scholarly journals Nighttime Mesospheric Ozone During the 2002 Southern Hemispheric Major Stratospheric Warming

2016 ◽  
Author(s):  
Christine Smith-Johnsen ◽  
Yvan Orsolini ◽  
Frode Stordal ◽  
Varavut Limpasuvan ◽  
Kristell Pérot
Keyword(s):  
Atomic Oxygen ◽  
Lower Stratosphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Ozone Layer ◽  
Stratospheric Warming ◽  
Mesospheric Ozone ◽  
Northern Hemispheric ◽  
Second Year ◽  
The Antarctic

Abstract. A Sudden Stratospheric Warming (SSW) affects the chemistry and dynamics of the middle atmosphere. The major warmings occur roughly every second year in the Northern Hemispheric (NH) winter, but has only been observed once in the Southern Hemisphere (SH), during the Antarctic winter of 2002. Using the National Center for Atmospheric Research's (NCAR) Whole Atmosphere Community Climate Model with specified dynamics (WACCM-SD), this study investigates the effects of this rare warming event on the ozone layer located around the SH mesopause. This secondary ozone layer changes with respect to hydrogen, oxygen, temperature, and the altered SH polar circulation during the major SSW. The 2002 SH winter was characterized by three zonal-mean zonal wind reductions in the upper stratosphere before a fourth wind reversal reaches the lower stratosphere, marking the onset of the major SSW. At the time of these four wind reversals, a corresponding episodic increase can be seen in the modeled nighttime ozone concentration in the secondary ozone layer. Observations by the Global Ozone Monitoring by Occultation of Stars (GOMOS, an instrument on board the satellite Envisat) demonstrate similar ozone enhancement as in the model. This ozone increase is attributable largely to enhanced upwelling and the associated cooling of the altitude region in conjunction with the wind reversal. Unlike its NH counterpart, the secondary ozone layer during the SH major SSW appeared to be impacted more by the effects of atomic oxygen than hydrogen.

scholarly journals Evaluation of CLaMS, KASIMA and ECHAM5/MESSy1 simulations in the lower stratosphere using observations of Odin/SMR and ILAS/ILAS-II

2009 ◽  
Vol 9 (1) ◽  
pp. 1977-2020
Author(s):  
F. Khosrawi ◽  
R. Müller ◽  
M. H. Proffitt ◽  
R. Ruhnke ◽  
O. Kirner ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
General Circulation ◽  
Lower Stratosphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Circulation Model ◽  
Lagrangian Model ◽  
Data Sets ◽  
Data Set ◽  
The Impact

Abstract. 1-year data sets of monthly averaged nitrous oxide (N2O) and ozone (O3) derived from satellite measurements were used as a tool for the evaluation of atmospheric photochemical models. Two 1-year data sets, one derived from the Improved Limb Atmospheric Spectrometer (ILAS and ILAS-II) and one from the Odin Sub-Millimetre Radiometer (Odin/SMR) were employed. Here, these data sets are used for the evaluation of two Chemical Transport Models (CTMs), the Karlsruhe Simulation Model of the Middle Atmosphere (KASIMA) and the Chemical Lagrangian Model of the Stratosphere (CLaMS) as well as for one Chemistry-Climate Model (CCM), the atmospheric chemistry general circulation model ECHAM5/MESSy1 (E5M1) in the lower stratosphere with focus on the Northern Hemisphere. Since the Odin/SMR measurements cover the entire hemisphere, the evaluation is performed for the entire hemisphere as well as for the low latitudes, midlatitudes and high latitudes using the Odin/SMR 1-year data set as reference. To assess the impact of using different data sets for such an evaluation study we repeat the evaluation for the polar lower stratosphere using the ILAS/ILAS-II data set. Only small differences were found using ILAS/ILAS-II instead of Odin/SMR as a reference, thus, showing that the results are not influenced by the particular satellite data set used for the evaluation. The evaluation of CLaMS, KASIMA and E5M1 shows that all models are in good agreement with Odin/SMR and ILAS/ILAS-II. Differences are generally in the range of ±20%. Larger differences (up to −40%) are found in all models at 500±25 K for N2O mixing ratios greater than 200 ppb. Generally, the largest differences were found for the tropics and the lowest for the polar regions. However, an underestimation of polar winter ozone loss was found both in KASIMA and E5M1 both in the Northern and Southern Hemisphere.

scholarly journals Results of microwave monitoring of middle atmosphereozone in polar latitudes for two winter seasons 2017-2018 and 2018-2019.

