scholarly journals Detecção de Mudanças Climáticas Através de Índices Pluviométricos Diários no Estado de Pernambuco (Detection of Climate Change Through Daily rainfall in the State of Pernambuco)

2013 ◽  
Vol 6 (4) ◽  
pp. 713 ◽  
Author(s):  
Priscila V. dos Santos ◽  
Rosaline Dos Santos ◽  
Maytê D. L. Coutinho

O objetivo do presente trabalho é estimar e analisar índices de detecção e monitoramento de mudanças climáticas, decorrentes da precipitação diária, para o Estado de Pernambuco, verificar sua possível dependência das anomalias de temperatura da superfície do mar e examinar suas influências sobre a dinâmica da vegetação, medida pelo Índice de Vegetação por Diferenças Normalizadas (IVDN), e variabilidade do clima, estimada pelo Índice Inverso de Aridez de Budyko (IIAB) anual. Para isso utilizou-se dados de precipitação totais diários de 26 localidades, anomalias de TSM para o período de 1964 a 2006, IVDN mensais de 1982 a 2001 e estimativa de temperaturas do ar média, máxima e mínima. Observou-se um decaimento da precipitação total anual, da intensidade simples diária da precipitação, dos dias consecutivos úmidos, dos dias com chuva superior a 20mm/dia e inferior a 50mm/dia, e aumento dos dias consecutivos secos. Verificou-se que, além do total anual de precipitação, o número de dias consecutivos secos, número de dias no ano com chuvas acima de 10mm/dia e intensidade simples diária de precipitação são dependentes dos padrões de anomalias de TSM nos Oceanos Pacífico Equatorial e Atlântico Tropical. O IVDN é influenciado pela precipitação total e pelo número de dias com chuvas superiores a 10mm/dia, principalmente no Alto Sertão do Estado. O índice inverso de aridez de Budyko é dependente das configurações das anomalias de TSM dos Oceanos Pacífico Equatorial e Atlântico Tropical Norte, e exerce influência sobre o IVDN. A B S T R A C T The objectives of the present work are: to compute and to analyze climate extreme indexes for monitoring and detecting climate change, for the state of Pernambuco; to verify the possible dependence of the extreme indexes of the anomalies of the sea surface temperature and to examine the influences of the extreme indexes on the dynamics of the vegetation, measured by NDVI (Normalized Difference Vegetation Index), and climate variability, evaluated for IIAB (Aridity Inverse Index of Budyko) annual. It was used precipitation diaries data from 26 meteorological stations, anomalies of SST for the period from 1964 to 2006, monthly NDVI from 1982 to 2001 and the mean, maxima and minima air temperature. It was observed a decline of the annual total precipitation, precipitation simple daily intensity index, consecutive wet days and days with superior rains to 20mm/day and inferior to 50mm/day. And it was verified an increase of the consecutive dry days. It was verified that the annual total of precipitation, number of consecutive dry days, number of days in the year with rains above 10mm/day and precipitation simple daily intensity index are dependent of the SST anomalies patterns on the Equatorial Pacific and Tropical Atlantic Oceans. NDVI is influenced by the total precipitation and for the number of days with superior rains to 10mm/day, mainly on the Sertão of the State. Aridity inverse index of Budyko is dependent of the SST anomalies configurations on the Equatorial Pacific and Northern Tropical Atlantic Oceans, and it exercises influence on NDVI. Keywords: climate, climatic changes, semiarid, coast.

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2616 ◽  
Author(s):  
David Dunkerley

Rainfall intensity extremes are relevant to many aspects of climatology, climate change, and landsurface processes. Intensity is described and analysed using a diversity of approaches, reflecting its importance in these diverse areas. The characteristics of short-interval intensity extremes, such as the maximum 5-min intensity, are explored here. It is shown that such indices may have marked diurnal cycles, as well as seasonal variability. Some indices of intensity, such as the SDII (simple daily intensity index), provide too little information for application to landsurface processes. Upper percentiles of the intensity distribution, such as the 95th and 99th percentiles (Q95 and Q99) are used as indices of extreme intensity, but problematically are affected by changes in intensity below the nominated threshold, as well as above it, making the detection of secular change, and application to sites with contrasting rainfall character, challenging. For application to landsurface processes, a new index is introduced. This index (RQ95), is that intensity or rainfall rate above which 5% of the total rainfall is delivered. This index better reflects intense rainfall than does Q95 of even 5-min accumulation duration (AD) rainfall depths. Such an index is helpful for detecting secular change at an observing station, but, like Q95, remains susceptible to the effects of change elsewhere in the distribution of intensities. For understanding impacts of climate and climate change on landsurface processes, it is argued that more inclusive indices of intensity are required, including fixed intensity criteria.


