scholarly journals Response of stratospheric water vapor and ozone to the unusual timing of El Niño and the QBO disruption in 2015–2016

2018 ◽  
Vol 18 (17) ◽  
pp. 13055-13073 ◽  
Author(s):  
Mohamadou Diallo ◽  
Martin Riese ◽  
Thomas Birner ◽  
Paul Konopka ◽  
Rolf Müller ◽  
...  
Keyword(s):  
Water Vapor ◽  
El Niño ◽  
Lower Stratosphere ◽  
El Nino ◽  
Trace Gases ◽  
Enso Event ◽  
Quasi Biennial Oscillation ◽  
Stratospheric Water Vapor ◽  
Enso Events ◽  
The Impact

Abstract. The stratospheric circulation determines the transport and lifetime of key trace gases in a changing climate, including water vapor and ozone, which radiatively impact surface climate. The unusually warm El Niño–Southern Oscillation (ENSO) event aligned with a disrupted Quasi-Biennial Oscillation (QBO) caused an unprecedented perturbation to this circulation in 2015–2016. Here, we quantify the impact of the alignment of these two phenomena in 2015–2016 on lower stratospheric water vapor and ozone from satellite observations. We show that the warm ENSO event substantially increased water vapor and decreased ozone in the tropical lower stratosphere. The QBO disruption significantly decreased global lower stratospheric water vapor and tropical ozone from early spring to late autumn. Thus, this QBO disruption reversed the lower stratosphere moistening triggered by the alignment of the warm ENSO event with westerly QBO in early boreal winter. Our results suggest that the interplay of ENSO events and QBO phases will be crucial for the distributions of radiatively active trace gases in a changing future climate, when increasing El Niño-like conditions and a decreasing lower stratospheric QBO amplitude are expected.

scholarly journals Response of stratospheric water vapor and ozone to the unusual timing of El Niño and QBO disruption in 2015–2016

2018 ◽  
Author(s):  
Mohamadou Diallo ◽  
Martin Riese ◽  
Thomas Birner ◽  
Paul Konopka ◽  
Rolf Müller ◽  
...  
Keyword(s):  
Water Vapor ◽  
Greenhouse Gases ◽  
El Niño ◽  
Lower Stratosphere ◽  
El Nino ◽  
Enso Event ◽  
Quasi Biennial Oscillation ◽  
Stratospheric Water Vapor ◽  
Enso Events ◽  
The Impact

Abstract. The stratospheric circulation determines the transport and lifetime of key greenhouse gases, including water vapor and ozone, which radiatively impact surface climate. The unusually warm El Niño Southern Oscillation (ENSO) event aligned with a disrupted Quasi-Biennial Oscillation (QBO) caused an unprecedented perturbation to this circulation in 2015–2016. Here, we quantify the impact of the alignment of these two phenomena in 2015–2016 on lower stratospheric water vapor and ozone from satellite observations. We show that the warm ENSO event substantially increases water vapor and decreases ozone in the tropical lower stratosphere. The QBO disruption significantly decreases global lower stratospheric water vapor and tropical ozone from early spring to late autumn. Thus, this QBO disruption reverses the lower stratosphere moistening triggered by the alignment of the warm ENSO event with westerly QBO in early boreal winter. Our results suggest that the interplay of ENSO events and QBO phases will be crucial for the distributions of radiatively active greenhouse gases in a changing future climate, when increasing El Niño-like conditions and decreasing lower stratospheric QBO amplitude are expected.

scholarly journals The effect of ENSO activity on lower stratospheric water vapor

2011 ◽  
Vol 11 (2) ◽  
pp. 4141-4166 ◽  
Author(s):  
F. Xie ◽  
W. Tian ◽  
J. Austin ◽  
J. Li ◽  
H. Tian ◽  
...  
Keyword(s):  
Water Vapor ◽  
Southern Hemisphere ◽  
Northern Hemisphere ◽  
El Niño ◽  
Lower Stratosphere ◽  
El Nino ◽  
La Niña ◽  
Stratospheric Water Vapor ◽  
La Nina ◽  
El Niño Events

