scholarly journals MIPAS detects Antarctic stratospheric belt of NAT PSCs caused by mountain waves

2006 ◽  
Vol 6 (5) ◽  
pp. 1221-1230 ◽  
Author(s):  
M. Höpfner ◽  
N. Larsen ◽  
R. Spang ◽  
B. P. Luo ◽  
J. Ma ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Michelson Interferometer ◽  
Sudden Onset ◽  
Abstract Space ◽  
Mountain Waves ◽  
Homogeneous Surface ◽  
Surface Nucleation ◽  
Atmospheric Sounding ◽  
Stratospheric Clouds ◽  
The Antarctic

Abstract. Space borne infrared limb emission measurements by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) reveal the formation of a belt of polar stratospheric clouds (PSCs) of nitric acid trihydrate (NAT) particles over Antarctica in mid-June 2003. By mesoscale microphysical simulations we show that this sudden onset of NAT PSCs was caused by heterogeneous nucleation on ice in the cooling phases of large-amplitude stratospheric mountain waves over the Antarctic Peninsula and the Ellsworth Mountains. MIPAS observations of PSCs before this event show no indication for the presence of NAT clouds with volume densities larger than about 0.3 µm3/cm3 and radii smaller than 3 µm, but are consistent with supercooled droplets of ternary H2SO4/HNO3/H2O solution (STS). Simulations indicate that homogeneous surface nucleation rates have to be reduced by three orders of magnitude to comply with the observations.

scholarly journals MIPAS detects Antarctic stratospheric belt of NAT PSCs caused by mountain waves

2005 ◽  
Vol 5 (5) ◽  
pp. 10723-10745 ◽  
Author(s):  
M. Höpfner ◽  
N. Larsen ◽  
R. Spang ◽  
B. P. Luo ◽  
J. Ma ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Michelson Interferometer ◽  
Sudden Onset ◽  
Abstract Space ◽  
Mountain Waves ◽  
Homogeneous Surface ◽  
Surface Nucleation ◽  
Atmospheric Sounding ◽  
Stratospheric Clouds ◽  
The Antarctic

Abstract. Space borne infrared limb emission measurements by the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) reveal the formation of a belt of polar stratospheric clouds (PSCs) of nitric acid trihydrate (NAT) particles over Antarctica in mid-June 2003. By mesoscale microphysical simulations we show that this sudden onset of NAT PSCs was caused by heterogeneous nucleation on ice in the cooling phases of large-amplitude stratospheric mountain waves over the Antarctic Peninsula and the Ellsworth Mountains. MIPAS observations of PSCs before this event show no indication for the presence of NAT clouds with volume densities larger than about 0.3 μm3/cm3 and radii smaller than 3 μm, but are consistent with supercooled droplets of ternary H2SO4/HNO3/H2O solution (STS). Simulations indicate that homogeneous surface nucleation rates have to be reduced by three orders of magnitude to comply with the observations.

scholarly journals Total depletion of ozone reached in the 2010–2011 Arctic winter as observed by MIPAS/ENVISAT using a 2-D tomographic approach

2011 ◽  
Vol 11 (12) ◽  
pp. 33191-33227
Author(s):  
E. Arnone ◽  
E. Castelli ◽  
E. Papandrea ◽  
M. Carlotti ◽  
B. M. Dinelli
Keyword(s):  
Potential Temperature ◽  
Michelson Interferometer ◽  
The Arctic ◽  
Late Winter ◽  
Infrared Measurements ◽  
Atmospheric Sounding ◽  
Depletion Rate ◽  
Horizontal Inhomogeneity ◽  
Stratospheric Clouds ◽  
The Antarctic

