El Niño impacts on the ozone column over Mato Grosso do Sul (original) (raw)
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The impacts of two types of El Niño on global ozone variations in the last three decades
Advances in Atmospheric Sciences, 2014
The effects of El Niño Modoki events on global ozone concentrations are investigated from 1980 to 2010 El Niño Modoki events cause a stronger Brewer-Dobson (BD) circulation which can transports more ozone-poor air from the troposphere to stratosphere, leading to a decrease of ozone in the lower-middle stratosphere from 90 • S to 90 • N. These changes in ozone concentrations reduce stratospheric column ozone. The reduction in stratospheric column ozone during El Niño Modoki events is more pronounced over the tropical eastern Pacific than over other tropical areas because transport of ozone-poor air from middle-high latitudes in both hemispheres to low latitudes is the strongest between 60 • W and 120 • W. Because of the decrease in stratospheric column ozone during El Niño Modoki events more UV radiation reaches the tropical troposphere leading to significant increases in tropospheric column ozone An empirical orthogonal function (EOF) analysis of the time series from 1980 to 2010 of stratospheric and tropospheric ozone monthly anomalies reveals that: El Niño Modoki events are associated with the primary EOF modes of both time series. We also found that El Niño Modoki events can affect global ozone more significantly than canonical El Niño events. These results imply that El Niño Modoki is a key contributor to variations in global ozone from 1980 to 2010. , 2014: The impacts of two types of El Niño on global ozone variations in the last three decades.
Journal of Geophysical Research, 2001
We present the first study of the E1 Nifio-Southern Oscillation (ENSO) interannual variability in tropical tropospheric ozone in a multiyear simulation with a global three-dimensional chemistry-transport model. A 15-year period (1979)(1980)(1981)(1982)(1983)(1984)(1985)(1986)(1987)(1988)(1989)(1990)(1991)(1992)(1993) was simulated using European Centre for Medium-Range Weather Forecasts meteorological reanalysis data and a time-varying emission data set. A comparison of model calculations with observations shows good agreement for surface ozone, seasonal cycles, and ozone concentrations at remote stations, but reveals an underestimate of ozone in the free troposphere, which is most pronounced during biomass burning seasons. The ENSO signal is the most important component of interannual variability in tropical tropospheric ozone columns (TTOC), being responsible for nearly 25% of the total interannual variability of ozone in the tropics. The amplitude of the modeled ENSO signal in TTOC is 3 Dobson units, in close agreement with satellite observations. This signal is evenly distributed with height, indicating that rapid vertical transport plays an important role. The ENSO signal is also detectable at the surface, for example at the Pacific island Samoa, for which model-calculated and measured ozone agree well. man et aI., 1990; Kim et aI., 1996; Hudson et al., 1995; Hudson and Thompson, 1998]. These studies are based on so-called residual methods, where TTOC is calculated Ocean ozone maximum. Ziemke et aI. [ 1998] used cloud observations from the TOMS instrument to estimate the stratospheric ozone content (cloud convective differential or CCD method). These two methods have been shown to be successful in reproducing TTOC values from ozonesondes [Ziemke et aI., 1998; Hudson and Thompson, 1998; Thompson and Hudson, 1999]. Satellite observations of TTOC have been used to describe the "zonal wave one" distribution of ozone in the tropics [Fishman and Larsen, 1987; Kim et al., 1996]. This zonal wave one pattern is characterized by an ozone minimum associated with strong convective upward motions over the Pacific warm pool, and an ozone maximum associated with oceanic anticyclones over the tropical Atlantic. These motions are part of large-scale zonal transport which is in-10,389 10,390 PETERS ET AL.: ENSO SIGNAL IN SIMULATED TROPOSPHERIC OZONE duced by convection, and their effect on TTOC has been described previously [Lelieveld and Crutzen, 1994; Krishnamurti et al., 1996; Chandra et al., 1998; Wang et al., 2000]. Fishman et al. [1990] recognized that the TTOC maximum over the Ariantic Ocean is strongest in Southern Hemisphere spring (September-November), when the biomass burning intensity reaches a maximum over Africa and Brazil. Later studies from the Transport and Atmospheric Chemistry Near the Equator-Atlantic (TRACE-A) campaign [Fishman et al., 1996; Thompson et al., 1996] indicated that production of ozone from precursors in biomass burning plumes can lead to a 10-15 Dobson unit (DU) increase of ozone over the Atlantic Ocean during austral spring. In addition, the observed mean distribution of tropospheric ozone is influenced by interannual variability in the tropics. Phenomena such as the E1 Nifio-Southern Oscillation (ENSO) introduce variability in tropospheric transport patterns, the amount and location of biomass burning emissions, the UV flux entering the troposphere, and other parameters. Signatures of ENSO were recognized previously in measurements of various chlorofluorocarbons (CFCs) at 10,400 PETERS ET AL.: ENSO SIGNAL IN SIMULATED TROPOSPHERIC OZONE
