Polar Amplification and Ice Free Conditions under 1.5, 2 and 3 degrees C of Global Warming as Simulated by CMIP5 and CMIP6 Models

Autor(es)

Casagrande, Fernanda ^[1] ; Neto, Francisco A. B. ^[1] ; de Souza, Ronald B. ^[1] ; Nobre, Paulo ^[1]

Afiliação do(s) autor(es)

^[1] Natl Inst Space Res INPE, Earth Syst Numer Modeling Div, Rod Presidente Dutra Km 40, BR-12630000 Cachoeira Paulista - Brazil

• Tipo de documento: Artigo Científico
• Fonte: ATMOSPHERE; v. 12, n. 11 NOV 2021.
• Citações Web of Science: 0

Resumo

Simple SummaryPolar regions are more sensitive to the increase in atmospheric CO2 concentration than the rest of the world. This phenomenon is known as the Polar Amplification and is related to many nonlinear, complex coupled ocean-atmosphere processes with effects beyond high latitudes. Aiming to account for the Polar Amplification, this study used global climate simulations to investigate the effects of three different global warming thresholds (1.5, 2 and 3 \& DEG;C) in the warming and sea ice conditions of both poles. Our results shown high climate sensitivity in the Arctic and Antarctica as a response to the increase in atmospheric CO2 concentration. The warming signal is not symmetric in the two poles: the Arctic warms faster than Antarctica in all climate scenarios. Global warming crosses the minimum (maximum) future scenarios thresholds of +1.5 \& DEG;C (+3 \& DEG;C) around 2024 (2063). The equivalent Arctic (Antarctic) warming for these years is 3.6 (1.5) \& DEG;C and (3.2) 6.6 \& DEG;C, respectively. Although limited, Global Climate models used here are important tools to help on better understand the projected effects of climate change in high latitudes.One of the most visible signs of global warming is the fast change in the polar regions. The increase in Arctic temperatures, for instance, is almost twice as large as the global average in recent decades. This phenomenon is known as the Arctic Amplification and reflects several mutually supporting processes. An equivalent albeit less studied phenomenon occurs in Antarctica. Here, we used numerical climate simulations obtained from CMIP5 and CMIP6 to investigate the effects of +1.5, 2 and 3 \& DEG;C warming thresholds for sea ice changes and polar amplification. Our results show robust patterns of near-surface air-temperature response to global warming at high latitudes. The year in which the average air temperatures brought from CMIP5 and CMIP6 models rises by 1.5 \& DEG;C is 2024. An average rise of 2 \& DEG;C (3 \& DEG;C) global warming occurs in 2042 (2063). The equivalent warming at northern (southern) high latitudes under scenarios of 1.5 \& DEG;C global warming is about 3 \& DEG;C (1.8 \& DEG;C). In scenarios of 3 \& DEG;C global warming, the equivalent warming in the Arctic (Antarctica) is close to 7 \& DEG;C (3.5 \& DEG;C). Ice-free conditions are found in all warming thresholds for both the Arctic and Antarctica, especially from the year 2030 onwards. (AU)

• Processo FAPESP: 14/50848-9 - INCT 2014: INCT para Mudanças Climáticas (INCT-MC)
• Beneficiário: Jose Antonio Marengo Orsini
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático