scholarly journals Evolution of Storm Surges over the Little Ice Age Indicated by Aeolian Sand Records on the Coast of the Beibu Gulf, China

Water ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 1941
Author(s):  
Zhi Chen ◽  
Baosheng Li ◽  
Fengnian Wang ◽  
Shuhuan Du ◽  
Dongfeng Niu ◽  
...  

The Wutou section, hereinafter referred to as “WTS”, lies in Jiangping, Guangxi Province, China (21°32′8.25″ N, 108°06′59.9″ E; thickness of 246 cm) and consists of fluvial-lacustrine facies and dune sands of the Late Holocene. This study reconstructed the evolution of storm surges along the coast of the Beibu Gulf, Guangxi over the Little Ice Age, based on three accelerator mass spectrometry (AMS)-14C, optically stimulated luminescence (OSL) dating ages, and the analyses of grain size and heavy minerals. The analysis results indicated that the storm sediments interspersed among aeolian sands, lagoon facies, and weak soil display a coarse mean grain size and poor sorting. The storm sediments also show high maturity of heavy minerals and low stability resulting from rapid accumulation due to storm surges originating from the land-facing side of the coastal dunes. Records of seven peak storm surge periods were recorded in the WTS over the past millennium and mainly occurred after 1400 AD, i.e., during the Little Ice Age. The peaks in storm surges, including the 14Paleostrom deposit (hereinafter referred to as “Pd”) (1425–1470AD), 10Pd (1655–1690AD), 6Pd (1790–1820AD), and 4Pd (1850–1885AD) approximately corresponded with the periods of minimum sunspot activity, suggesting that the periods of storm surge peaks revealed by the WTS were probably regulated to a great extent by solar activity.

The Holocene ◽  
2019 ◽  
Vol 30 (2) ◽  
pp. 289-299
Author(s):  
Tingwei Zhang ◽  
Xiaoqiang Yang ◽  
Qiong Chen ◽  
Jaime L Toney ◽  
Qixian Zhou ◽  
...  

A number of archives that span the past ~2000 years suggest that recent variability in hydroclimatic conditions that are influenced by the Asian monsoon in China are unusual in the longer term context. However, the lack of high-resolution precipitation records over this period hampered our ability to characterize and constrain the forcing mechanism(s) of the recent humidity variations. Here, we present the ratio of hematite to goethite (Hm/Gt) derived from the semiquantitative evaluation of the diffuse reflectance spectroscopic analysis as a reliable and effective precipitation proxy to reconstruct the humidity variations during the past 1400 years deduced from Tengchongqinghai Lake sediments, southwestern China. Hm/Gt varied synchronously with variations of Chinese temperature reconstructed from the historical documents and sunspot activity index over the past 1400 years. Critical periodicities of ~450 and ~250 years show that solar activity is the dominant control on precipitation change on centennial scales. However, the relationship determined from Hm/Gt in this study contradicts the stalagmite δ18O interpretations from different regions of China, which exhibit a more complex precipitation pattern that is influenced by the strength of westerly jet in addition to the Asian monsoon. The increased westerly jet during the ‘Little Ice Age’ (LIA) caused a humid climate in southern China and dry conditions in northern and western China.


Radiocarbon ◽  
1992 ◽  
Vol 34 (2) ◽  
pp. 263-270 ◽  
Author(s):  
Elizabeth Nesme-Ribes ◽  
Andre Mangeney

To understand better the Earth's climate, we need to know precisely how much radiation the Sun generates. We present here a simple physical mechanism describing the convective processes at the time of low sunspot activity. According to this model, the kinetic energy increased during the Maunder Minimum, causing a decrease of the solar radiation that was sufficient to produce a little Ice Age.


2020 ◽  
Vol 8 (2) ◽  
pp. 335-350 ◽  
Author(s):  
Filipe Galiforni-Silva ◽  
Kathelijne M. Wijnberg ◽  
Suzanne J. M. H. Hulscher

Abstract. Growth of coastal dunes requires a marine supply of sediment. Processes that control the sediment transfer between the subtidal and the supratidal zone are not fully understood, especially in sand flats close to inlets. It is hypothesised that storm surge events induce sediment deposition on sand flats, providing fresh material for aeolian transport and dune growth. The objective of this study is to identify which processes cause deposition on the sand flat during storm surge conditions and discuss the relationship between the supratidal deposition and sediment supply to the dunes. We use the island of Texel (NL) as a case study, of which multiannual topographic and hydrographic datasets are available. Additionally, we use the numerical model XBeach to simulate the most frequent storm surge events for the area. Results show that supratidal shore-parallel deposition of sand occurs in both the numerical model and the topographic data. The amount of sand deposited is directly proportional to surge level and can account for more than a quarter of the volume deposited at the dunes yearly. Furthermore, storm surges are also capable of remobilising the top layer of sediment of the sand flat, making fresh sediment available for aeolian transport. Therefore, in a sand flat setting, storm surges have the potential of reworking significant amounts of sand for aeolian transport in periods after the storm and as such can also play a constructive role in coastal dune development.


