Coast sea level and Asian monsoon system a downscaling exercise for Chinese coast

1998 ◽  
Vol 16 (2) ◽  
pp. 108-121 ◽  
Author(s):  
Cui Mao-chang ◽  
Lian Shu-min ◽  
Yang Dong-fang ◽  
Eduardo Zorita
Keyword(s):  
Sea Level ◽  
Asian Monsoon ◽  
System A ◽  
Chinese Coast ◽  
Monsoon System

scholarly journals Cyclone trends constrain monsoon variability during late Oligocene sea level highstands (Kachchh Basin, NW India)

2013 ◽  
Vol 9 (5) ◽  
pp. 2101-2115 ◽  
Author(s):  
M. Reuter ◽  
W. E. Piller ◽  
M. Harzhauser ◽  
A. Kroh
Keyword(s):  
Sea Level ◽  
Asian Monsoon ◽  
Vertical Wind Shear ◽  
Monsoon Circulation ◽  
Late Oligocene ◽  
Monsoon Variability ◽  
Kachchh Basin ◽  
Storm Wave ◽  
Monsoon System

Abstract. Climate change has an unknown impact on tropical cyclones and the Asian monsoon. Herein we present a sequence of fossil shell beds from the shallow-marine Maniyara Fort Formation (Kachcch Basin) as a recorder of tropical cyclone activity along the NW Indian coast during the late Oligocene warming period (~ 27–24 Ma). Proxy data providing information about the atmospheric circulation dynamics over the Indian subcontinent at this time are important since it corresponds to a major climate reorganization in Asia that ends up with the establishment of the modern Asian monsoon system at the Oligocene–Miocene boundary. The vast shell concentrations are comprised of a mixture of parautochthonous and allochthonous assemblages indicating storm-generated sediment transport from deeper to shallow water during third-order sea level highstands. Three distinct skeletal assemblages were distinguished, each recording a relative storm wave base. (1) A shallow storm wave base is shown by nearshore molluscs, reef corals and Clypeaster echinoids; (2) an intermediate storm wave base depth is indicated by lepidocyclinid foraminifers, Eupatagus echinoids and corallinacean algae; and (3) a deep storm wave base is represented by an Amussiopecten bivalve-Schizaster echinoid assemblage. These wave base depth estimates were used for the reconstruction of long-term tropical storm intensity during the late Oligocene. The development and intensification of cyclones over the recent Arabian Sea is primarily limited by the atmospheric monsoon circulation and strength of the associated vertical wind shear. Therefore, since the topographic boundary conditions for the Indian monsoon already existed in the late Oligocene, the reconstructed long-term cyclone trends were interpreted to reflect monsoon variability during the initiation of the Asian monsoon system. Our results imply an active monsoon over the Eastern Tethys at ~ 26 Ma followed by a period of monsoon weakening during the peak of the late Oligocene global warming (~ 24 Ma).

scholarly journals Cyclone trends constrain monsoon variability during Late Oligocene sea level highstands (Kachchh Basin, NW India)

2013 ◽  
Vol 9 (1) ◽  
pp. 583-613
Author(s):  
M. Reuter ◽  
W. E. Piller ◽  
M. Harzhauser ◽  
A. Kroh
Keyword(s):  
Tropical Cyclone ◽  
Sea Level ◽  
Asian Monsoon ◽  
Indian Monsoon ◽  
Late Oligocene ◽  
Third Order ◽  
Monsoon Variability ◽  
Kachchh Basin ◽  
Storm Wave ◽  
Monsoon System

