Ocean–atmosphere interaction identified in tree-ring time series from southern Brazil using cross-wavelet analysis

Abstract

Tropical dendrochronology has gained significant attention in recent years, particularly with the dendrochronological study of new species that produce annual growth rings and are responsive to environmental changes. Despite the progress, the extent to which ocean–atmosphere interactions influence regional climate and, consequently, tree growth, is not fully understood. Among the new species, Ocotea porosa (Nees & Mart.) Barroso (also known as Imbuia) has shown excellent potential for climate research. This study investigates the climatic and solar influences on a chronology of 41 Imbuia tree samples. Pearson’s correlation was used alongside Wavelet transform to evaluate periodicities between the tree-ring chronology and climatic parameters such as the southern-oscillation index (SOI), annual precipitation, El Niño 3.4 (PACE), and the South Atlantic Index (ATLS). Our analysis revealed evidence of the influence of the El Niño Southern Oscillation (SOI) on rainfall variability in the region, the Hale and Gleissberg solar cycles causing precipitation variation, likely due to the influence of the Atlantic Ocean, and the Brückner-Egeson-Lockyer climatic cycle, which is correlated with sunspot activity. Furthermore, our wavelet analysis identified possible connections to the Eastern Pacific-type El Niño events during five specific periods: 1911–1912, 1918–1919, 1976–1977, 1982–1983, and 1986–1987. The results indicate that southern Brazil is affected by several climatic and geophysical parameters from both the Atlantic and Pacific oceans, which directly affect the growth of Imbuia trees as their tree-ring series display sensitivity to these parameters.

Full text

https://doi.org/10.1007/s00704-023-04456-7
RESEARCH
Ocean–atmosphere interaction identified in tree-ring time series
from southern Brazil using cross-wavelet analysis
Daniela Oliveira Silva Muraja1·Virginia Klausner1·Alan Prestes1·Iuri Rojahn da Silva1
Received:19 April 2022 / Accepted:5 April 2023
© The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature 2023
Abstract
Tropical dendrochronology has gained significant attention in recent years, particularly with the dendrochronological study
of new species that produce annual growth rings and are responsive to environmental changes. Despite the progress, the extent
to which ocean–atmosphere interactions influence regional climate and, consequently, tree growth, is not fully understood.
Among the new species, Ocotea porosa (Nees & Mart.) Barroso (also known as Imbuia) has shown excellent potential
for climate research. This study investigates the climatic and solar influences on a chronology of 41 Imbuia tree samples.
Pearson’s correlation was used alongside Wavelet transform to evaluate periodicities between the tree-ring chronology and
climatic parameters such as the southern-oscillation index (SOI), annual precipitation, El Niño 3.4 (PACE), and the South
Atlantic Index (ATLS). Our analysis revealed evidence of the influence of the El Niño Southern Oscillation (SOI) on rainfall
variability in the region, the Hale and Gleissberg solar cycles causing precipitation variation, likely due to the influence of
the Atlantic Ocean, and the Brückner-Egeson-Lockyer climatic cycle, which is correlated with sunspot activity. Furthermore,
our wavelet analysis identified possible connections to the Eastern Pacific-type El Niño events during five specific periods:
1911–1912, 1918–1919, 1976–1977, 1982–1983, and 1986–1987. The results indicate that southern Brazil is affected by
several climatic and geophysical parameters from both the Atlantic and Pacific oceans, which directly affect the growth of
Imbuia trees as their tree-ring series display sensitivity to these parameters.
1 Introduction
The Brazilian territory is influenced by both the Atlantic and
Pacific oceans, which interact with the lower atmosphere in
different ways. These include 1) the winds above the sea
surface, which are responsible for cooling the sea surface
and balancing the heat flux, and are the main mechanisms
that generate ocean circulation; 2) the evaporation from the
Virginia Klausner, Alan Prestes and Iuri Rojahn da Silva contributed
equally to this work.
BDaniela Oliveira Silva Muraja
fys.dani@gmail.com
Virginia Klausner
viklausner@gmail.com
Alan Prestes
aprestes@gmail.com
Iuri Rojahn da Silva
iuri@univap.br
1Physics and Astronomy Department, University of Vale do
Paraíba, Shishima Hifumi avenue, São José dos Campos
2911, São Paulo, Brazil
ocean mixing across the marine atmospheric boundary layer,
and subsequently transporting moisture to the troposphere;
and 3) the atmospheric circulation driven by water vapor
resulting from evaporation from the ocean, which releases
latent heat associated with condensation of the vapor to form
clouds and precipitation (Chelton and Xie 2010).
This interaction between the oceans and the lower atmo-
sphere can result in climatic phenomena such as the El Ninõ
Southern Oscillation (ENSO). The ENSO is associated with
changes in the Sea Surface Temperature (SST) patterns and
trade winds in the Equatorial Pacific region. It is defined
as positive (El Ninõ) and negative (La Ninã) anomalies
(Sampaio 2000), affecting South America (Garreaud et al
2009; Rigozo et al 2012), and specifically, Southern Brazil.
In Southern Brazil, the El Ninõ events coincide with a higher
frequency of heavy rains, and the La Ninã events corre-
spond to severe droughts. Floods and severe droughts can
cause problems with tree growth performance. Tree growth
is highly dependent on the rainfall amounts in the most
humid sector during the dry season, whereas in sites settled
in areas of lower summer temperatures, the rainfall dur-
ing the warm-rainy season is the main determining factor
123
Theoretical and Applied Climatology (2023) 153:1177–1189
/ Published online: 18 June 2023
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