Tropopause fold occurrence rates over the Antarctic station Troll (72° S, 2.5° E)

Mihalikova, Maria; Kirkwood, S.

doi:10.5194/angeo-31-591-2013

Cited by 15 publications

(11 citation statements)

References 24 publications

(33 reference statements)

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“…Tropopause folds have long been known to form in the baroclinic zones beneath the polar jet streams (e.g. Danielsen, 1968); it occurs on the western flank of low system where the isentropes are steeped by the jet core (Mihalikova and Kirkwood, 2013) and consequently the tropopause is bend downwards (Fig. 7b, d).…”

Section: Meteorological Analysis Of Selected Nitrate Eventsmentioning

confidence: 99%

Insights on nitrate sources at Dome C (East Antarctic Plateau) from multi-year aerosol and snow records

Udisti¹,

Frosini²,

Becagli³

et al. 2014

Tellus B: Chemical and Physical Meteorology

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A B S T R A C THere we present the first multi-year record of nitrate in the atmospheric aerosol (2005Á2008) and surface snow (2006Á08) from central Antarctica. PM10 and size-segregated aerosol, together with superficial snow, have been collected all year-round at high resolution (daily for all the snow samples and for most of aerosol samples) at Dome C since the 2004/05 field season and analysed for main and trace ionic markers. The suitability of the sampling location in terms of possible contamination from the base is shown in detail. In spite of the relevance of nitrate in Antarctic atmosphere, both for better understanding the chemistry of N cycle in the plateau boundary layer and for improving the interpretation of long-term nitrate records from deep ice core records, nitrate sources in Antarctica are not well constrained yet, neither in extent nor in timing. A recurring seasonal pattern was pointed out in both aerosol and snow records, showing summer maxima and winter minima, although aerosol maxima lead the snow ones of 1Á2 months, possibly due to a higher acidity in the atmosphere in mid-summer, favouring the repartition of nitrate as nitric acid and thus its uptake by the surface snow layers. On the basis of a meteorological analysis of one major nitrate event, of data related to PSC I extent and of irradiance values, we propose that the high nitrate summer levels in aerosol and snow are likely due to a synergy of enhanced source of nitrate and/or its precursors (such as the stratospheric inputs), higher solar irradiance and higher oxidation rates in this season. Moreover, we show here a further evidence of the substantial contribution of HNO 3 /NOx re-emission from the snowpack, already shown in previous works, and which can explain a significant fraction of atmospheric nitrate, maintaining the same seasonal pattern in the snow. As concerning snow specifically, the presented data suggest that nitrate is likely to be controlled mainly by atmospheric processes, not on the daily timescale but rather on the seasonal one.

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Section: Meteorological Analysis Of Selected Nitrate Eventsmentioning

confidence: 99%

Insights on nitrate sources at Dome C (East Antarctic Plateau) from multi-year aerosol and snow records

Udisti¹,

Frosini²,

Becagli³

et al. 2014

Tellus B: Chemical and Physical Meteorology

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“…Nevertheless, the lack of observations restricted our ability amass more information. In addition, the Lagrangian tool based on ERA-Interim data may not have high enough spatial and vertical resolution to resolve the complex transport of stratospheric air masses down 430 to the Antarctic Plateau during STT events (Mihalikova and Kirkwood, 2013…”

Section: Discussionmentioning

confidence: 99%

Year-round record of near-surface ozone and O3 enhancement events (OEEs) at Dome A, East Antarctica

Ding

Tian

Ashley

et al. 2020

Preprint

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Abstract. To evaluate the characteristics of near-surface O3 over Dome A (Kunlun Station), which is located at the summit of the east Antarctic Ice Sheet, continuous observations were carried out in 2016. Together with observations from the Amundsen&#8211;Scott Station (South Pole) and Zhongshan Station, the seasonal and diurnal O3 variabilities were investigated. The results showed different patterns between coastal and inland Antarctic areas that were characterized by high concentrations in cold seasons and at night. The annual mean values at the three stations were 29.19&#8201;&#177;&#8201;7.52&#8201;ppb, 29.94&#8201;&#177;&#8201;4.97&#8201;ppb and 24.06&#8201;&#177;&#8201;5.79&#8201;ppb. Then, specific atmospheric processes, including synoptic-scale air mass transport, were analysed by Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectory analysis and the potential source contribution function (PSCF) model. Long-range transport was found to account for the O3 enhancement events (OEEs) during summer at Dome A, rather than efficient local production (consistent with previous studies in inland Antarctica). In addition, we observed OEEs during the polar night in the Dome A region, which was not previously found in Antarctica. To explain this unique finding, the occurrence of stratospheric intrusion (stratosphere-to-troposphere, STT) events was studied with the Stratosphere-to-Troposphere Exchange Flux (STEFLUX) tool. This finding suggested that STT events occurred frequently over Dome A and could account for 55&#8201;% of the total polar night period. The occurrence probability of OEEs agreed well with STT events, indicating that the STT process was the dominant factor affecting the near-surface O3 over Dome A in the absence of photochemical reaction sources during polar night. This work provides unique information on ozone variation at Dome A and expands our knowledge regarding such events in Antarctica.

