37 OZONE DRIVES ATMOSPHERIC DYNAMICS

In this post I give an account of the data provided in two papers from a group of authors who have described the the nature of the atmosphere and its dynamics in terms of its ozone content. The work creates a framework that advances our understanding of atmospheric processes and how they relate to external influences in an open system. In introducing the papers I provide an interpretation of atmospheric dynamics that goes beyond that of the authors and it will be best if readers go direct to the originals as a preliminary activity before reading what follows.

The Total Ozone Field Separated into Meteorological Regimes. Part I: Defining the Regimes ROBERT D. HUDSON, ALEXANDER D. FROLOV, MARCOS F. ANDRADE, AND MELANIE B. FOLLETTE  Published in 2003 and accessed here.

THE ABSTRACT

Traditionally, studies in the stratosphere using column ozone amount, ozone profiles, and dynamical variables at midlatitudes have centered on zonal averages of these quantities made over specific latitude bands. This is in sharp contrast to the studies made within the polar vortices where the average is made within regions defined by potential vorticity, a meteorological parameter. An analysis of the ozone field in the Northern Hemisphere outside of the polar vortex is presented in which it is shown that this field can also be separated into meteorological regimes. These regimes are defined as 1) the tropical regime, between the equator and the subtropical front; 2) the midlatitude regime, between the subtropical and polar fronts; 3) the polar regime, between the polar front and the polar vortex; and 4) the arctic regime, within the polar vortex. Within each regime the zonal daily mean total ozone value is relatively constant, with a clearly separate value for each regime. At the same time, the stratospheric ozone profiles are clearly distinguishable between regimes, each regime having a unique tropopause height. A midlatitude zonal average, whether of ozone profiles, total ozone, or dynamical variables, will depend on the relative mix of the respective values within each regime over the latitude range of the average. Because each regime has its own distinctive characteristic, these averages may not have physical significance.

Here is the  introduction to the work:

Dobson et al. (1927) reported ground-based measurements of the total column ozone using a spectrometer that observed the solar ultraviolet irradiance. They noted that when an upper-tropospheric front passed over the instrument, the total ozone value either dropped or rose sharply. Shalamyanskiy and Romanshkina (1980) and later Karol et al. (1987) divided ground-based total ozone measurements into three regions, separated by the polar and subtropical jet streams. They found that total ozone and temperature profiles had small variability within each region but changed sharply at the polar and subtropical fronts. The same change in ozone across a frontal boundary can be seen in the data from the Total Ozone Mapping Spectrometer (TOMS; McPeters et al. 1996).

Now, the authors don’t go on to say that the  jet streams at the fronts are a product of a contrast in air density in part due to the heating activity of ozone. They must give due respect to the school of climate science that sees the Earth as a closed system. If they took account of their own observation that, when moving from equator to Pole, the tropopause steps down in elevation at the subtropical front and again at the polar front where, on the polar side of the front there is no tropopause at all, thereby giving rise to severe gradients in atmospheric density then perhaps they might hypothesise that ozone is THE critical factor giving rise to jet streams, determining the weather patterns in the troposphere and the evolution of climate over time. But we must bear in mind that the climate establishment would punish them if they ventured that viewpoint. It is safer to leave the question open to interpretation. Those who would maintain that the distribution of ozone is a product of atmospheric dynamics in the lower troposphere and the chlorine content of the polar atmosphere due to the escape of chlorofluorocarbons into the atmosphere from refrigerants etc etc, can then interpret matters as they prefer.

In establishment climate science there is no concept of ozone variation on an inter annual basis due to the activity of the mesospheric vortex at the pole or ozone production due to cosmic radiation. The atmosphere is not an electromagnetic medium capable of change in its rate of rotation due to change in the solar wind. In the conventional viewpoint the temperature of the stratosphere is not driven by the absorption of long wave radiation from the Earth by ozone but by the interception of short wave radiation from the sun. In other words the direct impact of short wave radiation from the sun as held to be the reason for the temperature of the stratosphere even on the night side and regardless of latitude. The planetary winds are held to be driven according to the energy absorbed in near equatorial latitudes. Adherents don’t know how the atmosphere is shifted from high latitudes to low latitudes and wont be drawn to speculate on that matter at all. The blinkers are very firmly in place. Grant money and ones livelihood is at stake. Privately, one may admit in a whisper, that the Emperor has no clothes but publicly he is beautifully arrayed in the most impressive garments that money can buy.

