42 THE WARMING OF THE INDIAN OCEAN. THE CANARY IN THE COAL MINE

CAUSE OF WARMING

In general the planet warms as surface pressure increases in low and mid latitudes.

The chain of causation runs like this: Increased surface pressure is associated with increased geopotential height, extra warmth in the atmospheric column and a consequent reduction in the quotient of moisture held in the very expansive ice crystal form. As cloud cover diminishes more solar radiation reaches the surface of the planet. When energy is absorbed by the ocean it is stored to depth and, by virtue of ocean currents, re-distributed, fortuitously warming those parts that receive little solar energy.

In contrast, when solar energy falls on land it is swiftly, in the main overnight, returned to the atmosphere. The warming of the atmosphere that is occasioned in northern summer, due to the extensive land masses of that hemisphere,  results in a global deficit of cloud cover in the middle of the year producing the annual maximum in planetary temperature when the Earth is furthest from the sun and solar irradiance 6% diminished by comparison with January.  It should be obvious (how did climate scientists miss this?) that the primary dynamic determining surface temperature is the temperature of the atmosphere in relation to the moisture that it contains.

REDISTRIBUTION

Please inspect the map below. The planetary winds drive ocean currents that mix cold waters from high latitudes and the ocean deep into the warm waters of the tropics. This is evident on the eastern margins of the oceans and particularly so in the southern hemisphere. The Indian Ocean is the odd man out with a weak cold current on its western margins and a warm, southward travelling, current on its eastern margin. The consequence is a relative backwater that is less  affected by the mixing of cold with warm water.

global-sst

It follows that the circulation of the oceans results in a very different thermal regime in each basin according to the  the ocean currents that are primarily driven by the winds. As the winds evolve, so do the currents.

The table below documents the extent of the temperature increase  over the last 68 years according to latitude and longitude in the three major ocean basins. For economy I focus on those latitudes that are warm enough to be relatively hospitable  to man.

sst-in-numbers

It is obvious that the bulk of the Pacific Ocean has not warmed to the same extent as the Indian and Atlantic Oceans. In terms of basin averages, in January the Indian Ocean has warmed by 0.87°C, The Pacific by 0.42°C and the Atlantic by 0.46°C. In July the Indian has warmed by 0.84°C the Pacific by 0.12°C and the Atlantic by 0.6°C. It is in July that the contrast between the oceans is strongest.It is the Indian Ocean that has warmed to the greatest extent.

THE SURFACE PRESSURE DYNAMIC

annual-slp

If we are to understand the differences in the rate of warming of the Ocean basins we need to comprehend to role of polar cyclones in high latitudes. Enhanced polar cyclone activity in the Antarctic circumpolar trough (red and orange in the map above) has, over the period of record, shifted atmospheric mass into low and mid latitudes from latitudes south of the 50° parallel. In consequence the high latitude west wind drift that is coextensive with the circumpolar trough, that drives cold water into the tropics, has accelerated. The flow is restricted at the Drake Passage between the Pacific and the Atlantic. Accordingly the Pacific Ocean cooled in parts and generally warmed at a much reduced rate when compared to the Indian and Atlantic Oceans.

drake-passage

The Indian Ocean is like the canary in the coalmine, a companion to the miner to warn him of a change in the quality of the air. The evolution of surface temperature in the Indian Ocean offers a glimpse of unfettered reality in terms of the march of surface temperature across the globe as it is forced by change in cloud cover associated with shifts in atmospheric mass and the change in the planetary winds.

The remainder of this chapter explores the shift in atmospheric mass from high southern latitudes and its relationship to surface pressure in the rest of the globe and the Indian Ocean in particular.

The discussion is is not based on the hypothetical constructs of a climate model or the abstruse mysteries of so called ‘planetary forcings’.  Rather it is grounded in observation and measurement based on data as  presented in the reanalysis work of Kalnay et al accessible here.

