If you thought that ozone was confined to the stratosphere observe the concentration of ozone over Valentia Ireland (52° North Lat.) between 400hPa and 200hPa, an altitude that is well within the troposphere. Because ozone absorbs long wave radiation from the Earth (just like CO2 but more efficiently), it heats the surrounding atmosphere, dries it and evaporates cloud cover. A change in the ozone level of the upper troposphere changes surface temperature because more solar radiation reaches the surface when there is less cloud. Ozone is carried from the stratosphere into the troposphere over the oceans on the margins of the Antarctic and the Arctic and also in the high pressure cells of the mid latitudes. These cells intensify in winter. Change the ozone concentration of the upper troposphere and you change surface climate. The ozone concentration of the northern hemisphere troposphere has doubled over the last 50 years.
Man’s knowledge of the atmosphere and the manner in which it changes over time is still in its infancy. In the 1890s balloonists were very surprised to discover that at about 10km in elevation in the mid latitudes the atmosphere began to warm with increasing elevation. It was not until 1951 that Richard Scherhag first observed a sudden stratospheric warming. In 2013 opinion is still divided as to the cause of these phenomena.
The British meteorologist G. M. B. Dobson, developed a simple spectrophotometer (the Dobsonmeter) that could be used to measure the presence of ozone in the atmospheric column from the ground. Between 1928 and 1958 Dobson established a worldwide network of ozone monitoring stations.
The advent of satellites has enabled exploration of the upper more rarefied atmosphere. Vast resources in manpower and cash have been devoted to this work. Arguably we might have learnt more about the atmosphere and how surface temperature is determined if we devoted more effort to the study of the atmosphere where it is densest, that part of the atmosphere that gives rise to clouds that reflect sunlight. More than 75% of the atmosphere lies within the troposphere.
The presence of ozone, a strong absorber of long wave radiation from the Earth, accounts for the warming of the atmosphere at elevations above about 10 km (in the mid latitudes). But ozone is not confined to the stratosphere. The role of ozone in modulating air temperature and cloud cover in the middle and upper troposphere is undocumented in mainstream climate science.
Ozone in the troposphere is influential because of its effect on the temperature of the air, its local density and therefore the near surface circulation. Nowhere is this demonstrated as dramatically as in an annular ring of extremely low pressure air that surrounds Antarctica. Surface pressure relationships are vital in determining wind strength and direction, the distribution of heat at the surface by location and by season and the distribution of rainfall.
The pressure of the atmospheric at sea level indicates the weight of the molecules in the atmospheric column. If the atmospheric column gains in ozone content its density falls as its temperature rises. Molecules are displaced laterally into locations where the temperature has not changed . This changes the distribution of surface pressure, especially at high and mid latitudes. It is not generally appreciated that dramatic changes in ozone content occur in the polar regions over time that are influential in determining weather and climate at the surface.
Unlike the temperature record, surface pressure is unaffected by the activities of man. We can have much more confidence in the surface pressure record than the temperature record. Unfortunately however, there are parts of the globe where observations of surface pressure are recent and sparse. This is especially the case in the southern hemisphere in mid to high latitudes. It is fortunate that many research stations were established in Antarctica from the 1950’s onward because the atmosphere above Antarctica is vital for the evolution of surface climate in both hemispheres.
The data that presented here has been produced by reanalysis work documented by: Kalnay, E. and Coauthors, 1996: The NCEP/NCAR Reanalysis 40-year Project. Bull. Amer. Meteor. Soc., 77, 437-471. This data is accessible both in terms of monthly averages and graphically at; http://www.esrl.noaa.gov/psd/cgi-in/data/timeseries/timeseries1.pl
Figure 1 shows the monthly flux of temperature at 10hPa over Antarctica. We see that, between 60° and 90° of latitude in the late 1970’s there occurred a sudden increase in the temperature of the ozone bearing stratosphere at 10hPa (26km). Temperature increased by about 10°C both in summer and winter. This was a stepwise increase that was most dramatic in winter when the night jet bringing nitrogen oxides from the mesosphere into the stratosphere is most active. This temperature change is undoubtedly due to an increase in the ozone content of the upper stratosphere. That in turn is most likely due to a reduction in the flow of mesospheric nitrogen associated with a shift in the atmosphere that weakened the night jet. Since the stepwise change in the late 1970’s temperatures at 10hPa have tended to fall away.
A temperature increase in the Antarctic atmosphere at 30hPa (22km), in the late 1970’s, is apparent in figure 2, though much less obvious than at 10hPa. The stepwise change is more apparent in the maximum than the minimum. It is apparent from figures 1 and 2 that it is the upper margins of the stratosphere where interaction with the mesosphere is most active, that exhibits the more obvious stepwise change in temperature.