In spite of these niceties some very useful analytical work has been done that establishes the distribution of ozone in relation to the position of the subtropical and polar fronts and there are big surprises that have very important implications in furthering our understanding of atmospheric dynamics..

Dist of ozone
Fig 1

In terms of atmospheric dynamics in the northern hemisphere we can note that the situation is different to that in the southern hemisphere. The circumpolar trough in surface atmospheric pressure surrounding Antarctica is so deep, and persistent across all seasons as to act as a global sink, conditioning the movement of the atmosphere globally. By contrast, in the northern hemisphere a trough of sorts develops in the north Pacific in winter associated with regional ascent of ozone rich air to the top of the atmospheric column while high surface pressure that is associated with the Antarctic continent in winter is associated with the Eurasian continent during winter, in the same latitude as the North Pacific low pressure zone.

It should be emphasised at the outset that the data in this study relates to a single day, the 11th March 1990. I will explore the importance of this choice by way of a postscript. In now way is the legitimacy or the conclusions of this study adversely affected by the fact that the data represents a single day. In fact, it is only by concentrating ones effort on single day that one can discern the dynamics at work.

Of immediate interest is that the stretched Mercator’s projection of Fig 1 involves spatial distortion. The fingers of low ozone content air interlaced with fingers of high ozone content air would look different  in a polar stereo-graphic view and they are strictly an artefact of the circulation on a particular day. The configuration of the northern hemisphere circulation is complex and ever changing due to the distribution of land and sea. If we were looking at the very much simpler circulation in the southern hemisphere it would be immediately apparent that air of tropical origin is drawn into a super-rotating west to east circulation with its highest rate of rotation at the polar vortex. The vortex is a feature of the stratosphere linked to an ascending circulation  via a chain of polar cyclones that entrain air from the troposphere, air from the stratosphere and air from the polar cap that has descended  from the mesosphere. The vorticity of these polar cyclones and the stratospheric vortex depends upon contrasts in air density between one side of the vortex and the other.Note the  location of the blue area (high ozone) and the green area (low ozone) in relation to the  vortex.  The authors locate the vortex  in  this way:  The solid red line marks the position of the sharp gradient in the isentropic potential vorticity (IPV) contours on the 450- K isentropic surface, which traditionally is assumed to mark the edge of the polar vortex”.  

The 450-K  isentropic surface lies between 70 mb and 50 mb pressure surfaces. This is at the altitude where ozone is in greatest abundance in the vertical profile. It is unequivocally in the stratosphere. It will therefore be the location where the ozone density gradient  is steeper than anywhere else in the vertical profile giving rise to very strong winds. Notice that there are two gaps in the the blue-black zone of highest ozone content These are areas of downdraught of low ozone content mesospheric air associated with the high pressure cells over land. One lies over East Asia and the other in the vicinity of Iceland. It is no accident that the vortex follows the junction of high ozone content warm air to the south and low ozone content cold air to the north. Unequivocally, elevated vorticity is linked to differences in air density linked to the origin of the air, its trace gas content, including ozone and NOx (not shown but  always present in air from the troposphere),  the formation of polar cyclones and therefore the flux in surface pressure between high latitudes and elsewhere that varies on all time scales. This flux in the pressure differential between high and mid latitudes is measured as the Arctic Oscillation and the Antarctic Oscillation.

What is described as the polar front in this work is likely a near surface phenomenon, the outer interface of a chain of polar cyclones that feed air into the Polar Vortex. The zone between the polar font and the polar vortex has very high ozone values. It is a zone of intense convection that is generated at the elevation of the Polar Vortex, propagating down to the surface where its troposphere manifestation is called a ‘cold core’ polar cyclone. No cyclone can develop with a cold core. The warm core is aloft where ozone captures outgoing radiation from the Earth.