Abstract. We present observations of the 2010–2011 Arctic winter stratosphere from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard ENVISAT. Limb sounding infrared measurements were taken by MIPAS during the Northern polar winter and into the subsequent spring, giving a continuous vertically resolved view of the Arctic dynamics, chemistry and polar stratospheric clouds (PSCs). We adopted a 2-D tomographic retrieval approach to account for the strong horizontal inhomogeneity of the atmosphere present under vortex conditions, self-consistently comparing 2011 to the 2-D analysis of 2003–2010. Unlike most Arctic winters, 2011 was characterized by a strong stratospheric vortex lasting until early April. Lower stratospheric temperatures persistently remained below the threshold for PSC formation, extending the PSC season up to mid-March, resulting in significant chlorine activation leading to ozone destruction. Through inspection of MIPAS spectra, 84% of PSCs were identified as supercooled ternary solution (STS) or STS mixed with nitric acid trihydrate (NAT), 16% formed mostly by NAT particles, and only a few by ice. In the lower stratosphere at potential temperature 450 K, vortex average ozone showed a daily depletion rate reaching 100 ppbv day−1. In early April at 18 km altitude, 10% of vortex measurements displayed total depletion of ozone, and vortex average values dropped to 0.6 ppmv. This corresponds to a chemical loss from early winter greater than 80%. Ozone loss was accompanied by activation of ClO, associated depletion of its reservoir ClONO2, and significant denitrification, which further delayed the recovery of ozone in spring. Sporadic increases of NO2 associated with evaporation of sedimenting PSCs were also observed. Once the PSC season halted, ClO was reconverted into ClONO2. Compared to MIPAS observed 2003–2010 Arctic average values, the 2010–2011 vortex in late winter had 15 K lower temperatures, 40% lower HNO3 and 50% lower ozone, reaching the largest ozone depletion ever observed in the Arctic. The overall picture of this Arctic winter was remarkably closer to conditions typically found in the Antarctic vortex than ever observed before.

scholarly journals Polar stratospheric clouds initiated by mountain waves in a global chemistry–climate model: a missing piece in fully modelling polar stratospheric ozone depletion

2020 ◽  
Vol 20 (21) ◽  
pp. 12483-12497
Author(s):  
Andrew Orr ◽  
J. Scott Hosking ◽  
Aymeric Delon ◽  
Lars Hoffmann ◽  
Reinhold Spang ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Ozone Depletion ◽  
Stratospheric Ozone ◽  
Temperature Fluctuations ◽  
Synoptic Scale ◽  
Mountain Waves ◽  
Cooling Phase ◽  
Stratospheric Clouds ◽  
Ice Water ◽  
The Antarctic

Abstract. An important source of polar stratospheric clouds (PSCs), which play a crucial role in controlling polar stratospheric ozone depletion, is the temperature fluctuations induced by mountain waves. These enable stratospheric temperatures to fall below the threshold value for PSC formation in regions of negative temperature perturbations or cooling phases induced by the waves even if the synoptic-scale temperatures are too high. However, this formation mechanism is usually missing in global chemistry–climate models because these temperature fluctuations are neither resolved nor parameterised. Here, we investigate in detail the episodic and localised wintertime stratospheric cooling events produced over the Antarctic Peninsula by a parameterisation of mountain-wave-induced temperature fluctuations inserted into a 30-year run of the global chemistry–climate configuration of the UM-UKCA (Unified Model – United Kingdom Chemistry and Aerosol) model. Comparison of the probability distribution of the parameterised cooling phases with those derived from climatologies of satellite-derived AIRS brightness temperature measurements and high-resolution radiosonde temperature soundings from Rothera Research Station on the Antarctic Peninsula shows that they broadly agree with the AIRS observations and agree well with the radiosonde observations, particularly in both cases for the “cold tails” of the distributions. It is further shown that adding the parameterised cooling phase to the resolved and synoptic-scale temperatures in the UM-UKCA model results in a considerable increase in the number of instances when minimum temperatures fall below the formation temperature for PSCs made from ice water during late austral autumn and early austral winter and early austral spring, and without the additional cooling phase the temperature rarely falls below the ice frost point temperature above the Antarctic Peninsula in the model. Similarly, it was found that the formation potential for PSCs made from ice water was many times larger if the additional cooling is included. For PSCs made from nitric acid trihydrate (NAT) particles it was only during October that the additional cooling is required for temperatures to fall below the NAT formation temperature threshold (despite more NAT PSCs occurring during other months). The additional cooling phases also resulted in an increase in the surface area density of NAT particles throughout the winter and early spring, which is important for chlorine activation. The parameterisation scheme was finally shown to make substantial differences to the distribution of total column ozone during October, resulting from a shift in the position of the polar vortex.

scholarly journals Mountain-wave-induced polar stratospheric clouds and their representation in the global chemistry model ICON-ART

2021 ◽  
Vol 21 (12) ◽  
pp. 9515-9543
Author(s):  
Michael Weimer ◽  
Jennifer Buchmüller ◽  
Lars Hoffmann ◽  
Ole Kirner ◽  
Beiping Luo ◽  
...  
Keyword(s):  
Antarctic Peninsula ◽  
Scale Effects ◽  
Hot Spot ◽  
Orthogonal Polarization ◽  
Polar Stratospheric Clouds ◽  
Mountain Wave ◽  
Mountain Waves ◽  
Stratospheric Clouds ◽  
Wave Induced ◽  
The Antarctic