The graph below represents the evolution of surface pressure in the Indian Ocean south of the equator.We must to answer the question: Why is it so?

slp-indian-ocean-south-of-equator

WHY WORRY

The entire southern hemisphere has not warmed in the month of December in the last 68 years. If surface temperature were being forced by increased back radiation from the atmosphere the southern hemisphere should warm in all months.  There is no reason to expect the degree of warming due to a hypothetical increase in back radiation to be different in one month to another.  We therefore discard the hypothesis that temperature at the surface is driven by the carbon dioxide content of the atmosphere.  We look for other mechanisms to explain the flux in surface temperature. Radiation theory is all very well but in the real world, inoperable. The concept of anthropogenic warming is a distraction from fairyland. We can, to advantage, be more discriminating in what we choose to believe.

SURFACE PRESSURE DYNAMICS

sh-high-lat-surface-pressure
Figure 1 Sea level pressure in the region of the Antarctic circumpolar trough compared to sea level pressure in the entire region south of 50° south latitude.

Figure 1 compares the evolution of sea level atmospheric pressure in the Antarctic circumpolar trough to all latitudes south of 50° south. It is plain that the relatively short term fluctuations in surface pressure in the larger entity are greater than in the ‘trough’. In point of fact the trough expands and contracts across the parallels affecting surface pressure in adjacent latitudes and in particular across the Antarctic continent. The agent of change is polar cyclone activity that is energised by differences in atmospheric density between very different parcels of air that meet in the region of the trough in the very broad interface between the stratosphere and the troposphere between about 400 hPa and 50 hPa. It is in this region that the strongest winds are to be found. Polar cyclones are generated aloft. This is the nature of the ‘coupling of the troposphere with the stratosphere’, a concept that is a postulate of conventional climate science but remains a mystery so far as its modes of causation is concerned. If one is wedded to radiation theory it limits the mind.

slp-50-90-s-and-90n-to-50s
Figure 2 twelve month moving averages of sea level pressure either side of the 50° south latitude band encompassing the globe as a whole.

In figure 2 we compare the evolution of surface pressure south of the 50° south  parallel of latitude with surface pressure north of that same parallel. If the total mass of the atmosphere were to be invariable we would expect a strictly reciprocal relationship. As pressure falls on one side of the 50th parallel it should rise on the other. Plainly, the increase, decrease and subsequent increase in surface pressure in concert, between 1948 and 1964, is evidence of a planetary evolution in the quantum of atmospheric mass perhaps associated with enhanced loss in very active solar cycles and incremental gain in quiet cycles. That is a subject for another day.

Plainly, since 1964 it is the reciprocal transfer relationship that dominates. When atmospheric mass is lost south of the 50th parallel it moves north the 50th parallel and vice versa.This process of exchange is referred to as the Antarctic Oscillation.

slp-indian-versus-90n-50s
Figure 3

In figure 3 we compare the evolution of surface pressure in the Indian Ocean south of the equator through to 30°of latitude with that north of the 50th parallel.

indian-versus-90n-70-50s-two-axis
Figure 4

Figure 4 presents the same information as in figure 3 but on two axes with independent scales. It’s plain that broadly speaking the Indian Ocean south of the equator gains and loses atmospheric mass in parallel with all points north of the 50th south parallel but there are short term differences. These discrepancies are likely due to complex interactions between the southern and the northern hemispheres where, depending on the time of the year the Arctic Oscillation imposes change in the southern hemisphere or in the reverse, the Antarctic Oscillation imposes change on the northern hemisphere, tending to produce ‘mirror image’ results. Short term variations in these two data series  can be in opposite directions.

sst-indian

Figure 5

In figure 5 we compare the evolution of sea surface temperature in the Indian Ocean north of the equator  with that south of the equator.  The data is a twelve month moving average of monthly  means so as to remove the seasonal influence. It is plain that the more extreme variations occur north of the equator. Nevertheless the series are very similar in their evolution with generally coincident peaks.

sst-and-slp
Figure 6

In figure 6 we compare the evolution of sea level pressure in the Indian Ocean to the south of the equator with the evolution of sea surface temperature in the Indian Ocean north of the equator. Sea surface temperature tends to lag surface pressure by a few months. Plainly the Antarctic Oscillation affects sea surface temperature via coincident heating of the atmospheric column as reflected in increased geopotential height driving a reduction in cloud cover.