TRANSITIONS AND UNEXPECTED HOMOGENEITY

Hudson et al notes in respect of the ozone data: The average for all of the data slowly increases with latitude until the polar vortex is reached. On the other hand, the average for the tropical, mid latitude, and polar regimes is relatively constant over a wide range of overlapping latitudes. There is also a clear difference between the average total ozone amounts for each of these regimes.

The transition zone between these dissimilar regions  is referred to as a ‘front’. The Polar Front only exists in the winter months when mesospheric air descends  to jet stream altitudes its rate of flow and integration with the wider atmosphere  contributing to the flux in the ozone content of the atmosphere generally. But this is not a  dynamic that is mentioned in this work. In summer there is no descent of mesospheric air and its disappearance is described as the final warming of the stratosphere after which the air over the polar cap gently ascends. In summer a  high ozone values over the Arctic  Ocean contribute to generalised ascent and the jet stream structures are fragmented.

Hudson et al reports that the fronts between different ozone regimes exhibit the same ozone content around the entire globe at any particular time. However the values are different according to the month of the year.See figure 3 below: In winter the fronts have higher ozone values than in summer. This emphasises the basic cell like structure and the homogeneity found within cells.

At the polar front the ozone value is highest in February. Readers of earlier chapters in this work will know that surface temperature variability between 30° south and 90° north latitude is greatest in January and February. There is a causal connection. The year to year variability in ozone partial pressure at the polar front is greatest in winter when ozone partial pressure is highest. In the transition from autumn to winter surface pressure over the Arctic rises strongly in November as the Antarctic releases atmospheric mass as the final warming in the stratosphere takes place. The increase in mass in the Arctic in November is reflected in the Arctic Oscillation Index (low values). In December, as ozone builds giving rise to active polar cyclones, surface pressure in high latitudes falls just as strongly as it has risen in the transition from autumn to winter. In this way, as Gordon Dobson observed, surface pressure is linked to the ozone content of the air. More importantly, as surface pressure falls in the Arctic a warm wind from the south finds its way further north bringing clement conditions. The zone of Ascent in the North Pacific develops strongly taking ozone to the top of the column. The  return circulation brings ozone into the high pressure cells of the mid latitudes, warming the air, increasing geopotential height, reducing cloud cover and increasing surface temperature.

These points are worth repeating. Gordon Dobson pointed out that ozone maps surface pressure with high ozone values corresponding to low surface pressure. Low pressure in the Arctic brings a flood of warm air from the south. Cool air is replaced by warm air. This is the Arctic Oscillation in action. In more recent terminology the AO is called the ‘Northern Annular mode’. It is not in the interest of the authors of this study to link ozone dynamics to change in surface temperature wrought by a change in the origin of the air. The notion that surface temperature is a response to the presence of carbon dioxide in the atmosphere has to be maintained if ones work is to appear in academic journals like ‘Science’ although the newly appointed editor of Science is reported to be saying that ‘science’ has lost integrity in the process of suppressing competing viewpoints. See here where it is reported that:  “Science editor-in-chief sounds alarm over falling public trust. Jeremy Berg warns scientists are straying into policy commentator roles.” Are the publishers of ‘Science’ reacting to falling circulation related to negative reader response? If so, this will be good for small ‘s’ science.

EVOLUTION OF OZONE PARTIAL PRESSURE AT THE FRONTS

Ozone values at the fronts
Fig 2. Evolution of ozone partial pressure at the subtropical and polar fronts. Readers should be aware that the front referred to is in the upper air, not at the surface. The material expression of the front is a change in the height of the tropopause so that warm ozone rich air is found adjacent to cold ozone deficient air.

