South atlantic variability and change since 850 C.E: an ensemble approach with the NCAR - Community Earth System Model (CESM)

• Grant number: 15/17659-0
• Support Opportunities: Scholarships abroad - Research
• Start date: January 18, 2016
• End date: July 17, 2016
• Field of knowledge: Physical Sciences and Mathematics - Oceanography - Physical Oceanography
• Principal Investigator: Ilana Elazari Klein Coaracy Wainer
• Grantee: Ilana Elazari Klein Coaracy Wainer
• Host Investigator: Frank Otis Bryan
• Host Institution: Instituto Oceanográfico (IO). Universidade de São Paulo (USP). São Paulo , SP, Brazil
• Institution abroad: National Center for Atmospheric Research (NCAR), United States

Abstract

With changes in the winds due to climate, the South Atlantic Subtropical Gyre (SASG) is seen to strengthen/weaken, which impacts the frontal system at its boundary with the Southern Ocean (i.e. Subtropical Front - STF). Changes in the SASG related to shifts in the STF may certainly impact climate-related variability of the Atlantic through ocean-atmosphere exchanges affecting the formation of central and intermediate water masses. Changes in density in the regions of water formation are then linked to the displacement of the frontal zone. If the front shifts north or south (due to changes in the winds) warm subtropical waters will penetrate into the colder sub-polar regions or colder subpolar/polar waters will be entrained into the warmer subtropics. In either case, there will be changes in temperature gradients, which could enhance (inhibit) vertical stability and/or deep convection. Potentially these changes could modulate the variability of the Agulhas leakage as well. In order to understand these changes in the SASG and its interaction with the Southern Ocean, considering possible implications for climate change and variability, we choose to analyze the results of a an ensemble simulation (10 members) of the Last Millennium (LME) of the National Center for Atmospheric Research Community Earth System Model (NCAR-CESM). The motivation to investigate the SASG within the Last Millennium Ensemble runs (LME) is to understand the range of internal variability in the South Atlantic and the externally forced changes. (AU)

Scientific publications

(8)

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

SILVA, PAULO; CUSTODIO, IGOR STIVANELLI; WAINER, ILANA; DIAS, PEDRO LEITE DA SILVA; PRADO, LUCIANA FIGUEIREDO. Assessment of Tropical Atlantic ocean variability and associated rainfall sensibility due to atmospheric ozone changes. Atmospheric Environment, v. 290, p. 13-pg., 2022-12-01. (15/17659-0)

MARCELLO, FERNANDA; WAINER, ILANA; RODRIGUES, REGINA R.. South Atlantic Subtropical Gyre Late Twentieth Century Changes. JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS, v. 123, n. 8, p. 5194-5209, AUG 2018. (17/16511-5, 15/17659-0)

VERONA, L. S.; WAINER, I; STEVENSON, S.. Volcanically Triggered Ocean Warming Near the Antarctic Peninsula. SCIENTIFIC REPORTS, v. 9, JUL 1 2019. (15/50686-1, 15/17659-0)

WAINER, ILANA; GENT, PETER R.. Changes in the Atlantic Sector of the Southern Ocean estimated from the CESM Last Millennium Ensemble. ANTARCTIC SCIENCE, v. 31, n. 1, p. 37-51, FEB 2019. (15/17659-0)

SILVA, PAULO; WAINER, ILANA; KHODRI, MYRIAM. Changes in the equatorial mode of the Tropical Atlantic in terms of the Bjerknes Feedback Index. Climate Dynamics, v. 56, n. 9-10, p. 3005-3024, MAY 2021. (15/17659-0, 18/14789-9)

MARCELLO, FERNANDA; WAINER, ILANA; GENT, PETER R.; OTTO-BLIESNER, BETTE L.; BRADY, ESTHER C.. South Atlantic Surface Boundary Current System during the Last Millennium in the CESM-LME: The Medieval Climate Anomaly and Little Ice Age. GEOSCIENCES, v. 9, n. 7, JUL 2019. (17/16511-5, 15/17659-0)

TONELLI, MARCOS; MARCELLO, FERNANDA; FERRERO, BRUNO; WAINER, ILANA. Warm Deep Water Variability During the Last Millennium in the CESM-LME: Pre-Industrial Scenario versus Late 20th Century Changes. GEOSCIENCES, v. 9, n. 8, AUG 2019. (17/16511-5, 15/17659-0)

GORENSTEIN, IURI; WAINER, ILANA; MATA, MAURICIO M.; TONELLI, MARCOS. Revisiting Antarctic sea-ice decadal variability since 1980. POLAR SCIENCE, v. 31, p. 11-pg., 2022-03-01. (17/16511-5, 15/17659-0)