) weathercasters are a potentially promising source of climate education, in that weather is the primary reason viewers watch local TV news, large segments of the public trust TV weathercasters as a source of information about global warming, and extreme weather events are increasingly common (Leiserowitz et al.; U.S. Global Change Research Program). In an online experiment conducted in two South Carolina cities (Greenville, n = 394; Columbia, n = 352) during and immediately after a summer heat wave, the effects on global warming risk perceptions were examined following exposure to a TV weathercast in which a weathercaster explained the heat wave as a local manifestation of global warming versus exposure to a 72-h forecast of extreme heat. No main effect of the global warming video on learning was found. However, a significant interaction effect was found: subjects who evaluated the TV weathercaster more positively were positively influenced by the global warming video, and viewers who evaluated the weathercaster less positively were negatively influenced by the video. This effect was strongest among politically conservative viewers. These results suggest that weathercaster-delivered climate change education can have positive, albeit nuanced, effects on TV-viewing audiences.

scholarly journals Air Temperature Change in the Southern Tarim River Basin, China, 1964–2011

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Benfu Zhao ◽  
Jianhua Xu ◽  
Zhongsheng Chen ◽  
Ling Bai ◽  
Peng Li
Keyword(s):  
Correlation Analysis ◽  
River Basin ◽  
Air Temperature ◽  
Negative Correlation ◽  
Kendall Test ◽  
Temperature Data ◽  
Tarim River ◽  
Tarim River Basin ◽  
Change Rate ◽  
Mann Kendall Test

The temperature data from 3 meteorological stations (Kashi, Ruoqiang, and Hotan) in the South of Tarim River Basin (STRB) during 1964–2011 were analyzed by Mann-Kendall test and correlation analysis. The results from Mann-Kendall test show that the surface temperature (ST), 850 hPa temperature (T850), and 700 hPa temperature (T700) exhibited upward trends, while 300 hPa temperature (T300) revealed a downward trend. On the whole, the change rate of ST, T850, T700, and T300 was 0.26~0.46°C/10a, 0.15~0.40°C/10a, 0.03~0.10°C/10a, and −0.38~−0.13°C/10a, respectively. For the periods, ST and T850 declined during 1964–1997 and then rose during 1998–2011. T700 declined during 1964–2005 and then rose during 2006–2011, while T300 rose from 1964 to 1970s and then declined. The results from correlation analysis show that T850 and T700 positively correlated with ST (P<0.01) at the all three stations and there was a negative correlation between T300 and ST at Hotan (P<0.1), while the correlation is not significant at Kashi and Ruoqiang. The results indicate that there were gradient differences in the response of upper-air temperature (UT) to ST change.

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