It is  very interesting that the authors report that the ozone content of the air in the ‘Midlatitude Regime’ is invariable around the globe regardless of latitude or longitude. Apparently atmospheric mixing processes maintain this homogeneous state. This reinforces the long held view of a cellular structure in the atmosphere between the fronts. Inferentially, it supports the notion that elevated ozone in the ‘Midlatitude Regime’ is a product of in-situ ionisation of the polar atmosphere by cosmic rays during the polar night rather than transport from the tropics where the ozone content of the air is inferior. If one conceives the situation in this way  it is  obvious that the ozone content of the air in high and mid latitudes is driven by forces that are external to the system via polar dynamics rather than the interaction of short wave radiation with the atmosphere. The stratosphere warms in the winter hemisphere in the mid latitudes, obviously unrelated to the incidence of short wave radiation. This accentuates density differences across the fronts driving enhanced vorticity. External forces are capable of mediating the strength of the zonal wind in an electromagnetic medium such as the atmosphere, mediating the penetration of mesospheric air and the penetration of cosmic rays that very much depends on air temperature and density. Due to ionisation by cosmic rays it is possible for the synthesis of ozone to occur in the absence of short wave solar radiation.

EXTREME OZONE GRADIENTS, TROPOPAUSE STEPS, JET STREAMS ARE ALL LOCATED AT THE FRONTS

Hudson notes that using aircraft to measure ozone partial pressure  both Shapiro et al. (1987), and Uccellini et al. (1985), found a strong coincidence between large gradients in the total ozone measurements from TOMS and the position of upper-level jet streams, the frontal zones and  tropopause ‘foldings’ where there is a step up in the height of the tropopause.

Ozone field TOMS
Figure 3 Differentiation of the Polar, Midlatitude and Tropical Regimes
Rawinsonde profiles
Figure 4 Temperature profiles in the three regimes. Note that there is a step up in the temperature of the tropopause in moving from the tropical to the polar regime. Note the very different heights of the tropopause across the three regimes Bear in mind the impact on the atmosphere of the circulation that brings mid latitude and tropical air  to the poles to be mixed  and elevated per medium of polar cyclones and the stratospheric vortex.

Note the difference in the height of the tropopause across the three regimes for North America.on 11th March with Tropical (250 hPa), Midlatitude (300hPa) and Polar (400 hPa)   The fronts between these regimes consequently exhibit steps. At these steps marked differences in air temperature and density manifest in the horizontal plane. This is an unstable situation. From figure 4 (Hudsons Fig 9)  we see that in the tropical regime, the temperature of the air at the tropopause is -70°C, in the Midlatitude zone it is-60°C and in the Polar regime -50°C. In this circumstance, at the vortex, because temperature reflects density,  the vertical interval between 400 hPa and 300 hPa, a distance of some 2 kilometres will be marked by continuous upwards displacement of low density air  and as a result this displaced air will circulate about the globe as an ascending jet on the margins of the tongue of cold dense mesospheric air with occasional discontinuities (as noted above in relation to east Asia and Greenland) that will be marked by extreme turbulence. As this air ascends it must be replaced from below drawing in ozone rich, low density air from lower latitudes together with NOx rich air from the troposphere and some air from the region of the polar cap that is derived from the mesosphere via subsidence.

WHERE DOES THE ENERGY COME FROM TO DRIVE THIS SYSTEM

The energy is supplied via the Earth itself in the form of infrared radiation at twenty times the wave length of the energy originally derived from the sun. The agency for its transmission to the atmosphere is ozone that imparts energy with an efficiency that varies directly with surface pressure. It is here, at the polar vortex that the system exhibits the river of energy thus acquired, not in the tropics where the air is quiescent. The ascent does not respect a ‘tropopause’ because it goes to the top of the atmosphere giving rise to localised ozone ‘hot spots’ at 1 hPa.  These hot spots are likely found over the warmest part of the oceans in mid to high latitudes. When inspecting the temperature response in the upper stratosphere we see that temperature volatility increases with altitude, particularly above 30 hPa.

