The observation of nitric acid-containing particles in the tropical lower stratosphere

Popp, Peter; Marcy, T. P.; Jensen, E. J.; Kärcher, B.; Fahey, D. W.; Gao, R. S.; Thompson, Thomas L.; Rosenlof, Karen H.; Richard, E. C.; Herman, R. L.; Weinstock, E. M.; Smith, J. B.; May, R. D.; Vömel, H.; Wilson, J. C.; Heymsfield, Andrew J.; Mahoney, Michael J.; Thompson, Anne M.

doi:10.5194/acp-6-601-2006

Cited by 36 publications

(34 citation statements)

References 49 publications

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“…This could explain why the particles had not sublimated at the time of observation, but it would still be an open question how these particles were created in -or brought tothe lowest stratosphere. Particle "clouds" with number densities in the order of 10 −5 cm −3 containing nitric acid have been observed recently at the tropical cold point tropopause (Popp et al, 2005). The present observations are at higher altitude and the number density is much larger.…”

Section: Number Density and Compositionsupporting

confidence: 60%

“…Typical values of gas phase HNO 3 in the tropical tropopause lie around 0.1 ppbv and lower (Popp et al, 2005), which is also the saturation mixing ratio at the temperature minimum of O1, if one assumes a water vapor mixing ratio of 6.06 ppmv. Thus, for an airmass to form an amount of NAT corresponding to 0.13-2.3 ppbv, it would require an unexplained abnormally high HNO 3 abundance during the nucleation and growth of NAT particles.…”

Section: Number Density and Compositionmentioning

confidence: 99%

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Solid particles in the tropical lowest stratosphere

et al. 2007

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Abstract. We report in situ and remote observations proving occasional occurrence of solid particles in the tropical lowest stratosphere, 200 km from deep convective events. The particles were found during field campaigns in Southeast Brazil (49.03 W 22.36 S). They occur in the altitude range from 17.5 to 20.8 km, at temperatures up to at least 10 K above the expected frost point temperature. While stability of ice particles at these altitudes is unexpected from a theoretical point of view, it is argued that these observations are indications of tropospheric air masses penetrating into the stratosphere during convective overshoots. It is argued that the intrusion of tropospheric air must have carried a large amount of water with it, which effectively hydrated the lowest stratosphere, and consequently suppressed sublimation. This conclusion is further supported by a separate water vapor mixing ratio profile obtained at the same observation site.

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Section: Number Density and Compositionsupporting

confidence: 60%

Section: Number Density and Compositionmentioning

confidence: 99%

Solid particles in the tropical lowest stratosphere

et al. 2007

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“…13) in the vicinity of storm turrets reaching 20 (±1) km according to radar images (Nielsen et al, 2007). Though the 0.2-1.5 µm radius of those particles is similar to the 1-7-4.7 µm nitric acid containing crystals (NAT) observed at 18 km by the NASA WB-57F aircraft over the equatorial eastern Pacific Ocean in January 2004 (Popp et al, 2006), their number density of 0.03-1 cm −3 , far larger than the 10 −4 cm −3 of the NAT particles, requiring an additional nucleation process as discussed in Nielsen et al (2007). The presence of such dense particles was also reported in the same region at 18.2 km (410 K) by the Geophysica Aircraft during the TROCCINOX deployment in 2005 (Chaboureau et al, 2007).…”

Section: Hydration Of the Lower Stratosphere Over Land Convective Sysmentioning

confidence: 99%

An overview of the HIBISCUS campaign

et al. 2011

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Abstract. The EU HIBISCUS project consisted of a series of field campaigns during the intense convective summers in 2001, 2003 and 2004 in the State of São Paulo in Brazil. Its objective was to investigate the impact of deep convection on the Tropical Tropopause Layer (TTL) and the lower stratosphere by providing a new set of observational data on meteorology, tracers of horizontal and vertical transport, water vapour, clouds, and chemistry in the tropical Upper Troposphere/Lower Stratosphere (UT/LS). This was achieved using short duration research balloons to study local phenomena associated with convection over land, and long-durationCorrespondence to: J.-P. Pommereau (jean-pierre.pommereau@latmos.ipsl.fr) balloons circumnavigating the globe to study the contrast between land and oceans.Analyses of observations of short-lived tracers, ozone and ice particles show strong episodic local updraughts of cold air across the lapse rate tropopause up to 18 or 19 km (420-440 K) in the lower stratosphere by overshooting towers. The long duration balloon and satellite measurements reveal a contrast between the composition of the lower stratosphere over land and oceanic areas, suggesting significant global impact of such events. The overshoots are shown to be well captured by non-hydrostatic meso-scale Cloud Re- Weather Forecast Models (NWP) underestimating the overshooting process. Finally, the data collected by the HIBIS-CUS balloons have allowed a thorough evaluation of temperature NWP analyses and reanalyses, as well as satellite ozone, nitrogen oxide, water vapour and bromine oxide measurements in the tropics.

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“…They also conclude that the chemical composition of these larger particles in the tropical TTL depends on tropical dynamics, regional sources (implying boundary layer processes as well) and the occurrence of overshooting cumulonimbus clouds. Furthermore, evidence has been presented by Popp et al (2006), Hervig and McHugh (2002), suggesting (like Hamill and Fiocco based on theoretical considerations already in 1988) that nitric acid trihydrate (NAT) particles are present in the tropical transition layer. Based on numerical simulations of the microphysics and thermodynamics and on global modelling, it was hypothesised that these may even form a "tropical tropopause NAT belt" although robust evidence for this is still lacking.…”

Section: Introductionmentioning

confidence: 99%

Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility

et al. 2010

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Abstract. Processes occurring in the tropical upper troposphere (UT), the Tropical Transition Layer (TTL), and the lower stratosphere (LS) are of importance for the global climate, for stratospheric dynamics and air chemistry, and for their influence on the global distribution of water vapour, trace gases and aerosols. In this contribution we present aerosol and trace gas (in-situ) measurements from the tropical UT/LS over Southern Brazil, Northern Australia, and West Africa. The instruments were operated on board of the Russian high altitude research aircraft M-55 "Geophysica" and the DLR Falcon-20 during the campaigns TROCCI-

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The observation of nitric acid-containing particles in the tropical lower stratosphere

Cited by 36 publications

References 49 publications

Solid particles in the tropical lowest stratosphere

Solid particles in the tropical lowest stratosphere

An overview of the HIBISCUS campaign

Aerosols in the tropical and subtropical UT/LS: in-situ measurements of submicron particle abundance and volatility

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