Ocean University of China

About: Ocean University of China is a education organization based out in Qingdao, China. It is known for research contribution in the topics: Population & Sea surface temperature. The organization has 27604 authors who have published 27886 publications receiving 440181 citations. The organization is also known as: Zhōngguó Hǎiyáng Dàxué & OUC.

Yangtze sediment decline partly from Three Gorges Dam

Abstract: It could be argued that nowhere has the impact of dams on rivers been more important than in China, where since 1950 almost half of the world's large dams (higher than 15 meters) have been built ]Fuggle and Smith, 2000]. China's Yangtze River (Changjiang)—the largest river in south Asia (1.8 million square kilometers) and whose basin is home to more than 400 million inhabitants—alone has more than 50,000 dams within its watershed, including the world's largest, the Three Gorges Dam (TGD) (Figure 1a ). Water and sediment began being impounded behind the TGD in June 2003, and two years after impoundment, river sediment discharge downstream (at Datong Station) had decreased by nearly half of its 2002 load (Figure 1c). However, the decrease in Yangtze sediment load did not begin with TGD impoundment. Rather, the sediment load at Datong has declined continually since 1987 despite a slight increase in river discharge (Figure 1c ). The change in pre-TGD loads atYichang, just downstream from the TGD, has been even more extreme, decreasing by approximately 300 million tons in 1986–2002, before declining another 130 million tons after 2002 (Figure 1b). All of this suggests that collective changes on the Yangtze upstream (above Yichang) have been more important in decreasing the river's sediment load than the TGD.

Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters

Abstract: [1] For studies of heat transfer in the upper ocean, the vertical distribution of solar radiation (ESR) in the shortwave domain plays an important role. In earlier studies, a sum of multiple exponentials was used to describe the vertical transmittance of ESR. For those exponential terms, an attenuation coefficient for each term is assigned, and those attenuation coefficients are assumed to be vertically constant. Furthermore, those attenuation coefficients are empirically modeled as functions of chlorophyll concentration (Chl) to cope with varying water properties of the oceans. Since attenuation coefficients of ocean waters are generally determined by components more than Chl alone, we developed a generalized model bypassing the use of Chl on the basis of extensive numerical simulations. In this new model, vertical transmittance of ESR is separated into two exponential terms, with one for the contributions of wavelengths below 700 nm (the visible domain, EVIS) and one for wavelengths above 700 nm (the infrared domain, EIR). An attenuation coefficient is assigned for each of the two exponential terms. Unlike earlier models, these attenuation coefficients vary with depth as expected. Furthermore, the attenuation coefficient for the visible domain is modeled as a function of water's absorption and backscattering coefficients. Since absorption and backscattering coefficients of the world oceans can be adequately derived from observations of ocean color, the model we developed provides an effective and adequate means to describe the three-dimensional variation of both EVIS and ESR in the upper layer of the world oceans.

Anticyclonic Eddy Sheddings from Kuroshio Loop and the Accompanying Cyclonic Eddy in the Northeastern South China Sea

Abstract: Sheddings of Kuroshio Loop Current (KLC) eddies in the northeastern South China Sea (SCS) are investigated using mooring arrays, multiple satellite data, and data-assimilative HYCOM products. Based on altimeter sea surface heights between 1992 and 2014, a total of 19 prominent KLC eddy shedding (KLCES) events were identified, among which four events were confirmed by the concurrent moored and satellite observations. Compared to the leaping behavior of Kuroshio, KLCES is a relatively short-duration phenomenon that primarily occurs in boreal autumn and winter. The KLC and its shedding anticyclonic eddy (AE) trap a large amount of Pacific water with high temperature–salinity and low chlorophyll concentration in the upper layer. The corresponding annual-mean transport caused by KLCES reaches 0.24–0.38 Sv (1 Sv ≡ 106 m3 s−1), accounting for 6.8%–10.8% of the upper-layer Luzon Strait transport. Altimeter-based statistics show that among ~90% of the historical KLCES events, a cyclonic eddy (CE) is immedi...

Global surface warming enhanced by weak Atlantic overturning circulation.

Abstract: Evidence from palaeoclimatology suggests that abrupt Northern Hemisphere cold events are linked to weakening of the Atlantic Meridional Overturning Circulation (AMOC)1, potentially by excess inputs of fresh water2. But these insights—often derived from model runs under preindustrial conditions—may not apply to the modern era with our rapid emissions of greenhouse gases. If they do, then a weakened AMOC, as in 1975–1998, should have led to Northern Hemisphere cooling. Here we show that, instead, the AMOC minimum was a period of rapid surface warming. More generally, in the presence of greenhouse-gas heating, the AMOC’s dominant role changed from transporting surface heat northwards, warming Europe and North America, to storing heat in the deeper Atlantic, buffering surface warming for the planet as a whole. During an accelerating phase from the mid-1990s to the early 2000s, the AMOC stored about half of excess heat globally, contributing to the global-warming slowdown. By contrast, since mooring observations began3–5 in 2004, the AMOC and oceanic heat uptake have weakened. Our results, based on several independent indices, show that AMOC changes since the 1940s are best explained by multidecadal variability6, rather than an anthropogenically forced trend. Leading indicators in the subpolar North Atlantic today suggest that the current AMOC decline is ending. We expect a prolonged AMOC minimum, probably lasting about two decades. If prior patterns hold, the resulting low levels of oceanic heat uptake will manifest as a period of rapid global surface warming.

Targeting the mTOR Signaling Network for Alzheimer’s Disease Therapy

Abstract: The mammalian target of rapamycin (mTOR) is a highly conserved serine/threonine kinase that can sense environmental stimuli such as growth factors, energy state, and nutrients. It is essential for cell growth, proliferation, and metabolism, but dysregulation of mTOR signaling pathway is also associated with a number of human diseases. Encouraging data from experiments have provided sufficient evidence for the relationship between the mTOR signaling pathway and Alzheimer’s disease (AD). Upregulation of mTOR signaling pathway is thought to play an important role in major pathological processes of AD. The mTOR inhibitors such as rapamycin have been proven to ameliorate the AD-like pathology and cognitive deficits effectively in a broad range of animal models. Application of mTOR inhibitors indicates the potential value of reducing mTOR activity as an innovative therapeutic strategy for AD. In this review, we will focus on the recent process in understanding mTOR signaling pathway and the vital involvement of this signaling pathway in the pathology of AD, and discuss the application of mTOR inhibitors as potential therapeutic agents for the treatment of AD.