scholarly journals Polar Stratospheric Cloud evolution and chlorine activation measured by CALIPSO and MLS, and modelled by ATLAS

2015 ◽  
Vol 15 (16) ◽  
pp. 22141-22182
Author(s):  
H. Nakajima ◽  
I. Wohltmann ◽  
T. Wegner ◽  
M. Takeda ◽  
M. C. Pitts ◽  
...  
Keyword(s):  
The Arctic ◽  
Temperature History ◽  
Threshold Temperature ◽  
Limiting Factor ◽  
Temperature Decrease ◽  
Air Mass ◽  
Frost Point ◽  
Rapid Temperature ◽  
Cloud Evolution ◽  
Stratospheric Clouds

Abstract. We examined observations of polar stratospheric clouds (PSCs) by CALIPSO and of HCl, ClO and HNO3 by MLS along air mass trajectories to investigate the dependence of the inferred PSC composition on the temperature history of the air parcels, and the dependence of the level of chlorine activation on PSC composition. Several case studies based on individual trajectories from the Arctic winter 2009/10 were conducted, with the trajectories chosen such that the first processing of the air mass by PSCs in this winter occurred on the trajectory. Transitions of PSC composition classes were observed to be highly dependent on the temperature history. In cases of a gradual temperature decrease, nitric acid trihydrate (NAT) and super-cooled ternary solution (STS) mixture clouds were observed. In cases of rapid temperature decrease, STS clouds were first observed, followed by NAT/STS mixture clouds. When temperatures dropped below the frost point, ice clouds formed, and then transformed into NAT/STS mixture clouds when temperature increased above the frost point. The threshold temperature for rapid chlorine activation on PSCs is approximately 4 K below the NAT existence temperature, TNAT. Furthermore, simulations of the ATLAS chemistry and transport box model along the trajectories were used to corroborate the measurements and show good agreement with the observations. Rapid chlorine activation was observed when an airmass encountered PSCs. The observed and modelled dependence of the rate of chlorine activation on the PSC composition class was small. Usually, chlorine activation was limited by the amount of available ClONO2. Where ClONO2 was not the limiting factor, a large dependence on temperature was evident.

scholarly journals Polar stratospheric cloud evolution and chlorine activation measured by CALIPSO and MLS, and modeled by ATLAS

2016 ◽  
Vol 16 (5) ◽  
pp. 3311-3325 ◽  
Author(s):  
Hideaki Nakajima ◽  
Ingo Wohltmann ◽  
Tobias Wegner ◽  
Masanori Takeda ◽  
Michael C. Pitts ◽  
...  
Keyword(s):  
The Arctic ◽  
Temperature History ◽  
Threshold Temperature ◽  
Limiting Factor ◽  
Temperature Decrease ◽  
Air Mass ◽  
Frost Point ◽  
Rapid Temperature ◽  
Cloud Evolution ◽  
Stratospheric Clouds

Abstract. We examined observations of polar stratospheric clouds (PSCs) by CALIPSO, and of HCl and ClO by MLS along air mass trajectories, to investigate the dependence of the inferred PSC composition on the temperature history of the air parcels and the dependence of the level of chlorine activation on PSC composition. Several case studies based on individual trajectories from the Arctic winter 2009/2010 were conducted, with the trajectories chosen such that the first processing of the air mass by PSCs in this winter occurred on the trajectory. Transitions of PSC composition classes were observed to be highly dependent on the temperature history. In cases of a gradual temperature decrease, nitric acid trihydrate (NAT) and super-cooled ternary solution (STS) mixture clouds were observed. In cases of rapid temperature decrease, STS clouds were first observed, followed by NAT/STS mixture clouds. When temperatures dropped below the frost point, ice clouds formed and then transformed into NAT/STS mixture clouds when temperature increased above the frost point. The threshold temperature for rapid chlorine activation on PSCs is approximately 4 K below the NAT existence temperature, TNAT. Furthermore, simulations of the ATLAS chemistry and transport box model along the trajectories were used to corroborate the measurements and show good agreement with the observations. Rapid chlorine activation was observed when an air mass encountered PSCs. Usually, chlorine activation was limited by the amount of available ClONO2. Where ClONO2 was not the limiting factor, a large dependence on temperature was evident.