Abstract. Using the ECMWF/NCEP reanalysis data, satellite observations from AURA MLS and UARS HALOE, and Oceanic Niño Index (ONI) data, the effects of El Niño and La Niña events on the stratospheric water vapor changes are investigated. Overall, El Niño events tend to moisten the lower stratosphere but dry the middle stratosphere. La Niña events are likely to dry the lower stratosphere over a narrow band of tropics (5° S–5° N) but have a moistening effect on the whole stratosphere when averaged over a broader region of tropics between 25° S–25° N. The moistening effect of La Niña events mainly occurs in lower stratosphere in the Southern Hemisphere tropics where a significant 20% increase in the tropical upwelling is caused by La Niña events. El Niño events have a more significant effect on the tropical upwelling in the Northern Hemisphere extratropics than in Southern Hemisphere extratropics. The net effect of ENSO activities on the lower stratospheric water vapor is stronger in the Southern Hemisphere tropics than in the Northern Hemisphere tropics.

scholarly journals Response of the Antarctic stratosphere to warm pool El Niño Events in the GEOS CCM

2011 ◽  
Vol 11 (3) ◽  
pp. 9743-9767 ◽  
Author(s):  
M. M. Hurwitz ◽  
I.-S. Song ◽  
L. D. Oman ◽  
P. A. Newman ◽  
A. M. Molod ◽  
...  
Keyword(s):  
El Niño ◽  
Planetary Wave ◽  
Lower Stratosphere ◽  
El Nino ◽  
Warm Pool ◽  
Wave Activity ◽  
Central Pacific ◽  
Quasi Biennial Oscillation ◽  
South Central ◽  
The Antarctic

Abstract. A new formulation of the Goddard Earth Observing System Chemistry-Climate Model, Version 2 (GEOS V2 CCM), with an improved general circulation model and an internally generated quasi-biennial oscillation (QBO), is used to investigate the response of the Antarctic stratosphere to (1) warm pool El Niño (WPEN) events and (2) the sensitivity of this response to the phase of the QBO. Two 50-yr time-slice simulations are forced by repeating annual cycles of sea surface temperatures and sea ice concentrations composited from observed WPEN and neutral ENSO (ENSON) events. In these simulations, greenhouse gas and ozone-depleting substance concentrations represent the present-day climate. The modelled responses to WPEN, and to the phase of the QBO during WPEN, are compared with NASA's Modern Era Retrospective-Analysis for Research and Applications (MERRA) reanalysis. WPEN events enhance poleward planetary wave activity in the central South Pacific during austral spring, leading to relative warming of the Antarctic lower stratosphere in November/December. During the easterly phase of the QBO (QBO-E), the GEOS V2 CCM reproduces the observed 3–5 K warming of the polar region at 50 hPa, in the WPEN simulation relative to ENSON. In the recent past, the response to WPEN events was sensitive to the phase of the QBO: the enhancement in planetary wave driving and the lower stratospheric warming signal were mainly associated with WPEN events coincident with QBO-E. In the GEOS V2 CCM, however, the Antarctic response to WPEN events is insensitive to the phase of the QBO: the modelled response is always easterly QBO-like. OLR, streamfunction and Rossby wave energy diagnostics are used to show that the modelled QBO does not extend far enough into the lower stratosphere and upper troposphere to modulate convection and thus planetary wave activity in the south central Pacific.

scholarly journals Response of trace gases to the disrupted 2015–2016 quasi-biennial oscillation

2017 ◽  
Vol 17 (11) ◽  
pp. 6813-6823 ◽  
Author(s):  
Olga V. Tweedy ◽  
Natalya A. Kramarova ◽  
Susan E. Strahan ◽  
Paul A. Newman ◽  
Lawrence Coy ◽  
...  
Keyword(s):  
Water Vapor ◽  
Chemical Constituents ◽  
Trace Gases ◽  
Quasi Biennial Oscillation ◽  
Data Set ◽  
Uv Index ◽  
Stratospheric Water Vapor ◽  
Northern Summer ◽  
Tropical Tropopause ◽  
Biennial Oscillation

Abstract. The quasi-biennial oscillation (QBO) is a quasiperiodic alternation between easterly and westerly zonal winds in the tropical stratosphere, propagating downward from the middle stratosphere to the tropopause with a period that varies from 24 to 32 months ( ∼  28 months on average). The QBO wind oscillations affect the distribution of chemical constituents, such as ozone (O3), water vapor (H2O), nitrous oxide (N2O), and hydrochloric acid (HCl), through the QBO-induced meridional circulation. In the 2015–2016 winter, radiosonde observations revealed an anomaly in the downward propagation of the westerly phase, which was disrupted by the upward displacement of the westerly phase from  ∼  30 hPa up to 15 hPa and the sudden appearance of easterlies at 40 hPa. Such a disruption is unprecedented in the observational record from 1953 to the present. In this study we show the response of trace gases to this QBO disruption using O3, HCl, H2O, and temperature from the Aura Microwave Limb Sounder (MLS) and total ozone measurements from the Solar Backscatter Ultraviolet (SBUV) Merged Ozone Data Set (MOD). Results reveal the development of positive anomalies in stratospheric equatorial O3 and HCl over  ∼  50–30 hPa in May–September of 2016 and a substantial decrease in O3 in the subtropics of both hemispheres. The SBUV observations show near-record low levels of column ozone in the subtropics in 2016, resulting in an increase in the surface UV index during northern summer. Furthermore, cold temperature anomalies near the tropical tropopause result in a global decrease in stratospheric water vapor.