At 50-60° south where a ring of low pressure surrounds Antarctica, a relatively sudden warming is seen at 925hPa (close to the surface), in the late 1970’s. This is consistent with an increase in ozone in the air column in these latitudes.
The gradual loss of atmospheric pressure at 50-60° south consequent upon the increase in the ozone content of the air (and increase in temperature) is very evident in figure 4. A survey of atmospheric pressure by latitude shows that the atmosphere between 50° and 90° south was progressively depleted. The severe collapse that occurred in the late 1970s is very noticeable. This collapse followed a short reprieve just after the middle of the decade.
The fall in atmospheric pressure that took place after 1950, south of 50° south latitude, is associated with increasing atmospheric pressure elsewhere. The increase in pressure is nowhere greater than at latitude 30-40° south. As pressure falls at 50-60° south it rises at 30-40° south and the differential between the two increases. This differential determines the strength of the prevailing wind, the north westerlies.
Figure 5 shows the increasing, then stabilising, and post 1998 declining difference in atmospheric pressure, between 30-40°south and 50-60° south latitudes. This data is derived quite simply by subtracting the average monthly surface pressure at 50-60°south from the pressure at 30-40° south. The winds between these latitudes are the strongest on the planet. These winds are described by sailors as the ‘Roaring Forties’, the Furious Fifties and the ‘Screaming Sixties’. As noted above, the Roaring Forties are winds of north westerly origin blowing towards the margins of Antarctica. Over the fifty years to 1998 wind strength gradually and relentlessly increased.
This is a phenomenon that is of little interest to mainstream climate science. This is not the first time that these winds have experienced a change in vigour. A similar change is documented in the logs of sailing ships that frequented these latitudes in the eighteen hundreds.
The pressure differential driving the Roaring Forties et al in winter increased from about 15 mb in1948 to about 23mb in 1997-8. However, the polynomial curve suggests that after peaking in the late 1990’s the differential is now decreasing.
The pressure differential in summer increased from 15 mb to 20mb. Again, the polynomial curve suggests that the differential is now decreasing.
- The pressure differential driving the north westerlies is a function of the strength of the Southern Annular Mode. This mode relates to the annular ring of extremely low surface pressure on the margins of Antarctica and its relationship to the annular ring of high pressure at 30-40° south. There is no plausible explanation in climate science for the existence of this annular ring of low pressure on the margins of Antarctica and no apparent interest in accounting for its existence, let alone the change that occurs over time.
- While there is no agreement in academic circles as to the reason behind variations in the SAM, it is plain that atmospheric pressure in the polar atmosphere is a function of air temperature in the Antarctic vis a vis the rest of the globe. That is in turn heavily dependent upon the ozone content of the polar atmosphere, especially in winter when enhanced ozone is excited by long wave radiation from the Earth, long wave energy from the Earth being the only source of energy available at that time.
- The increase in the temperature of the atmosphere in Antarctic regions is at odds with the ideology that suggests that there is a recently developed ‘hole’ in the Antarctic ozone-sphere due to the activities of man. In fact one must recognise the generalised deficiency in ozone in the southern hemisphere by comparison with the northern hemisphere, in all seasons, a phenomenon that is inconsistent with the notion of an atmosphere that is ‘well mixed’ and subject to depletion of ozone only when atmospheric conditions favour depletion by chlorofluorocarbons of anthropogenic origin in spring. This breast beating narrative would be spoiled if the realities of observed status and change were to be recognised.
- The primary force determining the ozone content in the polar stratosphere is the degree to which nitrogen oxides, that are hungry for oxygen, descend from the mesosphere. This phenomenon is primarily a function of the interaction between the stratosphere and the mesosphere and it responds to changes in surface pressure.
- Secondarily, ozone is wasted into the troposphere where it dissolves in water.
- These two forces depleting ozone from above and wasting it into the troposphere below are much more important than the springtime depletion that aligns with the natural loss of ozone due to impinging sunlight at the end of the winter.
- The paucity of ozone in the southern hemisphere by comparison with the northern hemisphere is a reflection of the nature of the much stronger atmospheric circulation over Antarctica.
- The interaction between the mesosphere and the stratosphere and the stratosphere and the troposphere is strongest in winter when the polar atmosphere receives no sunlight and ozone tends to accumulate. In summer the large ozone molecule is easily broken down by short wave energy from the sun. But in winter the polar atmosphere is shaded. So, in winter the breakdown of ozone is of chemical origin. This breakdown is readily apparent in the high altitude night jet directly over the pole. A collapse in the night jet is associated with a plunge in polar surface pressure. These changes are conjunctional. A loss of pressure results in an increase in ozone and marked warming of the stratosphere. That in turn reinforces the loss in pressure.