The impacts of the El Niño-Southern Oscillation (ENSO) on the tropical total 27 column ozone, the tropical tropopause pressure, and on the 3.5-year ozone signal in the 28 mid-latitude total column ozone are examined using the Goddard Earth Observation 29 System Chemistry-Climate Model (GEOS CCM). Observed monthly-mean sea surface 30 temperature and sea ice between 1951 and 2004 were used as boundary conditions for the 31 model. Since the model includes no solar cycle, Quasi-biennial Oscillation or volcanic 32 forcing, the ENSO signal is the dominant mode in the tropical total column ozone 33 variability in the GEOS CCM. Principal component analysis is applied to the detrended, 34 deseasonalized, and low-pass filtered model outputs. The first mode of model total 35 column ozone captures 65.8% of the total variance. The spatial pattern of this mode is 36 similar to that in Total Ozone Mapping Spectrometer (TOMS) observations. ENSO signal 37 in the total column ozone is also well simulated in WACCM3. There is also a clear 38 ENSO signal in the tropical tropopause pressure in the GEOS CCM, which is related to 39 the ENSO signal in the total column ozone in the GEOS CCM. The regression coefficient 40 between the model total column ozone and the model tropopause pressure is 0.78 41 DU/hPa. GEOS CCM is also used to investigate possible mechanism for the 3.5-year 42 signal observed in the mid-latitude total column ozone. Since the 3.5-year signal also 43 appears in the GEOS CCM column ozone as those in the observations, it suggests that a 44 model with realistic ENSO can reproduce the 3.5-year signal. Hence, it is likely that the 45 3.5-year signal is from the ENSO signal. 46 47 48
Environmental Research Letters, 2014
Some studies showed that since the 1980s Modoki activity-a different sea surface temperature anomaly pattern from canonical El Niño-Southern Oscillation (ENSO) in the tropics-has been increasing in frequency. In the light of an analysis of the observations and simulations, we found that Modoki, as a new driver of global climate change, can modulate the tropical upwelling that significantly affects mid-lower stratospheric ozone. As a result, it has an important impact on the variations of tropical total column ozone (TCO), alongside quasibiennial oscillation or canonical ENSO. Our results suggest that, in the context of future global warming, Modoki activity may continue to be a primary driver of tropical TCO changes. Besides, it is possible can serve as a predictor of tropical TCO variations since Modoki events precede tropical ozone changes.
Effects of the 2004 El Niño on tropospheric ozone and water vapor
Geophysical Research Letters, 2007
1] The global effects of the 2004 El Niño on tropospheric ozone and H 2 O based on Aura OMI and MLS measurements are analyzed. Although it was a weak El Niñ o from a historical perspective, it produced significant changes in these parameters in tropical latitudes. Tropospheric ozone increased by 10-20% over most of the western Pacific region and decreased by about the same amount over the eastern Pacific region. H 2 O in the upper troposphere showed similar changes but with opposite sign. These zonal changes in tropospheric ozone and H 2 O are caused by the eastward shift in the Walker circulation in the tropical pacific region during El Niño. During the 2004 El Niño, biomass burning did not have a significant effect on the ozone budget in the troposphere, unlike the 1997 El Niño. Zonally averaged tropospheric column ozone did not change significantly either globally or over tropical latitudes.
The combined influence of ENSO and PDO on the spring UTLS ozone variability in South America
Climate Dynamics, 2020
Ozone in the upper troposphere-lower stratosphere (UTLS) is primarily regulated by tropospheric dynamics. Understanding mechanisms driving ozone variability at the UTLS is crucial to evaluate the transport of mass to and from the lower stratosphere. The El Niño-Southern Oscillation (ENSO) is the primary coupled mode acting on interannual timescales modulating tropospheric circulation worldwide. ENSO teleconnections can depend on the phases of the Pacific Decadal Oscillation (PDO) and on the characteristics of the warming over central and eastern tropical Pacific. This study investigates the role of ENSO on UTLS ozone variability with focus on South America and examines patterns of teleconnections in the two recent warm (1980-1997) and cool (1998-2012) PDO phases. The dominant mode of ozone variability is identified by applying a principal component analysis (PCA) to modern-era retrospective analysis for research and applications, Version 2 (MERRA-2) ozone data from September-November (SON). SON is the season with the largest UTLS ozone variance over South America. The first mode resembles a Rossby wave train across South America with spatial patterns dependent on PDO phase. We show that the ENSO teleconnections and respective influences on SON UTLS ozone are stronger during the cool PDO when ENSO and PDO are mostly in phase. Additionally, the strength of the ENSO teleconnection appears to depend on patterns of SST anomalies over tropical Pacific. The decadal variability in the ENSO-PDO relationships and teleconnections with the Southern Hemisphere resulted in a shift in upper tropospheric circulation in tropical and subtropical regions of South America.
