Chesapeake Bay Nitrogen Fluxes Derived From a Land-Estuarine Ocean Biogeochemical Modeling System: Model Description, Evaluation, and Nitrogen Bonds

The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land-estuarine-ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within-estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite-derived data, and a simulation using environmental conditions for 2001-2005 was conducted to quantify the Chesapeake Bay nitrogen budget. The 5 year simulation was characterized by large riverine inputs of nitrogen (154 x 109 g N yr-1) split roughly 60: 40 between inorganic: organic components. Much of this was denitrified (34 x 109 g N yr-1) and buried (46 x 109 g N yr-1) within the estuarine system. A positive net annual ecosystem production for the bay further contributed to a large advective export of organic nitrogen to the shelf (91 x 109 g N yr-1) and negligible inorganic nitrogen export. Interannual variability was strong, particularly for the riverine nitrogen fluxes. In years with higher than average riverine nitrogen inputs, most of this excess nitrogen (50-60%) was exported from the bay as organic nitrogen, with the remaining split between burial, denitrification, and inorganic export to the coastal ocean. In comparison to previous simulations using generic shelf biogeochemical model formulations inside the estuary, the estuarine biogeochemical model described here produced more realistic and significantly greater exports of organic nitrogen and lower exports of inorganic nitrogen to the shelf

Based on knowledge capital value for disease cost accounting of diagnosis related groups

BackgroundThe National Health Commission and the other relevant departments in China have initiated testing of the Diagnosis Related Groups (DRGs) system in 30 pilot locations since 2019. In the process of DRG payment reform, accounting for the costs of diseases has become a highly challenging issue. The traditional method of disease accounting method overlooks the compensation for the knowledge capital value of medical personnel.ObjectiveThe primary objective of this study is to analyze the cost accounting scheme of China’s Diagnosis Related Groups (C-DRG), focusing on the value of knowledge capital.MethodsThe study initially proposes a measurement index system for the value of knowledge-based capital, including the difficulty of disease treatment, labor intensity of disease treatment, risk of disease treatment, and operation/treatment time for diseases. The Analytic Hierarchy Process (AHP) is then utilized to weigh the features of medical workers’ knowledge capital value. First, pairwise comparisons are conducted in this stage to develop a two-pair judgment matrix of the primary indicators. Second, the eigenvectors corresponding to the maximum eigenvalues of the matrix are calculated to generate the weight coefficient of each feature. The consistency test is carried out after this stage. An empirical analysis is conducted by collecting data, including the full costs of treating three types of diseases—hip replacement, acute simple appendicitis, and heart bypass surgery—from one public medical institution.ResultsThe empirical analysis examines whether this DRG costing accounting can address the issue of neglecting the value of medical workers’ knowledge capital. The methods reconfigure the positive incentive mechanism, stimulate the endogenous motivation of the medical service system, foster independent changes in medical behavior, and achieve the goals of reasonable cost control.ConclusionIn the cost accounting system of C-DRG, the value of medical workers’ knowledge capital is acknowledged. This acknowledgment not only boosts the enthusiasm and creativity of medical workers in optimizing and standardizing the diagnosis and treatment process but also improves the transparency and authenticity of DRG pricing. This is particularly evident in the optimization and standardization of the diagnosis and treatment processes within medical institutions and in monitoring inadequate medical practices within these institutions

Chesapeake Bay nitrogen fluxes derived from a land-estuarine ocean biogeochemical modeling system: Model description, evaluation, and nitrogen budgets

