The current lack of high-precision information on subsurface seawater is a constraint in fishery research. Based on Argo temperature and salinity profiles, this study applied the gradient-dependent optimal interpolation to reconstruct daily subsurface oceanic environmental information according to fishery dates and locations. The relationship between subsurface information and matching yellowfin tuna(YFT) in the western and central Pacific Ocean(WCPO) was examined using catch data from January 1... 相似文献
Spartina alterniflora as an alien invasive plant, poses a serious threat to the ecological functions of the coastal wetland of the Jiaozhou Bay. As of 2019, the distribution area of S. alterniflora in the Jiaozhou Bay has reached more than 500 hm2. For this reason, combined with field surveys, remote sensing monitoring of the invasion S.alterniflora in the Jiaozhou Bay has been carried out. To accurately identify S. alterniflora within the Jiaozhou Bay coastal wetland, we used a new m... 相似文献
During the self-weight penetration process of the suction foundation on the dense sand seabed, due to the shallow penetration depth, the excess seepage seawater from the outside to the inside of the foundation may cause the negative pressure penetration process failure. Increasing the self-weight penetration depth has become an important problem for the safe construction of the suction foundation. The new suction anchor foundation has been proposed, and the self-weight penetration characteristics of the traditional suction foundation and the new suction anchor foundation are studied and compared through laboratory experiments and analysis. For the above two foundation types, by considering five foundation diameters and two bottom shapes, 20 models are tested with the same penetration energy. The effects of different foundation diameters on the penetration depth, the soil plug characteristics, and the surrounding sand layer are studied. The results show that the penetration depth of the new suction foundation is smaller than that of the traditional suction foundation. With the same penetration energy, the penetration depth of the suction foundation becomes shallower as the diameter increases. The smaller the diameter of the suction foundation, the more likely it is to be fully plugged, and the smaller the height of the soil plug will be. In the stage of self-weight penetration, the impact cavity appears around the foundation, which may affect the stability of the suction foundation.
China Ocean Engineering - Four ships, a twin-propeller naval ship, two single-propeller container ships, and a single-propeller very large crude carrier (VLCC), were studied to investigate the... 相似文献
To assess the performances of state-of-the-art global climate models on simulating the Arctic clouds and surface radiation balance, the 2001–2014 Arctic Basin surface radiation budget, clouds, and the cloud radiative effects(CREs) in 22 coupled model intercomparison project 6(CMIP6) models are evaluated against satellite observations. For the results from CMIP6 multi-model mean, cloud fraction(CF) peaks in autumn and is lowest in winter and spring, consistent with that from three satellite observation products(Cloud Sat-CALIPSO, CERESMODIS, and APP-x). Simulated CF also shows consistent spatial patterns with those in observations. However,almost all models overestimate the CF amount throughout the year when compared to CERES-MODIS and APP-x.On average, clouds warm the surface of the Arctic Basin mainly via the longwave(LW) radiation cloud warming effect in winter. Simulated surface energy loss of LW is less than that in CERES-EBAF observation, while the net surface shortwave(SW) flux is underestimated. The biases may result from the stronger cloud LW warming effect and SW cooling effect from the overestimated CF by the models. These two biases compensate each other,yielding similar net surface radiation flux between model output(3.0 W/m~2) and CERES-EBAF observation(6.1 W/m~2). During 2001–2014, significant increasing trend of spring CF is found in the multi-model mean,consistent with previous studies based on surface and satellite observations. Although most of the 22 CMIP6 models show common seasonal cycles of CF and liquid water path/ice water path(LWP/IWP), large inter-model spreads exist in the amounts of CF and LWP/IWP throughout the year, indicating the influences of different cloud parameterization schemes used in different models. Cloud Feedback Model Intercomparison Project(CFMIP)observation simulator package(COSP) is a great tool to accurately assess the performance of climate models on simulating clouds. More intuitive and credible evaluation results can be obtained based on the COSP model output. In the future, with the release of more COSP output of CMIP6 models, it is expected that those inter-model spreads and the model-observation biases can be substantially reduced. Longer term active satellite observations are also necessary to evaluate models' cloud simulations and to further explore the role of clouds in the rapid Arctic climate changes. 相似文献
An approach based on individual rainfall events is introduced to mathematically describe the hydrologic responses and estimate the stormwater capture efficiencies of permeable pavement systems (PPSs). A stochastic model describing the instantaneous dynamic water balance of a PPS is established, from which the probability distribution of the antecedent moisture content of the PPS at the beginning of a rainfall event is analytically derived. Based on this probability distribution and the event‐based approach, an analytical equation that can be used for estimating the stormwater capture efficiencies of PPSs is also derived. The derived analytical equation is verified by comparing its results with those from continuous simulations for a wide range of PPSs with different sizes and underlying soils and operating under various climate conditions. It was found that the antecedent moisture contents of PPSs at the test locations are usually fairly close to zero, suggesting that PPSs at these locations are always almost empty at the start of a rainfall event. The derived analytical equation accounts for many key processes influencing the behaviour and operation of PPSs; it may serve as an easy‐to‐use tool that is essential for the planning and design of PPSs. 相似文献
To simplify the complex snow structures that occur in nature, polycrystalline ice spheres were produced and arranged vertically to model the sintering process. By controlling the temperatures on both the top and bottom of the ice sphere array, the effect of upward and downward vapor transfers was examined. The evolution of the neck areas between ice spheres was observed using X‐ray computed microtomography. As frequently observed under the basal part of a snow layer and previous experiments of snow temperature gradient metamorphism, depth hoar structures were formed along neck areas and their formation was found to be directly related to the vapor transfer direction. To model the temperature gradient inversion that can be induced in nature by daily cycles of radiative heating and cooling, we also performed sign‐alternating temperature gradient experiments on the ice sphere arrays. The morphological evolution of the neck and the associated vapor transfer were examined through image analysis and 2D modeling. The final microstructures of the neck area turned out to be a symmetrical distribution of ice protrusions bridging neighboring ice spheres. 相似文献