2020 ◽  
Author(s):  
Y.Y. Kulikov ◽  
◽  
A.F. Andriyanov ◽  
V.G. Ryskin ◽  
V.M. Demkin ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Continuous Series ◽  
Vertical Profiles ◽  
Stratospheric Warming ◽  
Geophysical Institute ◽  
Sudden Stratospheric Warming ◽  
Polar Geophysical Institute ◽  
Mesospheric Ozone ◽  
Dynamic Components ◽  
Microwave Data

We present data continuous series of microwave observations of the middle atmosphere in winters 2017-2018, 2018-2019 and 2019-2020. In each of these winters sudden stratospheric warming were marked.Measurements were carried out with the help of mobile ozonemeter (observation frequency 110836.04 MHz), which was established at Polar Geophysical Institute in Apatity (67N, 33E). The parameters of the device allow to measure a spectrum of the ozone emission line for time about 15 min a precision of 2%. On the measured spectra were appreciated of ozone vertical profiles in the layer of 22 60 km which were compared to satellite data MLS/Aura and with the data of ozonesonde at station Sodankyla (67N, 27E). The microwave data on the behavior of mesospheric ozone (altitude 60 km) indicate the presence of bothphotochemical and dynamic components in its changes.

scholarly journals Climatological Ertel's potential-vorticity flux and mean meridional circulation in the extratropical troposphere − lower stratosphere

1998 ◽  
Vol 16 (2) ◽  
pp. 250-265 ◽  
Author(s):  
J. Bartels ◽  
D. Peters ◽  
G. Schmitz
Keyword(s):  
Potential Vorticity ◽  
Seasonal Cycle ◽  
General Circulation ◽  
Lower Stratosphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Meridional Circulation ◽  
Statistical Significance ◽  
Baroclinic Wave ◽  
Mean Meridional Circulation

Abstract. We investigated to what extent the isentropic, non-geostrophic formulation of zonally averaged circulation derived for stratospheric conditions is applicable to climatological transport in the extratropical troposphere and lower stratosphere. The study is based on 10 years of daily data of ECMWF analysis and on the ECHAM3 climate model of the German Climate Computing Centre. The main result is a scalar isentropic mixing coefficient, Kyy, and a mean meridional transport circulation consistently derived from the same data base. For both data sources, isentropic mean meridional circulation is derived from horizontal mass flow rate for 4 representative months. Alternatively, a mean meridional circulation is calculated from total diabatic heating rates of the ECHAM3 model. It is shown that only the latter is in good agreement with the ECMWF mean meridional circulation. Isentropic analysis also comprises the seasonal cycle of the climatological meridional gradient and flux of Ertel's potential vorticity (PV). Application of Tung's flux-gradient relation yields that for all seasons Kyy is positive in height-latitude regions where statistical significance is reached. Large Kyy values, marking regions of more efficient mixing, have been found in the subtropical vertical band of weak westerly wind and in mid-latitudes in regions of upward-propagating baroclinic wave activity in the middle and upper troposphere. Based on the ECMWF data and results of baroclinic-wave behaviour, strong indications are presented that positive zonally averaged PV flux polewards of the jet core in the NH is strengthened by stationary waves and nonlinear effects. Reduced eddy transport is apparent in winter and spring slightly below the subtropical tropopause jet. The seasonal cycle of Kyy from ECHAM3 data is to a great extent in agreement with the result based on ECMWF analysis. In the model, reduced interannual variability enlarges the height-latitude range where sign of Kyy is significant.Key words. Meteorology and atmospheric dynamics · Climatology · General circulation · Middle atmosphere is significant.

scholarly journals Past and future conditions for polar stratospheric cloud formation simulated by the Canadian Middle Atmosphere Model

2009 ◽  
Vol 9 (2) ◽  
pp. 483-495 ◽  
Author(s):  
P. Hitchcock ◽  
T. G. Shepherd ◽  
C. McLandress
Keyword(s):  
Climate Change ◽  
Low Temperature ◽  
Ozone Depletion ◽  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
The Arctic ◽  
Temperature Extremes ◽  
Polar Stratospheric Cloud ◽  
Atmosphere Model ◽  
The Antarctic

