scholarly journals Differences in Arctic and Antarctic PSC occurrence as observed by lidar in Ny-Ålesund (79° N, 12° E) and McMurdo (78° S, 167° E)

2005 ◽  
Vol 5 (8) ◽  
pp. 2081-2090 ◽  
Author(s):  
M. Maturilli ◽  
R. Neuber ◽  
P. Massoli ◽  
F. Cairo ◽  
A. Adriani ◽  
...  
Keyword(s):  
Large Fraction ◽  
Particle Surface ◽  
The Arctic ◽  
Ozone Loss ◽  
Polar Stratospheric Cloud ◽  
Antarctic Ozone ◽  
Stratospheric Cooling ◽  
Hole Dimensions ◽  
Activation Rates ◽  
The Relationship

Abstract. The extent of springtime Arctic ozone loss does not reach Antarctic ``ozone hole'' dimensions because of the generally higher temperatures in the northern hemisphere vortex and consequent less polar stratospheric cloud (PSC) particle surface for heterogeneous chlorine activation. Yet, with increasing greenhouse gases stratospheric temperatures are expected to further decrease. To infer if present Antarctic PSC occurrence can be applied to predict future Arctic PSC occurrence, lidar observations from McMurdo station (78° S, 167° E) and NyÅlesund (79° N, 12° E) have been analysed for the 9 winters between 1995 (1995/1996) and 2003 (2003/2004). Although the statistics may not completely cover the overall hemispheric PSC occurrence, the observations are considered to represent the main synoptic cloud features as both stations are mostly situated in the centre or at the inner edge of the vortex. Since the focus is set on the occurrence frequency of solid and liquid particles, the analysis has been restricted to volcanic aerosol free conditions. In McMurdo, by far the largest part of PSC observations is associated with NAT PSCs. The observed persistent background of NAT particles and their potential ability to cause denoxification and irreversible denitrification is presumably more important to Antarctic ozone chemistry than the scarcely observed ice PSCs. Meanwhile in Ny-Ålesund, ice PSCs have never been observed, while solid NAT and liquid STS clouds both occur in large fraction. Although they are also found solely, the majority of observations reveals solid and liquid particle layers in the same profile. For the Ny-Ålesund measurements, the frequent occurrence of liquid PSC particles yields major significance in terms of ozone chemistry, as their chlorine activation rates are more efficient. The relationship between temperature, PSC formation, and denitrification is nonlinear and the McMurdo and Ny-Ålesund PSC observations imply that for predicted stratospheric cooling it is not possible to directly apply current Antarctic PSC occurrence to the Arctic stratosphere. Future Arctic PSC occurrence, and thus ozone loss, is likely to depend on the shape and barotropy of the vortex rather than on minimum temperature alone.

scholarly journals Differences in Arctic and Antarctic PSC occurrence as observed by lidar in Ny-Ålesund (79° N, 12° E) and McMurdo (78° S, 167° E)

2004 ◽  
Vol 4 (5) ◽  
pp. 6837-6866 ◽  
Author(s):  
M. Müller ◽  
R. Neuber ◽  
P. Massoli ◽  
F. Cairo ◽  
A. Adriani ◽  
...  
Keyword(s):  
Large Fraction ◽  
Particle Surface ◽  
The Arctic ◽  
Type Ii ◽  
Ozone Loss ◽  
Type Ia ◽  
Antarctic Ozone ◽  
Stratospheric Cooling ◽  
Hole Dimensions ◽  
Activation Rates