indian-ocean-sst-and-gph
Figure 7

Figure 7 looks at the relationship between geopotential height and sea surface temperature. Note that geopotential height is strongly related to sea surface temperature but the relationship is  not proportional. It is not the increase in sea surface temperature that drives the increase in geopotential height but warming of the air column due to the increase in the ozone content of the air within descending columns of air. These air columns reflect in their temperature the increased surface pressure, the increased warming at the surface and the increase in the ozone content of the descending air. At 200 hPa the air is warmer in winter than in summer due to enhanced ozone content in winter. The temperature of the air is independent of the temperature of the surface over which it lies.

slp-and-sst-monthly-indian
Figure 8 Sea level pressure in the Indian Ocean south of the equator compared to sea surface temperature north of the equator. Temperature lags pressure.by several months. There is pronounced warming in southern hemisphere winter months and occasional warming cycles in the summer months, notably in 2009-2010 and 2012- 2013. This warming is tied to the ozone content of the air in high latitudes.

In figure 8 we focus on monthly data.  Shown is the departure of a particular month’s data from the whole of period average for that month.

This graph reveals a climate system that is capable of swinging between a sea surface temperature anomaly of about -0.3°C and +1.2°C in an interval of between one and six years. The amplitude of this variation is almost double the increase in temperature that has occurred in the Indian Ocean over the last 68 years.  In this circumstance we should simply move on. There is nothing exceptional about this increase in temperature. There is no need to invoke new modes of causation to explain this phenomenon.

RECAP

Why has surface pressure and sea surface temperature in the Indian Ocean increased almost continuously since 2011? The answer lies in the forces that determine polar cyclone activity in the Antarctic circumpolar trough. Those circumstances relate to the  changing nature of the atmosphere in the area of overlap between the stratosphere and the troposphere in high southern latitudes.

As Gordon Dobson observed back in 1925, surface pressure is a by-product of total column ozone. Low pressure cells have more ozone aloft and exhibit a lower tropopause than high pressure cells.

Ultimately polar cyclone activity and surface temperature together with wind direction and intensity and the extent of mixing in the ocean  are a function of the ozone content of the air in high latitudes.

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17 thoughts on “42 THE WARMING OF THE INDIAN OCEAN. THE CANARY IN THE COAL MINE

  1. This chapter led me to wonder the implications of the recent, and relatively extreme values in the AO, ENSO, and the SOI. although I do see a lot of commentary moderating the likelihood of high intensity la nina. The 30yr charts I have seen show the Atlantic heat content is falling away, and perhaps faster than it built up. This BOM site http://www.bom.gov.au/climate/mjo/#tabs=Cloudiness also says to me Australia has experienced less cloudiness 2016 YTD. Pity I canot acess same radiation charts as other reader/commenter REN. Be nice to look at current high radiation and magnetic field as drivers of ozone production rather than DWIR.

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    1. Sorry Erl, DWIR downward longwave Infrared. Ie what I read as back radiation. Anyway, I am all over the place reading and analysing bits from this article at the moment. I keep gettin fixated on energy relating to GHGs, when in know it’s irrelevant. Moving on.
      I have since found, but not verfied, that the Atlantic Ocean is a net evaporative basin and is thus more saline at the surface than the Pacific where the latter rains more than evaporates. As a consequence, the global oceanic circulation must therefore induce a net water transport from the Pacific to the Atlantic to achieve a water balance. But the ocran heat is not circulated at the surface, hence appearance in high latitude North Atlantic. Sea surface temps are more crucial to air temps due to heat capacity of water far exceeding air – regardless of composition.

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      1. DWIR is what you get when you model the climates feed back of the Sun using the linear Bodes amplification equation and you insert a highly non-linear equation in the feed back loop – namely, the Stefan-Boltzmann equation – which changes the output of Bodes equation from energy flux (which were units of the input) to temperature.

        This equation was invented by Hansen and is flawed on so many levels.

