@Article{BencherifPDMPBBMSSMA:2024:OzTrAn,
author = "Bencherif, Hassan and Pinheiro, Damaris Kirsch and Delage, Olivier
and Millet, Tristan and Peres, Lucas Vaz and B{\`e}gue, Nelson
and Bittencourt, Gabriela and Martins, Maria Paulete Pereira and
Silva, Francisco Raimundo da and Steffenel, Luiz Angelo and
Mbatha, Nkanyiso and Anabor, Vagner",
affiliation = "Universit{\'e} de la R{\'e}union, M{\'e}t{\'e}o-France and
{Universidade Federal de Santa Maria (UFSM)} and Universit{\'e}
de la R{\'e}union, M{\'e}t{\'e}o-France and Universit{\'e} de
la R{\'e}union, M{\'e}t{\'e}o-France and {Universidade Federal
do Oeste do Par{\'a} (UFOPA)} and Universit{\'e} de la
R{\'e}union, M{\'e}t{\'e}o-France and {Instituto Nacional de
Pesquisas Espaciais (INPE)} and {Instituto Nacional de Pesquisas
Espaciais (INPE)} and {Instituto Nacional de Pesquisas Espaciais
(INPE)} and {Universit{\'e} de Reims Champagne Ardenne} and
{University of Zululand} and {Universidade Federal de Santa Maria
(UFSM)}",
title = "Ozone Trend Analysis in Natal (5.4°S, 35.4°W, Brazil) Using
Multi-Linear Regression and Empirical Decomposition Methods over
22 Years of Observations",
journal = "Remote Sensing",
year = "2024",
volume = "16",
number = "1",
pages = "e208",
month = "Jan.",
keywords = "Brazil, EAWD, EMD, empirical decompositions, multi-linear
regression, ozone variability and trends, southern tropics,
stratospheric ozone, tropospheric ozone.",
abstract = "Ozone plays an important role in the Earths atmosphere. It is
mainly formed in the tropical stratosphere and is transported by
the BrewerDobson Circulation to higher latitudes. In the
stratosphere, ozone can filter the incoming solar ultraviolet
radiation, thus protecting life at the surface. Although
tropospheric ozone accounts for only ~10%, it is a powerful GHG
and pollutant, harmful to the health of the environment and living
beings. Several studies have highlighted biomass burning as a
major contributor to the tropospheric ozone budget. Our study
focuses on the Natal site (5.40°S, 35.40°W, Brazil), one of the
oldest ozone-observing stations in Brazil, which is expected to be
influenced by fire plumes in Africa and Brazil. Many studies that
examined ozone trends used the total atmospheric columns of ozone,
but it is important to assess ozone separately in the troposphere
and the stratosphere. In this study, we have used radiosonde ozone
profiles and daily TCO measurements to evaluate the variability
and changes of both tropospheric and stratospheric ozone
separately. The dataset in this study comprises daily total
columns of colocalized ozone and weekly ozone profiles collected
between 1998 and 2019. The tropospheric columns were estimated by
integrating ozone profiles measured by ozone sondes up to the
tropopause height. The amount of ozone in the stratosphere was
then deduced by subtracting the tropospheric ozone amount from the
total amount of ozone measured by the Dobson spectrometer. It was
assumed that the amount of ozone in the mesosphere is negligible.
This produced three distinct time series of ozone: tropospheric
and stratospheric columns as well as total columns. The present
study aims to apply a new decomposition method named Empirical
Adaptive Wavelet Decomposition (EAWD) that is used to identify the
different modes of variability present in the analyzed signal.
This is achieved by summing up the most significant Intrinsic Mode
Functions (IMF). The Fourier spectrum of the original signal is
broken down into spectral bands that frame each IMF obtained by
the Empirical Modal Decomposition (EMD). Then, the Empirical
Wavelet Transform (EWT) is applied to each interval. Unlike other
methods like EMD and multi-linear regression (MLR), the EAWD
technique has an advantage in providing better frequency
resolution and thus overcoming the phenomenon of mode-mixing, as
well as detecting possible breakpoints in the trend mode. The
obtained ozone datasets were analyzed using three methods: MLR,
EMD, and EAWD. The EAWD algorithm exhibited the advantage of
retrieving ~90% to 95% of ozone variability and detecting possible
breakpoints in its trend component. Overall, the MRL and EAWD
methods showed almost similar trends, a decrease in the
stratosphere ozone (\−1.3 ± 0.8%) and an increase in the
tropospheric ozone (+4.9 ± 1.3%). This study shows the relevance
of combining data to separately analyze tropospheric and
stratospheric ozone variability and trends. It highlights the
advantage of the EAWD algorithm in detecting modes of variability
in a geophysical signal without prior knowledge of the underlying
forcings.",
doi = "10.3390/rs16010208",
url = "http://dx.doi.org/10.3390/rs16010208",
issn = "2072-4292",
language = "en",
targetfile = "remotesensing-16-00208.pdf",
urlaccessdate = "12 maio 2024"
}