Abstract. The extent of springtime Arctic ozone loss does not reach Antarctic "ozone hole" dimensions because of the generally higher temperatures in the northern hemisphere vortex and consequent less polar stratospheric cloud (PSC) particle surface for heterogeneous chlorine activation. Yet, with increasing greenhouse gases stratospheric temperatures are expected to further decrease. To infer if present Antarctic PSC occurrence can be applied to predict future Arctic PSC occurrence, lidar observations from McMurdo station (78° S, 167° E) and Ny-Ålesund (79° N, 12° E) have been analysed for the 9 winters between 1995 (1995/1996) and 2003 (2003/2004). Although the statistics may not completely cover the overall hemispheric PSC occurrence, the observations are considered to represent the main synoptic cloud features as both stations are mostly situated in the centre or at the inner edge of the vortex. Since the focus is set on the occurrence frequency of solid and liquid particles, the analysis has been restricted to volcanic aerosol free conditions. In McMurdo, by far the largest part of PSC observations is associated with PSC type Ia. The observed constant background of NAT particles and their potential ability to cause denoxification and irreversible denitrification is presumably more important to Antarctic ozone chemistry than the scarcely observed PSC type II. Meanwhile in Ny-Ålesund, PSC type II has never been observed, while type Ia and Ib both occur in large fraction. Although they are also found solely, the majority of observations reveals solid and liquid particle layers in the same profile. For the Ny-Ålesund measurements, the frequent occurrence of liquid PSC particles yields major significance in terms of ozone chemistry, as their chlorine activation rates are more efficient. The relationship between temperature, PSC formation, and denitrification is nonlinear and the McMurdo and Ny-Ålesund PSC observations imply that for predicted stratospheric cooling it is not possible to directly apply current Antarctic PSC occurrence directly to the Arctic stratosphere. Future Arctic PSC occurrence, and thus ozone loss, will depend on the shape and barotropy of the vortex rather than on the minimum temperatures.

scholarly journals Discovery of a New Ozone Hole over the Tropics

2022 ◽  
Author(s):  
Qing-Bin Lu
Keyword(s):  
Lower Stratosphere ◽  
Global Climate ◽  
Ground Level ◽  
Ozone Hole ◽  
The Arctic ◽  
Ozone Loss ◽  
Global Concern ◽  
Antarctic Ozone ◽  
Stratospheric Cooling ◽  
The Tropics

Abstract This paper reveals a new ozone hole that exists in the lower stratosphere over the tropics (30°N-30°S) across the seasons since the 1980s, where an ozone hole is defined as an area of ozone loss larger than 25% compared with the undisturbed atmosphere. The depth of this all-season tropical ozone hole is comparable to that of the well-known springtime ozone hole over Antarctica, while its area is about seven times that of the latter. At the center of the deepest tropical or Antarctic ozone hole, approximately 80% of the normal ozone value is depleted, whereas annual mean ozone depletion in the lower stratosphere over the tropics due to the coldest temperature is about 1.6 times that over Antarctica and is about 7.7 times that over the Arctic. The whole-year ozone hole over the tropics could cause a serious global concern as it can lead to increases in ground-level ultraviolet radiation and affect 50% of Earth's surface area, which is home to approximately 50% of the world's population. Moreover, since ozone loss is well-known to lead to stratospheric cooling, the presence of the all-season tropical ozone hole and the seasonal polar ozone holes is equivalent to the formation of three ‘temperature holes’ in the global lower stratosphere. These findings will play a far-reaching role in understanding fundamental atmospheric processes and global climate change.

scholarly journals Polar processing in a split vortex: early winter Arctic ozone loss in 2012/13

2015 ◽  
Vol 15 (4) ◽  
pp. 4973-5029 ◽  
Author(s):  
G. L. Manney ◽  
Z. D. Lawrence ◽  
M. L. Santee ◽  
N. J. Livesey ◽  
A. Lambert ◽  
...  
Keyword(s):  
Nitric Acid ◽  
Lower Stratosphere ◽  
Polar Vortex ◽  
The Arctic ◽  
Early Winter ◽  
Sudden Stratospheric Warming ◽  
Ozone Loss ◽  
Chlorine Monoxide ◽  
Polar Stratospheric Cloud ◽  
Vortex Split

