Environmental Conditions Determining the Timing of the Lifetime Maximum Intensity of Tropical Cyclones over the Western North Pacific and Their Frequency of Occurrence

Environmental conditions determining the timing of the lifetime maximum intensities of tropical cyclones(TCs)are investigated for the TCs over the western North Pacific during the period 2008-2017.The results show that the land controls the timings of the lifetime maximum intensities in 42% of the TCs over this basin,indicating that accurate track forecasts are beneficial for TC intensity forecasts.With respect to other TCs that are not affected by the land(i.e.,Ocean-TCs),the timings of their lifetime maximum intensities are determined by multiple oceanic factors.In particular,interactions between TCs and cold-core eddies occur in a large proportion(nearly 60%)of Ocean-TCs at or shortly after the times of their lifetime maximum intensities,especially in strong TCs(categories 4 and 5),suggesting that a consideration of the above interactions is necessary for improving TC intensity forecasting skills.In addition,unfavorable oceanic heat content conditions become common as the latitude increases over 25°N,influencing half of the Ocean-TCs.Strong vertical wind shear contributes detrimentally to the atmospheric environment in 17% of the TCs over this basin,especially in moderate and weak TCs.In contrast,neither the maximum potential intensity nor the humidity in the middle level of the atmosphere plays dominant roles when TCs turn from their peak intensities to weakening.

Inventory models for deteriorating items with fixed lifetime, partial backordering and carbon emissions policies

In this study,a sustainable inventory model is devised to obtain the retailer’s optimal pricing and replenishment policies for degrading items having a certain lifetime incorporating partial back order as a shortage and dynamic demand under two different scenarios(a)carbon cap and trade policy(b)carbon tax policy.The primary objective of this study is to maximize the retailer’s annual total profit.The retailer’s profit function has been optimized with the help of convexity/concavity criteria employing classical optimization techniques.Based on a real case study,two different numerical examples and corresponding optimal solutions have been shown for both models with the help of Lingo 17 software.Moreover,the impact of the major inventory parameters and prominent managerial insights are presented for the robustness of the proposed model that can cooperate with industrial managers/decision-makers for the overall improvement of his/her industry to take effective and qualitative decisions.