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“…This air is rich in ozone and reactive nitrogen due to the stratospheric origin and can influence the chemical composition of the Antarctic troposphere (Stohl and Sodemann, 2010;Mihalikova and Kirkwood, 2013). The thermal tropopause, for instance, is characterized by a low temperature lapse rate (≤ 2 K km −1 ) and coincides with a change in the static stability.…”

Section: Introductionmentioning

confidence: 99%

“…Rossby wave-induced stratospheric intrusions, such as tropopause folds, occur more often further north and in the midlatitudes than directly above the Antarctic continent (Sprenger et al, 2003;Škerlak et al, 2014). However, the frequency, the seasonality, and the process behind tropopause folds and stratospheric intrusions in the Antarctic region are still under debate (Stohl and Sodemann, 2010;Ndarana et al, 2012;Mihalikova and Kirkwood, 2013).…”

Section: Introductionmentioning

confidence: 99%

Transport of Antarctic stratospheric strongly dehydrated air into the troposphere observed during the HALO-ESMVal campaign 2012

Rolf¹,

Afchine²,

Bozem

et al. 2015

Atmos. Chem. Phys.

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Abstract. Dehydration in the Antarctic winter stratosphere is a well-known phenomenon that is annually observed by satellites and occasionally observed by balloon-borne measurements. However, in situ measurements of dehydrated air masses in the Antarctic vortex are very rare. Here, we present detailed observations with the in situ and GLO-RIA remote sensing instrument payload aboard the German aircraft HALO. Strongly dehydrated air masses down to 1.6 ppmv of water vapor were observed as far north as 47 • S in an altitude between 12 and 13 km in the lowermost stratosphere. The dehydration can be traced back to individual ice formation events above the Antarctic Peninsula and Plateau, where ice crystals sedimented out and water vapor was irreversibly removed. Within these dehydrated stratospheric air masses, filaments of moister air reaching down to the tropopause are detected with the high-resolution limb sounder, GLORIA. Furthermore, dehydrated air masses are observed with GLORIA in the Antarctic lowermost stratosphere down to 7 km. With the help of a backward trajectory analysis, a midlatitude origin of the moist filaments in the vortex can be identified, while the dry air masses down to 7 km have stratospheric origins. Antarctic stratospheretroposphere exchange (STE) and transport of dehydrated air masses into the troposphere are investigated. Further, it is shown that the exchange process can be attributed to several successive Rossby wave events in combination with an isentropic exchange of air masses across the thermal tropopause.The transport into the troposphere is caused by air masses that are detached from the potential vorticity (PV) structure by Rossby wave breaking events and subsequently transported diabatically across the dynamical tropopause. Once transported to the troposphere, air masses with stratospheric origin can reach near-surface levels within several days.

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Tropopause fold occurrence rates over the Antarctic station Troll (72° S, 2.5° E)

Cited by 15 publications

References 24 publications

Insights on nitrate sources at Dome C (East Antarctic Plateau) from multi-year aerosol and snow records

Insights on nitrate sources at Dome C (East Antarctic Plateau) from multi-year aerosol and snow records

Year-round record of near-surface ozone and O<sub>3</sub> enhancement events (OEEs) at Dome A, East Antarctica

Transport of Antarctic stratospheric strongly dehydrated air into the troposphere observed during the HALO-ESMVal campaign 2012

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Tropopause fold occurrence rates over the Antarctic station Troll (72° S, 2.5° E)

Cited by 15 publications

References 24 publications

Insights on nitrate sources at Dome C (East Antarctic Plateau) from multi-year aerosol and snow records

Insights on nitrate sources at Dome C (East Antarctic Plateau) from multi-year aerosol and snow records

Year-round record of near-surface ozone and O&lt;sub&gt;3&lt;/sub&gt; enhancement events (OEEs) at Dome A, East Antarctica

Transport of Antarctic stratospheric strongly dehydrated air into the troposphere observed during the HALO-ESMVal campaign 2012

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Product

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Year-round record of near-surface ozone and O<sub>3</sub> enhancement events (OEEs) at Dome A, East Antarctica