Spatiotemporal changes of precipitation extremes in Bangladesh during 1987–2017 and their connections with climate changes, climate oscillations, and monsoon dynamics

2021 ◽  
pp. 103712
Author(s):  
Gazi Tawfiq Ezaz ◽  
Ke Zhang ◽  
Xin Li ◽  
Md Halim Shalehy ◽  
Mohammad Akram Hossain ◽  
...  
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Bianca Saladin ◽  
Loïc Pellissier ◽  
Catherine H. Graham ◽  
Michael P. Nobis ◽  
Nicolas Salamin ◽  
...  

Abstract Scientific understanding of biodiversity dynamics, resulting from past climate oscillations and projections of future changes in biodiversity, has advanced over the past decade. Little is known about how these responses, past or future, are spatially connected. Analyzing the spatial variability in biodiversity provides insight into how climate change affects the accumulation of diversity across space. Here, we evaluate the spatial variation of phylogenetic diversity of European seed plants among neighboring sites and assess the effects of past rapid climate changes during the Quaternary on these patterns. Our work shows a marked homogenization in phylogenetic diversity across Central and Northern Europe linked to high climate change velocity and large distances to refugia. Our results suggest that the future projected loss in evolutionary heritage may be even more dramatic, as homogenization in response to rapid climate change has occurred among sites across large landscapes, leaving a legacy that has lasted for millennia.


2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Xianghu Li ◽  
Qi Hu

Spatiotemporal changes in extreme precipitation at local scales in the context of climate warming are overwhelmingly important for prevention and mitigation of water-related disasters and also provide critical information for effective water resources management. In this study, the variability and trends of extreme precipitation in both time and space in the Poyang Lake basin over the period of 1960–2012 are analyzed. Also, changes in precipitation extremes with topography are investigated, and possible causes are briefly discussed. The results show that extreme precipitation over the Poyang Lake basin is intensified during the last 50 years, especially the increasing trends are more significant before the end of the 1990s. Moreover, high contribution rates of extreme precipitation to the total rainfall (40–60%) indicated that extreme precipitation plays an important role to the total water resources in this area. The precipitation extremes also exhibited a significant spatial dependence in the basin. The northeastern and eastern areas are exposed to high risk of flood disaster with the higher frequency of extreme precipitation events. In addition, the distribution of precipitation extremes had a clear dependence on elevation, and the topography is an important factor affecting the variability of extreme precipitation over the Poyang Lake basin.


2013 ◽  
Vol 9 (2) ◽  
pp. 2059-2094 ◽  
Author(s):  
L. Sadori ◽  
E. Ortu ◽  
O. Peyron ◽  
G. Zanchetta ◽  
B. Vannière ◽  
...  

Abstract. The aim of this study is to investigate climate changes and human activities under the lens of palynology. Based on a new high-resolution pollen sequence (PG2) from Lago di Pergusa (667 m a.s.l., central Sicily, Italy) covering the last 6700 yr, we propose a reconstruction of climate and landscape changes over the recent past in central Sicily. Compared to former studies from Lago di Pergusa (Sadori and Narcisi, 2001), this work provides a reconstruction of the evolution of vegetation and climate over the last millennia in central Sicily, indeed completing previous results with new data which is particularly detailed on the last 3000 yr. Joint actions of increasing dryness, climate oscillations, and human impact shaped the landscape of this privileged site. Lago di Pergusa, in fact, besides being the main inland lake of Sicily, is very sensitive to climate change and its territory was inhabited and exploited continuously since the prehistory. The lake sediments turned out to be a good observatory for the natural phenomena occurred in the last thousands of years. Results of the pollen-based study are integrated with changes in magnetic susceptibility and a tephra layer characterization. The tephra layer was shown to be related to the Sicanians' event, radiocarbon dated at 3055 ± 75 yr BP (Sadori and Narcisi, 2001). We performed palaeoclimate reconstructions by MAT and WA-PLS. Palaeoclimate reconstructions based on the core show important climate fluctuations throughout the Holocene. Climate reconstruction points out four phases of cooling and enhanced wetness in the last three millennia (2600–2000, 1650–1100, 850–550, 400–200 cal BP). This appears to be the evidence of local responses to global climate oscillations during the recent past.


2013 ◽  
Vol 9 (4) ◽  
pp. 1969-1984 ◽  
Author(s):  
L. Sadori ◽  
E. Ortu ◽  
O. Peyron ◽  
G. Zanchetta ◽  
B. Vannière ◽  
...  

Abstract. The aim of this study is to investigate climate changes and human activities under the lens of palynology. Based on a new high-resolution pollen sequence (PG2) from Lago di Pergusa (667 m a.s.l., central Sicily, Italy) covering the last 6700 yr, we propose a reconstruction of climate and landscape changes over the recent past in central Sicily. Compared to former studies from Lago di Pergusa (Sadori and Narcisi, 2001), this work provides a reconstruction of the evolution of vegetation and climate over the last millennia in central Sicily, indeed completing previous results with new pollen data, which is particularly detailed on the last 3000 yr. Joint actions of increasing dryness, climate oscillations, and human impact shaped the landscape of this privileged site. Lago di Pergusa, besides being the main inland lake of Sicily, is very sensitive to climate change and its territory was inhabited and exploited continuously since the Palaeolithic. The lake sediments turned out to be a good observatory for natural phenomena that occurred in the last thousands of years. Results of the pollen-based study are integrated with changes in magnetic susceptibility and a tephra layer characterization. The tephra layer was shown to be related to the Sicanians' event, radiocarbon dated at 3055 ± 75 yr BP (Sadori and Narcisi, 2001). We performed palaeoclimate reconstructions by MAT (Modern Analogues Technique) and WAPLS (Weighted Average Partial Least Square). Palaeoclimate reconstructions based on the core show important climate fluctuations throughout the Holocene. Climate reconstruction points out four phases of cooling and enhanced wetness in the last three millennia (2600–2000, 1650–1100, 850–550, 400–200 cal BP, corresponding to the periods between 650–50 BC, and 300–850, 1100–1400, 1550–1750 AD, respectively). This appears to be the evidence of local responses to global climate oscillations during the recent past.


1995 ◽  
Vol 165 ◽  
pp. 79-87
Author(s):  
O.B Olesen ◽  
A Weidick ◽  
N Reeh ◽  
H.H Thomsen ◽  
R.J Braithwaite

The main emphasis of present investigations of Greenland glaciers concerns former climate oscillations and the variations in glacier cover related to these changes. The data acquired on climate and glacier variations provide a basis for prediction of future environmental consequences of climate changes. These include local change of ice cover and related coastal changes caused by variations in glacier load on the earth's crust in Greenland as well as global change of sea level in the oceans caused by the storage or release of melt water and calf ice from the Greenland ice cover.


2015 ◽  
Vol 126 (3-4) ◽  
pp. 519-531 ◽  
Author(s):  
Zengyun Hu ◽  
Qingxiang Li ◽  
Xi Chen ◽  
Zhidong Teng ◽  
Changchun Chen ◽  
...  

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