Abstract. Polar stratospheric clouds (PSCs) are a driver for ozone depletion in the lower polar stratosphere. They provide surface for heterogeneous reactions activating chlorine and bromine reservoir species during the polar night. The large-scale effects of PSCs are represented by means of parameterisations in current global chemistry–climate models, but one process is still a challenge: the representation of PSCs formed locally in conjunction with unresolved mountain waves. In this study, we investigate direct simulations of PSCs formed by mountain waves with the ICOsahedral Nonhydrostatic modelling framework (ICON) with its extension for Aerosols and Reactive Trace gases (ART) including local grid refinements (nesting) with two-way interaction. Here, the nesting is set up around the Antarctic Peninsula, which is a well-known hot spot for the generation of mountain waves in the Southern Hemisphere. We compare our model results with satellite measurements of PSCs from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and gravity wave observations of the Atmospheric Infrared Sounder (AIRS). For a mountain wave event from 19 to 29 July 2008 we find similar structures of PSCs as well as a fairly realistic development of the mountain wave between the satellite data and the ICON-ART simulations in the Antarctic Peninsula nest. We compare a global simulation without nesting with the nested configuration to show the benefits of adding the nesting. Although the mountain waves cannot be resolved explicitly at the global resolution used (about 160 km), their effect from the nested regions (about 80 and 40 km) on the global domain is represented. Thus, we show in this study that the ICON-ART model has the potential to bridge the gap between directly resolved mountain-wave-induced PSCs and their representation and effect on chemistry at coarse global resolutions.

scholarly journals Extreme ozone depletion in the 2010–2011 Arctic winter stratosphere as observed by MIPAS/ENVISAT using a 2-D tomographic approach

2012 ◽  
Vol 12 (19) ◽  
pp. 9149-9165 ◽  
Author(s):  
E. Arnone ◽  
E. Castelli ◽  
E. Papandrea ◽  
M. Carlotti ◽  
B. M. Dinelli
Keyword(s):  
Ozone Depletion ◽  
Potential Temperature ◽  
Michelson Interferometer ◽  
The Arctic ◽  
Late Winter ◽  
Infrared Measurements ◽  
Depletion Rate ◽  
Horizontal Inhomogeneity ◽  
Stratospheric Clouds ◽  
The Antarctic

Abstract. We present observations of the 2010–2011 Arctic winter stratosphere from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) onboard ENVISAT. Limb sounding infrared measurements were taken by MIPAS during the Northern polar winter and into the subsequent spring, giving a continuous vertically resolved view of the Arctic dynamics, chemistry and polar stratospheric clouds (PSCs). We adopted a 2-D tomographic retrieval approach to account for the strong horizontal inhomogeneity of the atmosphere present under vortex conditions, self-consistently comparing 2011 to the 2-D analysis of 2003–2010. Unlike most Arctic winters, 2011 was characterized by a strong stratospheric vortex lasting until early April. Lower stratospheric temperatures persistently remained below the threshold for PSC formation, extending the PSC season up to mid-March, resulting in significant chlorine activation leading to ozone destruction. On 3 January 2011, PSCs were detected up to 30.5 ± 0.9 km altitude, representing the highest PSCs ever reported in the Arctic. Through inspection of MIPAS spectra, 83% of PSCs were identified as supercooled ternary solution (STS) or STS mixed with nitric acid trihydrate (NAT), 17% formed mostly by NAT particles, and only two cases by ice. In the lower stratosphere at potential temperature 450 K, vortex average ozone showed a daily depletion rate reaching 100 ppbv day−1. In early April at 18 km altitude, 10% of vortex measurements displayed total depletion of ozone, and vortex average values dropped to 0.6 ppmv. This corresponds to a chemical loss from early winter greater than 80%. Ozone loss was accompanied by activation of ClO, associated depletion of its reservoir ClONO2, and significant denitrification, which further delayed the recovery of ozone in spring. Once the PSC season halted, ClO was reconverted primarily into ClONO2. Compared to MIPAS observed 2003–2010 Arctic average values, the 2010–2011 vortex in late winter had 15 K lower temperatures, 40% lower HNO3 and 50% lower ozone, reaching the largest ozone depletion ever observed in the Arctic. The overall picture of this Arctic winter was remarkably closer to conditions typically found in the Antarctic vortex than ever observed before.

scholarly journals HOCl chemistry in the Antarctic stratospheric vortex 2002, as observed with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS)

