scholarly journals Investigation of polar stratospheric clouds in January 2008 by means of ground-based and spaceborne lidar measurements and microphysical box model simulations

2011 ◽  
Vol 116 (D7) ◽  
Author(s):  
P. Achtert ◽  
F. Khosrawi ◽  
U. Blum ◽  
K. H. Fricke
Keyword(s):  
Box Model ◽  
Polar Stratospheric Clouds ◽  
Model Simulations ◽  
Lidar Measurements ◽  
Stratospheric Clouds

scholarly journals Simultaneous lidar observations of a polar stratospheric cloud on the east and west sides of the Scandinavian mountains and microphysical box model simulations

2006 ◽  
Vol 24 (12) ◽  
pp. 3267-3277 ◽  
Author(s):  
U. Blum ◽  
F. Khosrawi ◽  
G. Baumgarten ◽  
K. Stebel ◽  
R. Müller ◽  
...  
Keyword(s):  
Wave Field ◽  
Weight Percent ◽  
Box Model ◽  
Narrow Particle Size Distribution ◽  
Polar Stratospheric Clouds ◽  
Distribution Width ◽  
Model Simulations ◽  
East And West ◽  
Stratospheric Clouds ◽  
Lidar Observations

Abstract. The importance of polar stratospheric clouds (PSC) for polar ozone depletion is well established. Lidar experiments are well suited to observe and classify polar stratospheric clouds. On 5 January 2005 a PSC was observed simultaneously on the east and west sides of the Scandinavian mountains by ground-based lidars. This cloud was composed of liquid particles with a mixture of solid particles in the upper part of the cloud. Multi-colour measurements revealed that the liquid particles had a mode radius of r≈300 nm, a distribution width of σ≈1.04 and an altitude dependent number density of N≈2–20 cm−3. Simulations with a microphysical box model show that the cloud had formed about 20 h before observation. High HNO3 concentrations in the PSC of 40–50 weight percent were simulated in the altitude regions where the liquid particles were observed, while this concentration was reduced to about 10 weight percent in that part of the cloud where a mixture between solid and liquid particles was observed by the lidar. The model simulations also revealed a very narrow particle size distribution with values similar to the lidar observations. Below and above the cloud almost no HNO3 uptake was simulated. Although the PSC shows distinct wave signatures, no gravity wave activity was observed in the temperature profiles measured by the lidars and meteorological analyses support this observation. The observed cloud must have formed in a wave field above Iceland about 20 h prior to the measurements and the cloud wave pattern was advected by the background wind to Scandinavia. In this wave field above Iceland temperatures potentially dropped below the ice formation temperature, so that ice clouds may have formed which can act as condensation nuclei for the nitric acid trihydrate (NAT) particles observed at the cloud top above Esrange.

10 years of Polar Stratospheric Clouds lidar measurements at the French antarctic station Dumont d’Urville

2020 ◽  
Author(s):  
Florent Tencé ◽  
Julien Jumelet ◽  
Alain Sarkissian ◽  
Slimane Bekki ◽  
Philippe Keckhut
Keyword(s):  
Stratospheric Ozone ◽  
Atmospheric Composition ◽  
Polar Regions ◽  
Primary Role ◽  
Atmospheric Conditions ◽  
Polar Stratospheric Clouds ◽  
Ice Clouds ◽  
Yearly Average ◽  
Lidar Measurements ◽  
Stratospheric Clouds

<p><span>Polar Stratospheric Clouds (PSCs) play a primary role in polar stratospheric ozone depletion processes. </span><span>Aside from recent improvements in both spaceborne PSCs monitoring as well as investigations on PSCs microphysics and modeling, there are still uncertainties associated to solid particle formation and their denitrification potential. In that regard, groundbased instruments deliver detailed and valuable measurements that complement the global spaceborne coverage.</span></p><p>Operated since 1989 at the French antarctic station Dumont d’Urville (DDU) in the frame of the international Network for the Detection of Atmospheric Composition Change (NDACC), the Rayleigh/Mie/Raman lidar provides over the years a solid dataset to feed both process and classification studies, by monitoring cloud and aerosol occurrences in the upper troposphere and lower stratosphere. Located on antarctic shore (66°S - 140°E), the station has a privileged access to polar vortex dynamics. Measurements are weather-dependent with a yearly average of 130 nights of monitoring. Expected PSC formation temperatures are used to evaluate the whole PSC season occurrences.</p><p>We hereby present a consolidated dataset from 10 years of lidar measurements using the 532nm backscatter ratio, the aerosol depolarisation and local atmospheric conditions to help in building an aerosol/cloud classification. Using the different PSC classes and associated optical properties thresholds established in the recent PSC CALIOP classification, we build a picture of the 2007-2019 events, from march to october.</p><p>Overall, the DDU PSC pattern is very consistent with expected typical temperature controlled microphysical calculations. Outside of background sulfate aerosols and anomalies related to volcanic activity (like in 2015), Supercooled Ternary Solution (STS) particles are the most observed particle type, closely followed by Nitric Acid Trihydrate (NAT). ICE clouds are less but regularly observed. ICE clouds also have to be cleary separated from cirrus clouds, raising the issue of accurate dynamics tropopause calculations.</p><p><span>Validation of the spaceborne measurements as well as multiple signatures of volcanic or even biomass originated aerosol plumes strengthens the need for groundbased monitoring </span><span>especially in polar regions where instrumental facilities remain sparse.</span></p>

scholarly journals A climatological study of polar stratospheric clouds (1989–1997) from LIDAR measurements over Dumont d’Urville (Antarctica)

