On the role of the lower-stratospheric circulation to the vertical ozone structure

1999 ◽  
Vol 24 (5) ◽  
pp. 481-485
Author(s):  
C Varotsos ◽  
D Alexandris ◽  
G Chronopoulos
Keyword(s):  
Stratospheric Circulation ◽  
Vertical Ozone

scholarly journals Simulating age of air and the distribution of SF<sub>6</sub> in the stratosphere with the SILAM model

2020 ◽  
Vol 20 (9) ◽  
pp. 5837-5859
Author(s):  
Rostislav Kouznetsov ◽  
Mikhail Sofiev ◽  
Julius Vira ◽  
Gabriele Stiller
Keyword(s):  
Transport Model ◽  
Michelson Interferometer ◽  
Direct Calculation ◽  
Chemistry Transport Model ◽  
Simultaneous Application ◽  
Separation Of Gases ◽  
Stratospheric Circulation ◽  
Tracer Accumulation ◽  
Accumulation Method

Abstract. The paper presents a comparative study of age of air (AoA) derived from several approaches: a widely used passive-tracer accumulation method, the SF6 accumulation, and a direct calculation of an ideal-age tracer. The simulations were performed with the Eulerian chemistry transport model SILAM driven with the ERA-Interim reanalysis for 1980–2018. The Eulerian environment allowed for simultaneous application of several approaches within the same simulation and interpretation of the obtained differences. A series of sensitivity simulations revealed the role of the vertical profile of turbulent diffusion in the stratosphere, destruction of SF6 in the mesosphere, and the effect of gravitational separation of gases with strongly different molar masses. The simulations reproduced well the main features of the SF6 distribution in the atmosphere observed by the MIPAS (Michelson Interferometer for Passive Atmospheric Sounding) satellite instrument. It was shown that the apparent very old air in the upper stratosphere derived from the SF6 profile observations is a result of destruction and gravitational separation of this gas in the upper stratosphere and the mesosphere. These processes make the apparent SF6 AoA in the stratosphere several years older than the ideal-age AoA, which, according to our calculations, does not exceed 6–6.5 years. The destruction of SF6 and the varying rate of emission make SF6 unsuitable for reliably deriving AoA or its trends. However, observations of SF6 provide a very useful dataset for validation of the stratospheric circulation in a model with the properly implemented SF6 loss.

scholarly journals Assessing the role of planetary and gravity waves in the vertical structure of ozone over midlatitudinal Europe

2019 ◽  
Vol 37 (4) ◽  
pp. 525-533
Author(s):  
Peter Križan
Keyword(s):  
Gravity Waves ◽  
Vertical Profile ◽  
Annual Variation ◽  
Vertical Structure ◽  
Planetary Waves ◽  
Ozone Content ◽  
Ozone Profile ◽  
Vertical Ozone Profile ◽  
Vertical Ozone

Abstract. Planetary and gravity waves play an important role in the dynamics of the atmosphere. They are present in the atmospheric distribution of temperature, wind, and ozone content. These waves are detectable also in the vertical profile of ozone and they cause its undulation. One of the structures occurring in the vertical ozone profile is laminae, which are narrow layers of enhanced or depleted ozone concentrations in the vertical ozone profile. They are connected with the total amount of ozone in the atmosphere and with the activity of the planetary and gravity waves. The aim of this paper is to quantify these processes in midlatitudinal Europe. We compare the occurrence of laminae induced by planetary waves (PL) with the occurrence of these induced by gravity waves (GL). We show that the PL are 10–20 times more frequent than that of GL. There is a strong annual variation of PL, while GL exhibit only a very weak variation. With the increasing lamina size the share of GL decreases and the share of PL increases. The vertical profile of lamina occurrence is different for PL and GL smaller than 2 mPa. For laminae greater than 2 mPa this difference is smaller.

scholarly journals Changing lower stratospheric circulation: The role of ozone and greenhouse gases

1998 ◽  
Vol 103 (D10) ◽  
pp. 11251-11261 ◽  
Author(s):  
Hans-F. Graf ◽  
Ingo Kirchner ◽  
Judith Perlwitz
Keyword(s):  
Greenhouse Gases ◽  
Stratospheric Circulation

scholarly journals Simulating age of air and distribution of SF<sub>6</sub> in the stratosphere with SILAM model

2019 ◽  
Author(s):  
Rostislav Kouznetsov ◽  
Mikhail Sofiev ◽  
Julius Vira ◽  
Gabriele Stiller
Keyword(s):  
Transport Model ◽  
Direct Calculation ◽  
Passive Tracer ◽  
Chemistry Transport Model ◽  
Simultaneous Application ◽  
Separation Of Gases ◽  
Stratospheric Circulation ◽  
Tracer Accumulation ◽  
Accumulation Method