2013 ◽  
Vol 5 (5) ◽  
pp. 1019 ◽  
Author(s):  
Gildarte Barbosa Silva ◽  
Werônica Meira Souza ◽  
Pedro Vieira Azevedo

Este trabalho teve como objetivo investigar a ocorrência ou ausência de mudanças climáticas no período de 1970 a 2006, em algumas microrregiões do estado da Bahia: Irecê, Oeste, Sudoeste e Baixo Médio São Francisco, através de índices de tendências de mudanças climáticas obtidos da precipitação pluviométrica e das temperaturas máxima e mínima diárias das estações climatológicas das respectivas regiões e de cenários de mudanças climáticas. Utilizou-se os índices de detecção de mudanças climáticas sugeridos pela OMM calculados a partir dos dados de precipitação e das temperaturas máxima e mínima diárias através do software RClimdex 1.9.0. No estudo numérico foi utilizado o modelo BRAMS. Observou-se que na região de Irecê houve tendência de diminuição da precipitação total anual e aumento da intensidade das chuvas diárias. Na região Oeste houve aumento no número de dias com temperaturas elevadas, aumento nas temperaturas mínimas diárias e aumento na intensidade das chuvas. Na região Sudoeste houve uma  tendência de um pequeno aumento dos totais anuais de chuvas. Na região do Baixo Médio São Francisco houve aumento no número de dias com temperatura máxima diária, diminuição das chuvas diárias e da precipitação total anual. Essa variação na precipitação na região pode ser atribuída à circulação de grande escala, enquanto a intensidade das chuvas pode ter influência na variabilidade climática. Cabe aos gestores desse país encarar essa realidade com muita responsabilidade e, sugira ações e medidas eficazes para combatê-la, capacitando a sociedade como um todo para conviver com essa nova realidade. Palavras-chave: Mudanças climáticas; estudos numéricos; índices de tendências climáticas.   Climate Change Scenarios in Bahia through Numerical and Statistical Studies   ABSTRACT This work had as objective to investigate the occurrence or absence of climatic changes in the period of 1970 the 2006, in some microregions of the state of the Bahia: Irecê, Oeste, Sudoeste and Baixo Médio São Francisco, through indexes of trends of climatic changes with data of daily total precipitation and the daily temperatures maximum and minimum of the climatological stations of the respective regions and climate change scenarios. One used the indexes of detection of climatic changes suggested by WMO calculated from the data of daily precipitation and the daily temperature through software RClimdex 1.9.0. The study used numerical model BRAMS. It was observed that in the region of Irecê it had trend of reduction of the annual total precipitation and increase in the intensity of daily rains. In the region Oeste it had increase in the number of days with raised temperatures, increase in the daily minimum temperatures and increase in the intensity of rains. In the Sudeste region it had a trend of a small increase of the annual rain totals. In the region of the Baixo Médio São Francisco it had increase the number of days with daily maximum temperature, reduction of daily rains and the annual total precipitation. This variation in the precipitation in the region can be attributed to the circulation of great scale, while the intensity of rains can have influence in the climatic variability. It is the managers of this country face that reality as something that must be faced with great responsibility, and suggest actions and effective measures to combat it enabling the society as a whole to deal with this new reality.Keywords: Climatic changes; numerical studies; climate trends. 


Climate ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 160
Author(s):  
Ezéchiel Obada ◽  
Eric Adechina Alamou ◽  
Eliezer Iboukoun Biao ◽  
Esdras B. Josué Zandagba

Observed rainfall data (1961–2016) were used to analyze variability, trends and changes of extreme precipitation indices over Benin. Nine indices out of the ones developed by the Expert Team on Climate Change Detection and Indices (ETCCDI) were used. The results indicate a mix of downward and upward trends for maximum 1-day precipitation (RX1day) and maximum 5-days precipitation (RX5day). Decrease trends are observed for annual total precipitation of wet days (P), while significant increases are found for the simple daily intensity index (SDII). The number of wet days (RR1) and maximum consecutive dry days (CDD) show a mix of increase/decrease trends. However, the number of heavy (R10) and very heavy (R20) wet days and maximum consecutive wet days (CWD) show decreased trends. All wet indices increased over 1991–2010 in relation to 1971–1990. The increase in all wet indices over Benin could explain the intensification of hydrology, and the increase in the frequency and the intensity of floods. It caused damages such as soil erosion, crop destruction, livestock destruction, displacement of populations, proliferation of waterborne diseases and loss of human life. Some adaptive strategies are suggested to mitigate the impacts of changes in extreme rainfall.