2008 ◽  
Vol 8 (6) ◽  
pp. 18967-18992
Author(s):  
T. von Clarmann ◽  
N. Glatthor ◽  
R. Ruhnke ◽  
G. P. Stiller ◽  
O. Kirner ◽  
...  
Keyword(s):  
Heterogeneous Reaction ◽  
Michelson Interferometer ◽  
Polar Vortex ◽  
Heterogeneous Chemistry ◽  
Polar Stratospheric Clouds ◽  
Mean Values ◽  
Mixing Ratios ◽  
Atmospheric Sounding ◽  
Antarctic Polar Vortex ◽  
Stratospheric Clouds

Abstract. In the 2002 Antarctic polar vortex enhanced HOCl mixing ratios were detected by the Michelson Interferometer for Passive Atmospheric Sounding both at altitudes of around 35 km, where HOCl abundances are ruled by gas phase chemistry and at around 24 km, which belongs to the altitude domain where heterogeneous chlorine chemistry is relevant. At altitudes of 33 to 40 km, where in midlatitudinal and tropical atmospheres peak HOCl mixing ratios significantly above 0.2 ppbv (in terms of daily mean values) are observed, polar vortex HOCl mixing ratios were found to be around 0.14 ppbv as long as the polar vortex was intact, centered at the pole, and thus received relatively little sunlight. After deformation and displacement of the polar vortex in the course of a major warming, ClO rich vortex air was more exposed to sunlight, where enhanced HOx abundances led to largely increased HOCl mixing ratios (up to 0.3 ppbv), exceeding typical midlatitudinal and tropical amounts significantly. The HOCl increase was preceded by an increase of ClO. Model runs could reproduce these measurements only when the Stimpfle et al. (1979) rate constant for the reaction ClO+HO2→HOCl+O2 was used but not with the current JPL recommendation. At an altitude of 24 km, HOCl mixing ratios of up to 0.15 ppbv were detected. This HOCl enhancement, which is already visible in 18 September data, is attributed to heterogeneous chemistry, which is in agreement with observations of polar stratospheric clouds. Comparison with a model run where no polar stratospheric clouds appeared during the observation period suggests that a significant part of HOCl was generated from ClO rather than directly via heterogeneous reaction. Excess ClO and HOCl in the measurements is attributed to ongoing heterogeneous chemistry which is not reproduced by the model. In the following days, a decay of HOCl abundances was observed and on 11 October, polar vortex mean daytime mixing ratios were only 0.03 ppbv.

scholarly journals MIPAS database: new HNO<sub>3</sub> line parameters at 7.6  µm validated with MIPAS satellite measurements

2016 ◽  
Vol 9 (5) ◽  
pp. 2067-2076 ◽  
Author(s):  
Agnès Perrin ◽  
Jean-Marie Flaud ◽  
Marco Ridolfi ◽  
Jean Vander Auwera ◽  
Massimo Carlotti
Keyword(s):  
Nitric Acid ◽  
Cross Sections ◽  
Michelson Interferometer ◽  
Absorption Cross ◽  
Satellite Measurements ◽  
Line Intensities ◽  
Atmospheric Sounding ◽  
New Generation ◽  
Line Positions ◽  
Individual Line

Abstract. Improved line positions and intensities have been generated for the 7.6 µm spectral region of nitric acid. They were obtained relying on a recent reinvestigation of the nitric acid band system at 7.6 µm and comparisons of HNO3 volume mixing ratio profiles retrieved from the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) limb emission radiances in the 11 and 7.6 µm domains. This has led to an improved database called MIPAS-2015. Comparisons with available laboratory information (individual line intensities, integrated absorption cross sections, and absorption cross sections) show that MIPAS-2015 provides an improved description of the 7.6 µm region of nitric acid. This study should help to improve HNO3 satellite retrievals by allowing measurements to be performed simultaneously in the 11 and 7.6 µm micro-windows. In particular, it should be useful to analyze existing MIPAS and IASI spectra as well as spectra to be recorded by the forthcoming Infrared Atmospheric Sounding Interferometer – New Generation (IASI-NG) instrument.

scholarly journals Lagrangian simulation of ice particles and resulting dehydration in the polar winter stratosphere

2019 ◽  
Vol 19 (1) ◽  
pp. 543-563 ◽  
Author(s):  
Ines Tritscher ◽  
Jens-Uwe Grooß ◽  
Reinhold Spang ◽  
Michael C. Pitts ◽  
Lamont R. Poole ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Michelson Interferometer ◽  
Ice Nucleation ◽  
The Arctic ◽  
Orthogonal Polarization ◽  
Satellite Orbits ◽  
Lagrangian Simulation ◽  
Ice Particles ◽  
The Antarctic ◽  
Good Agreement

