Banca de DEFESA: LANZOERQUES GOMES DA SILVA JÚNIOR

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : LANZOERQUES GOMES DA SILVA JÚNIOR
DATE: 31/08/2023
TIME: 08:30
LOCAL: VIA GOOGLE MEET
TITLE:

ATMOSPHERIC CIRCULATION IN THE LAST GLACIAL AGE IN THE SOUTHERN HEMISPHERE: COMPARISON WITH THE PRE-INDUSTRIAL PERIOD

KEY WORDS:

SPEEDY/HYCOM, Paleoclimate, Last Glacial Maximum, Extratropical Cyclone.

PAGES: 177
BIG AREA: Ciências Exatas e da Terra
AREA: Geociências
SUBÁREA: Meteorologia
SPECIALTY: Meteorologia Dinâmica
SUMMARY:

The Last Glacial Maximum (LGM) occurred about 21,000 years before the present (21 Ka BP), a period marked by the decrease in air temperature and mean sea level, as well as the increase in surfaces covered by continental and sea ice, obtained through proxy records and in paleoclimate reconstructions, being naturally caused by the change in orbital parameters known as Milankovitch cycles. The use of Atmosphere-Ocean General Circulation Model (AOGCM) such as the Simplified Parameterization, primitivE Equation Dynamics and the Hybrid Coordinate Ocean Model (SPEEDY/HYCOM) can simulate the climate conditions and the atmospheric circulation pattern of the LGM. The objective of this study is to evaluate the physical and dynamic characteristics of the atmospheric conditions of the LGM period in the Southern Hemisphere through simulations with the SPEEDY/HYCOM coupled model, distinguishing the climatic behavior of meteorological variables and transient systems of the Pre-Industrial period (PI). For this, a simulation of 1500 years was performed with the coupled model SPEEDY/HYCOM with the Antarctic and Greenland Ice Sheet Model (AGISM) to represent better the melting water input from the ice sheets to the ocean, based on the data of insolation, orbital parameters and concentration of Greenhouse Gases (GHG), adjusted to values of 21 Ka BP. The PI experiment, on the other hand, is carried out using a control climate that began in the year 1870 and ended in 2000, in which the atmospheric concentration of CO₂ is replicated with an increase of 1% per year from the year 1950. Preliminary results showed cooler surface air temperature conditions in all seasons of the year for LGM, especially in winter, with values close to -70°C. A comparison more objective between the summer and winter seasons of both periods, it was found that part of the Central and Eastern Pacific Ocean was warmer in the UMG, mainly in summer. On the rainfall regime, in general, the seasonal average in the PI showed greater volume in all seasons, especially in winter in tropical latitudes, particularly in the northeast sector of South America and the oceanic region north of Australia. Another aspect refers to the lower volume of rainfall in mid and high latitudes during LGM in all seasons, where in Antarctica it occurs up to 1 mm/day, while in the PI period values can reach 2 mm/day in parts of the coast of the frozen continent.

COMMITTEE MEMBERS:
Interno - 1280761 - CRISTIANO PRESTRELO DE OLIVEIRA
Presidente - 1858120 - DAVID MENDES
Externa à Instituição - GYRLENE APARECIDA MENDES DA SILVA - UNIFESP
Externo à Instituição - JOSÉ FRANCISCO DE OLIVEIRA JÚNIOR - UFAL
Interno - 1164414 - WEBER ANDRADE GONCALVES