Water ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 2848
Author(s):  
Wenfeng Hu ◽  
Junqiang Yao ◽  
Qing He ◽  
Jing Chen

The Tibetan Plateau (TP) are regions that are most sensitive to climate change, especially extreme precipitation changes with elevation, may increase the risk of natural disasters and have attracted attention for the study of extreme events in order to identify adaptive actions. Based on daily observed data from 113 meteorological stations in the Tibetan Plateau and the surrounding regions in China during 1971–2017, we calculated the annual total precipitation and extreme precipitation indices using the R ClimDex software package and explored elevation-dependent precipitation trends. The results demonstrate that the annual total precipitation increased at a rate of 6.7 mm/decade, and the contribution of extreme precipitation to total precipitation increased over time, and the climate extremes were enhanced. The annual total, seasonal precipitation, and precipitation extreme trends were observed in terms of elevation dependence in the Tibetan Plateau (TP) and the surrounding area of the Tibetan Plateau (TPS) during 1971–2017. There is growing evidence that the elevation-dependent wetting (EDWE) is complex over the TP. The trends in total precipitation have a strong dependence on elevation, and the EDWE is highlighted by the extreme precipitation indices, for example, the number of heavy precipitation days (R10) and consecutive wet days (CWD). The dependence of extreme precipitation on elevation is heterogeneous, as other extreme indices do not indicate EDWE. These findings highlight the precipitation complexity in the TP. The findings of this study will be helpful for improving our understanding of variabilities in precipitation and extreme precipitation in response to climate change and will provide support for water resource management and disaster prevention in plateaus and mountain ranges.


2017 ◽  
Author(s):  
Chris Brierley ◽  
Ilana Wainer

Abstract. Tropical Atlantic Variability (TAV) plays an important role in driving year-to-year changes in rainfall over Africa and South America. In this study, its response to global climate change is investigated through a series of multi-model experiments. We explore the leading modes of TAV during the historical, last glacial maximum, mid-Holocene and future simulations in the multi-model ensemble known as PMIP3/CMIP5. Despite their known sea surface temperature biases, most of the models are able to capture the Tropical Atlantic's two leading modes of SST-variability patterns – the Atlantic Meridional Mode (AMM) and the Atlantic zonal mode (also called the Atlantic Niño or ATL3). The ensemble suggests that AMM amplitude was less during the mid-Holocene and increased during the last glacial maximum; but is equivocal about future changes. ATL3 appears stronger under both the last glacial maximum and future climate changes, with little consistent message about the mid-Holocene. The patterns and the regions under the influence of the two modes alters under climate change – in concert with changes in the mean climate state. Both modes demonstrate a coupling with the equatorial Pacific that depends on the climate period being considered – especially for the ATL3 mode of equatorial Pacific. In the future climate experiment, the equatorial mode weakens, the whole northern hemisphere warms up while the south Atlantic displays an hemisphere-wide weak oscillating pattern. For the LGM, the AMM projects onto a pattern that resembles the Pan-Atlantic Decadal Oscillation. No robust relationships between the amplitude of the zonal and meridional temperature gradients and their respective variability was found.


2021 ◽  
Vol 13 (12) ◽  
pp. 6803
Author(s):  
Derbetini A. Vondou ◽  
Guy Merlin Guenang ◽  
Tchotchou Lucie Angennes Djiotang ◽  
Pierre Honore Kamsu-Tamo

Central African citizens are highly vulnerable to extreme hydroclimatic events due to excess precipitation or to dry spells. This study makes use of CHIRPS precipitation data gridded at 0.05° × 0.05° resolution and extended from 1981 to 2019 to analyze spatial variabilities and trends of six extreme precipitation indices defined by the Expert Team on Climate Change Detection and Indices (ETCCDI) over Cameroon. They are the number of wet days (RR1), the simple daily intensity index (SDII), the annual total precipitation from days greater than the 95th percentile (R95ptot), the maximum number of consecutive wet days (CWD), the maximum number of consecutive dry days (CDD), the number of very heavy rainfall (RR20). The standard precipitation index (SPI) time series were also examined in the five agro-climatic regions of the domain. The pattern of annual precipitation was first checked over the entire domain. We obtain a well-known pattern showing a decreased precipitation northward with the highest values around the Atlantic Ocean coast. The analysis shows that all indices represent patterns approximately similar to that of annual rainfall except CDD where the spatial south-north gradient is reversed. RR20 shows the lowest spatial variability. Trend study of RR1 indicates negative values south of the domain and predominated positive values in the northern part, where CDD, on the contrary, shows a decreased trend. The highest trends are observed in the northernmost area for CWD and around the coast for SDII and R95ptot. SPI time series indicate an alternative dry and wet period and the years between 1990 and 2000 witnessed more annual wet conditions. Such a study is very important in this domain where variabilities of climatic components are very high due to climate change impact and diversified relief. The results can serve as a reference for agricultural activity, hydropower management, civil engineering, planning of economic activities and can contribute to the understanding of the climate system in Cameroon.