Abstract. Polar stratospheric clouds (PSCs) and cold stratospheric aerosols drive heterogeneous chemistry and play a major role in polar ozone depletion. The Chemical Lagrangian Model of the Stratosphere (CLaMS) simulates the nucleation, growth, sedimentation, and evaporation of PSC particles along individual trajectories. Particles consisting of nitric acid trihydrate (NAT), which contain a substantial fraction of the stratospheric nitric acid (HNO3), were the focus of previous modeling work and are known for their potential to denitrify the polar stratosphere. Here, we carried this idea forward and introduced the formation of ice PSCs and related dehydration into the sedimentation module of CLaMS. Both processes change the simulated chemical composition of the lower stratosphere. Due to the Lagrangian transport scheme, NAT and ice particles move freely in three-dimensional space. Heterogeneous NAT and ice nucleation on foreign nuclei as well as homogeneous ice nucleation and NAT nucleation on preexisting ice particles are now implemented into CLaMS and cover major PSC formation pathways. We show results from the Arctic winter 2009/2010 and from the Antarctic winter 2011 to demonstrate the performance of the model over two entire PSC seasons. For both hemispheres, we present CLaMS results in comparison to measurements from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS), and the Microwave Limb Sounder (MLS). Observations and simulations are presented on season-long and vortex-wide scales as well as for single PSC events. The simulations reproduce well both the timing and the extent of PSC occurrence inside the entire vortex. Divided into specific PSC classes, CLaMS results show predominantly good agreement with CALIOP and MIPAS observations, even for specific days and single satellite orbits. CLaMS and CALIOP agree that NAT mixtures are the first type of PSC to be present in both winters. NAT PSC areal coverages over the entire season agree satisfactorily. However, cloud-free areas, next to or surrounded by PSCs in the CALIOP data, are often populated with NAT particles in the CLaMS simulations. Looking at the temporal and vortex-averaged evolution of HNO3, CLaMS shows an uptake of HNO3 from the gas into the particle phase which is too large and happens too early in the simulation of the Arctic winter. In turn, the permanent redistribution of HNO3 is smaller in the simulations than in the observations. The Antarctic model run shows too little denitrification at lower altitudes towards the end of the winter compared to the observations. The occurrence of synoptic-scale ice PSCs agrees satisfactorily between observations and simulations for both hemispheres and the simulated vertical redistribution of water vapor (H2O) is in very good agreement with MLS observations. In summary, a conclusive agreement between CLaMS simulations and a variety of independent measurements is presented.

scholarly journals Diurnal variations of BrONO<sub>2</sub> observed by MIPAS-B at mid-latitudes and in the Arctic

2017 ◽  
Author(s):  
Gerald Wetzel ◽  
Hermann Oelhaf ◽  
Michael Höpfner ◽  
Felix Friedl-Vallon ◽  
Andreas Ebersoldt ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Climate Model ◽  
Michelson Interferometer ◽  
Diurnal Variations ◽  
The Arctic ◽  
Late Winter ◽  
Mixing Ratios ◽  
Reservoir Species ◽  
Atmospheric Sounding ◽  
Stratospheric Clouds

Abstract. The first stratospheric measurements of the diurnal variation of the inorganic bromine (Bry) reservoir species BrONO2 around sunrise and sunset are reported. Arctic flights of the balloon-borne Michelson Interferometer for Passive Atmospheric Sounding (MIPAS-B) were carried out from Kiruna (68°N, Sweden) in January 2010 and March 2011 inside the stratospheric polar vortices where diurnal variations of BrONO2 around sunrise have been observed. High nighttime BrONO2 volume mixing ratios of up to 21 parts per trillion by volume (pptv) were detected in the late winter 2011 in the absence of polar stratospheric clouds (PSCs). In contrast, the amount of measured BrONO2 was significantly lower in January 2010 due to low available NO2 amounts (for the build-up of BrONO2), heterogeneous destruction of BrONO2 on PSC particles, and the gas-phase interaction of BrO (the source to form BrONO2) with ClO. A further balloon flight took place at mid-latitudes from Timmins (49°N, Canada) in September 2014. Mean BrONO2 mixing ratios of 22 pptv were observed after sunset in the altitude region between 21 and 29 km. Measurements are compared and discussed with the results of a multi-year simulation performed with the chemistry climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC). The calculated temporal variation of BrONO2 is in principal agreement with the balloon-borne observations. Using the nighttime simulated ratio between BrONO2 and Bry, the amount of Bry observed by MIPAS-B was estimated to about 21–25 pptv in the lower stratosphere.

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