Abstract. We analyze here the polar stratospheric temperatures in an ensemble of three 150-year integrations of the Canadian Middle Atmosphere Model (CMAM), an interactive chemistry-climate model which simulates ozone depletion and recovery, as well as climate change. A key motivation is to understand possible mechanisms for the observed trend in the extent of conditions favourable for polar stratospheric cloud (PSC) formation in the Arctic winter lower stratosphere. We find that in the Antarctic winter lower stratosphere, the low temperature extremes required for PSC formation increase in the model as ozone is depleted, but remain steady through the twenty-first century as the warming from ozone recovery roughly balances the cooling from climate change. Thus, ozone depletion itself plays a major role in the Antarctic trends in low temperature extremes. The model trend in low temperature extremes in the Arctic through the latter half of the twentieth century is weaker and less statistically robust than the observed trend. It is not projected to continue into the future. Ozone depletion in the Arctic is weaker in the CMAM than in observations, which may account for the weak past trend in low temperature extremes. In the future, radiative cooling in the Arctic winter due to climate change is more than compensated by an increase in dynamically driven downwelling over the pole.

scholarly journals Past and future conditions for polar stratospheric cloud formation simulated by the Canadian Middle Atmosphere Model

2008 ◽  
Vol 8 (4) ◽  
pp. 16555-16583
Author(s):  
P. Hitchcock ◽  
T. G. Shepherd ◽  
C. McLandress
Keyword(s):  
Climate Change ◽  
Low Temperature ◽  
Ozone Depletion ◽  
Lower Stratosphere ◽  
Middle Atmosphere ◽  
The Arctic ◽  
Temperature Extremes ◽  
The Future ◽  
Atmosphere Model ◽  
The Antarctic

Abstract. Observations of the Arctic winter lower stratosphere over the past four decades suggest that the thermodynamic conditions required for the formation of polar stratospheric clouds (PSCs) have become increasingly widespread in the Northern Hemisphere. The trend is apparent only in the coldest winters during which the Arctic stratosphere is minimally disturbed by upwelling wave activity from the troposphere. The mechanism responsible for this increase remains unclear. In an effort to evaluate possible mechanisms, we analyze here the polar stratospheric temperatures in an ensemble of three 150-year integrations of the Canadian Middle Atmosphere Model (CMAM), an interactive chemistry-climate model which simulates ozone depletion and recovery, as well as climate change. We find that in the Antarctic winter lower stratosphere, the low temperature extremes required for PSC formation increase in the model as ozone is depleted, but remain steady through the twenty-first century as the warming from ozone recovery roughly balances the cooling from climate change. Thus, ozone depletion itself plays a major role in the Antarctic response. The model trend in low temperature extremes in the Arctic through the latter half of the twentieth century is weaker and less statistically robust than the observed trend. It is not projected to continue into the future. Ozone depletion in the Arctic is weaker in the CMAM than in observations, which may account for the weak past trend in low temperature extremes. In the future, radiative cooling in the Arctic winter due to climate change is more than compensated by an increase in dynamically driven downwelling over the pole.

How turbulent mountain stress influences sudden stratospheric warming ocurrence in WACCM

2020 ◽  
Author(s):  
Froila M. Palmeiro ◽  
Rolando R. Garcia ◽  
Natalia Calvo ◽  
David Barriopedro ◽  
Bernat Jiménez-Esteve
Keyword(s):  
Lower Stratosphere ◽  
Climate Model ◽  
Polar Vortex ◽  
Wave Drag ◽  
Late Winter ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Subtropical Jet ◽  
Vertical Propagation ◽  
Stress Influences

<p><span>The implementation of the Turbulent Mountain Stress (TMS) parametrization in the Whole Atmospheric Community Climate Model (WACCM) is found to be critical to obtain a realistic Sudden Stratospheric Warming (SSW) frequency in the Northern Hemisphere. Comparing two 50-year simluations, one with TMS (TMS-on) and one without (TMS-off) reveals lower than observed SSW frequency in TMS-off from December to February, while in March both simulations show SSW frequencies comparable to reanalysis. Meridional eddy heat fluxes in the lower stratosphere are stronger in TMS-on than in TMS-off, except in March. These differences are accompanied by increased orographic gravity wave drag (OGWD) in TMS-off that comes mainly from the Himalayas and the Rocky Mountains in response to stronger surface winds. Two different mechanisms of how planetary and GWs interact are identified in the simulations. In the lower stratosphere, enhanced dissipation of GWs in TMS-off modifies the subtropical jet and thus the conditions for refraction of planetary waves. </span><span>In early winter, w</span><span>ave</span><span> geometry diagnostics shows </span><span>waveguides </span><span>formation </span><span>from 55N to 75N </span><span>in TMS-on</span><span>, enhancing wave propagation to the polar vortex. On the contrary, vertical propagation </span><span>in TMS-off is </span><span>in inhibited above the lower stratosphere and confined to latitudes </span><span>s</span><span>outh of 50N. </span><span>C</span><span>ompensation between resolved and parametrized GWs </span><span>is also </span><span>observed</span><span>, </span><span>lead</span><span>ing</span><span> to weaker Eliassen-Palm flux divergence in response to stronger OGWD in TMS-off. </span><span>In late winter, conditions for </span><span>propagation are similar in both simulations by late winter, which </span><span>explain</span><span>s</span><span> the reduced TMS-off bias in the frequency of March SSWs. </span></p>