- Swings in the ratio of high to mid latitude atmospheric pressure in the northern hemisphere are described as the ‘Arctic Oscillation’. The AO manifests in the Atlantic Ocean as the North Atlantic Oscillation (NAO) and in the Pacific as a strengthening and weakening of the Aleutian Low in relation to atmospheric pressure in the mid latitudes. When surface air pressure is high in relation to mid latitudes cold air streams southwards. This produces freezing conditions to the continental land masses of the northern hemisphere. Conversely when polar pressure is low in relation to the mid latitudes warm westerlies stream north and winter temperatures are more benign. The habitability of northern latitudes in the northern hemisphere is associated with relatively low atmospheric pressure in the Arctic. This is a dynamic that has been observed for centuries.
- Variations in the Arctic Oscillation Index have been statistically related to solar activity that is measured in terms of ‘geomagnetic activity’ indices.
Implications for surface climate of change in the Annular modes.
- The high pressure cell that lies in the Indian Ocean off the coast of Western Australia strengthens in winter. The relative strength of this cell affects the passage of fronts that bring rain to the southern part of Australian continent. The fronts represent the conjunction cold dry air of Antarctic origin and moist air of tropical origin. The formation of a strong high pressure cell off the coast of Western Australia in winter can be observed in the rainfall distribution shown in this animation: http://earthobservatory.nasa.gov/GlobalMaps/view.php?d1=TRMM_3B43M
- Increasing air pressure at 50-60°south is associated with a weakening of the winter high pressure cell in the Indian Ocean. Increased winter rainfall in the SW of Western Australia will be experienced as the annular mode in the southern hemisphere reverses the trend of the last sixty years.
- The decline in Western Australian rainfall in the populated south west has coincided with a period of increasing temperature in the northern hemisphere, primarily in winter. This is associated with a dominance of El Nino phenomena in the tropical oceans. El Nino dominance is in turn related to diminished cloud cover associated with the enhanced ozone in the counter westerly circulation that carries ozone towards the equator warming the air and reducing high altitude cloud cover, This phenomena is comprehensively described in the last post on this blog.
- The warming of the northern hemisphere in winter that occurred between 1976 and 1998 associated with a positive AO index is now reversing as the AO index moves into the negative mode (increased polar pressure). This confounds the predictions of those who forecast that the AO would continue to strengthen in association with an increase in the CO2 content of the atmosphere.
- With the turning point in southern hemisphere pressure relations that occurred in the late 1990s the globe is experiencing a stable temperature regime. There has been no warming since 1998. As the SAM moves into a negative mode (increasing Antarctic air pressure and a cooling stratosphere) surface cooling should be expected, especially in winter. Neutral to La Nina conditions should prevail in the tropics, continuing a trend that became well established after the turn of the century.
Politics, ideology, resource use, and waste
The narrative that associates increased CO2 in the atmosphere to surface warming and ‘climate change’ is confounded by the cessation of surface warming after the El Nino event of 1998. Those who promoted that idea should now admit that their notion is false. Predictions based upon that notion were and have always been ill founded. This is not the first time that society has been the victim of an evangelistic movement with an appealing political agenda.
A new narrative is required that accounts for the seasonal and hemispheric differences in the advance and retreat of surface temperature that we observe. That narrative will describe the annual modes linking them to the state of surface pressure relations that drive the winds, cloud cover, surface temperature and rainfall. Change in the annual modes will be linked to variation in the ozone content of the stratosphere. Variation in the ozone content of the stratosphere will in turn be linked to the influence of the sun in ionising the atmosphere and the solar wind affecting the electromagnetic environment of the ionised atmosphere. The atmosphere will be seen to move to and from the poles and to pile up in equatorial latitudes when it departs the poles, chiefly Antarctica. This initiates change in the annular modes. Once initiated, forces within the Earth system tend to enhance and exaggerate change in the atmosphere, promoting and lending persistence to new states.
Scarce resources are currently being wasted on a ruinous scale in pursuit of an objective that is based on a false understanding of the atmosphere. The drivers of surface climate relate to ozone not carbon dioxide. The political agenda derived from the CO2 narrative is unbelievably wasteful. Much is to be gained if, and only if, those who have pushed the global warming bandwagon come to their senses and admit their error. Politicians cannot do this for them. It was the ‘science’ that was in error. Too many who claim to be ‘scientists’ have misled us. Now is the time to put matters right.