El Niño–Southern Oscillation in Tropical and Midlatitude Column Ozone
Journal of the Atmospheric Sciences, 2011
The impacts of El Niñ o-Southern Oscillation (ENSO) on the tropical total column ozone, the tropical tropopause pressure, and the 3.5-yr ozone signal in the midlatitude total column ozone were examined using the Goddard Earth Observing System Chemistry-Climate Model (GEOS CCM). Observed monthly mean sea surface temperature and sea ice between 1951 and 2004 were used as boundary conditions for the model. Since the model includes no solar cycle, quasi-biennial oscillation, or volcanic forcing, the ENSO signal was found to dominate the tropical total column ozone variability. Principal component analysis was applied to the detrended, deseasonalized, and low-pass filtered model outputs. The first mode of model total column ozone captured 63.8% of the total variance. The spatial pattern of this mode was similar to that in Total Ozone Mapping Spectrometer (TOMS) observations. There was also a clear ENSO signal in the tropical tropopause pressure in the GEOS CCM, which is related to the ENSO signal in the total column ozone. The regression coefficient between the model total column ozone and the model tropopause pressure was 0.71 Dobson units (DU) hPa 21 . The GEOS CCM was also used to investigate a possible mechanism for the 3.5-yr signal observed in the midlatitude total column ozone. The 3.5-yr signal in the GEOS CCM column ozone is similar to that in the observations, which suggests that a model with realistic ENSO can reproduce the 3.5-yr signal. Hence, it is likely that the 3.5-yr signal was caused by ENSO.
From Phase Transition to Interdecadal Changes of ENSO, Altered by the Lower Stratospheric Ozone
Remote Sensing, 2022
This paper shows more evidence for the existing spatial–temporal synchronization of the air surface temperature and pressure within the lower stratospheric ozone, which is unevenly distributed over the globe. The focus of this study is put on the region of formation and manifestation of El Niño Southern Oscillation (ENSO). Statistical analysis of data (covering the period 1900–2019) displays a well pronounced covariance of ozone at 70 hPa with (i) Nino3.4 index, (ii) air surface temperature, and (iii) sea level pressure, in each grid-point with spatial resolution of 5° in latitude and longitude. The ozone impact could be found at different time scales—from interannual (altering the ENSO phase transition) to interdecadal. Moreover, the centers of action of ozone on the sea level temperature and pressure are positioned at different places, depending on the temporal scale of variability—from the tropical Central Pacific—at interannual and interdecadal, to extratropics—at subdecadal tim...
ENSO influence on zonal mean temperature and ozone in the tropical lower stratosphere
Geophysical Research Letters, 2009
1] Analyses of a whole atmosphere chemistry-climate model simulation forced by historical sea-surface temperature variations show that tropospheric El Nino -Southern Oscillation (ENSO) events are linked to coherent variations of zonal mean temperature and ozone in the tropical lower stratosphere, tied to fluctuations in tropical upwelling. ENSO temperature variations in the lower stratosphere are out of phase with tropospheric variations, and stratospheric ozone and temperatures are in phase. These model results motivated revisiting observational data sets for both temperature and ozone, and the observational data reveal coherent signals in the tropical stratosphere, very similar to the model results. The stratospheric ENSO variability has been masked in the observational data to some degree by the volcanic eruptions of El Chichon (1982) and Pinatubo (1991), which both occurred during ENSO warm events. The coherent temperature and ozone signals are evidence that ENSO modulates upwelling in the tropical lower stratosphere.
Journal of Geophysical Research, 2011
1] Long-term observations of stratospheric ozone from the Stratospheric Aerosol and Gas Experiment II (SAGE II) satellite are combined with ozonesonde measurements from the Southern Hemisphere Additional Ozonesondes (SHADOZ) network (1998)(1999)(2000)(2001)(2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009) to study interannual variability and trends in tropical ozone. Excellent agreement is found comparing the two data sets for the overlap period 1998-2005, and the data are combined to form a continuous time series covering 1984-2009. SHADOZ measurements also provide temperature profiles, and interannual changes in ozone and temperature are highly correlated throughout the tropical lower stratosphere (16-27 km). Interannual variability in stratospheric ozone is dominated by effects of the quasi-biennial oscillation and El Niño-Southern Oscillation, and there are also significant negative trends (−2 to −4% per decade) in the tropical lower stratosphere (over 17-21 km). These tropical ozone trends are consistent with results from chemistry-climate model simulations, wherein the trends result from increases in upwelling circulation in the tropical lower stratosphere.