Tellus B ◽  
2001 ◽  
Vol 53 (3) ◽  
pp. 306-321
Author(s):  
Vincenzo Santacesaria ◽  
A. Robert Mackenzie ◽  
Leopoldo Stefanutti
Keyword(s):  
Polar Stratospheric Clouds ◽  
Lidar Measurements ◽  
Stratospheric Clouds

10 years of Polar Stratospheric Clouds lidar measurements at the French antarctic station Dumont d’Urville

2021 ◽  
Author(s):  
Julien Jumelet ◽  
Florent Tencé ◽  
Alain Sarkissian ◽  
Slimane Bekki ◽  
Philippe Keckhut
Keyword(s):  
Stratospheric Ozone ◽  
Polar Vortex ◽  
Atmospheric Composition ◽  
Primary Role ◽  
Atmospheric Conditions ◽  
Polar Stratospheric Clouds ◽  
Yearly Average ◽  
Lidar Measurements ◽  
Spaceborne Monitoring ◽  
Stratospheric Clouds

<p>Polar Stratospheric Clouds (PSCs) play a primary role in polar stratospheric ozone depletion processes. Aside from recent improvements in both spaceborne monitoring as well as investigations on microphysics and modeling, there are still caveats on building a comprehensive picture of the PSC particle population, especially considering the fine optical signatures of some particles. In that regard, groundbased instruments provide fine and long term reference measurements that complement the global spaceborne coverage.</p><p>Operated at the French antarctic station Dumont d’Urville (DDU) in the frame of the international Network for the Detection of Atmospheric Composition Change (NDACC), the Rayleigh/Mie/Raman lidar provides over the years a solid dataset to feed both process and classification studies, by monitoring cloud and aerosol occurrences in the upper troposphere and lower stratosphere. Located on antarctic shore (66°S - 140°E), the station has a privileged access to polar vortex dynamics. Measurements are weather-dependent with a yearly average of 130 nights of monitoring. Expected PSC formation temperatures are used to evaluate the whole PSC season occurrence statistics.</p><p>We hereby present a consolidated dataset from 10 years of lidar measurements using the 532nm backscatter ratio, the aerosol depolarisation and local atmospheric conditions to help in building an aerosol/cloud classification. Overall, the DDU PSC pattern is very consistent with expected typical temperature controlled thresholds. Supercooled Ternary Solution (STS) particles are the most observed particle type, closely followed by Nitric Acid Trihydrate (NAT). ICE clouds are more rarely observed. The measurements also feature significant and detailed signatures of various aerosols events having reached the polar antarctic stratosphere, like the Calbuco eruption (2015) or the 2 australian wildfires episodes (2009 and 2019). We aim at refining the identification of those aerosols to include their impact in the scope of the scientific questions studied at DDU.</p>

scholarly journals On the linkage between tropospheric and Polar Stratospheric clouds in the Arctic as observed by space–borne lidar

2012 ◽  
Vol 12 (8) ◽  
pp. 3791-3798 ◽  
Author(s):  
P. Achtert ◽  
M. Karlsson Andersson ◽  
F. Khosrawi ◽  
J. Gumbel
Keyword(s):  
Lower Stratosphere ◽  
Satellite Observation ◽  
Heterogeneous Reactions ◽  
The Arctic ◽  
Polar Stratospheric Clouds ◽  
Cloud Systems ◽  
Lidar Measurements ◽  
Polar Stratosphere ◽  
Temporal And Spatial ◽  
Stratospheric Clouds

Abstract. The type of Polar stratospheric clouds (PSCs) as well as their temporal and spatial extent are important for the occurrence of heterogeneous reactions in the polar stratosphere. The formation of PSCs depends strongly on temperature. However, the mechanisms of the formation of solid PSCs are still poorly understood. Recent satellite studies of Antarctic PSCs have shown that their formation can be associated with deep-tropospheric clouds which have the ability to cool the lower stratosphere radiatively and/or adiabatically. In the present study, lidar measurements aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite were used to investigate whether the formation of Arctic PSCs can be associated with deep-tropospheric clouds as well. Deep-tropospheric cloud systems have a vertical extent of more than 6.5 km with a cloud top height above 7 km altitude. PSCs observed by CALIPSO during the Arctic winter 2007/2008 were classified according to their type (STS, NAT, or ice) and to the kind of underlying tropospheric clouds. Our analysis reveals that 172 out of 211 observed PSCs occurred in connection with tropospheric clouds. 72% of these 172 observed PSCs occurred above deep-tropospheric clouds. We also find that the type of PSC seems to be connected to the characteristics of the underlying tropospheric cloud system. During the Arctic winter 2007/2008 PSCs consisting of ice were mainly observed in connection with deep-tropospheric cloud systems while no ice PSC was detected above cirrus. Furthermore, we find no correlation between the occurrence of PSCs and the top temperature of tropospheric clouds. Thus, our findings suggest that Arctic PSC formation is connected to adiabatice cooling, i.e. dynamic effects rather than radiative cooling.

Sign in / Sign up

Export Citation Format

Share Document