Abstract. A sudden stratospheric warming (SSW) in early January 2013 caused the polar vortex to split. After the lower stratospheric vortex split on 8 January, the two offspring vortices – one over Canada and the other over Siberia – remained intact, well-confined, and largely at latitudes that received sunlight until they reunited at the end of January. As the SSW began, temperatures abruptly rose above chlorine activation thresholds throughout the lower stratosphere. The vortex was very disturbed prior to the SSW, and was exposed to much more sunlight than usual in December 2012 and January 2013. Aura Microwave Limb Sounder (MLS) nitric acid (HNO3) data and observations from CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) indicate extensive polar stratospheric cloud (PSC) activity, with evidence of PSCs containing solid nitric acid trihydrate particles during much of December 2012. Consistent with the sunlight exposure and PSC activity, MLS observations show that chlorine monoxide (ClO) became enhanced early in December. Despite the cessation of PSC activity with the onset of the SSW, enhanced vortex ClO persisted until mid-February, indicating lingering chlorine activation. The smaller Canadian offspring vortex had lower temperatures, lower HNO3, lower hydrogen chloride (HCl), and higher ClO in late January than the Siberian vortex. Chlorine deactivation began later in the Canadian than in the Siberian vortex. HNO3 remained depressed within the vortices after temperatures rose above the PSC existence threshold, and passive transport calculations indicate vortex-averaged denitrification of about 4 ppbv; the resulting low HNO3 values persisted until the vortex dissipated in mid-February. Consistent with the strong chlorine activation and exposure to sunlight, MLS measurements show rapid ozone loss commencing in mid-December and continuing through January. Lagrangian transport estimates suggest ~ 0.7–0.8 ppmv (parts per million by volume) vortex-averaged chemical ozone loss by late January near 500 K (~ 21 km), with substantial loss occurring from ~ 450 to 550 K. The surface area of PSCs in December 2012 was larger than that in any other December observed by CALIPSO. As a result of denitrification, HNO3 abundances in 2012/13 were among the lowest in the MLS record for the Arctic. ClO enhancement was much greater in December 2012 through mid-January 2013 than that at the corresponding time in any other Arctic winter observed by MLS. Furthermore, reformation of HCl appeared to play a greater role in chlorine deactivation than in more typical Arctic winters. Ozone loss in December 2012 and January 2013 was larger than any previously observed in those months. This pattern of exceptional early winter polar processing and ozone loss resulted from the unique combination of dynamical conditions associated with the early January 2013 SSW, namely unusually low temperatures in December 2012 and offspring vortices that remained well-confined and largely in sunlit regions for about a month after the vortex split.

scholarly journals Polar processing in a split vortex: Arctic ozone loss in early winter 2012/2013

2015 ◽  
Vol 15 (10) ◽  
pp. 5381-5403 ◽  
Author(s):  
G. L. Manney ◽  
Z. D. Lawrence ◽  
M. L. Santee ◽  
N. J. Livesey ◽  
A. Lambert ◽  
...  
Keyword(s):  
Polar Vortex ◽  
Sunlight Exposure ◽  
The Arctic ◽  
Stratospheric Polar Vortex ◽  
Ozone Loss ◽  
Chlorine Monoxide ◽  
Polar Stratospheric Cloud ◽  
Gas Measurements ◽  
Time Of Year ◽  
The One

