This paper presents an overview and a detailed description of the key logic steps mathematical-physics framework behind development practical algorithms for seismic exploration derived from inverse scattering series.

Abstract. In the East China Sea, hypoxia (oxygen ≤ 62.5 mmol m−3) is frequently observed off Changjiang (or Yangtze River) estuary covering up to about 15 000 km2. The a major contributor formation because it discharges large amounts of freshwater and nutrients into region. However, modeling observational studies have suggested that intrusions nutrient-rich oceanic water from Kuroshio Current also contribute formation. relative contributions riverine vs. nutrient sources not been estimated...

Abstract. A three-dimensional physical-biological model of the marginal seas China was used to analyze interannual and intra-seasonal variations in hypoxic conditions identify main processes controlling their generation off Changjiang (or Yangtze River) estuary. The compared against available observations reproduces observed temporal spatial variability physical biological properties including bottom oxygen. Interannual extent simulation are partly explained by river discharge but not...

Abstract In the deep central part of Bohai Sea off coast northern China, long-term observations show significantly lower dissolved oxygen (DO) concentration near bottom in summer during 2006–2018 than 1978–2005. The decrease DO is closely linked to changes phytoplankton community driven by nutrient structure water column. From literature review, indicate an increase abundant proportion dinoflagellate diatom and miniaturization since 21st century. new dominate species dinoflagel-late pico-...

A task-specific, multiparameter (more than one mechanical property changes across a reflector), direct nonlinear inversion subseries of the inverse-scattering series is derived and tested for an acoustic medium in which velocity density vary vertically. Task-specific means that terms distinct corresponding to tasks imaging only are identified separated. Direct there formulas solve explicitly output physical properties, without, e.g., search algorithms, model matching optimization schemes,...

Linear inversion is defined as the linear approximation of a direct-inverse solution. This definition leads to data requirements and specific algorithms, which differ with all current nonlinear approaches, immediately relevant for target identification in an elastic earth. Common practice typically starts direct forward or modeling expression seeks solve equation inverse sense. Attempting problem sense not same solving directly. Distinctions include differences need priori information,...

In the direct nonlinear inversion method and in algorithms for 1D elastic media, P-wave velocity, S-wave density are depth dependent. “Direct nonlinear” means that uses explicit formulas (1) input data directly output changes material properties without need indirect procedures such as model matching, searching, optimization, or other assumed aligned objectives proxies (2) recognize invert intrinsic relationship between recorded reflection wavefields. To achieve full inversion, all...

Being a biologically diversed hotspot in the global marine ecosystem, Beibu Gulf is inhabited by high diversity of fish and serves as vital fishing ground China. Due to continuous overfishing, fishery resource has drastically declined Gulf. However, information about ichthyoplankton assemblages this area still lacking. In present study, diversity, spatial temporal distribution patterns, assemblage structures were examined using specimens collected late summer–autumn winter 2022 Gulf,...

A key factor for imaging geology below complex salt bodies is identifying and defining the shape of geometry. In recent years, a combination improved algorithms, increased computational speed, integrated interpretation platforms have made it increasingly possible to use in near real-time as an interactive aid model process. The availability feedback showing effect changes velocity on seismic image can significantly improve quality reduce cycle times building interpretation. this study, we...

The melting of NiN clusters (N = 29, 50-150) has been investigated by using molecular dynamics (MD) simulations with a quantum corrected Sutton-Chen (Q-SC) many-body potential. Surface for Ni147, direct Ni79, and the glass transition Ni29 have found, those points are equal to 540, 680, 940 K, respectively. It shows that temperatures not only size-dependent but also symmetrical structure effect; in neighborhood clusters, cluster higher symmetry point. From reciprocal slopes caloric curves,...

Understanding how environmental factors impact the interannual variation in scallop growth and subsequently developing an easily obtained parameter to indicate this could provide a scientific basis for optimizing their aquaculture. In study, we have set scenario of uniformly sowed scallops same initial size Changhai sea area. The Yesso culture ecosystem model was used simulate bottom-cultured each year from December 1, 2006 November 30, 2017. results show that annual rate higher northwest...

Figuring out the influences of carbonaceous particle properties on ice nucleation is important to atmospheric science, but it still a challenge, especially for experimental investigations due coupling effect multiple properties. Here we separately investigate effects oxidation degree and size, two typical debated factors, efficiency by choosing graphene oxide (GO) as model. The results show that with decrease degree, increases through decreasing free energy barrier (ΔGheter*) GO surface....

Lack of suitable towed array has existed as a main problem for further extended use small underwater mobile platforms such UUV. In this paper, an ultra-thin fiber-optic hydrophone is developed based on DFB fiber laser, which diameter only 12mm. And the performance tested by towboat. The experimental results show that noise 69dB re. uPa/√Hz@1kHz. addition, can precisely determine spatial characteristics acoustic field at 6 knots, verifies feasibility laser in UUV and other platforms.

We present a one‐dimensional analytical analysis of the phase and amplitude internal multiples predicted using inverse scattering series based multiple attenuation algorithm. Our focus is on amplitudes second higher order multiples. Through comparison with analogous free‐surface removal algorithm, we develop insight into additional complexity prediction. The relationship between actual suggests greater dependency adaptive subtraction than in case. indicates that, prediction beyond first...

Abstract. The Changjiang is the largest river in Asia and main terrestrial source of freshwater nutrients to East China Sea (ECS). Nutrient concentrations have long been increasing Changjiang, especially after 1960 with urbanization, development industrial animal production, fertilizer application agriculture, resulting coastal eutrophication recurring summer hypoxia. supply anthropogenic nitrogen (N) exceeds that phosphorus (P) relative Redfield ratio. This results seasonal P limitation...

Abstract. A three-dimensional physical-biological model of marginal seas China was used to analyze variations in hypoxic conditions and identify the main processes controlling their generation off Changjiang Estuary. The validated against available observations reproduces observed temporal spatial variability hypoxia. Dissolved oxygen concentrations undergo a seasonal cycle, with minima generally occurring August or September, vary latitudinally longer duration low-oxygen southern part...

Abstract In the southern Yellow Sea (SYS) there are temperature and salinity inversions associated with presence of middepth low water. Many questions regarding inversions, such as seasonal variation transformation mechanism, still remain unexplained. this study, based on hydrographic measurements obtain from 12 cruises within 6‐year (2017–2022), we explored distribution, seasonality, generation, mechanism in SYS. Observations reveal widespread (YS) during both spring summer. More found...

Jellyfish blooms have become a marine environmental issue with detrimental effects on ecosystems around the world. The jellyfish Aurelia aurita is one of dominant species worldwide and also in Bohai Yellow Seas (BYSs) China. To investigate population dynamics controlling factors biomass, complex population-dynamic model developed for A. BYSs that includes three components, namely, three-dimensional coupled physical–biogeochemical model, Lagrangian particle-tracking an energy balance life...

S1 Simulated circulation in the East China SeaZhang et al. (same special issue) assessed skill of applied ROMS model with respect to physics based on sea surface temperature and salinity, which provides a ba-