Cultural Responses to Environmental Catastrophes: Post-El Niño Subsistence on the Prehistoric North Coast of Peru

1991 ◽  
Vol 2 (1) ◽  
pp. 27-47 ◽  
Author(s):  
Jerry D. Moore
Keyword(s):  
El Niño ◽  
El Nino ◽  
Southern Oscillation ◽  
Enso Event ◽  
North Coast ◽  
Archaeological Data ◽  
Enso Events ◽  
The North ◽  
Cultural Responses ◽  
North Coast Of Peru

Recent debate about the development of complex societies on the north coast of Peru has turned on the relative importance of marine vs. terrestrial resources and the extent to which different resource zones are upset by El Niño/Southern Oscillation (ENSO) events. While ENSO events are cited frequently as having important consequences for Prehispanic Andean societies, in fact there are few archaeological data about the nature of cultural responses to a specific ENSO event. Archaeological data from two Chimu settlements in the Casma Valley, Peru—Quebrada Sta. Cristina and Manchan—document the occurrence of a fourteenth-century A.D. ENSO event and some of the cultural responses to that prehistoric El Niño.

scholarly journals The impact of organic pollutants from Indonesian peatland fires on the tropospheric and lower stratospheric composition

2021 ◽  
Vol 21 (14) ◽  
pp. 11257-11288
Author(s):  
Simon Rosanka ◽  
Bruno Franco ◽  
Lieven Clarisse ◽  
Pierre-François Coheur ◽  
Andrea Pozzer ◽  
...  
Keyword(s):  
Biomass Burning ◽  
El Niño ◽  
Lower Stratosphere ◽  
El Nino ◽  
Lower Troposphere ◽  
Atmospheric Composition ◽  
Voc Emissions ◽  
Upper Troposphere ◽  
Upward Transport ◽  
The Impact

Abstract. The particularly strong dry season in Indonesia in 2015, caused by an exceptionally strong El Niño, led to severe peatland fires resulting in high volatile organic compound (VOC) biomass burning emissions. At the same time, the developing Asian monsoon anticyclone (ASMA) and the general upward transport in the Intertropical Convergence Zone (ITCZ) efficiently transported the resulting primary and secondary pollutants to the upper troposphere and lower stratosphere (UTLS). In this study, we assess the importance of these VOC emissions for the composition of the lower troposphere and the UTLS and investigate the effect of in-cloud oxygenated VOC (OVOC) oxidation during such a strong pollution event. This is achieved by performing multiple chemistry simulations using the global atmospheric model ECHAM/MESSy (EMAC). By comparing modelled columns of the biomass burning marker hydrogen cyanide (HCN) and carbon monoxide (CO) to spaceborne measurements from the Infrared Atmospheric Sounding Interferometer (IASI), we find that EMAC properly captures the exceptional strength of the Indonesian fires. In the lower troposphere, the increase in VOC levels is higher in Indonesia compared to other biomass burning regions. This has a direct impact on the oxidation capacity, resulting in the largest regional reduction in the hydroxyl radical (OH) and nitrogen oxides (NOx). While an increase in ozone (O3) is predicted close to the peatland fires, simulated O3 decreases in eastern Indonesia due to particularly high phenol concentrations. In the ASMA and the ITCZ, the upward transport leads to elevated VOC concentrations in the lower stratosphere, which results in the reduction of OH and NOx and the increase in the hydroperoxyl radical (HO2). In addition, the degradation of VOC emissions from the Indonesian fires becomes a major source of lower stratospheric nitrate radicals (NO3), which increase by up to 20 %. Enhanced phenol levels in the upper troposphere result in a 20 % increase in the contribution of phenoxy radicals to the chemical destruction of O3, which is predicted to be as large as 40 % of the total chemical O3 loss in the UTLS. In the months following the fires, this loss propagates into the lower stratosphere and potentially contributes to the variability of lower stratospheric O3 observed by satellite retrievals. The Indonesian peatland fires regularly occur during El Niño years, and the largest perturbations of radical concentrations in the lower stratosphere are predicted for particularly strong El Niño years. By activating the detailed in-cloud OVOC oxidation scheme Jülich Aqueous-phase Mechanism of Organic Chemistry (JAMOC), we find that the predicted changes are dampened. Global models that neglect in-cloud OVOC oxidation tend to overestimate the impact of such extreme pollution events on the atmospheric composition.

