224 research outputs found

    Discretization of sea ice dynamics in the tangent plane to the sphere by a CD-grid-type finite element

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    We present a new discretization of sea ice dynamics on the sphere. The approach describes sea ice motion in tangent planes to the sphere. On each triangle of the mesh, the ice dynamics are discretized in a local coordinate system using a CD-grid-like non-conforming finite element method. The development allows a straightforward coupling to the C-grid like ocean model in Icosahedral Non-hydrostatic-Ocean model, which uses the same infrastructure as the sea ice module. Using a series of test examples, we demonstrate that the non-conforming finite element discretization provides a stable realization of large-scale sea ice dynamics on the sphere. A comparison with observation shows that we can simulate typical drift patterns with the new numerical realization of the sea ice dynamics. © 2022 The Authors. Journal of Advances in Modeling Earth Systems published by Wiley Periodicals LLC on behalf of American Geophysical Union

    CD-type discretization for sea ice dynamics in FESOM version 2

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    Two recently proposed variants of CD-type discretizations of sea ice dynamics on triangular meshes are implemented in the Finite-VolumE Sea ice–Ocean Model (FESOM version 2). The implementations use the finite element method in spherical geometry with longitude–latitude coordinates. Both are based on the edge-based sea ice velocity vectors but differ in the basis functions used to represent the velocities. The first one uses nonconforming linear (Crouzeix–Raviart) basis functions, and the second one uses continuous linear basis functions on sub-triangles obtained by splitting parent triangles into four smaller triangles. Test simulations are run to show how the performance of the new discretizations compares with the A-grid discretization using linear basis functions. Both CD discretizations are found to simulate a finer structure of linear kinematic features (LKFs). Both show some sensitivity to the representation of scalar fields (sea ice concentration and thickness). Cell-based scalars lead to a finer LKF structure for the first CD discretization, but the vertex-based scalars may be advantageous in the second case.</p

    Effects of seed lots and seed production time on growth, flowering and cut flower quality in Bupleurum rotundifolium L.

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    Effects of three planting patterns; two-row-planting high density (25 plants·m(-2)), two-row-planting low density (12.5 plants·m(-2)), and four-row-planting (25 plants·m(-2)) on the cut flower number and quality of spray carnation (Dianthus caryophyllus L.) cv. ‘Barbara’ and ‘Cherry Tessino’ grown by fertigation cultivation were investigated. In ‘Barbara’, there was no difference in total cut flower number between two-row-planting high density and four-row-planting. Total cut flower number of two-row-planting low density decreased to 60% of two-row-planting high density or four-row-planting. In ‘Cherry Tessino’, the total cut flower number of two-row-planting high density was 15% more than that of four-row-planting. The total cut flower number of two-row-planting low density decreased to 60~70% of two-row-planting high density or four-row-planting. There was no difference in cut flower quality between two-row-planting high density and four-row-planting in both cultivars. Cut flower weight and stem diameter of two-row-planting low density increased compared to those of two-row-planting high density or four-row-planting. Thus, the result indicates that two-row-planting high density may be suitable for fertigation cultivation in carnation

    ICON-O: The Ocean Component of the ICON Earth System Model - Global simulation characteristics and local telescoping capability

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    Abstract We describe the ocean general circulation model ICON-O of the Max Planck Institute for Meteorology, which forms the ocean-sea ice component of the Earth system model ICON-ESM. ICON-O relies on innovative structure-preserving finite volume numerics. We demonstrate the fundamental ability of ICON-O to simulate key features of global ocean dynamics at both uniform and non-uniform resolution. Two experiments are analyzed and compared with observations, one with a nearly uniform and eddy-rich resolution of ?10?km and another with a telescoping configuration whose resolution varies smoothly from globally ?80?km to ?10?km in a focal region in the North Atlantic. Our results show first, that ICON-O on the nearly uniform grid simulates an ocean circulation that compares well with observations and second, that ICON-O in its telescope configuration is capable of reproducing the dynamics in the focal region over decadal time scales at a fraction of the computational cost of the uniform-grid simulation. The telescopic technique offers an alternative to the established regionalization approaches. It can be used either to resolve local circulation more accurately or to represent local scales that cannot be simulated globally while remaining within a global modeling framework
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