2013 ◽  
Vol 20 (1) ◽  
Author(s):  
Elhoucine Essefi ◽  
Hayet Ben Jmaa ◽  
Jamel Touir ◽  
Mohamed Ali Tagortig ◽  
Chokri Yaicha

AbstractThis paper covers work intended to study the interplay of sedimentary dynamics and climatic variability over the last two millennia within Tunisia’s sebkha Souassi. Based on the Visual Core Description, and magnetic susceptibility, we date the core from sebkha Souassi to the last two millennia. Genetic grain-size distribution then provided a basis for the identification of six climatic stages, i.e. the Warming Present (WP), the Late Little Ice Age (Late LIA), the Early Little Ice Age (ELIA), the Medieval Climatic Anomaly (MCA), the Dark Ages (DA), and the Roman Warm Period (RWP). The WP stretches across the uppermost 3 cm, with a high grey scale indicating a dry climate. The Late LIA is located between 3 and 7 cm, and the ELIA between 7 and 28 cm. Intermediate values for GS indicate that this stage may be classified as moderate. The MCA spanning from 28 to 40 cm is marked by a sharp decrease in GS indicative of a wet period. The DA appear along the part between 40 and 79 cm, a shift from light to dark sediments being recorded. The RWP in turn appears between 79 and 114 cm. Based on the grain-size distribution, two low-frequency cycles were identified, indicating radical global changes in climatic conditions, differential tectonics and groundwater fluctuations. High-frequency cycles in turn attest to local modifications of climatic conditions.


2015 ◽  
Vol 12 (6) ◽  
pp. 2783-2805
Author(s):  
Y. Luo ◽  
D. Sui ◽  
H. Shi ◽  
Z. Zhou ◽  
D. Wang

Abstract. We use a novel statistical approach-MGPD to analyze the joint probability distribution of storm surge events at two sites and present a warning method for storm surges at two adjacent positions in Beibu Gulf, using the sufficiently long field data on surge levels at two sites. The methodology also develops the procedure of application of MGPD, which includes joint threshold and Monte Carlo simulation, to handle multivariate extreme values analysis. By comparing the simulation result with analytic solution, it is shown that the relative error of the Monte Carlo simulation is less than 8.6 %. By running MGPD model based on long data at Beihai and Dongfang, the simulated potential surge results can be employed in storm surge warnings of Beihai and joint extreme water level predictions of two sites.


2019 ◽  
Author(s):  
Filipe Galiforni Silva ◽  
Kathelijne M. Wijnberg ◽  
Suzanne J. M. H. Hulscher

Abstract. Marine supply of sand can control the development and morphology of coastal dunes. However, processes that control the sediment transfer between sub-tidal and the supra-tidal zone are not fully understood, especially in coastal settings such as sand-flats close to inlets. It is hypothesised that storm surge events induce sediment deposition on sand-flats, so that this may influence dune development significantly. Therefore, the objective of this study is to identify which processes causes deposition on the sand-flat during storm-surge conditions and discuss the relation between the supra-tidal deposition and sediment supply to the dunes. We use the island of Texel as a case study, on which multi-annual topographic and hydrographic data sets are available. Additionally, we use the numerical model XBeach to simulate the most frequent storm surge events for the area. Results show that a supra-tidal shore-parallel deposition of sand occurs in both the numerical model and the data. The amount of sand deposition is directly proportional to surge level, and can account for more than half of the volume deposited at the dunes on a yearly basis. Furthermore, storms are also capable of remobilising the top layer of sediment of the sand-flat, making fresh sediment available for aeolian transport. Therefore, in a sand-flat setting, storm surges have the potential of adding significant amounts of sand for aeolian transport in periods after the storm, suggesting that storms play a significant role in the onshore sand supply between sub-tidal and subaerial zones in those areas.


The Holocene ◽  
2016 ◽  
Vol 27 (2) ◽  
pp. 315-316 ◽  
Author(s):  
Colin P Summerhayes

The recent re-evaluation of sunspot data by Clette et al. strongly suggests that the total solar irradiance (TSI) values for the late 20th century were (apart from 1960) not significantly different from those of the periods of sunspot maxima in the 1780s and the 1840s–1860s in the latter part of the ‘Little Ice Age’. In effect, the re-evaluation removed the previously supposed sunspot maximum of the ‘modern’ period. That means that the supposed recovery of TSI levels to values significantly higher in the late 20th century than those of the ‘Medieval Quiet (or Warm) Period’ (Figure 1 of Bradley et al., 2016) must be an artefact of the solar data. Orbital data suggest that the northern hemisphere cooled significantly over the past 2000 years, a trend confirmed by global temperature proxies. Variations about that trend were driven by small variations in sunspot activity that led to the warmth of the ‘Medieval Quiet (Warm) Period’ and the subsequent cooling of the ‘Little Ice Age’. In fact, the ‘Little Ice Age’ contained several short warm periods when sunspots were at a maximum. It seems highly likely given the new sunspot calibration that the mid- to late 20th century warming was yet another of these ‘Little Ice Age’ warm episodes (e.g. no different from that in 1780) superimposed on which was a growing additional warming supplied by expanding emissions of greenhouses gases.