scholarly journals Composition analysis of liquid particles in the Arctic stratosphere under synoptic conditions

2006 ◽  
Vol 6 (3) ◽  
pp. 689-696 ◽  
Author(s):  
C. Weisser ◽  
K. Mauersberger ◽  
J. Schreiner ◽  
N. Larsen ◽  
F. Cairo ◽  
...  
Keyword(s):  
Equilibrium Temperature ◽  
Solid Particles ◽  
The Arctic ◽  
Composition Analysis ◽  
Molar Ratios ◽  
Frost Point ◽  
Synoptic Conditions ◽  
Lee Waves ◽  
Stratospheric Clouds ◽  
First Time

Abstract. Synoptic scale polar stratospheric clouds (PSCs) that formed without the presence of mountain lee waves were observed in early December 2002 from Kiruna/Sweden using balloon-borne instruments. The physical, chemical, and optical properties of the particles were measured. Within the PSC solid particles existed whenever the temperature was below the equilibrium temperature for nitric acid trihydrate and liquid particles appeared when the temperature fell below an even lower threshold about 3 K above the frost point with solid particles still present. The correlation of liquid supercooled ternary solution aerosols with local temperatures is a pronounced feature observed during this flight; average molar ratios H2O/HNO3 were somewhat higher than predicted by models. In addition HCl has been measured for the first time in liquid aerosols. The chlorine isotope signature served as a unique tool to identify unambiguously HCl dissolved in STS particles. Within a narrow temperature range of about three degrees above the frost point, the measured average amount of HCl in liquid particles is below 1 weight%.

scholarly journals Composition analysis of liquid particles in the Arctic stratosphere

2004 ◽  
Vol 4 (3) ◽  
pp. 2513-2531
Author(s):  
C. Weisser ◽  
K. Mauersberger ◽  
J. Schreiner ◽  
N. Larsen ◽  
F. Cairo ◽  
...  
Keyword(s):  
Equilibrium Temperature ◽  
Solid Particles ◽  
The Arctic ◽  
Composition Analysis ◽  
Synoptic Scale ◽  
Molar Ratios ◽  
Frost Point ◽  
Model Predictions ◽  
Stratospheric Clouds ◽  
First Time

Abstract. Synoptic scale polar stratospheric clouds (PSCs) that formed without the presence of mountain leewaves were observed in early December 2002 from Kiruna/Sweden using balloon-borne instruments. The physical, chemical, and optical properties of the particles were measured. Within the PSC solid particles existed whenever the temperature was below the equilibrium temperature for nitric acid trihydrate and liquid particles appeared when the temperature fell below an even lower threshold about 3 K above the frost point. The correlation of liquid supercooled ternary solution aerosols with local temperatures is a pronounced feature observed during this flight although the molar ratios H2O/HNO3 were about a factor of 2 higher than model predictions. In addition HCl has been measured for the first time in liquid aerosols. The chlorine isotope signature served as a unique tool to identify unambiguously HCl dissolved in STS particles. Within a narrow temperature range of about three degrees above the frost point, measured HCl molar ratios are below 1 weight%. There is only fair agreement with model predictions.

scholarly journals Stratospheric water vapour as tracer for Vortex filamentation in the Arctic winter 2002/2003

2003 ◽  
Vol 3 (6) ◽  
pp. 1991-1997 ◽  
Author(s):  
M. Müller ◽  
R. Neuber ◽  
F. Fierli ◽  
A. Hauchecorne ◽  
H. Vömel ◽  
...  
Keyword(s):  
Water Vapour ◽  
Large Scale ◽  
Polar Vortex ◽  
The Arctic ◽  
Edge Region ◽  
Particle Sedimentation ◽  
Frost Point ◽  
Lagrangian Advection ◽  
Stratospheric Clouds ◽  
Stratospheric Water Vapour