The system continuously elevates ozone to the top of the atmosphere from where it must return within the  Midlatitude cell. If there is appreciable loss of ozone via ionisation or chemical erosion in the upper upper levels of the Midlatitude cell there must be sufficient ozone created to  remedy the loss and so provide the means to energise the system on a continuous basis, day and night. The Earth obliges in terms of the energy requirement. But where does the ozone come from to replace that lost to chemical depletion and destruction by short wave energy from the sun?

A seasonal low in the incidence of short wave radiation from the sun means that the ozone necessary to sustain this system is not available from the solar source in the winter hemisphere. It’s unlikely that the requisite ozone could be sourced from the  subtropical zone in the summer hemisphere that is remote, across the equator where in any case ozone partial pressure is quite low and always so. So much for the Brewer Dobson Hypothesis! There is however another source of ionisation via cosmic rays.

Vert profile Arctic
Fig 5 illustrating the marked warming of the stratosphere in January and February bucking the winter cooling trend that manifests strongly after November, but very unevenly from year to year.

The waxing and waning of the polar jet stream will reflect atmospheric dynamics due to the changing ozone content of the air, inducing changes in density gradients  across the polar front that in turn affects the rate of intake of mesospheric air. Ionisation by cosmic rays depends upon air temperature almost certainly generating an ozone production dynamic that will amplify change according to the activity of the sun. These interactions affect vortex and polar cyclone activity that vary from week to week, year to year and across the decades according to the incidence of solar activity. Note the incidence of stratospheric ‘warmings’ in figure 5 from January through to April during which the muon count from cosmic ray activity, as measured at the surface and in ice cores is known to respond directly to the changing temperature of the stratosphere. The muon count is a direct proxy for the incidence of cosmic rays and indirectly a proxy for solar activity. See here for background or here for a lecture presentation.

INCIDENCE OF CHANGE IN THE CHARACTER OF THE AIR BETWEEN 400 HPA AND 40 HPA.

Ozonesonde profiles March
Fig 6 Ozone profiles. Note the variation in ozone content and the elevations at which these variations occur, an excellent indication  of the extent of ‘wandering’ across the latitude bands that is characteristic of  the fronts between regimes. When this ‘wandering’ is viewed from the perspective of a person on the ground, the passage of a front is perceived as a change in the origin of the upper winds that are either  cold and ozone poor, coming from low latitudes or ozone rich and warm when the upper air arrives from high latitudes. The change  in the upper air is accompanied by a change in surface air pressure

From figure 6 (Hudson 10) we can infer that the degree of variability in the source and ozone content of the air in the upper troposphere/lower stratosphere increases from the equator to the pole and is most marked in the polar regime that only manifests in winter.  We see that the largest variations in ozone partial pressure in the North American polar regime manifest between 400 hPa and 40 hPa. This interval carries 36% of the  mass of the atmospheric column. Because ozone maps surface pressure and it produces the lowest surface pressures in high latitudes this guarantees that the atmosphere must move from the equator towards the poles. Om the southern hemisphere this movement occurs in a gentle spiral with the air coming from west north west to east south east. Such is the strength of the Antarctic circumpolar vortex that the direction of movement is the same in the northern hemisphere. The vertical intervals where this movement is strongest can be inferred from fig 6. The region between 400 hPa and 40 hPa encompasses the upper troposphere and the lower stratosphere. That this region sees the greatest mobility has implications for the ozone content of the air over the polar cap when the final warming of the stratosphere occurs and mesospheric air is replaced by troposphere air rich in NOx giving rise to an ‘ozone hole’ and so ending the period where the Polar Front is in existence. This circumstance was not appreciated at the time when environmental activists succeeded in having many nations subscribe to the Montreal Protocol to limit emissions of certain halogens supposedly responsible for the ozone deficit. The dynamics behind the creation of the celebrated Ozone Hole are a mystery to climate science to this day.

