@Article{CasagrandeSouzNobrMarq:2020:InSeCo,
               author = "Casagrande, Fernanda and Souza, Ronald Buss de and Nobre, Paulo 
                         and Marquez, Andre Lanfer",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)} and {Instituto Nacional de 
                         Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)}",
                title = "An inter-hemispheric seasonal comparison of polar amplification 
                         using radiative forcing of a quadrupling CO2 experiment",
              journal = "Annales Geophysicae",
                 year = "2020",
               volume = "38",
               number = "5",
                pages = "1123--1138",
                month = "Oct.",
             abstract = "The numerical climate simulations from the Brazilian Earth System 
                         Model (BESM) are used here to investigate the response of the 
                         polar regions to a forced increase in CO2 (Abrupt-4ŚCO2) and 
                         compared with Coupled Model Intercomparison Project phase 5 
                         (CMIP5) and 6 (CMIP6) simulations. The main objective here is to 
                         investigate the seasonality of the surface and vertical warming as 
                         well as the coupled processes underlying the polar amplification, 
                         such as changes in sea ice cover. Polar regions are described as 
                         the most climatically sensitive areas of the globe, with an 
                         enhanced warming occurring during the cold seasons. The asymmetry 
                         between the two poles is related to the thermal inertia and the 
                         coupled ocean-atmosphere processes involved. While at the northern 
                         high latitudes the amplified warming signal is associated with a 
                         positive snow- and sea ice-albedo feedback, for southern high 
                         latitudes the warming is related to a combination of ozone 
                         depletion and changes in the wind pattern. The numerical 
                         experiments conducted here demonstrated very clear evidence of 
                         seasonality in the polar amplification response as well as linkage 
                         with sea ice changes. In winter, for the northern high latitudes 
                         (southern high latitudes), the range of simulated polar warming 
                         varied from 10 to 39K (-0.5 to 13K). In summer, for northern high 
                         latitudes (southern high latitudes), the simulated warming varies 
                         from 0 to 23K (0.5 to 14K). The vertical profiles of air 
                         temperature indicated stronger warming at the surface, 
                         particularly for the Arctic region, suggesting that the albedo-sea 
                         ice feedback overlaps with the warming caused by meridional 
                         transport of heat in the atmosphere. The latitude of the maximum 
                         warming was inversely correlated with changes in the sea ice 
                         within the model's control run. Three climate models were 
                         identified as having high polar amplification for the Arctic cold 
                         season (DJF): IPSL-CM6A-LR (CMIP6), HadGEM2-ES (CMIP5) and CanESM5 
                         (CMIP6). For the Antarctic, in the cold season (JJA), the climate 
                         models identified as having high polar amplification were 
                         IPSL-CM6A-LR (CMIP6), CanESM5(CMIP6) and FGOALS-s2 (CMIP5). The 
                         large decrease in sea ice concentration is more evident in models 
                         with great polar amplification and for the same range of latitude 
                         (75-90°N). Also, we found, for models with enhanced warming, 
                         expressive changes in the sea ice annual amplitude with 
                         outstanding ice-free conditions from May to December 
                         (EC-Earth3-Veg) and June to December (HadGEM2-ES). We suggest that 
                         the large bias found among models can be related to the 
                         differences in each model to represent the feedback process and 
                         also as a consequence of each distinct sea ice initial condition. 
                         The polar amplification phenomenon has been observed previously 
                         and is expected to become stronger in the coming decades. The 
                         consequences for the atmospheric and ocean circulation are still 
                         subject to intense debate in the scientific community.",
                  doi = "10.5194/angeo-38-1123-2020",
                  url = "http://dx.doi.org/10.5194/angeo-38-1123-2020",
                 issn = "0992-7689",
             language = "en",
           targetfile = "casagrande_inter.pdf",
        urlaccessdate = "27 abr. 2024"
}