Global budget of tropospheric ozone: Evaluating recent model advances with satellite (OMI), aircraft (IAGOS), and ozonesonde observations

Hu, Li; Jacob, Daniel J.; Liu, Xueliang; Zhang, Yi; Zhang, Lin; Kim, Patrick S.; Sulprizio, Melissa P.; Yantosca, Robert M.

doi:10.1016/j.atmosenv.2017.08.036

Cited by 104 publications

(140 citation statements)

References 74 publications

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“…However, we have no measure of how often the detached ozone intrusion reascends into the stratosphere, which would lead to a reduced stratospheric impact. The estimated tropospheric ozone columns modelled by GEOS-Chem may be biased; for instance, Hu et al (2017) suggest that in general GEOS-Chem (with GEOS-5 meteorological fields) underestimates STT, with ∼ 360 Tg a −1 simulated globally compared to ∼ 550 Tg a −1 observationally constrained. Transport uncertainty is very difficult to estimate with the disparate point measurements; it is possible that detected events are (at least partially) advected out of the analysis regions, which would mean we overestimate the influx into the region, and it is also possible that we are influenced by STT events outside the regions of analysis.…”

Section: Flux Calculationsmentioning

confidence: 99%

“…Recently Hu et al (2017) examined GEOS-Chem ozone simulations and found a similar overestimation of upper troposphere ozone in the mid-southern latitudes when using the GEOS5 meteorological fields. Figure 11 compares modelled (red) and observed (black) ozone profiles on 3 example days when STT events were detected using the ozonesondes.…”

Section: Simulated Ozone Columnsmentioning

confidence: 99%

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Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

et al. 2017

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Abstract. Stratosphere-to-troposphere transport (STT) provides an important natural source of ozone to the upper troposphere, but the characteristics of STT events in the Southern Hemisphere extratropics and their contribution to the regional tropospheric ozone budget remain poorly constrained. Here, we develop a quantitative method to identify STT events from ozonesonde profiles. Using this method we estimate the seasonality of STT events and quantify the ozone transported across the tropopause over Davis (69 • S, 2006Davis (69 • S, -2013, Macquarie Island (54 • S, 2004-2013), and Melbourne (38 • S, 2004-2013). STT seasonality is determined by two distinct methods: a Fourier bandpass filter of the vertical ozone profile and an analysis of the Brunt-Väisälä frequency. Using a bandpass filter on 7-9 years of ozone profiles from each site provides clear detection of STT events, with maximum occurrences during summer and minimum during winter for all three sites. The majority of tropospheric ozone enhancements owing to STT events occur within 2.5 and 3 km of the tropopause at Davis and Macquarie Island respectively. Events are more spread out at Melbourne, occurring frequently up to 6 km from the tropopause. The mean fraction of total tropospheric ozone attributed to STT during STT events is ∼ 1.0-3.5 % at each site; however, during individual events, over 10 % of tropospheric ozone may be directly transported from the stratosphere. The cause of STTs is determined to be largely due to synoptic low-pressure frontal systems, determined using coincident ERA-Interim reanalysis meteorological data. Ozone enhancements can also be caused by biomass burning plumes transported from Africa and South America, which are apparent during austral winter and spring and are determined using satellite measurements of CO. To provide regional context for the ozonesonde observations, we use the GEOS-Chem chemical transport model, which is too coarsely resolved to distinguish STT events but is able to accurately simulate the seasonal cycle of tropospheric ozone columns over the three southern hemispheric sites. Combining the ozonesonde-derived STT event characteristics with the simulated tropospheric ozone columns from GEOS-Chem, we estimate STT ozone flux near the three sites and see austral summer dominated yearly amounts of between 5.7 and 8.7 × 10 17 molecules cm −2 a −1 .