scholarly journals Chemistry–Climate Model Simulations of Twenty-First Century Stratospheric Climate and Circulation Changes

2010 ◽  
Vol 23 (20) ◽  
pp. 5349-5374 ◽  
Author(s):  
Neal Butchart ◽  
I. Cionni ◽  
V. Eyring ◽  
T. G. Shepherd ◽  
D. W. Waugh ◽  
...  
Keyword(s):  
Climate Models ◽  
Lower Stratosphere ◽  
Climate Model ◽  
First Century ◽  
The Arctic ◽  
Positive Trend ◽  
Rate Of Recovery ◽  
Twenty First Century ◽  
The Antarctic ◽  
Subtropical Jets

Abstract The response of stratospheric climate and circulation to increasing amounts of greenhouse gases (GHGs) and ozone recovery in the twenty-first century is analyzed in simulations of 11 chemistry–climate models using near-identical forcings and experimental setup. In addition to an overall global cooling of the stratosphere in the simulations (0.59 ± 0.07 K decade−1 at 10 hPa), ozone recovery causes a warming of the Southern Hemisphere polar lower stratosphere in summer with enhanced cooling above. The rate of warming correlates with the rate of ozone recovery projected by the models and, on average, changes from 0.8 to 0.48 K decade−1 at 100 hPa as the rate of recovery declines from the first to the second half of the century. In the winter northern polar lower stratosphere the increased radiative cooling from the growing abundance of GHGs is, in most models, balanced by adiabatic warming from stronger polar downwelling. In the Antarctic lower stratosphere the models simulate an increase in low temperature extremes required for polar stratospheric cloud (PSC) formation, but the positive trend is decreasing over the twenty-first century in all models. In the Arctic, none of the models simulates a statistically significant increase in Arctic PSCs throughout the twenty-first century. The subtropical jets accelerate in response to climate change and the ozone recovery produces a westward acceleration of the lower-stratospheric wind over the Antarctic during summer, though this response is sensitive to the rate of recovery projected by the models. There is a strengthening of the Brewer–Dobson circulation throughout the depth of the stratosphere, which reduces the mean age of air nearly everywhere at a rate of about 0.05 yr decade−1 in those models with this diagnostic. On average, the annual mean tropical upwelling in the lower stratosphere (∼70 hPa) increases by almost 2% decade−1, with 59% of this trend forced by the parameterized orographic gravity wave drag in the models. This is a consequence of the eastward acceleration of the subtropical jets, which increases the upward flux of (parameterized) momentum reaching the lower stratosphere in these latitudes.

scholarly journals Evaluation of CLaMS, KASIMA and ECHAM5/MESSy1 simulations in the lower stratosphere using observations of Odin/SMR and ILAS/ILAS-II

2009 ◽  
Vol 9 (15) ◽  
pp. 5759-5783 ◽  
Author(s):  
F. Khosrawi ◽  
R. Müller ◽  
M. H. Proffitt ◽  
R. Ruhnke ◽  
O. Kirner ◽  
...  
Keyword(s):  
Atmospheric Chemistry ◽  
General Circulation ◽  
Lower Stratosphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Circulation Model ◽  
Lagrangian Model ◽  
Data Sets ◽  
Data Set ◽  
The Impact