Abstract. Balloon-borne frost point hygrometers measured three high-resolution profiles of stratospheric water vapour above Ny-Ålesund, Spitsbergen during winter 2002/2003. The profiles obtained on 12 December 2002 and on 17 January 2003 provide an insight into the vertical distribution of water vapour in the core of the polar vortex. The water vapour sounding on 11 February 2003 was obtained within the vortex edge region of the lower stratosphere. Here, a significant reduction of water vapour mixing ratio was observed between 16 and 19 km. The stratospheric temperatures indicate that this dehydration was not caused by the presence of polar stratospheric clouds or earlier PSC particle sedimentation. Ozone observations on this day indicate a large scale movement of the polar vortex and show laminae in the same altitude range as the water vapour profile. The link between the observed water vapour reduction and filaments in the vortex edge region is indicated in the results of the semi-lagrangian advection model MIMOSA, which show that adjacent filaments of polar and mid latitude air can be identified above the Spitsbergen region. A vertical cross-section produced by the MIMOSA model reveals that the water vapour sonde flew through polar air in the lowest part of the stratosphere below 425 K, then passed through filaments of mid latitude air with lower water vapour concentrations, before it finally entered the polar vortex above 450 K. These results indicate that on 11 February 2003 the frost point hygrometer measured different water vapour concentrations as the sonde detected air with different origins. Instead of being linked to dehydration due to PSC particle sedimentation, the local reduction in the stratospheric water vapour profile was in this case caused by dynamical processes in the polar stratosphere.

scholarly journals Sudden Collapse of Vacuoles in Saintpaulia sp. Palisade Cells Induced by a Rapid Temperature Decrease

PLoS ONE ◽  
2013 ◽  
Vol 8 (2) ◽  
pp. e57259 ◽  
Author(s):  
Noriaki Kadohama ◽  
Tatsuaki Goh ◽  
Miwa Ohnishi ◽  
Hidehiro Fukaki ◽  
Tetsuro Mimura ◽  
...  
Keyword(s):  
Temperature Decrease ◽  
Rapid Temperature ◽  
Palisade Cells ◽  
Sudden Collapse

scholarly journals Accuracy and precision of polar lower stratospheric temperatures from reanalyses evaluated from A-Train CALIOP and MLS, COSMIC GPS RO, and the equilibrium thermodynamics of supercooled ternary solutions and ice clouds

2018 ◽  
Vol 18 (3) ◽  
pp. 1945-1975 ◽  
Author(s):  
Alyn Lambert ◽  
Michelle L. Santee
Keyword(s):  
Pressure Range ◽  
Equilibrium Thermodynamics ◽  
Polar Stratospheric Clouds ◽  
Ice Clouds ◽  
Warm Bias ◽  
Frost Point ◽  
Ternary Solutions ◽  
Accuracy And Precision ◽  
Temperature Reference ◽  
Stratospheric Clouds