        It invalidates the Bodes equation since Bodes equation doesn’t hold for nonlinear feed backs – and it violates energy conservation – not to mention the Second Law of Thermodynamics.

        The so-called DWIR used by climatology is the part of Hansen’s modification of Bodes equation which violates energy conversation.

        Further, net heat flows from hot to cold and the re-radiation of the absorb radiation by molecules in the atmosphere is omni-directional, i.e., the heat percolates to the stratosphere.

        It is physically impossible for CO2 to trap heat – it’s excited state in the band in question lasts on the order nanoseconds – not to mention it’s well mixed and it always lags the temperature change.

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  2. Downwelling Infra Red. That through me. Because it doesn’t have any association with the production of ozone. And DWIR is a function of surface and atmospheric temperature. It is not the agent of change in surface temperature but a response to surface temperature change that depends on incoming radiation as mediated by clouds.

    In the southern hemisphere where most of the ocean is located surface temperature follows surface pressure between the equator and 50° south while surface pressure in this region is a mirror image of surface pressure south of the 50th parallel. The agent of change of surface pressure is polar cyclone activity forced by the ozone content of the air.

    If we could relate what is happening to temperature to a single parameter, like surface pressure its a lot easier to understand than relating it to indices like the SOI, the AO, and the AAO that are a complete mystery to most people.

    This graph is up to date with the latest monthly data: https://i0.wp.com/reality348.files.wordpress.com/2016/10/sst-n-and-s-to-50-parallel.jpg?ssl=1&w=450

    The northern hemisphere is tied to what happens in the southern by a short rope. But in the short term, like seasonally, the northern hemisphere atmosphere is forced to a mirror image response to what happens in the southern hemisphere by the dominating influence of the Antarctic circumpolar trough. It appears that the flow of moisture from low to high latitudes is affected by a changing balance of surface pressure between the mid latitudes of both hemispheres. Specifically, it appears as if rising pressure in the mid latitudes of the southern hemisphere is associated with a change in the balance of surface pressure between the mid latitudes of the two hemispheres and a diversion of wet tropical air to the north, increasing cloud cover and reducing surface temperature even though surface pressure may be rising in the low to mid latitudes latitudes of the northern hemisphere. So, a different rule for the south and the north.

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  3. Erl, I dont suppose you have access to the Wiley online library….lots of interesting stuff. Take this for example. http://onlinelibrary.wiley.com/doi/10.1002/2016JD025268/full. All about winds speed and pressure bands isolating air parcels leading to cloud cover and temperature change….duh..
    We investigated the atmospheric processes over high sea surface temperature called Hot Event (HE) in the western equatorial Pacific. The suppressed convection above high SST area resulted from the deep convection from the northern and southern areas outside HE. The suppressed convection created a band-shaped structure of low cloud cover along HE area increasing solar radiation during the development stage. surface wind had an important role to influence the variability of solar radiation by controlling the water vapor supply in the upper troposphere through surface evaporation and surface convergence variation. Thus, surface wind was the key factor for HE.
    The Chinese seem to be on track with some good stuff.
    Be nice to have access, eh?

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  4. Thanks for another fascinating installment.

    Thanks for the good work in explaining the observed climate and weather pattern of this world and not some modeled theoretical nonsense about an innocent gas.
    Gordon Dobson’s work on ozone and atmospheric pressure is the key that powers this message here. Maybe it would be useful to have a permanent link to the Dobson’s papers on the header at the top of the page for reference. Maybe that would help stall a few questions about astrophysics and/or gases holding/re-radiating ‘heat’.

    Hopefully your work here will get wider appreciation now that Donald Trump is on his way into power.

    I note currently there is a vast high pressure zone over most of the Northern Hemisphere, I assume that this does not bode well for a mild winter over most of Eurasia and North America. Would that be correct?

    Now I need to go an cogitate a bit longer on the implications of this information.

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    1. Tom, Thanks for the kind words. You are right about the importance of Dobson’s observations. Air temperature relates to the origin of the wind and that depends upon surface pressure dynamics. Surface pressure depends on the ozone content of the atmospheric column. That’s the same as saying that surface pressure is determined in the stratosphere.

