Guest post by Erl Happ
The presumption that ‘the science is settled’ is incorrect.
This post aims to give readers an understanding of the dynamics of the coupled circulation of the stratosphere and the troposphere at the poles that drives surface pressure, the temperature of the troposphere, cloud cover and surface temperature.
Shifts in the atmosphere to and from Antarctica occur on daily and weekly time scales. These shifts have delivered a sixty year increase followed by a sixty year decline in atmospheric pressure. Witness the change between the decade starting 1948 and the decade starting 2001 shown in figure 1.
Figure 1 Change in sea level pressure according to latitude mb.
The shift in the atmosphere over Antarctica occurs in winter, spring and summer with greatest effect on 10hPa temperature at 80-90°south latitude in August and September.
Figure 2 Temperature by month at 10hPa and 80-90° south. °C
Figure 3 below shows that the temperature change is highest at the highest altitude. Temperature peaked in 1978 and has fallen away since that time. In ‘Climate Science’ the fact and the implication of these changes in the southern polar stratosphere are unrecognized.
Figure 3 Evolution of temperature in the stratosphere at 80-90°south. Twelve month moving average. °C.
The change in atmospheric pressure at the poles can be monitored as the Arctic Oscillation Index (AO) or the Antarctic Oscillation Index (AAO) as depicted in figure 4 and 5. Although these indices are computed as a ratio of atmospheric pressure between the poles and the high mid latitudes, most of the change in pressure occurs at the highest latitudes as is clearly apparent in figure 1.
The right axis in figures 4 and 5 is inverted. The Arctic Oscillation Index and the Antarctic Oscillation index both vary inversely with polar pressure at 80-90°north latitude.
Figure 5 Sea level pressure at 80-80°south and the AAO. Left axis SLP mb.
Daily data for both the AO and the AAO can be found at:
In figure 6 we can see that a fall in the AO (increased surface pressure) is always associated with a strong increase in the temperature of the atmosphere below 100hPa. The warming extends all the way to the surface. As air descends, the net of ozone molecules gathering long wave radiation becomes finer. This is classic greenhouse activity. The warming seems to diminish below 500hPa, perhaps because the surface at the poles is always cooler than the air above it.
The latitudinal coverage of figure 6 extends between 65° and 90°north. So figure 6 does not encompass the zone where the troposphere is affected by ozone (latitude 50-60°north). This is responsible for the zone of ‘negative velocity’ (ascending air) in figures 8, 9 and 10 that are colored mauve through to blue. A zone of descending air colored red is located between 70 and 90° of latitude. This confirms the dynamic described in relation to figure 6 relating a low AO index (high polar pressure) with warming of the air column below 100hPa.
Zones of descending stratospheric air at 60-70° south are discontinuous. Figure 7 shows that the recent cooling of the stratosphere at 60-70° south and 10hPa is most evident between the Greenwich meridian and 180° east.
Source of figures 8,9 and10: http://ds.data.jma.go.jp/gmd/jra/atlas/eng/atlas-tope.htm
November is the transition month when coupled circulation is enhanced in the Arctic and loses strength in the Antarctic. In the Antarctic, the lowering of the cold point from its winter altitude of about 25hPa diminishes the coupling of the stratosphere and troposphere via its effect on the strength of convection.
From figure 11 we discover that:
1. When the Arctic upper stratosphere warms the equatorial upper stratosphere cools. This should be expected given the thickening of the atmosphere at the equator and a slight outward movement of the zone of heaviest ionization. That we see this activity suggests a significant plasma presence in the equatorial middle and upper stratosphere.
2. Relating the timing of warming events shown in figure 11 to the date of their occurrence in figure 6 we see that, as the upper stratosphere warms at the pole, the AO index increases, confirming a loss of surface pressure at the pole. This warming of the polar atmosphere, greater with altitude is consistent with a reduced flow of NOx from the mesosphere via a weakened night jet.
3. Going back to figure 6 we observe a cooling of the air in the lower profile as the polar upper stratosphere warms suggesting a commencement of a general uplift of the entire polar air mass. This is consistent with an increased flux of ozone into the troposphere on the margins of the night zone, a lowering of surface pressure there, cloud loss and increased surface temperature.
How much of this coupling is maintained over summer when the cold point in the stratosphere descends? To assess this we can simply look at the pattern of geopotential height anomalies at 200hpa (upper troposphere) bearing in mind that no month or season can be ‘typical’ and the concept of an ‘average flow’ is inappropriate at anything less than the time scale required for the complete evolution of the phenomenon. Our records are not long enough to support such an analysis. However, flux in wind strength in the southern high latitudes, a direct consequence of pressure fluctuation, suggest an evolution over a period of at least 120 years.
Lastly, in figures 11 and 12 we can observe that zones of anomalous warmth in the stratosphere are cool in the upper troposphere and vice versa. In the coupled circulation it is the coolest parts of the stratosphere that descend into the troposphere.
Note: The dynamic described here is arguably ‘the’ climate change dynamic that accounts for climate change over recent time.
I have suggested elsewhere that there is nothing internal to the climate system that could drive this dynamic. Change in pressure is likely related to electromagnetic influences that are amplified by the coupled circulation. A fall in surface pressure begets a further fall in surface pressure.
If this dynamic is acknowledged climate science as we know it today would be turned on its head.