Abstract. We investigate the accuracy and precision of polar lower stratospheric temperatures (100–10 hPa during 2008–2013) reported in several contemporary reanalysis datasets comprising two versions of the Modern-Era Retrospective analysis for Research and Applications (MERRA and MERRA-2), the Japanese 55-year Reanalysis (JRA-55), the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-I), and the National Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) Climate Forecast System Reanalysis (NCEP-CFSR). We also include the Goddard Earth Observing System model version 5.9.1 near-real-time analysis (GEOS-5.9.1). Comparisons of these datasets are made with respect to retrieved temperatures from the Aura Microwave Limb Sounder (MLS), Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) Global Positioning System (GPS) radio occultation (RO) temperatures, and independent absolute temperature references defined by the equilibrium thermodynamics of supercooled ternary solutions (STSs) and ice clouds. Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) observations of polar stratospheric clouds are used to determine the cloud particle types within the Aura MLS geometric field of view. The thermodynamic calculations for STS and the ice frost point use the colocated MLS gas-phase measurements of HNO3 and H2O. The estimated bias and precision for the STS temperature reference, over the 68 to 21 hPa pressure range, are 0.6–1.5 and 0.3–0.6 K, respectively; for the ice temperature reference, they are 0.4 and 0.3 K, respectively. These uncertainties are smaller than those estimated for the retrieved MLS temperatures and also comparable to GPS RO uncertainties (bias  <  0.2 K, precision  >  0.7 K) in the same pressure range. We examine a case study of the time-varying temperature structure associated with layered ice clouds formed by orographic gravity waves forced by flow over the Palmer Peninsula and compare how the wave amplitudes are reproduced by each reanalysis dataset. We find that the spatial and temporal distribution of temperatures below the ice frost point, and hence the potential to form ice polar stratospheric clouds (PSCs) in model studies driven by the reanalyses, varies significantly because of the underlying differences in the representation of mountain wave activity. High-accuracy COSMIC temperatures are used as a common reference to intercompare the reanalysis temperatures. Over the 68–21 hPa pressure range, the biases of the reanalyses with respect to COSMIC temperatures for both polar regions fall within the narrow range of −0.6 K to +0.5 K. GEOS-5.9.1, MERRA, MERRA-2, and JRA-55 have predominantly cold biases, whereas ERA-I has a predominantly warm bias. NCEP-CFSR has a warm bias in the Arctic but becomes substantially colder in the Antarctic. Reanalysis temperatures are also compared with the PSC reference temperatures. Over the 68–21 hPa pressure range, the reanalysis temperature biases are in the range −1.6 to −0.3 K with standard deviations  ∼  0.6 K for the CALIOP STS reference, and in the range −0.9 to +0.1 K with standard deviations  ∼  0.7 K for the CALIOP ice reference. Comparisons of MLS temperatures with the PSC reference temperatures reveal vertical oscillations in the MLS temperatures and a significant low bias in MLS temperatures of up to 3 K.

Record springtime stratospheric ozone depletion at 80°N in 2020

2021 ◽  
Author(s):  
Ramina Alwarda ◽  
Kristof Bognar ◽  
Kimberly Strong ◽  
Martyn Chipperfield ◽  
Sandip Dhomse ◽  
...  
Keyword(s):  
Ozone Depletion ◽  
Transport Model ◽  
Stratospheric Ozone ◽  
Polar Vortex ◽  
The Arctic ◽  
Optical Absorption Spectroscopy ◽  
Chemical Transport Model ◽  
Polar Stratospheric Clouds ◽  
Ozone Loss ◽  
Stratospheric Clouds

&lt;p&gt;The Arctic winter of 2019-2020 was characterized by an unusually persistent polar vortex and temperatures in the lower stratosphere that were consistently below the threshold for the formation of polar stratospheric clouds (PSCs). These conditions led to ozone loss that is comparable to the Antarctic ozone hole. Ground-based measurements from a suite of instruments at the Polar Environment Atmospheric Research Laboratory (PEARL) in Eureka, Canada (80.05&amp;#176;N, 86.42&amp;#176;W) were used to investigate chemical ozone depletion. The vortex was located above Eureka longer than in any previous year in the 20-year dataset and lidar measurements provided evidence of polar stratospheric clouds (PSCs) above Eureka. Additionally, UV-visible zenith-sky Differential Optical Absorption Spectroscopy (DOAS) measurements showed record ozone loss in the 20-year dataset, evidence of denitrification along with the slowest increase of NO&lt;sub&gt;2&lt;/sub&gt; during spring, as well as enhanced reactive halogen species (OClO and BrO). Complementary measurements of HCl and ClONO&lt;sub&gt;2&lt;/sub&gt; (chlorine reservoir species) from a Fourier transform infrared (FTIR) spectrometer showed unusually low columns that were comparable to 2011, the previous year with significant chemical ozone depletion. Record low values of HNO&lt;sub&gt;3&lt;/sub&gt; in the FTIR dataset are in accordance with the evidence of PSCs and a denitrified atmosphere. Estimates of chemical ozone loss were derived using passive ozone from the SLIMCAT offline chemical transport model to account for dynamical contributions to the stratospheric ozone budget.&lt;/p&gt;

scholarly journals Effects of polar stratospheric clouds in the Nimbus 7 LIMS Version 6 data set

