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The immersed boundary–lattice Boltzmann (IB-LB) coupling scheme is known as an efficient scheme for fluid–structure interactions (FSIs). However, the conventional IB-LB schemes suffer from instability because they involve a high-Reynolds-number flow or a larger stiffness structure. An averagely weighted iteration approach is presented to improve the stability restriction in this paper. This new approach, which improves the stability by mitigating the high-frequency fluctuations, is implemented by iteratively calculating the external force, and averagely weighting the force obtained at every iterative step. Five cases are simulated to verify the accuracy and effectiveness of the present approach. Under the premise of maintaining the accuracy of the conventional IB-LB method, the implementation of the present approach can significantly enhance the numerical stability. Compared with the conventional IB-LB method, the present approach can significantly expand the material parameter range for simulation; in particular, this approach qualitatively improves the upper limit of the bending rigidity coefficient by approximately 8000 times. To use the outstanding stability of the present approach, the IB inertia force can be directly incorporated into the simulation. In addition, under the low-viscosity condition, the present approach can effectively simulate the large-deformation FSI problem. [ABSTRACT FROM AUTHOR]

As an important component of the global climate systems, ocean-continent interaction influences hydrological cycles at regional and local scales. Eastern China is a typical region where oceanic moisture (OM) has significant influences on summer precipitation. Due to its simplicity and accuracy, physical water vapor tracer method based on the stable isotope has been widely employed to estimate the contributions of different sources to precipitation. However, dense and long-term isotopic observations are limited by technical and economic reasons. Isotope-equipped global climate models (iGCMs) provide potential solutions to to improve our knowledge of hydrological processes. Accordingly, this study investigates the potential of using iGCMs to quantify the contributions of the OM to precipitation, which aim at better understanding of the hydrologic cycle processes. A new bias correction method is proposed to correct biases of precipitation isotopes simulated by five iGCMs (i.e. CAM2, GISS-modelE, LMDZ4, MIROC32, and HadAM3). A modified two-component mixing model taking 18O as a tracer is employed to assess the spatiotemporal contributions of summer OM for eastern China. Results show that iGCMs are biased in simulating preciptiation isotopes at local and regional scales. The bias correction method performs reasonable well in terms of reducing the biases. Based on biased-corrected precipitation isoscapes, the influence of OM on summer precipitation is investigated and found that OM plays an important role in summer precipitation, and spatially decreases along the transport route and the passage of time in summer. In addition, the OM contribution to precipitation contain a considerable uncertainty associated with the choice of a given iGCM for each sub-region and sub-period. Overall, bias correction is necessay before applying iGCMs to study hydrological cycles at the regional scale and the application of multi-iGCMs is critical to delineate uncertainty in studying oecanic-land interaction. [ABSTRACT FROM AUTHOR]