Twenty years ago, the multidimensional, positive de nite, advection transport algorithm was introduced by Smolarkiewicz. Over the two decades since, it has been applied countless times to numerous problems, however almost always on rectilinear grids. One of the few exceptions is the Operational Multiscale Environment model with Grid Adaptivity (OMEGA), an atmospheric simulation system originall...

Advection schemes with time step restrictions are widely used in weather and climate models. This can lead to instability the presence of high flow speeds (relative mesh spacing) such as occurs convective updraughts, regions convergence, or where winds unusually high. An adaptively implicit advection scheme is proposed that treats implicitly only Courant number Flux correction ensure monotonici...

We present a new finite difference code for modeling three-dimensional thermal convection in a spherical shell using the “cubed sphere” method of Ronchi et al. [1]. The equation of motion is solved using a poloidal potential formulation for an iso-viscous, infinite Prandtl number fluid on a finite difference grid and advective transport is implemented using the 2nd-order MPDATA scheme of Smolar...

A three-dimensional semi-implicit edge-based unstructured-mesh model is developed that integrates nonhydrostatic anelastic equations, suitable for simulation of small-to-mesoscale atmospheric flows. The model builds on nonoscillatory forwardin-time MPDATA approach using finite-volume discretization and admitting unstructured meshes with arbitrarily shaped cells. The numerical advancements are e...

سابقه و هدف: به ­دلیل توسعه رشد جمعیت انسان، نیاز انسان منابع ضروری افزایش یافته است. فعالیت‌های مربوط صنایع همچنین کشاورزی به­ طور گسترده‌ای زمین‌های را آلوده کرده ترکیبات نفتی فلزات سنگین هر دو از آلاینده‌های رایج موجود در خاک‌هایی هستند که با فاضلاب تصفیه نشده آبیاری شده‌اند سلامت محیط زیست خطر مواجه می‌کنند. آلودگی خاک می‌تواند سبب کاهش امکان زراعت، نهایت تولید غذا برای شود. جنوب شهر تهران ...