scholarly journals The Influence of Wind Direction during Storms on Sea Temperature in the Coastal Water of Muping, China

2021 ◽  
Vol 9 (7) ◽  
pp. 710
Author(s):  
Xiangyang Zheng ◽  
Yana Ding ◽  
Yandong Xu ◽  
Tao Zou ◽  
Chunlei Wang ◽  
...  

Sea temperature structures are important for water stratification and marine ecosystems. In the coastal water of Muping, China, stationary measurements of sea temperature captured temporal temperature changes during two summer storm events. The north component of the wind during the two storms was opposite. The temperature responded differently to wind directions in the two storm events. A well-validated numerical ocean model was used to investigate the mechanism of sea temperature variation of the coast of Muping. The model revealed that the southerly and easterly wind was upwelling-favorable in the study area. They generated the shoreward transport of bottom cold water, which induced bottom water cooling, enhanced stratification, and weakened vertical mixing. On the other hand, the northerly and westerly wind was downwelling-favorable and enhanced turbulent mixing. The alongshore upwelling-favorable wind caused more cross-shore transport than cross-shore upwelling-favorable wind, which resulted in stronger bottom cooling. Similarly, alongshore downwelling-favorable wind generated lower temperature than cross-shore wind. A surface cold-water band was formed in the second storm. Although it was formed during upwelling-favorable wind, the temperature balance analysis indicated that vertical mixing and westward horizontal advection were the two dominant processes compared to upwelling.

2005 ◽  
Vol 56 (7) ◽  
pp. 1005 ◽  
Author(s):  
Christian Hénin ◽  
G. R. Cresswell

Temperature decreases of up to 5°C at an automatic station at ~10 m depth at the outer reef of western New Caledonia signalled the occurrence of upwelling. The decreases are related to south-easterly wind events and they can take up to 5 days to develop. Successive wind events can depress the temperature for as much as 1 month. An upwelling shows in thermal satellite imagery as a band of cold water ~10 km wide and as long as several hundred kilometres just outside the reef. The cold water frequently spreads out to sea. The upwellings are more common in summer (October to March) than in winter. During lengthy periods of low wind speeds, the waters outside the reef appear to be overrun by warm water from farther north. The frequent occurrence of the warm water layer in the north may partly explain why upwellings are more common along the southern half of the reef. The entire lagoon cools in winter; most of the lagoon warms in summer, except at the southern end where the waters are cool, perhaps from tidal mixing.


2014 ◽  
Vol 31 (2) ◽  
pp. 531-544 ◽  
Author(s):  
Wen-Yu Huang ◽  
Bin Wang ◽  
Yong-Qiang Yu ◽  
Li-Juan Li

Abstract Better computational stability is achieved in an improved version of the National Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG)/Institute of Atmospheric Physics (IAP) Climate Ocean Model, version 2 (LICOM2, the standard version), after improvements to the implementations of the vertical mixing, mesoscale eddy parameterization, and bottom drag schemes. The large warm biases of LICOM2 in the western Pacific Ocean and eastern Indian Ocean warm pool and on the east coast of the Pacific Ocean are significantly improved. The salinity bias in the tropical Pacific Ocean related to the warm bias of the warm pool is also alleviated. The simulation of the Atlantic meridional overturning circulation is improved because of enhanced vertical mixing in the high latitudes of the North Atlantic Ocean. The new version also presents a stronger Deacon cell, and thus a more powerful Antarctic Circumpolar Current that is closer to the observation, due to weaker southward mesoscale eddy transport in the Southern Ocean.


2021 ◽  
Author(s):  
Ting Liu ◽  
Jianping Li ◽  
Cheng Sun ◽  
Tao Lian ◽  
Yazhou Zhang

AbstractAlthough the impact of the extratropical Pacific signal on the El Niño–Southern Oscillation has attracted increasing concern, the impact of Southern Hemisphere Annular Mode (SAM)-related signals from outside the southern Pacific Basin on the equatorial sea temperature has received less attention. This study explores the lead correlation between the April–May (AM) SAM and central tropical Pacific sea temperature variability over the following three seasons. For the positive AM SAM case, the related simultaneous warm SST anomalies in the southeastern Indian Ocean favor significant regulation of vertical circulation in the Indian Ocean with anomalous ascending motion in the tropics. This can further enhance convection over the Marine Continent, which induces a significant horizontal Kelvin response and regulates the vertical Walker circulation. These two processes both result in the anomalous easterlies east of 130° E in the equatorial Pacific during AM. These easterly anomalies favor oceanic upwelling and eastward propagation of the cold water into the central Pacific. The cold water in turn amplifies the development of the easterly wind and further maintains the cold water into the boreal winter. The results presented here not only provide a possible link between extratropical climate variability in the Indian Ocean and climate variation in the equatorial Pacific, but also shed new light on the short-term prediction of tropical central Pacific sea temperature.