Abstract. Important concerns about the consequences of climate change for India are the potential impact on tropical cyclones and the monsoon. Herein we present a sequence of fossil shell beds from the shallow-marine Maniyara Fort Formation (Kachcch Basin) as an indicator of tropical cyclone activity along the NW Indian coast during the Late Oligocene warming period (~27–24 Ma). Direct proxies providing information about the atmospheric circulation dynamics over the Indian subcontinent at this time are important since it corresponds to a major climate reorganization in Asia that ends up with the establishment of the modern Asian monsoon system in the Early Miocene. The vast shell concentrations comprise a mixture of parautochthonous and allochthonous assemblages indicating storm-generated sediment transport from deep to shallow water during third-order sea level highstands. Three distinct skeletal assemblages were distinguished each recording a relative storm wave base depth. (1) A shallow storm wave base is shown by nearshore mollusks, corals and Clypeaster echinoids; (2) an intermediate storm wave base depth is indicated by lepidocyclind foraminifers, Eupatagus echinoids and corallinaceans; and (3) a deep storm wave base is represented by an Amussiopecten–Schizaster echinoid assemblage. Vertical changes in these skeletal associations give evidence of gradually increasing tropical cyclone intensity in line with third-order sea level rise. The intensity of cyclones over the Arabian Sea is primarily linked to the strength of the Indian monsoon. Therefore and since the topographic boundary conditions for the Indian monsoon already existed in the Late Oligocene, the longer-term cyclone trends were interpreted to reflect monsoon variability during the initiation of the Asian monsoon system. Our results imply an active monsoon over the Eastern Tethys at ~26 Ma followed by a period of monsoon weakening during the peak of the Late Oligocene global warming (~24 Ma).

scholarly journals Effect of high altitude on human placental amino acid transport

2020 ◽  
Vol 128 (1) ◽  
pp. 127-133 ◽  
Author(s):  
Owen. R. Vaughan ◽  
Fredrick Thompson ◽  
Ramón. A. Lorca ◽  
Colleen G. Julian ◽  
Theresa L. Powell ◽  
...  
Keyword(s):  
Birth Weight ◽  
Amino Acid ◽  
High Altitude ◽  
Sea Level ◽  
Amino Acid Transport ◽  
Acid Uptake ◽  
Acid Transport ◽  
Transport Capacity ◽  
System A ◽  
Low Altitude

Women residing at high altitudes deliver infants of lower birth weight than at sea level. Birth weight correlates with placental system A-mediated amino acid transport capacity, and severe environmental hypoxia reduces system A activity in isolated trophoblast and the mouse placenta. However, the effect of high altitude on human placental amino acid transport remains unknown. We hypothesized that microvillous membrane (MVM) system A and system L amino acid transporter activity is lower in placentas of women living at high altitude compared with low-altitude controls. Placentas were collected at term from healthy pregnant women residing at high altitude (HA; >2,500 m; n = 14) or low altitude (LA; <1,700 m; n = 14) following planned, unlabored cesarean section. Birth weight, but not placenta weight, was 13% lower in HA pregnancies (2.88 ± 0.11 kg) compared with LA (3.30 ± 0.07 kg, P < 0.01). MVM erythropoietin receptor abundance, determined by immunoblot, was greater in HA than in LA placentas, consistent with lower placental oxygen levels at HA. However, there was no effect of altitude on MVM system A or L activity, determined by Na+-dependent [14C]methylaminoisobutyric acid uptake and [3H]leucine uptake, respectively. MVM abundance of glucose transporters (GLUTs) 1 and 4 and basal membrane GLUT4 were also similar in LA and HA placentas. Low birth weights in the neonates of women residing at high altitude are not a consequence of reduced placental amino acid transport capacity. These observations are in general agreement with studies of IUGR babies at low altitude, in which MVM system A activity is downregulated only in growth-restricted babies with significant compromise. NEW & NOTEWORTHY Babies born at high altitude are smaller than at sea level. Birth weight is dependent on growth in utero and, in turn, placental nutrient transport. We determined amino acid transport capacity in placentas collected from women resident at low and high altitude. Altitude did not affect system A amino acid transport across the syncytiotrophoblast microvillous membrane, suggesting that impaired placental amino acid transport does not contribute to reduced birth weight in this high-altitude population.

Climate response of the south Asian monsoon system to West Asia, Tibetan Plateau and local dust emissions

2019 ◽  
Vol 53 (9-10) ◽  
pp. 6245-6264 ◽  
Author(s):  
Charu Singh ◽  
Dilip Ganguly ◽  
Puneet Sharma ◽  
Shiwansha Mishra
Keyword(s):  
Tibetan Plateau ◽  
South Asian ◽  
Asian Monsoon ◽  
South Asian Monsoon ◽  
Climate Response ◽  
The South ◽  
Dust Emissions ◽  
Monsoon System ◽  
Local Dust

Sedimentary responses to the East Asian monsoon and sea level variations recorded in the northern South China Sea over the past 36 kyr