Abstract. A sudden stratospheric warming (SSW) in early January 2013 caused the Arctic polar vortex to split and temperatures to rapidly rise above the threshold for chlorine activation. However, ozone in the lower stratospheric polar vortex from late December 2012 through early February 2013 reached the lowest values on record for that time of year. Analysis of Aura Microwave Limb Sounder (MLS) trace gas measurements and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) polar stratospheric cloud (PSC) data shows that exceptional chemical ozone loss early in the 2012/13 Arctic winter resulted from a unique combination of meteorological conditions associated with the early-January 2013 SSW: unusually low temperatures in December 2012, offspring vortices within which air remained well isolated for nearly 1 month after the vortex split, and greater-than-usual vortex sunlight exposure throughout December 2012 and January 2013. Conditions in the two offspring vortices differed substantially, with the one overlying Canada having lower temperatures, lower nitric acid (HNO3), lower hydrogen chloride, more sunlight exposure/higher ClO in late January, and a later onset of chlorine deactivation than the one overlying Siberia. MLS HNO3 and CALIPSO data indicate that PSC activity in December 2012 was more extensive and persistent than at that time in any other Arctic winter in the past decade. Chlorine monoxide (ClO, measured by MLS) rose earlier than previously observed and was the largest on record through mid-January 2013. Enhanced vortex ClO persisted until mid-February despite the cessation of PSC activity when the SSW started. Vortex HNO3 remained depressed after PSCs had disappeared; passive transport calculations indicate vortex-averaged denitrification of about 4 parts per billion by volume. The estimated vortex-averaged chemical ozone loss, ~ 0.7–0.8 parts per million by volume near 500 K (~21 km), was the largest December/January loss in the MLS record from 2004/05 to 2014/15.

scholarly journals Nitric acid trihydrate (NAT) formation at low NAT supersaturations

2004 ◽  
Vol 4 (6) ◽  
pp. 8579-8607 ◽  
Author(s):  
C. Voigt ◽  
H. Schlager ◽  
B. P. Luo ◽  
A. Dörnbrack ◽  
A. Roiger ◽  
...  
Keyword(s):  
Nitric Acid ◽  
High Altitude ◽  
Equilibrium Temperature ◽  
In Situ Measurements ◽  
The Arctic ◽  
Ozone Loss ◽  
Polar Stratospheric Cloud ◽  
Research Aircraft ◽  
Polar Ozone

Abstract. A polar stratospheric cloud (PSC) was observed on 6 February 2003 in the Arctic stratosphere by in-situ measurements onboard the high-altitude research aircraft Geophysica. Low number densities (~10−4 cm−3) of nitric acid (HNO3) containing particles – probably NAT – with diameters up to 6 µm were measured at altitudes between 18 and 20 km. These particles have the potential to grow further and to remove HNO3 from the stratosphere, thereby enhancing polar ozone loss. Interestingly, the NAT particles formed in less than a day at temperatures T>TNAT−3.5 K, just slightly below the NAT equilibrium temperature TNAT. This unique measurement of PSC formation at extremely low NAT saturation ratios (SNAT≤11) constrains current NAT nucleation theories. In particular, NAT formation on ice can for certain be excluded. Conversely, we suggest that meteoritic particles may be favorable candidates for triggering nucleation of NAT at the observed low number densities.

scholarly journals Modelling the effect of denitrification on polar ozone depletion for Arctic winter 2004/2005

2011 ◽  
Vol 11 (13) ◽  
pp. 6559-6573 ◽  
Author(s):  
W. Feng ◽  
M. P. Chipperfield ◽  
S. Davies ◽  
G. W. Mann ◽  
K. S. Carslaw ◽  
...  
Keyword(s):  
Transport Model ◽  
Three Dimensional ◽  
The Arctic ◽  
Chemical Transport Model ◽  
Particle Sedimentation ◽  
Ozone Loss ◽  
Highly Sensitive ◽  
Polar Stratospheric Cloud ◽  
Column Ozone ◽  
Polar Ozone