ORIGIN OF THE DRIVER OF THE GLOBAL CIRCULATION

The surface pressure differential between low and high latitudes directly governs the circulation of the air near the surface and to first order determines the equator to pole temperature gradient. In addition, minor change in the ozone content of the air in the tropical and mid latitudes will drive change in geopotential height at all elevations and with it cloud cover and surface temperature. It should be born in mind that the circulation of the air at the 10 hPa level is equator-wards rather than pole-wards. Accordingly, ozone descends from the top of the atmosphere in mid and low latitudes within high pressure cells.Apart from the surface temperature effect due to change in the origin of the surface winds, the variability in the ozone content of the air in mid and low latitudes drives  a  change in cloud cover to further amplify the temperature effect due to the change in the origin of the wind. These are the central dynamics behind climate change on week to week through to inter-centennial time scales. Surface temperature varies directly with surface pressure and geopotential height. This is the nature of climate change.

The natural variation in sea surface temperature in the southern hemisphere is seen in Figure 7. In terms of causation that figure is instructive.

SH SST
Figure 7 Sea surface temperature in the southern hemisphere according to the Kalnay reconstruction.

Climate change in the southern hemisphere, considered as an entity, measured in terms of sea surface temperature, is largely a matter of temperature change in the winter months. The hemisphere is no warmer in December in the latest decade than it was seven decades ago. An inference as to the origins of climate change is not hard to draw. There is no room here to infer an anthropogenic effect via back radiation.

 

Temp and ozone dist
Fig  8 Ozone and the temperature of the air. Note the higher tropopause is in low latitudes where convection and NOx sculpts the ozone content of the air giving rise to a marked deficiency in ozone below 50 hPa by comparison withe mid and low latitudes. That is why the tropopause in low latitudes is as cold as the mesosphere over the poles and distinctly colder than the tropopause in the mid or high latitudes.

The relationship between the ozone content of the air and its temperature is provided in figure 8 ( Hudson 11). The lack of a 1/1 correspondence between the ozone content of the air and its temperature, given that ozone is an absorber of long wave radiation from the Earth and that this activity is the primarily cause for the unexpected warmth of the stratosphere, is due to the marked flux in the direction of the movement of the air in the stratosphere with warmer air of polar origin that has a lower temperature but a higher ozone content tending to move towards the equator above the 50 hPa pressure level while cold ozone deficient air from the mid latitudes and the tropics moves pole-wards between  the 400 hPa and 40 hPa pressure levels. The latter produces tongues of cold, relatively ozone deficient air showing up in daily and weekly data but obliterated in averaged data over longer time intervals. This phenomenon is reflected in figure 10 as a higher standard deviation in the partial pressure of ozone  between 400 hPa and 40 hPa in the mid latitude and polar regimes. This marked variability due to the origin of the air finds its ultimate expression in the Antarctic ozone hole that manifests below 50 hPa at the time of the final warming of the upper air in spring. Its absence in the northern hemisphere is due to the configuration of land and sea.

The acute reader will realise that there is no room in this circulatory regime for the Brewer Dobson  hypothesis generated in the 1950’s as a possible explanation for the elevated ozone content of the air in high latitudes. The air below 40 hPa moves in the direction of Antarctica or to the Arctic and is generally ozone deficient. The air above 40 hPa comprising just 4% of the atmospheric mass, moves equator-wards and as it does so is increasingly subject to ionisation of ozone by ultraviolet B from the sun.

THE FLUX IN OZONE ACROSS THE SEASONS

Average and STd Devn of TC ozone
Fig 9

Mean total ozone in Dobson units exhibits a different pattern of seasonality in each regime as seen in Fig 9, (Hudson’s figure 13).

Variability in total ozone in the tropics peaks in January and February with a subsidiary  volatility emanating from the Antarctic from August through to December that is associated with final warming dynamics.