2021 ◽  
Author(s):  
Shah Parth ◽  
James M Russell ◽  
Nicolas Waldmann

<p>There is a major knowledge gap in the past climate oscillation of the Arabian desert, especially during the past two millennium. Reliable continuous continental records that archives at high resolution past environmental variability are useful sentinels of paleoclimate changes. Reliable interpretation from climatic proxies retrieved from lake records are crucial for identifying periodicities and the onset of climatic events and evaluating inter-annual and decadal trends driven by shifting of the Intertropical Convergence Zone (ITCZ). A multiproxy approach is presented for a ~3.3 m composite core from a karst lake located in Gayal el Bazal, southern Yemen. Sedimentary proxies, including grain size distribution and magnetic susceptibility (MS) coupled with geochemistry (XRF), provide an initial picture of centennial-scale environmental changes over the southern Arabian desert. The chronology of the core was anchored by five radiocarbon (<sup>14</sup>C) dates of terrestrial plants (wood) extracted from sediment samples and indicates the core extends to ~800 AD. Our data provides a snapshot for better understanding the impact of Indian Ocean monsoon variability at an exceptional resolution for a region that lacks sufficient information. Our data indicates that during the ‘Little Ice Age’ (~1500-1800 AD) was arid relative to the warm conditions that prevailed during the Medieval Warming Period (~800 to 1200 AD). The arid phase was marked by high Ca/(Al, Fe, Ti) values, increased inorganic carbon content, decreased MS values, and gypsum precipitation. Furthermore, end-member mixing analyses (EMMA) derived from the grain-size distribution corroborates the production of carbonate sand probably due to an increase in flash floods occurring concurrently with low lake levels under generally dry conditions. Aridity during the Little Ice Age is consistent with evidence and theory for weakened boreal summer monsoons during intervals of northern hemisphere cooling. Overall, this study will provide insight into the monsoon variability and a record for understanding the interactions between northward migrations of the ITCZ and tropical monsoonal dynamics during the late Holocene. In the context of current climate change and increasing population pressure, a deeper understanding of their long-term hydrological variability, this study is highly essential to satisfactorily forecast the sustainability of lakes as a resource in a warming world.</p>


2020 ◽  
Author(s):  
Filipe Galiforni-Silva ◽  
Kathelijne M. Wijnberg ◽  
Suzanne J. M. H. Hulscher

Abstract. Growth of coastal dunes requires a marine supply of sediment. Processes that control the sediment transfer between the sub-tidal and the supra-tidal zone are not fully understood, especially in sand flats close to inlets. It is hypothesised that storm surge events induce sediment deposition on sand flats, providing fresh material for aeolian transport and dune growth. The objective of this study is to identify which processes cause deposition on the sand flat during storm surge conditions and discuss the relationship between the supra-tidal deposition and sediment supply to the dunes. We use the island of Texel as a case study, of which multi-annual topographic and hydrographic data sets are available. Additionally, we use the numerical model XBeach to simulate the most frequent storm surge events for the area. Results show that supra-tidal shore-parallel deposition of sand occurs in both the numerical model and the topographic data. The amount of sand deposition is directly proportional to surge level and can account for more than a quarter of the volume deposited at the dunes yearly. Furthermore, storm surges are also capable of remobilising the top layer of sediment of the sand flat, making fresh sediment available for aeolian transport. Therefore, in a sand flat setting, storm surges have the potential of reworking significant amounts of sand for aeolian transport in periods after the storm, and as such can also play a constructive role in coastal dune development.


Author(s):  
W.P. De Lange

The Greenhouse Effect acts to slow the escape of infrared radiation to space, and hence warms the atmosphere. The oceans derive almost all of their thermal energy from the sun, and none from infrared radiation in the atmosphere. The thermal energy stored by the oceans is transported globally and released after a range of different time periods. The release of thermal energy from the oceans modifies the behaviour of atmospheric circulation, and hence varies climate. Based on ocean behaviour, New Zealand can expect weather patterns similar to those from 1890-1922 and another Little Ice Age may develop this century.


Sign in / Sign up

Export Citation Format

Share Document