The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land-estuarine-ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within-estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite-derived data, and a simulation using environmental conditions for 2001-2005 was conducted to quantify the Chesapeake Bay nitrogen budget. The 5 year simulation was characterized by large riverine inputs of nitrogen (154 x 10(9) g N yr(-1)) split roughly 60: 40 between inorganic: organic components. Much of this was denitrified (34 x 10(9) g N yr(-1)) and buried (46 x 10(9) g N yr(-1)) within the estuarine system. A positive net annual ecosystem production for the bay further contributed to a large advective export of organic nitrogen to the shelf (91 x 10(9) g N yr(-1)) and negligible inorganic nitrogen export. Interannual variability was strong, particularly for the riverine nitrogen fluxes. In years with higher than average riverine nitrogen inputs, most of this excess nitrogen (50-60%) was exported from the bay as organic nitrogen, with the remaining split between burial, denitrification, and inorganic export to the coastal ocean. In comparison to previous simulations using generic shelf biogeochemical model formulations inside the estuary, the estuarine biogeochemical model described here produced more realistic and significantly greater exports of organic nitrogen and lower exports of inorganic nitrogen to the shelf

Chesapeake Bay Nitrogen Fluxes Derived From a Land-Estuarine Ocean Biogeochemical Modeling System: Model Description, Evaluation, and Nitrogen Budgets

The Chesapeake Bay plays an important role in transforming riverine nutrients before they are exported to the adjacent continental shelf. Although the mean nitrogen budget of the Chesapeake Bay has been previously estimated from observations, uncertainties associated with interannually varying hydrological conditions remain. In this study, a land-estuarine-ocean biogeochemical modeling system is developed to quantify Chesapeake riverine nitrogen inputs, within-estuary nitrogen transformation processes and the ultimate export of nitrogen to the coastal ocean. Model skill was evaluated using extensive in situ and satellite-derived data, and a simulation using environmental conditions for 2001–2005 was conducted to quantify the Chesapeake Bay nitrogen budget. The 5 year simulation was characterized by large riverine inputs of nitrogen (154 × 109 g N yr−1) split roughly 60:40 between inorganic:organic components. Much of this was denitrified (34 × 109 g N yr−1) and buried (46 × 109 g N yr−1) within the estuarine system. A positive net annual ecosystem production for the bay further contributed to a large advective export of organic nitrogen to the shelf (91 × 109 g N yr−1) and negligible inorganic nitrogen export. Interannual variability was strong, particularly for the riverine nitrogen fluxes. In years with higher than average riverine nitrogen inputs, most of this excess nitrogen (50–60%) was exported from the bay as organic nitrogen, with the remaining split between burial, denitrification, and inorganic export to the coastal ocean. In comparison to previous simulations using generic shelf biogeochemical model formulations inside the estuary, the estuarine biogeochemical model described here produced more realistic and significantly greater exports of organic nitrogen and lower exports of inorganic nitrogen to the shelf

Observed wintertime tidal and subtidal currents over the continental shelf in the northern South China Sea

Author Posting. © American Geophysical Union, 2014. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research: Oceans 119 (2014): 5289–5310, doi:10.1002/2014JC009931.Synthesis analyses were performed to examine characteristics of tidal and subtidal currents at eight mooring sites deployed over the northern South China Sea (NSCS) continental shelf in the 2006–2007 and 2009–2010 winters. Rotary spectra and harmonic analysis results showed that observed tidal currents in the NSCS were dominated by baroclinic diurnal tides with phases varying both vertically and horizontally. This feature was supported by the CC-FVCOM results, which demonstrated that the diurnal tidal flow over this shelf was characterized by baroclinic Kelvin waves with vertical phase differences varying in different flow zones. The northeasterly wind-induced southwestward flow prevailed over the NSCS shelf during winter, with episodic appearances of mesoscale eddies and a bottom-intensified buoyancy-driven slope water intrusion. The moored current records captured a warm-core anticyclonic eddy, which originated from the southwestern coast of Taiwan and propagated southwestward along the slope consistent with a combination of β-plane and topographic Rossby waves. The eddy was surface-intensified with a swirl speed of >50 cm/s and a vertical scale of ∼400 m. In absence of eddies and onshore deep slope water intrusion, the observed southwestward flow was highly coherent with the northeasterly wind stress. Observations did not support the existence of the permanent wintertime South China Sea Warm Current (SCSWC). The definition of SCSWC, which was based mainly on thermal wind calculations with assumed level of no motion at the bottom, needs to be interpreted with caution since the observed circulation over the NSCS shelf in winter included both barotropic and baroclinic components.R. Li was supported by the SOA 908 Special Project Foundation of China (908-01-ST07 and 908-01-BC10), the National High Tech Project Foundation (863) of China (2008AA09A401), the Administrator Foundation of South Branch, SOA (0683). The development of FVCOM was funded by the US NSF Office of Polar Programs through grants ARC0712903, ARC0732084, ARC0804029, and ARC1203393.2015-02-1