Abstract. A three-dimensional (3-D) chemical transport model (CTM), SLIMCAT, has been used to quantify the effect of denitrification on ozone loss for the Arctic winter 2004/2005. The simulated HNO3 is found to be highly sensitive to the polar stratospheric cloud (PSC) scheme used in the model. Here the standard SLIMCAT full chemistry model, which uses a thermodynamic equilibrium PSC scheme, overpredicts the ozone loss for Arctic winter 2004/2005 due to the overestimation of denitrification and stronger chlorine activation than observed. A model run with a coupled detailed microphysical denitrification scheme, DLAPSE (Denitrification by Lagrangian Particle Sedimentation), is less denitrified than the standard model run and better reproduces the observed HNO3 as measured by Airborne SUbmillimeter Radiometer (ASUR) and Aura Microwave Limb Sounder (MLS) instruments. Overall, denitrification is responsible for a ~30 % enhancement in O3 depletion compared with simulations without denitrification for Arctic winter 2004/2005, which is slightly larger than the inferred impact of denitrification on Arctic ozone loss for previous winters from different CTMs simulations. The overestimated denitrification from standard SLIMCAT simulation causes ~5–10 % more ozone loss at ~17 km compared with the simulation using the DLAPSE PSC scheme for Arctic winter 2004/2005. The calculated partial column ozone loss from SLIMCAT using the DLAPSE scheme is about 130 DU by mid-March 2005, which compares well with the inferred column ozone loss from ozonesondes and satellite data (127±21 DU).

scholarly journals Arctic on the verge of an ozone hole?

2021 ◽  
Author(s):  
Jayanarayanan Kuttippurath ◽  
Wuhu Feng ◽  
Rolf Müller ◽  
Pankaj Kumar ◽  
Sarath Raj ◽  
...  
Keyword(s):  
Ultra Violet ◽  
Ozone Hole ◽  
The Arctic ◽  
Extreme Weather Events ◽  
Ozone Loss ◽  
Ultra Violet Radiation ◽  
Weather Events ◽  
Antarctic Ozone ◽  
Near Future ◽  
First Time

Abstract. Severe vortex-wide ozone loss in the Arctic would expose nearly 650 million people and ecosystem to unhealthy ultra-violet radiation levels. Adding to these worries, and extreme weather events as the harbingers of climate change, clear signature of an ozone hole (ozone column values below 220 DU) appeared over the Arctic in March and April 2020. Sporadic occurrences of ozone hole values at different regions of vortex for almost three weeks were found for the first time in the observed history in the Arctic. Furthermore, a record-breaking ozone loss of about 2.0–3.4 ppmv triggered by an unprecedented chlorine activation (1.5–2.2 ppbv) matching to the levels of Antarctic ozone hole conditions was also observed. The polar processing situation led to the first-ever appearance of loss saturation in the Arctic. Apart from these, there were also ozone-mini holes in December 2019 and January 2020 driven by atmospheric dynamics. The large loss in ozone in the colder Arctic winters is intriguing and that demands rigorous monitoring of the region. Our study suggests that the very colder Arctic winters in near future would also very likely to experience even more ozone loss and encounter ozone hole situations, provided the stratospheric chlorine levels still stay high there.

scholarly journals Ozone loss and chlorine activation in the Arctic winters 1991–2003 derived with the TRAC method

2004 ◽  
Vol 4 (3) ◽  
pp. 2167-2238
Author(s):  
S. Tilmes ◽  
R. Müller ◽  
J.-U. Grooß ◽  
J. M. Russell
Keyword(s):  
Linear Relation ◽  
Polar Vortex ◽  
Meteorological Conditions ◽  
The Arctic ◽  
Threshold Temperature ◽  
Ozone Loss ◽  
Horizontal Mixing ◽  
Column Ozone ◽  
The Relationship ◽  
Potential Area