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Section: Flux Calculationsmentioning

confidence: 99%

Section: Simulated Ozone Columnsmentioning

confidence: 99%

Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

et al. 2017

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“…The model has been applied in a number of studies on global and regional tropospheric ozone Fiore et al, 2014;Zhang et al, 2014;Yan et al, 2016;Zhao et 140 al., 2017). A recent model evaluation with global tropospheric ozone datasets shows that GEOS-Chem (v10-01) provides an improved ozone simulation relative to previous model versions (e.g., v8-01 in Zhang et al, (2010)) with no significant seasonal and latitudinal biases (Hu et al, 2017).…”

Section: Stratospheric Ozone Chemistry Is Represented By the Linearizmentioning

confidence: 99%

Lower tropospheric ozone over India and its linkage to the South Asian monsoon

Lu¹,

Zhang²,

Liu³

et al. 2017

Preprint

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Lower tropospheric (surface to 600 hPa) ozone over India poses serious risks to local human and crops, and potentially affects global ozone distribution through frequent deep convection in tropical regions. Our current understanding of processes controlling seasonal to long-term variations in lower 20 tropospheric ozone over this region is rather limited due to spatially and temporally sparse observations. Here we present an integrated process analysis of the seasonal cycle, interannual Atmos. Chem. Phys. Discuss., https://doi

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“…The model has been extensively evaluated against observations Evans and Jacob, 2005;Nassar et al, 2009;Mao et al, 2010;Zhang et al, 2010;Parrella et al, 2012;Hu et al, 2017). The model is driven by assimilated winds calculated by the Goddard Earth Observing System at a horizontal resolution of 4 • × 5 • , with 47 vertical levels from the surface to 50 hPa.…”

Section: Global Modelmentioning

confidence: 99%

Impacts of bromine and iodine chemistry on tropospheric OH and HO<sub>2</sub>: comparing observations with box and global model perspectives

et al. 2018

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Abstract. The chemistry of the halogen species bromine and iodine has a range of impacts on tropospheric composition, and can affect oxidising capacity in a number of ways. However, recent studies disagree on the overall sign of the impacts of halogens on the oxidising capacity of the troposphere. We present simulations of OH and HO 2 radicals for comparison with observations made in the remote tropical ocean boundary layer during the Seasonal Oxidant Study at the Cape Verde Atmospheric Observatory in 2009. We use both a constrained box model, using detailed chemistry derived from the Master Chemical Mechanism (v3.2), and the three-dimensional global chemistry transport model GEOSChem. Both model approaches reproduce the diurnal trends in OH and HO 2 . Absolute observed concentrations are well reproduced by the box model but are overpredicted by the global model, potentially owing to incomplete consideration of oceanic sourced radical sinks. The two models, however, differ in the impacts of halogen chemistry. In the box model, halogen chemistry acts to increase OH concentrations (by 9.8 % at midday at the Cape Verde Atmospheric Observatory), while the global model exhibits a small increase in OH at the Cape Verde Atmospheric Observatory (by 0.6 % at midday) but overall shows a decrease in the global annual mass-weighted mean OH of 4.5 %. These differences reflect the variety of timescales through which the halogens impact the chemical system. On short timescales, photolysis of HOBr and HOI, produced by reactions of HO 2 with BrO and IO, respectively, increases the OH concentration. On longer timescales, halogen-catalysed ozone destruction cycles lead to lower primary production of OH radicals through ozone photolysis, and thus to lower OH concentrations. The global model includes more of the longer timescale responses than the constrained box model, and overall the global impact of the longer timescale response (reduced primary production due to lower O 3 concentrations) overwhelms the shorter timescale response (enhanced cycling from HO 2 to OH), and thus the global OH concentration decreases. The Earth system contains many such responses on a large range of timescales. This work highlights the care that needs to be taken to understand the full impact of any one process on the system as a whole.

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Global budget of tropospheric ozone: Evaluating recent model advances with satellite (OMI), aircraft (IAGOS), and ozonesonde observations

Cited by 104 publications

References 74 publications

Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

Lower tropospheric ozone over India and its linkage to the South Asian monsoon

Impacts of bromine and iodine chemistry on tropospheric OH and HO<sub>2</sub>: comparing observations with box and global model perspectives

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Global budget of tropospheric ozone: Evaluating recent model advances with satellite (OMI), aircraft (IAGOS), and ozonesonde observations

Cited by 104 publications

References 74 publications

Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

Stratospheric ozone intrusion events and their impacts on tropospheric ozone in the Southern Hemisphere

Lower tropospheric ozone over India and its linkage to the South Asian monsoon

Impacts of bromine and iodine chemistry on tropospheric OH and HO&lt;sub&gt;2&lt;/sub&gt;: comparing observations with box and global model perspectives

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Impacts of bromine and iodine chemistry on tropospheric OH and HO<sub>2</sub>: comparing observations with box and global model perspectives