Mid latitude and tropical regimes in both hemispheres exhibit strong variability in  northern winter driven from the Arctic. This translates directly to variability in surface temperature. This is natural climate change in action driven by the ozone content of the air in the upper troposphere and lower stratosphere. As noted above it operates by changing the origin of the wind and the extent of the Earths natural umbrella, cloud cover that on average shields 70% of the surface of the earth, less in northern summer and more in northern winter. Accordingly the greater amount of cloud is present when the Earth is closest to the sun in January and the greatest variability in surface temperature across the most of the surface of the earth including the all important southern oceans also occurs in that month. It is no accident that the Pacific Ocean tends to exhibit its largest swings in temperature in January and that marked variability in surface temperature in January  can be discerned in temperature data even in high southern latitudes.

The Arctic Polar regime shows a strong maximum and peak standard deviation in the middle of winter but also a marked amount of variability driven from Antarctica in northern autumn / southern spring at the time when surface pressure falls to its annual minimum at 60-70° south latitude. This is where polar cyclones  are generated on the margins of Antarctica and is the location of the absolutely dominant southern vortex..

CHANGE OVER TIME AND THE MANNER OF CHANGE

There is a second paper from these authors to be found here.:

The total ozone field separated into meteorological regimes – Part II: Northern Hemisphere mid-latitude total ozone trends R. D. Hudson1 , M. F. Andrade2 , M. B. Follette1 , and A. D. Frolov3  Published 2006.

ABSTRACT

Previous studies have presented clear evidence that the Northern Hemisphere total ozone field can be separated into distinct regimes (tropical, midlatitude, polar, and arctic) the boundaries of which are associated with the subtropical and polar upper troposphere fronts, and in the winter, the polar vortex. This paper presents a study of total ozone variability within these regimes, from 1979–2003, using data from the TOMS instruments. The change in ozone within each regime for the period January 1979–May 1991, a period of rapid total ozone change, was studied in detail. Previous studies had observed a zonal linear trend of −3.15% per decade for the latitude band 25°–60° N. When the ozone field is separated by regime, linear trends of −1.4%, 2.3%, and 3.0%, per decade for the tropical, midlatitude, and polar regimes, respectively, are observed. The changes in the relative areas of the regimes were also derived from the ozone data. The relative area of the polar regime decreased by about 20%; the tropical regime increased by about 10% over this period. No significant change was detected for the midlatitude regime. From the trends in the relative area and total ozone it is deduced that 35% of the trend between 25◦ and 60◦ N, from January 1979–May 1991 is due to movement of the upper troposphere fronts. The changes in the relative areas can be associated with a change in the mean latitude of the subtropical and polar fronts within the latitude interval 25◦ to 60◦ N. Over the period from January 1979 to May 1991, both fronts moved northward by 1.1±0.2 degrees per decade. Over the entire period of the study, 1979–2003, the subtropical front moved northward at a rate of 1.1±0.1 degrees per decade, while the polar front moved by 0.5±0.1 degrees per decade.

The subtropical and polar fronts are associated with the subtropical and polar jet streams, and have mean latitudes of about 30° and 60° N, respectively

The positions of the subtropical and polar fronts defined in Hudson et al. (2003) vary on a daily basis as the Rossby waves meander about their mean latitudes. These fronts  are not be confused with the cold and warm fronts associated with cyclonic flow close to the surface.

Note that: When the ozone field is separated by regime, linear trends of −1.4%, 2.3%, and 3.0%, per decade for the tropical, midlatitude, and polar regimes, respectively, are observed.  It is not possible that a linear trend of 3% per decade could be driven from the tropical regime where the trend is -1.4% per decade. To achieve this disparity the ozone trend has to be independently created in high latitudes, and likely more from one pole than the other. It is in fact the Antarctic that drives the multi-decadal and inter-centennial trend.

The authors note that: Between January 1979 and May 1991, the relative area of the Polar regime decreased by about 20%, while that of the Tropical regime increased by about 10%. There was no significant change in the relative area of the Midlatitude regime over this time period. These changes imply a net poleward movement of the subtropical and polar upper-troposphere fronts. That in itself warms the surface.

The fronts define the extent of the hemisphere occupied by masses of air of different temperature.  If the  northern hemsiphere fronts move north the hemisphere warms. The northward migration of the subtropical front implies an expansion of the relatively cloud free area and an increase in the energy absorbed by the oceans.