Abstract. 1-year data sets of monthly averaged nitrous oxide (N2O) and ozone (O3) derived from satellite measurements were used as a tool for the evaluation of atmospheric photochemical models. Two 1-year data sets, one solar occultation data set derived from the Improved Limb Atmospheric Spectrometer (ILAS and ILAS-II) and one limb sounding data set derived from the Odin Sub-Millimetre Radiometer (Odin/SMR) were employed. Here, these data sets are used for the evaluation of two Chemical Transport Models (CTMs), the Karlsruhe Simulation Model of the Middle Atmosphere (KASIMA) and the Chemical Lagrangian Model of the Stratosphere (CLaMS) as well as for one Chemistry-Climate Model (CCM), the atmospheric chemistry general circulation model ECHAM5/MESSy1 (E5M1) in the lower stratosphere with focus on the Northern Hemisphere. Since the Odin/SMR measurements cover the entire hemisphere, the evaluation is performed for the entire hemisphere as well as for the low latitudes, midlatitudes and high latitudes using the Odin/SMR 1-year data set as reference. To assess the impact of using different data sets for such an evaluation study we repeat the evaluation for the polar lower stratosphere using the ILAS/ILAS-II data set. Only small differences were found using ILAS/ILAS-II instead of Odin/SMR as a reference, thus, showing that the results are not influenced by the particular satellite data set used for the evaluation. The evaluation of CLaMS, KASIMA and E5M1 shows that all models are in agreement with Odin/SMR and ILAS/ILAS-II. Differences are generally in the range of ±20%. Larger differences (up to −40%) are found in all models at 500±25 K for N2O mixing ratios greater than 200 ppbv, thus in air masses of tropical character. Generally, the largest differences were found for the tropics and the lowest for the polar regions. However, an underestimation of polar winter ozone loss was found both in KASIMA and E5M1 both in the Northern and Southern Hemisphere.

THE MICROWAVE MONITORING OF THE MIDDLE ATMOSPHERE OZONE ON KOLA PENINSULA DURING LAST THREE WINTERS

2021 ◽  
Vol 44 ◽  
pp. 168-171
Author(s):  
Y.Y. Kulikov ◽  
◽  
A.F. Andriyanov ◽  
V.G. Ryskin ◽  
V.M. Demkin ◽  
...  
Keyword(s):  
Middle Atmosphere ◽  
Microwave Radiometry ◽  
Vertical Profiles ◽  
Stratospheric Warming ◽  
Geophysical Institute ◽  
Sudden Stratospheric Warming ◽  
Polar Geophysical Institute ◽  
Mesospheric Ozone ◽  
The Vertical Distribution

This work presents long-term investigation of a nature of the middle atmosphere ozone variability using a method ground-based microwave radiometry. Measurements were carried out with the help of mobile microwave ozonemeter (observation frequency 110836.04 MHz) which was established in Polar Geophysical Institute at Apatity (67N, 33E). The parameters of the device allow to measure a spectrum of the emission ozone line for time about 15 min with a precision of ~ 2%. The error of estimating the vertical distribution of ozone on the measured spectra by above described device does not exceed 10-15%. On the measured spectra were appreciated of ozone vertical profiles in the layer of 22 – 60 km which were compared to satellite data MLS/Aura and with the data of ozonesondes at station Sodankyla (67N, 27E). The analysis of the microwave data on behavior of polar mesospheric ozone in past winters shows, that sudden stratospheric warming (SSW) can cause significant and long influence on its diurnal variation which should be determined by photochemical processes.

scholarly journals The Climatology of the Middle Atmosphere in a Vertically Extended Version of the Met Office’s Climate Model. Part II: Variability

2010 ◽  
Vol 67 (11) ◽  
pp. 3637-3651 ◽  
Author(s):  
Scott M. Osprey ◽  
Lesley J. Gray ◽  
Steven C. Hardiman ◽  
Neal Butchart ◽  
Andrew C. Bushell ◽  
...  
Keyword(s):  
Lower Stratosphere ◽  
Climate Model ◽  
Middle Atmosphere ◽  
Global Climate ◽  
Global Climate Model ◽  
Occurrence Rate ◽  
Extended Version ◽  
Quasi Biennial Oscillation ◽  
Annular Modes ◽  
Biennial Oscillation

Abstract Stratospheric variability is examined in a vertically extended version of the Met Office global climate model. Equatorial variability includes the simulation of an internally generated quasi-biennial oscillation (QBO) and semiannual oscillation (SAO). Polar variability includes an examination of the frequency of sudden stratospheric warmings (SSW) and annular mode variability. Results from two different horizontal resolutions are also compared. Changes in gravity wave filtering at the higher resolution result in a slightly longer QBO that extends deeper into the lower stratosphere. At the higher resolution there is also a reduction in the occurrence rate of sudden stratospheric warmings, in better agreement with observations. This is linked with reduced levels of resolved waves entering the high-latitude stratosphere. Covariability of the tropical and extratropical stratosphere is seen, linking the phase of the QBO with disturbed NH winters, although this linkage is sporadic, in agreement with observations. Finally, tropospheric persistence time scales and seasonal variability for the northern and southern annular modes are significantly improved at the higher resolution, consistent with findings from other studies.

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