Forests ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 1015
Author(s):  
Xuan Wu ◽  
Liang Jiao ◽  
Dashi Du ◽  
Changliang Qi ◽  
Ruhong Xue

It is important to explore the responses of radial tree growth in different regions to understand growth patterns and to enhance forest management and protection with climate change. We constructed tree ring width chronologies of Picea crassifolia from different regions of the Qilian Mountains of northwest China. We used Pearson correlation and moving correlation to analyze the main climate factors limiting radial growth of trees and the temporal stability of the growth–climate relationship, while spatial correlation is the result of further testing the first two terms in space. The conclusions were as follows: (1) Radial growth had different trends, showing an increasing followed by a decreasing trend in the central region, a continuously increasing trend in the eastern region, and a gradually decreasing trend in the isolated mountain. (2) Radial tree growth in the central region and isolated mountains was constrained by drought stress, and tree growth in the central region was significantly negatively correlated with growing season temperature. Isolated mountains showed a significant negative correlation with mean minimum of growing season and a significant positive correlation with total precipitation. (3) Temporal dynamic responses of radial growth in the central region to the temperatures and SPEI (the standardized precipitation evapotranspiration index) in the growing season were unstable, the isolated mountains to total precipitation was unstable, and that to SPEI was stable. The results of this study suggest that scientific management and maintenance plans of the forest ecosystem should be developed according to the response and growth patterns of the Qinghai spruce to climate change in different regions of the Qilian Mountains.


2021 ◽  
Vol 37 (2) ◽  
pp. 119-136
Author(s):  
Rick Mitchell

As today’s catastrophic Covid-19 pandemic exacerbates ongoing crises, including systemic racism, rising ethno-nationalism, and fossil-fuelled climate change, the neoliberal world that we inhabit is becoming increasingly hostile, particularly for the most vulnerable. Even in the United States, as armed white-supremacist, pro-Trump forces face off against protesters seeking justice for African Americans, the hostility is increasingly palpable, and often frightening. Yet as millions of Black Lives Matter protesters demonstrated after the brutal police killing of George Floyd, the current, intersecting crises – worsened by Trump’s criminalization of anti-racism protesters and his dismissal of science – demand a serious, engaged, response from activists as well as artists. The title of this article is meant to evoke not only the state of the unusually cruel moment through which we are living, but also the very different approaches to performance of both Brecht and Artaud, whose ideas, along with those of others – including Benjamin, Butler, Latour, Mbembe, and Césaire – inform the radical, open-ended, post-pandemic theatre practice proposed in this essay. A critically acclaimed dramatist as well as Professor of English and Playwriting at California State University, Northridge, Mitchell’s published volumes of plays include Disaster Capitalism; or Money Can’t Buy You Love: Three Plays; Brecht in L.A.; and Ventriloquist: Two Plays and Ventriloquial Miscellany. He is the editor of Experimental O’Neill, and is currently at work on a series of post-pandemic plays.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
J. Huntley ◽  
M. Aubert ◽  
A. A. Oktaviana ◽  
R. Lebe ◽  
B. Hakim ◽  
...  

AbstractThe equatorial tropics house some of the earliest rock art yet known, and it is weathering at an alarming rate. Here we present evidence for haloclasty (salt crystallisation) from Pleistocene-aged rock art panels at 11 sites in the Maros-Pangkep limestone karsts of southern Sulawesi. We show how quickly rock art panels have degraded in recent decades, contending that climate-catalysed salt efflorescence is responsible for increasing exfoliation of the limestone cave surfaces that house the ~ 45 to 20-thousand-year-old paintings. These artworks are located in the world’s most atmospherically dynamic region, the Australasian monsoon domain. The rising frequency and severity of El Niño-induced droughts from anthropogenic climate change (that is, higher ambient temperatures and more consecutive dry days), combined with seasonal moisture injected via monsoonal rains retained as standing water in the rice fields and aquaculture ponds of the region, increasingly provide ideal conditions for evaporation and haloclasty, accelerating rock art deterioration.


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