Abstract. In this paper chemical ozone loss in the Arctic stratosphere was investigated for twelve years between 1991 and 2003. The accumulated local ozone loss and the column ozone loss were consistently derived mainly on the basis of HALOE observations. The ozone-tracer correlation (TRAC) method is used, where the relation between ozone and a long-lived tracer is considered over the lifetime of the polar vortex. A detailed quantification of uncertainties was performed. This study demonstrates the interaction between meteorology and ozone loss. The correlation between temperature conditions and chlorine activation becomes obvious in the HALOE HCl measurements, as well as the dependence between chlorine activation and ozone loss. Additionally, the degree of homogeneity of ozone loss is shown to depend on the meteorological conditions, as there is a possible influence of horizontal mixing of the air inside a weak polar vortex edge. Results estimated here are in agreement with the results obtained from other methods. However, there is no sign of very strong ozone losses as deduced from SAOZ for January considering HALOE measurements. In general, strong accumulated ozone loss is found to occur in conjunction with a strong cold vortex containing a large potential area of PSCs, whereas moderate ozone loss is found if the vortex is less strong and moderately warm. Hardly any ozone loss was calculated for very warm winters with small amounts of the area of possible PSC existence (APSC) during the entire winter. Nevertheless, the analysis of the relationship between APSC (derived using the PSC threshold temperature) and the accumulated ozone loss indicates that this relationship is not a strictly linear relation. An influence of other factors could be identified. A significant increase of ozone loss (of ≈40 DU) was found due to the different duration of illumination of the polar vortex in different years. Further, the increased burden of aerosols in the atmosphere after the Pinatubo volcanic eruption in 1991 and the location of the cold parts of the vortex in different years may impact the extent of chemical ozone loss.

scholarly journals Chemical ozone loss and ozone mini-hole event during the Arctic winter 2010/2011 as observed by SCIAMACHY and GOME-2

2014 ◽  
Vol 14 (7) ◽  
pp. 3247-3276 ◽  
Author(s):  
R. Hommel ◽  
K.-U. Eichmann ◽  
J. Aschmann ◽  
K. Bramstedt ◽  
M. Weber ◽  
...  
Keyword(s):  
Transport Model ◽  
Polar Vortex ◽  
The Arctic ◽  
Optical Absorption Spectroscopy ◽  
Late Winter ◽  
Total Column Ozone ◽  
Bromine Oxide ◽  
Ozone Loss ◽  
Catalytic Cycles ◽  
Total Column

Abstract. Record breaking loss of ozone (O3) in the Arctic stratosphere has been reported in winter–spring 2010/2011. We examine in detail the composition and transformations occurring in the Arctic polar vortex using total column and vertical profile data products for O3, bromine oxide (BrO), nitrogen dioxide (NO2), chlorine dioxide (OClO), and polar stratospheric clouds (PSC) retrieved from measurements made by SCIAMACHY (Scanning Imaging Absorption SpectroMeter for Atmospheric CHartography) on-board Envisat (Environmental Satellite), as well as total column ozone amount, retrieved from the measurements of GOME-2 (Global Ozone Monitoring Experiment) on MetOp-A (Meteorological Experimental Satellite). Similarly we use the retrieved data from DOAS (Differential Optical Absorption Spectroscopy) measurements made in Ny-Ålesund (78.55° N, 11.55° E). A chemical transport model (CTM) has been used to relate and compare Arctic winter–spring conditions in 2011 with those in the previous year. In late winter–spring 2010/2011 the chemical ozone loss in the polar vortex derived from SCIAMACHY observations confirms findings reported elsewhere. More than 70% of O3 was depleted by halogen catalytic cycles between the 425 and 525 K isentropic surfaces, i.e. in the altitude range ~16–20 km. In contrast, during the same period in the previous winter 2009/2010, a typical warm Arctic winter, only slightly more than 20% depletion occurred below 20 km, while 40% of O3 was removed above the 575 K isentrope (~23 km). This loss above 575 K is explained by the catalytic destruction by NOx descending from the mesosphere. In both Arctic winters 2009/2010 and 2010/2011, calculated O3 losses from the CTM are in good agreement to our observations and other model studies. The mid-winter 2011 conditions, prior to the catalytic cycles being fully effective, are also investigated. Surprisingly, a significant loss of O3 around 60%, previously not discussed in detail, is observed in mid-January 2011 below 500 K (~19 km) and sustained for approximately 1 week. The low O3 region had an exceptionally large spatial extent. The situation was caused by two independently evolving tropopause elevations over the Asian continent. Induced adiabatic cooling of the stratosphere favoured the formation of PSC, increased the amount of active chlorine for a short time, and potentially contributed to higher polar ozone loss later in spring.

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