2016 ◽  
Vol 9 (7) ◽  
pp. 2927-2946 ◽  
Author(s):  
Ellis Remsberg ◽  
V. Lynn Harvey
Keyword(s):  
Stratospheric Aerosol ◽  
Transport Processes ◽  
The Arctic ◽  
Additional Parameter ◽  
Polar Stratospheric Clouds ◽  
Data Set ◽  
Screening Criteria ◽  
Temperature Thresholds ◽  
Level 3 ◽  
Stratospheric Clouds

Abstract. The historic Limb Infrared Monitor of the Stratosphere (LIMS) measurements of 1978–1979 from the Nimbus 7 satellite were re-processed with Version 6 (V6) algorithms and archived in 2002. The V6 data set employs updated radiance registration methods, improved spectroscopic line parameters, and a common vertical resolution for all retrieved parameters. Retrieved profiles are spaced about every 1.6° of latitude along orbits and include the additional parameter of geopotential height. Profiles of O3 are sensitive to perturbations from emissions of polar stratospheric clouds (PSCs). This work presents results of implementing a first-order screening for effects of PSCs using simple algorithms based on vertical gradients of the O3 mixing ratio. Their occurrences are compared with the co-located, retrieved temperatures and related to the temperature thresholds needed for saturation of H2O and/or HNO3 vapor onto PSC particles. Observed daily locations where the major PSC screening criteria are satisfied are validated against PSCs observed with the Stratospheric Aerosol Monitor (SAM) II experiment also on Nimbus 7. Remnants of emissions from PSCs are characterized for O3 and HNO3 following the screening. PSCs may also impart a warm bias in the co-located LIMS temperatures, but by no more than 1–2 K at the altitudes of where effects of PSCs are a maximum in the ozone; thus, no PSC screening was applied to the V6 temperatures. Minimum temperatures vary between 187 and 194 K and often occur 1 to 2 km above where PSC effects are first identified in the ozone (most often between about 21 and 28 hPa). Those temperature–pressure values are consistent with conditions for the existence of nitric acid trihydrate (NAT) mixtures and to a lesser extent of super-cooled ternary solution (STS) droplets. A local, temporary uptake of HNO3 vapor of order 1–3 ppbv is indicated during mid-January for the 550 K surface. Seven-month time series of the distributions of LIMS O3 and HNO3 are shown based on their gridded Level 3 data following the PSC screening. Zonal coefficients of both species are essentially free of effects from PSCs on the 550 K surface, based on their average values along PV contours and in terms of equivalent latitude. Remnants of PSCs are still present in O3 on the 450 K surface during mid-January. It is judged that the LIMS Level 3 data are of good quality for analyzing the larger-scale, stratospheric chemistry and transport processes during the Arctic winter of 1978–1979.

scholarly journals Denitrification, dehydration and ozone loss during the Arctic winter 2015/2016

2017 ◽  
Author(s):  
Farahnaz Khosrawi ◽  
Oliver Kirner ◽  
Björn-Martin Sinnhuber ◽  
Sören Johansson ◽  
Michael Höpfner ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
Stratospheric Ozone ◽  
Satellite Observations ◽  
The Arctic ◽  
Cold Pool ◽  
Polar Stratospheric Clouds ◽  
Airborne Measurements ◽  
Ozone Loss ◽  
Polar Stratosphere ◽  
Stratospheric Clouds