scholarly journals Upwelling into the lower stratosphere forced by breaking tropical waves: evidence from chemical tracers

2012 ◽  
Vol 12 (8) ◽  
pp. 19571-19615 ◽  
Author(s):  
Z. Engida ◽  
I. Folkins
Keyword(s):  
Water Vapor ◽  
Spatial Pattern ◽  
Lower Stratosphere ◽  
Time Window ◽  
Time Windows ◽  
Time Lag ◽  
Time Lags ◽  
Quasi Biennial Oscillation ◽  
Stratospheric Water Vapor ◽  
Temperature Anomalies

Abstract. Measurements from the Microwave Limb Sounder (MLS) on the 68 hPa pressure level from 1 January 2005 to 31 December 2010 are used to calculate the coherence between anomalies in the tropical mean mixing ratios of H2O, CO, and N2O, and 100 hPa temperature. We show that the fluctuations of lower stratospheric water vapor in the subseasonal and multiyear time windows are generated by different physical mechanisms. In the subseasonal time window, the spatial pattern of the coherence between 100 hPa temperature and water vapor, and the time lag, show that the variability in lower stratospheric water vapor is dominated by fluctuations in upwelling forced by the dissipation of tropical Rossby waves. In the multiyear time window, the variability of lower stratospheric water vapor is more strongly coherent with temperature fluctuations on the 100 hPa surface in regions where the annual mean temperature is colder than 194 K. In addition, the 68 hPa water vapor anomalies lag the 100 hPa temperature anomalies by roughly 140 days. In this time window, the variability of lower stratospheric water vapor is therefore dominated by changes in the temperature dependent dehydration efficiency which modulate the water vapor stratospheric entry mixing ratio. On subseasonal timescales, the spatial pattern of the coherence between 100 hPa temperature and 68 hPa CO anomalies is very similar to the pattern of coherence between 100 hPa temperature and the Real-time Multivariate MJO series 1 (RMM1) index of the Madden Julian Oscillation (MJO). The MJO therefore has a strong influence on the subseasonal variability of CO in the lower stratosphere. The subseasonal 68 hPa CO and H2O anomalies lag the 100 hPa temperature anomalies by 3.16 and 2.51 days, respectively. The similarity between the two time lags suggests that the subseasonal CO anomalies can also be attributed to changes in upwelling. The multiyear variability in lower stratospheric N2O appears to be dominated by the Quasi Biennial Oscillation (QBO).

scholarly journals How unusual was late 20th century El Niño-Southern Oscillation (ENSO)? Assessing evidence from tree-ring, coral, ice-core and documentary palaeoarchives, A.D. 1525-2002

2006 ◽  
Vol 6 ◽  
pp. 173-179 ◽  
Author(s):  
J. L. Gergis ◽  
A. M. Fowler
Keyword(s):  
20Th Century ◽  
Tree Ring ◽  
El Niño ◽  
Large Scale ◽  
El Nino ◽  
Southern Oscillation ◽  
Enso Event ◽  
Late 20Th Century ◽  
Enso Events ◽  
Proxy Records

Abstract. Multiple proxy records (tree-ring, coral, ice and documentary) were examined to isolate ENSO signals associated with both phases of the phenomenon for the period A.D. 1525-2002. To avoid making large-scale inferences from single proxy analysis, regional signals were aggregated into a network of high-resolution records, revealing large-scale trends in the frequency, magnitude and duration of pre-instrumental ENSO using novel applications of percentile analysis. Here we use the newly introduced coupled ocean-atmosphere ENSO index (CEI) as a baseline for the calibration of proxy records. The reconstruction revealed 83 extreme or very strong ENSO episodes since A.D. 1525, expanding considerably on existing ENSO event chronologies. Significantly, excerpts of the most comprehensive list of La Niña events complied to date are presented, indicating peak activity during the 16th to mid 17th and 20th centuries. Although extreme events are seen throughout the 478-year reconstruction, 43% of the extreme ENSO events noted since A.D. 1525 occur during the 20th century, with an obvious bias towards enhanced El Niño conditions in recent decades. Of the total number of extreme event years reconstructed, 30% of all reconstructed ENSO event years occur post-1940 alone suggesting that recent ENSO variability appears anomalous in the context of the past five centuries.

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