2019 ◽  
Vol 171 ◽  
pp. 213-224 ◽  
Author(s):  
Mingkun Li ◽  
Tingping Ouyang ◽  
Chengjing Tian ◽  
Zhaoyu Zhu ◽  
Shasha Peng ◽  
...  
Keyword(s):  
South China Sea ◽  
Sea Level ◽  
South China ◽  
Asian Monsoon ◽  
East Asian Monsoon ◽  
Northern South China Sea ◽  
East Asian ◽  
China Sea ◽  
The Past ◽  
Sea Level Variations

scholarly journals A Flow-Calibrated Method to Project Groundwater Infiltration into Coastal Sewers Affected by Sea Level Rise

Water ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1934
Author(s):  
Adrienne Fung ◽  
Roger Babcock
Keyword(s):  
Sea Level Rise ◽  
Sea Level ◽  
Monitoring Data ◽  
Groundwater Levels ◽  
Flow Monitoring ◽  
System A ◽  
Coastal Cities ◽  
The Mean ◽  
Groundwater Infiltration

Collection systems in coastal cities are often below the groundwater table, leading to groundwater infiltration (GWI) through defects such as cracks and poor lateral connections. Climate-change-induced sea level rise (SLR) will raise groundwater levels, increasing the head and thus the inflow. A method has been developed to predict GWI when groundwater levels change using calibration with sewershed flow monitoring data. The calibration results in a parameter that characterizes the porosity of the collection system. A case study is presented for a coastal city with reliable flow monitoring data for eight days that resulted in a large range of effective defect sizes (minimum 0.0044 to maximum 0.338 radians), however, the range of predicted future GWI in currently submerged pipes varied by only 12% from the mean. The mean effective defect predicts 70 to 200% increases in GWI due to SLR of 0.3 to 0.9 m (1 to 3 ft), respectively, for currently submerged pipes. Predicted additional GWI for pipes that will become submerged due to SLR will increase GWI to values that approach or exceed the current average dry weather flow. This methodology can be used for planning of infrastructure improvements to enhance resiliency in coastal communities.

Early and late Holocene paleoenvironmental reconstruction of the Pearl River estuary, South China Sea

2020 ◽  
Author(s):  
Huixian Chen ◽  
Jianhua Wang ◽  
Nicole S. Khan ◽  
Jiaxue Wu ◽  
Benjamin P. Horton
Keyword(s):  
Sea Level ◽  
Late Holocene ◽  
Asian Monsoon ◽  
River Estuary ◽  
Pearl River Estuary ◽  
Pearl River ◽  
Sea Level Changes ◽  
The Pearl River Estuary ◽  
The Pearl River ◽  
Middle Estuary

&lt;p&gt;Proxy reconstructions of estuarine evolution provide perspectives on regional to global environmental changes, including relative sea-level changes, climatic changes, and agricultural developments. Although there are studies of the Holocene sedimentary processes in the Pearl River estuary, the understanding of early Holocene sedimentation in unknown due to limited preservation.&lt;/p&gt;&lt;p&gt;Here, we present a new record of lithological, benthic foraminiferal, and geochemical (&amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and C/N) change from a sediment core in the west shoal of the modern Lingding Bay along a paleo-valley. The lithologic and foraminiferal record reveal the transgressive evolution from fluvial, inner estuary to middle estuary in the early Holocene between 11300 and 8100 cal a BP in response to rapid sea-level rise. &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and C/N data indicate high freshwater discharge from 10500 to 8100 cal a BP driven by a strong Asian monsoon. The middle Holocene (8100 - 3300 cal a BP) sediment is absent in this core and others in the northward of the Lingding Bay. Seismic profiles reveal a tidal ravinement surface across Lingding Bay, which contributed to subaqueous erosion on the mid-Holocene sedimentation hiatus, might be resulted from unique geomorphology of the Pearl River Delta. In the late Holocene (3300 cal a BP to the present), the lithology and foraminiferal assemblages suggest further regressive evolution from outer estuary, middle estuary channel, to middle estuary shoal due to deltaic progradation under stable relative sea levels. In the last 2000 years, &amp;#948;&lt;sup&gt;13&lt;/sup&gt;C and C/N values reveal the intensive development of agriculture coupled with the reduction of freshwater input derived from a weakening Asian monsoon. Our study illustrates the interaction of Asian monsoon and sea-level changes within the Pearl River estuary landform and their impact on Holocene sedimentary processes.&lt;/p&gt;

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