Effects of 1997–1998 El Niño on tropospheric ozone and water vapor

Chandra, Sushil; Ziemke, J. R.; Wang, Min; Read, W. G.

doi:10.1029/98gl02695

Cited by 178 publications

(176 citation statements)

References 11 publications

(4 reference statements)

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“…These atmospheric composition changes were found in observations (Chandra et al, 1998;Ziemke and Chandra, 1999;Fujiwara et al, 1999;Chandra et al, 2007;Logan et al, 2008) and confirmed by modelling studies (Hauglustaine et al, 1999;Sudo and Takashashi, 2001;Chandra et al, 2002;Doherty et al, 2006;Chandra et al, 2009;Nassar et al, 2009) which also tried to quantify the relative importance of the dynamically induced and the emissiondriven atmospheric composition changes. The reasons for the TCO 3 increase over the western Pacific and Indonesia durPublished by Copernicus Publications on behalf of the European Geosciences Union.…”

Section: Introductionsupporting

confidence: 67%

The ENSO signal in atmospheric composition fields: emission-driven versus dynamically induced changes

et al. 2015

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Abstract. The El Niño-Southern Oscillation (ENSO) not only affects meteorological fields but also has a large impact on atmospheric composition. Atmospheric composition fields from the Monitoring Atmospheric Composition and Climate (MACC) reanalysis are used to identify the ENSO signal in tropospheric ozone, carbon monoxide, nitrogen oxide and smoke aerosols, concentrating on the months October to December. During El Niño years, all of these fields have increased concentrations over maritime South East Asia in October. The MACC Composition Integrated Forecasting System (C-IFS) model is used to quantify the relative magnitude of dynamically induced and emission-driven changes in the atmospheric composition fields. While changes in tropospheric ozone are a combination of dynamically induced and emission-driven changes, the changes in carbon monoxide, nitrogen oxides and smoke aerosols are almost entirely emission-driven in the MACC model. The ozone changes continue into December, i.e. after the end of the Indonesian fire season while changes in the other fields are confined to the fire season.

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Section: Introductionsupporting

confidence: 67%

The ENSO signal in atmospheric composition fields: emission-driven versus dynamically induced changes

et al. 2015

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“…The response is highly linear in the tropics, so La Niña conditions produce an antisymmetric response (DeWeaver and Nigam, 2002). This influence on tropical tropospheric ozone has been observed in satellite data (e.g., Chandra et al, 1998;Thompson et al, 2001;Ziemke et al, 2010Ziemke et al, , 2015 and ground-based measurements (e.g., Fujiwara et al, 1999;Lee et al, 2010). Both chemical transport models (CTMs) driven by analyzed meteorology and free-running models have simulated this impact of ENSO on the tropical ozone (e.g., Sudo and Takahashi, 2001;Zeng and Pyle, 2005;Doherty et al, 2006;Oman et al, 2011).…”

Section: Introductionmentioning

confidence: 99%

Tropospheric column ozone response to ENSO in GEOS-5 assimilation of OMI and MLS ozone data

2016

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Abstract. We use GEOS-5 analyses of Ozone Monitoring Instrument (OMI) and Microwave Limb Sounder (MLS) ozone observations to investigate the magnitude and spatial distribution of the El Niño Southern Oscillation (ENSO) influence on tropospheric column ozone (TCO) into the middle latitudes. This study provides the first explicit spatially resolved characterization of the ENSO influence and demonstrates coherent patterns and teleconnections impacting the TCO in the extratropics. The response is evaluated and characterized by both the variance explained and sensitivity of TCO to the Niño 3.4 index. The tropospheric response in the tropics agrees well with previous studies and verifies the analyses. A two-lobed response symmetric about the Equator in the western Pacific/Indonesian region seen in some prior studies and not in others is confirmed here. This two-lobed response is consistent with the large-scale vertical transport. We also find that the large-scale transport in the tropics dominates the response compared to the small-scale convective transport. The ozone response is weaker in the middle latitudes, but a significant explained variance of the TCO is found over several small regions, including the central United States. However, the sensitivity of TCO to the Niño 3.4 index is statistically significant over a large area of the middle latitudes. The sensitivity maxima and minima coincide with anomalous anti-cyclonic and cyclonic circulations where the associated vertical transport is consistent with the sign of the sensitivity. Also, ENSO related changes to the mean tropopause height can contribute significantly to the midlatitude response. Comparisons to a 22-year chemical transport model simulation demonstrate that these results from the 9-year assimilation are representative of the longer term. This investigation brings insight to several seemingly disparate prior studies of the El Niño influence on tropospheric ozone in the middle latitudes.

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“…The effects of El Niño on atmospheric composition, including ozone, have been studied from both satellite and ground-based measurements (e.g., Chandra et al, 1998;Fujiwara et al, 1999;Thompson et al, 2001;Nasser et al, 2009;Lee et al, 2010;Ziemke et al, 2010;Randel and Thompson, 2011;Neu et al, 2014), global chemical transport models driven by specified meteorology (e.g., Valks et al, 2003;Duncan et al, 2003;Chandra et al, 2009;Murray et al, 2013) and general circulation models (GCMs) (e.g., Sudo and Takahashi, 2001;Zeng and Pyle, 2005;Doherty et al, 2006;Randel et al, 2009;Oman et al, 2011;Sekiya and Sudo, 2014). Tropospheric ozone is important as both a greenhouse gas and precursor of the hydroxyl radical (OH), the primary atmospheric oxidant.…”

Section: Introductionmentioning

confidence: 99%

Tropospheric ozone variability in the tropics from ENSO to MJO and shorter timescales

et al. 2015

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Abstract. Aura OMI and MLS measurements are combined to produce daily maps of tropospheric ozone beginning October 2004. We show that El Niño-Southern Oscillation (ENSO) related inter-annual change in tropospheric ozone in the tropics is small in relation to combined intra-seasonal/Madden-Julian Oscillation (MJO) and shorter timescale variability by a factor of ∼ 3-10 (largest in the Atlantic). Outgoing longwave radiation (OLR), taken as a proxy for convection, suggests that convection is a dominant driver of large-scale variability of tropospheric ozone in the Pacific from inter-annual (e.g., ENSO) to weekly periods. We compare tropospheric ozone and OLR satellite observations with two simulations: (1) the Goddard Earth Observing System (GEOS) chemistry-climate model (CCM) that uses observed sea surface temperatures and is otherwise free-running, and (2) the NASA Global Modeling Initiative (GMI) chemical transport model (CTM) that is driven by Modern Era Retrospective-Analysis for Research and Applications (MERRA) analyses. It is shown that the CTM-simulated ozone accurately matches measurements for timescales from ENSO to intra-seasonal/MJO and even 1-2-week periods. The CCM simulation reproduces ENSO variability but not shorter timescales. These analyses suggest that a model used to delineate temporal and/or spatial properties of tropospheric ozone and convection in the tropics must reproduce both ENSO and non-ENSO variability.

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Effects of 1997–1998 El Niño on tropospheric ozone and water vapor

Cited by 178 publications

References 11 publications

The ENSO signal in atmospheric composition fields: emission-driven versus dynamically induced changes

The ENSO signal in atmospheric composition fields: emission-driven versus dynamically induced changes

Tropospheric column ozone response to ENSO in GEOS-5 assimilation of OMI and MLS ozone data

Tropospheric ozone variability in the tropics from ENSO to MJO and shorter timescales

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