Weather and Climate Modeling

Abstract

AbstractThe current manuscript documents a summary of the evolution of Numerical Weather Prediction (NWP) as an inevitable component of modern meteorology and its growth and development toward future climate and earth system models. NWP is essentially an initial-boundary value problem and the basic assumption of atmospheric continuum led to the development of subgrid scale physical parameterization schemes. The errors are inherent to the initial conditions and science formulations in the deterministic models and the natural chaotic behavior of the atmosphere brought out the importance of the ensemble approach to assess the uncertainty in forecasts and a probability-based narrative. The growth of recent high-resolution global models necessitates resolving more and more intricate processes, which were so far relevant only in climate models, and signaling toward a merger with seamless weather and climate prediction system across all scales and earth system models. Society at large needs to adapt and respond to the climate change impacts and to the natural transformation processes in the earth’s climate system. High-resolution global ensemble-based data assimilation-forecast systems can better resolve the scale interactions and improve the skill of the NWP models in simulating the under-resolved components of the coupled atmosphere-earth-ocean-cryosphere systems. There is a significant uncertainty in the forcings and the actual internal variability of the climate system, posing the problem of a large spread in the climate projections of global warming by the models from different leading centers. The treatment of cloud processes, scale-aware parameterizations, atmosphere-land-vegetation coupling, and aerosol processes are the immediate major challenges in weather, climate, and earth system modeling. Carbon and methane cycles are important for the realistic estimation of greenhouse gas forcing, compounded by the dynamic vegetation, ocean biogeochemistry, hydrology and water cycle, ecosystem, land–ocean-ice coupling, and the representation of the intrinsic modes of intra-seasonal to decadal variability that play crucial roles in the projection of future climate.