Author(s):  
Xiaoyi Shen ◽  
Chang-Qing Ke ◽  
Bin Cheng ◽  
Wentao Xia ◽  
Mengmeng Li ◽  
...  

AbstractIn August 2018, a remarkable polynya was observed off the north coast of Greenland, a perennial ice zone where thick sea ice cover persists. In order to investigate the formation process of this polynya, satellite observations, a coupled ice-ocean model, ocean profiling data, and atmosphere reanalysis data were applied. We found that the thinnest sea ice cover in August since 1978 (mean value of 1.1 m, compared to the average value of 2.8 m during 1978–2017) and the modest southerly wind caused by a positive North Atlantic Oscillation (mean value of 0.82, compared to the climatological value of −0.02) were responsible for the formation and maintenance of this polynya. The opening mechanism of this polynya differs from the one formed in February 2018 in the same area caused by persistent anomalously high wind. Sea ice drift patterns have become more responsive to the atmospheric forcing due to thinning of sea ice cover in this region.


2021 ◽  
pp. 1-30
Author(s):  
Daniel Wolf ◽  
Thomas Kolb ◽  
Karolin Ryborz ◽  
Susann Heinrich ◽  
Imke Schäfer ◽  
...  

Abstract During glacial times, the North Atlantic region was affected by serious climate changes corresponding to Dansgaard-Oeschger cycles that were linked to dramatic shifts in sea temperature and moisture transfer to the continents. However, considerable efforts are still needed to understand the effects of these shifts on terrestrial environments. In this context, the Iberian Peninsula is particularly interesting because of its close proximity to the North Atlantic, although the Iberian interior lacks paleoenvironmental information so far because suitable archives are rare. Here we provide an accurate impression of the last glacial environmental developments in central Iberia based on comprehensive investigations using the upper Tagus loess record. A multi-proxy approach revealed that phases of loess formation during Marine Isotope Stage (MIS) 2 (and upper MIS 3) were linked to utmost aridity, coldness, and highest wind strengths in line with the most intense Greenland stadials also including Heinrich Events 3–1. Lack of loess deposition during the global last glacial maximum (LGM) suggests milder conditions, which agrees with less-cold sea surface temperatures (SST) off the Iberian margin. Our results demonstrate that geomorphological system behavior in central Iberia is highly sensitive to North Atlantic SST fluctuations, thus enabling us to reconstruct a detailed hydrological model in relation to marine–atmospheric circulation patterns.


2017 ◽  
Vol 67 (2) ◽  
pp. 211-235 ◽  
Author(s):  
Alexandra Gronholz ◽  
Ulf Gräwe ◽  
André Paul ◽  
Michael Schulz

Author(s):  
Andrey N. Sharov

Based on the study of the spatio-temporal aspects of the development of phytoplankton in the lakes of the North and North-West of the European territory of Russia (large lakes – Imandra, Onega and Chudsko-Pskovskoye and small lakes of the Arctic and Subarctic), the features of its structure and dynamics under the influence of natural and anthropogenic factors (eutrophication, heavy metal pollution, acidification, thermification). The species composition and quantitative characteristics of phytoplankton of large lakes of the North of Russia, small arctic lakes and lakes of subarctic regions are studied. It has been shown that diatoms predominate in arctic water bodies according to species diversity, and green and diatoms predominate in boreal ones. By biomass, diatoms dominate mainly in all cold-water lakes, with the exception of small arctic lakes, where golden algae lead. The features of the reorganization of phytoplankton in response to the action of anthropogenic factors are revealed. It is proved that in the northern water bodies the complex action of heavy metals and nutrients does not lead to inhibition of phytoplankton, and the effect of acidification in combination with heavy metals enhances the toxic effect of the latter. A feature of the response to acidification is an increase in the variability of the dynamics of the biomass of phytoplankton. It has been shown that in different types of lakes of East Antarctica under severe climate conditions under light and biogenic limitation, redistribution of autotrophic components in the formation of the biota of water bodies occurs: against the background of a decrease in the abundance and diversity of phytoplankton, the role of microphytobenthos and periphyton increases.


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