Abstract. The paper presents a comparative study of age of air (AoA) derived with several approaches: a widely used passive tracer accumulation method, the SF6 accumulation, and a direct calculation of an "ideal age" tracer. The simulations have been performed with the Eulerian chemistry transport model SILAM driven with the ERA-Interim reanalysis for 1980–2018. The Eulerian environment allowed for simultaneous application of several approaches within the same simulation, and interpretation of the obtained differences. A series of sensitivity simulations revealed the role of the vertical profile of turbulent diffusion in the stratosphere, destruction of SF6 in the mesosphere, as well as the effect of gravitational separation of gases with strongly different molar masses. The simulations reproduced well the main features of the SF6 distribution in the atmosphere retrieved from the MIPAS satellite instrument. It was shown that the apparent very old air in the upper stratosphere derived from the SF6 profile observations is a result of destruction and gravitational separation of this gas in the upper stratosphere and mesosphere. The effect of these processes add over 4 years to the actual AoA, which, according to our calculations, does not exceed 6–6.5 years. The destruction of SF6 and varying rate of emission make it unsuitable to reliably derive AoA or its trends. However, observations of SF6 provide a very useful means for validation of stratospheric circulation in a model with properly implemented SF6 loss.

Association of the vertical ozone structure with the lower‐stratospheric circulation

2008 ◽  
Vol 29 (9) ◽  
pp. 2685-2695 ◽  
Author(s):  
C. A. Varotsos ◽  
A. P. Cracknell ◽  
C. Tzanis ◽  
S. Tsitomeneas ◽  
L. Viras
Keyword(s):  
Stratospheric Circulation ◽  
Vertical Ozone

scholarly journals Tropopause Structure and the Role of Eddies

2011 ◽  
Vol 68 (12) ◽  
pp. 2930-2944 ◽  
Author(s):  
Jacob Haqq-Misra ◽  
Sukyoung Lee ◽  
Dargan M. W. Frierson
Keyword(s):  
General Circulation ◽  
Three Dimensional ◽  
Circulation Model ◽  
Moist Convection ◽  
Symmetric Flow ◽  
Eddy Fluxes ◽  
Stratospheric Circulation ◽  
Extratropical Tropopause ◽  
Tropospheric Layer

Abstract This paper presents a series of dynamical states using an idealized three-dimensional general circulation model with gray radiation and latent heat release. Beginning with the case of radiative–convective equilibrium, an eddy-free two-dimensional state with zonally symmetric flow is developed, followed by a three-dimensional state that includes baroclinic eddy fluxes. In both dry and moist cases, it is found that the deepening of the tropical tropospheric layer and the shape of the extratropical tropopause can be understood through eddy-driven processes such as the stratospheric Brewer–Dobson circulation. These results suggest that eddies alone can generate a realistic tropopause profile in the absence of moist convection and that stratospheric circulation is an important contributor to tropopause structure.

scholarly journals Assessing the role of planetary and gravity waves on the vertical structure of ozone over central Europe

2018 ◽  
Author(s):  
Peter Križan
Keyword(s):  
Gravity Wave ◽  
Central Europe ◽  
Gravity Waves ◽  
Vertical Profile ◽  
Planetary Wave ◽  
Annual Variation ◽  
Ozone Profile ◽  
Vertical Ozone Profile ◽  
Vertical Ozone

Abstract. Planetary and gravity waves play an important role in the dynamics of the atmosphere. They are present in the atmospheric distribution of temperature, wind and ozone content. These waves are detectable also in the vertical profile of ozone and they cause its undulation. One of the structures occurring in the vertical ozone profile is laminae, which are narrow layers of enhanced or depleted ozone concentration in the vertical ozone profile. They are connected with the total amount of ozone in the atmosphere and with the activity of the planetary and the gravity waves. The aim of this paper is quantifying these processes in the central Europe. We compare the occurrence of laminae induced by planetary waves (PL) with the occurrence of these induced by gravity waves (GL). We show that the PL are 3–5 times more frequent than the gravity wave ones. There is a strong annual variation of PL, while GL exhibit only a very weak variation. With the increasing lamina size the share of GL decreases and the share of PL increases. The vertical profile of lamina occurrence is different for small planetary wave and gravity wave laminae. The trend of large lamina occurrence frequency is given by the trend in PL, not by GL.

Role of dactinomycin in the improved survival of children with Wilms' tumor

JAMA ◽  
1966 ◽  
Vol 195 (12) ◽  
pp. 1005-1009 ◽  
Author(s):  
D. J. Fernbach
Keyword(s):  
Wilms Tumor
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