In this way, change in the ozone content of the air brings about a change in the surface temperature and the energy circulating within the Earth system. When one looks at the data as seen here, this mode of change is entirely consistent with the pattern of temperature change observed between 1948 and the present time.

CONCLUSION

The manner in which the top down generation of surface weather occurs, from stratosphere to troposphere, has been a matter of debate for almost twenty years in connection with what has been described as the ‘annular mode phenomenon’. The papers reviewed in this post are amongst the more significant works published in the field of climate science since the work of Gordon Dobson who devoted his life to the measurement of total column ozone. If we are to be critical, the shortcoming lies in failing to look at the historical record over a longer time interval, to examine the situation in the southern hemisphere and to speculate about mechanisms responsible for change. Simple questions like ‘Why is it so? and ‘What does this mean for the evolution of surface temperature?’ are of the greatest importance but it is precisely in this area that the politics of climate change get in the way.  Accordingly, the link between ozone and the formation of polar cyclones that relates to the evolution of surface pressure in high latitudes is not made. Nevertheless these papers ably support the most cogent explanation of the manner in which natural variations in weather and climate can occur on week to week through to centennial time scales.

Unfortunately, climate scientists are off with the fairies with their CO2 forcing hypothesis and show no sign of a desire to  research the manner in which the climate of the Earth responds to external influences. Work that suggests that the climate system is subject to external forcing is simply ignored… much to the detriment of humanity.

Postscript.

Variability in the distribution of ozone is a  feature of the northern hemisphere as the following diagrams reveal.

2014 850 hPa
Centres of polar cyclone development associated with elevated ozone content in the air.

 

2014 ozone
The circulation is moving west to east entraining ozone from centres of accumulation .

 

2014 N2O
N2O in trace quantities is associated descending air from the mesosphere that is largely devoid of ozone.

 

2014 500 hPa
Surface pressure and circulation of the air at 500 hPa
2014 1 hPa ozone
Accumulation of ozone over the north American continent at 1 hPa as a result of convection.
2015 TC
On 11th March 2015 the ozone concentrations are more dispersed.
2015 50 hPa Ozone
At 50 hPa the core of the circulation over the Arctic is relatively deficient in ozone
2015 50 hPa Ozone
At 50 hPa trace quantities of N2O are associated with air from the mesosphere and an ozone deficit. A wide band over the Eurasian continent also shows evidence of descent.
11th March 2016 TCO
On 11th March 2016 total column ozone is much enhanced over the Arctic Ocean and to a lesser extent over the north Pacific.

11 Mar 2016 50

At 50 hPa there is an ozone deficiency over the Eurasian continent.

At 50 hPa the distribution of ozone is similar with some contraction over the north Pacific and a clearer definition of the ozone deficient zone over the Eurasian continent.

2016 N2O
The ozone deficiency over the Antarctic continent is associated with low N2O content mesospheric air.

The circulation of the air in the stratosphere is about an elongated core of high surface pressure located over the Eurasian continent stretching from Scotland to Mongolia. Within this cell very cold air that has little ozone but tracers of N2O descends from the mesosphere. N2O is primarily derived from soils due to organic decomposition. It is abundant in low latitudes where it scalps ozone to produce an elevated tropopause.

20160311 SLP
An elongated band of high surface pressure is associated with the descent of mesospheric air entering the circulation tangentially.

 

20160311 10hPa
Mesospheric air enters the elongated core of a fast moving descending circulation at 10 hPa. At left is an ascending circulation that is rich in ozone.
2016-03-11 1 hPa ozone
The ascending circulation produces an ozone hot spot at 1 hPa. The descending circulation is associated with low ozone values at 1 hPa. In fact ozone rich air is spilling into this descending circulation changing its character as it descends. Pressure from short wave ionising radiation from the sun in high northern latitudes in March, at which time the sun is over the equator  will deplete  ozone at 1 hPa. The question arises: Where does the ozone come from that is required to energise this circulation?

 

 

 

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