Grazing weakens competitive interactions between active methanotrophs and nitrifiers modulating greenhouse-gas emissions in grassland soils

This work was financially supported by Natural Science Foundation of China (41977033, 41907026, and 41721001), Fundamental Research Funds for the Central Universities (2019QNA6011), National Key Basic Research Program of China (2014CB138801), Shandong Provincial Natural Science Foundation (ZR2019BD032), China Postdoctoral Science Foundation (2020T130387 and 2019M652448). CG-R was funded by a Royal Society University Research Fellowship (UF150571). Special thanks to ChunMei Meng, Yu Luo, and Yan Zheng for their assistance in laboratory analyses.Peer reviewedPublisher PD

Observational and modeling studies of oceanic responses and feedbacks to typhoons Hato and Mangkhut over the northern shelf of the South China Sea

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Dong, W., Feng, Y., Chen, C., Wu, Z., Xu, D., Li, S., Xu, Q., Wang, L., Beardsley, R. C., Lin, H., Li, R., Chen, J., & Li, J. Observational and modeling studies of oceanic responses and feedbacks to typhoons Hato and Mangkhut over the northern shelf of the South China Sea. Progress in Oceanography, 191, (2021): 102507, https://doi.org/10.1016/j.pocean.2020.102507.Meteorological and oceanic responses to Typhoons Hato and Mangkhut were captured by storm-monitoring network buoys over the northern shelf of the South China Sea. With similar shelf-traversing trajectories, these two typhoons exhibited distinctly different features in storm-induced oceanic mixing and oceanic heat transfer through the air-sea interface. A well-defined cold wake was detected underneath the storm due to a rapid drop in sea surface temperature during the Hato crossing, but not during the Mangkhut crossing. Impacts of oceanic mixing on forming a storm-produced cold wake were associated with the pre-storm condition of water stratification. In addition to oceanic mixing produced through the diffusion process by shear and buoyancy turbulence productions, the short-time scale of mixing suggested convection/overturning may play a critical role in the rapid cooling at the sea surface. The importance of convection/overturning to mixing depended on the duration of atmospheric cooling above the sea surface-the longer the atmospheric cooling, the more significant effect on mixing. Including the oceanic mixed layer (OML) in the WRF model was capable of reproducing the observed storm-induced variations of wind and air pressure, but not the air and sea surface temperatures. Process-oriented numerical experiments with the OML models supported both observational and modeling findings. To simulate the storm-induced mixing in a coupled atmospheric and oceanic model, we need to improve the physics of vertical mixing with non-hydrostatic convection/overturning. Warming over the shelf is projected to have a more energetic influence on future typhoon intensities and trajectories.This work was supported by the National Key Research and Development Programs of China with grant numbers 2018YFC-1406201; 2016YFA-0602700; 2018YFC-1506903; 2018YFC-1406205, and the National Sciences Foundation of China with grant number U1811464. S. Li was supported by the oversea Ph.D. fellowship from the China Scholarship Council (No. 1409010025) and Dr. Chen’s Montgomery Charter Chair graduate education funds at the University of Massachusetts-Dartmouth

Crystalline superlattices from single-sized quantum dots

通讯作者地址: Feng, PY (通讯作者), Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA 地址: 1. Univ Calif Riverside, Dept Chem, Riverside, CA 92521 USA 2. Calif State Univ Long Beach, Dept Chem & Biochem, Long Beach, CA 90840 USA 电子邮件地址: [email protected]