Modes of Atmospheric Energetics Based on HadGEM3-GC3.1-LL Simulations in the Framework of CMIP6

Abstract

In this study, the focus is on investigating how different climate scenarios, as they have been adopted in Phase 6 of the Coupled Model Intercomparison Project (CMIP6), can lead to different regimes in the energetics components in Lorenz’s energy cycle, hence impacting the “working rate” of the climate system, which is considered as a “heat engine.” The four energy forms on which this investigation is based on are the zonal and eddy components of the available potential and kinetic energies. The permissible correspondingly considered transformations between these forms of energy are also studied. Generation of available potential energy and dissipation of kinetic energy complete the Lorenz energy cycle that is adopted here. In the CMIP6 approach, the results of different climate change analyses were collected in a matrix defined by two dimensions: climate exposure as characterized by a radiative forcing or temperature level and socioeconomic development as classified by the pathways, known as Shared Socioeconomic Pathways (SSPs). The basis of the calculations in this study is the climatic projection produced by the HadGEM3-GC3.1-LL climatic model in the period from 2015 to 2100. In this respect, the results are presented in terms of time projections of the energetics components under different SSPs. The results have shown that the different SSPs yield diverse energetics regimes, consequently impacting on Lorenz energy cycle and, hence, a “working rate” of the climate system based on the components of this cycle. In this respect, Lorenz energy cycle projections are presented, under different SSPs. The results are also contrasted to the calculations for the historical period 1929 to 2014 as this is simulated by the same climatic model.