Abstract. The Arctic winter 2015/2016 was one of the coldest stratospheric winters in recent years. A stable vortex formed by early December and the early winter was exceptionally cold. Cold pool temperatures dropped below the Nitric Acid Trihydrate (NAT) existence temperature of about 195 K, thus allowing Polar Stratospheric Clouds (PSCs) to form. The low temperatures in the polar stratosphere persisted until early March allowing chlorine activation and catalytic ozone destruction. Satellite observations indicate that sedimentation of PSC particles led to denitrification as well as dehydration of stratospheric layers. Model simulations of the Arctic winter 2015/2016 nudged toward European Center for Medium-Range Weather Forecasts (ECMWF) analyses data were performed with the atmospheric chemistry–climate model ECHAM5/MESSy Atmospheric Chemistry (EMAC) for the Polar Stratosphere in a Changing Climate (POLSTRACC) campaign. POLSTRACC is a High Altitude and LOng Range Research Aircraft (HALO) mission aimed at the investigation of the structure, composition and evolution of the Arctic Upper Troposphere and Lower Stratosphere (UTLS). The chemical and physical processes involved in Arctic stratospheric ozone depletion, transport and mixing processes in the UTLS at high latitudes, polar stratospheric clouds as well as cirrus clouds are investigated. In this study an overview of the chemistry and dynamics of the Arctic winter 2015/2016 as simulated with EMAC is given. Further, chemical-dynamical processes such as denitrification, dehydration and ozone loss during the Arctic winter 2015/2016 are investigated. Comparisons to satellite observations by the Aura Microwave Limb Sounder (Aura/MLS) as well as to airborne measurements with the Gimballed Limb Observer for Radiance Imaging of the Atmosphere (GLORIA) performed on board of HALO during the POLSTRACC campaign show that the EMAC simulations are in fairly good agreement with observations. We derive a maximum polar stratospheric O3 loss of ~ 2 ppmv or 100 DU in terms of column in mid March. The stratosphere was denitrified by about 8 ppbv HNO3 and dehydrated by about 1 ppmv H2O in mid to end of February. While ozone loss was quite strong, but not as strong as in 2010/2011, denitrification and dehydration were so far the strongest observed in the Arctic stratosphere in the at least past 10 years.

scholarly journals Multilevel Cloud Structures over Svalbard

2017 ◽  
Vol 145 (4) ◽  
pp. 1149-1159 ◽  
Author(s):  
Andreas Dörnbrack ◽  
Sonja Gisinger ◽  
Michael C. Pitts ◽  
Lamont R. Poole ◽  
Marion Maturilli
Keyword(s):  
Large Scale ◽  
Wave Structure ◽  
Horizontal Resolution ◽  
Temperature Fields ◽  
The Arctic ◽  
Mountain Waves ◽  
Air Masses ◽  
Flow Features ◽  
Stratospheric Clouds ◽  
Lidar Observations

Abstract The presented picture of the month is a superposition of spaceborne lidar observations and high-resolution temperature fields of the ECMWF Integrated Forecast System (IFS). It displays complex tropospheric and stratospheric clouds in the Arctic winter of 2015/16. Near the end of December 2015, the unusual northeastward propagation of warm and humid subtropical air masses as far north as 80°N lifted the tropopause by more than 3 km in 24 h and cooled the stratosphere on a large scale. A widespread formation of thick cirrus clouds near the tropopause and of synoptic-scale polar stratospheric clouds (PSCs) occurred as the temperature dropped below the thresholds for the existence of cloud particles. Additionally, mountain waves were excited by the strong flow at the western edge of the ridge across Svalbard, leading to the formation of mesoscale ice PSCs. The most recent IFS cycle using a horizontal resolution of 8 km globally reproduces the large-scale and mesoscale flow features and leads to a remarkable agreement with the wave structure revealed by the spaceborne observations.

Sign in / Sign up

Export Citation Format

Share Document