      A cold winter in the northern hemisphere this year? I have no off the cuff answer. The pressure and temperature dynamics in the northern hemisphere are very complex. At the simplest level low pressure zones (with an ozone dynamic) are established over the sea in high latitudes in winter while the sea supports high pressure cells in the mid latitudes and the enormous land masses also support high pressure cells in winter.

      The surface pressure of the entire northern hemisphere is dependent on surface dynamics in the Antarctic circumpolar trough that is in turn dependent on an ozone dynamic.

      If we look at the evolution of surface pressure in the mid latitudes of the northern hemisphere where most of the population resides we have this: http://www.esrl.noaa.gov/psd/tmp/climindex.101.177.92.161.329.15.15.46.png
      So, lots of variability in both summer and winter.

      When we look at surface air temperature in the mid latitudes we have this: http://www.esrl.noaa.gov/psd/tmp/climindex.101.177.92.161.329.14.52.28.png

      When we look at sea surface temperature in the same latitudes we have this: http://www.esrl.noaa.gov/psd/tmp/climindex.101.177.92.161.329.15.13.49.png

      Temperature was warmer in the fifties and again in recent decades with no advance in summer and lots of variability in winter. There is no relationship with CO2.

      All that we can say is that there is no obvious relationship between surface pressure and air temperature in the mid latitudes of the northern hemisphere and that to be usefully analytical we should look separately at summer and winter conditions.

      But there is a long appreciated relationship between the temperature of the air and its origin that is captured in the relationship between surface pressure in high latitudes vis a vis the mid latitudes and its called the Arctic Oscillation Index. This dynamic may be more important in the European/Atlantic sector than in East Asia where surface pressure tends to be highest and its in times of high surface pressure over East Asia that the Siberian, Mongolian, Chinese and Vietnamese peoples experience very cold conditions. It is possible for the Arctic to be warm and east Asia very cold.

      I will say that without an appreciation of the evolution of surface pressure in high southern latitudes and its impact on the uptake of energy by the southern oceans one can not begin to understand the evolution of surface temperature anywhere on the globe or the aggregated average for the globe as a whole.

      Again, the northern hemisphere is not simple. If there was a simple rule I would be very happy to present it.

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      1. Thank-you for the reply.
        Lots more for me to think about. As I keep seeing low pressure from the American eastern seaboard head towards Europe across the Atlantic only to deviate either North or South ending up going to either Greenland or Spain, all the while a huge high pressure wobbles about between Britain and Scandinavia.
        Looks odd, quite unseasonal compared to recent years.
        The high pressures over Britain/Scandinavia are really doing nothing good for all the windfarms they’ve littered across the countries, throwing talk of possible black-outs if it continues.

        Ho-hum, we live in interesting times.

        PS hope your grape harvest have been better than those in France. Poor weather they say causing worse harvest for 30 years — good for you, eh?

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  5. Hi Tom, Thanks for your observations. It helps to keep one interested.

    The local grape harvest is likely to be down due to an unusually cool late winter and spring with damage to the developing primordia due to strong winds and poor shoot development due to cooler temperatures. Could be a similar year to 2006 when we struggled to ripen a small crop in another skinny year where spring was cold.

    Research reported this week from glass house experiments with grape vines reveals that time of maturation relates to the CO2 content of the atmosphere. Warming alarmists have been promoting the notion that earlier maturation experienced in recent decades is due to high temperatures. In fact its due in part or whole to the fact that the vine can produce carbohydrates faster when CO2 is enhanced and the vine water requirement (its a summer growing crop in a winter rainfall regime) is reduced. So, arid zones like Australia have been greening up as parts, like the west coast where I live, have seen a 20% reduction in rainfall. Wheat production has been growing fast in parts formerly considered desert.

    From a plants point of view 250ppm carbon dioxide in the atmosphere represents starvation levels. As the planet greens we can expect the CO2 content of the atmosphere to increase at a reduced rate and perhaps even stabilise.

    In any case there is no causative relationship between surface temperature and the CO2 content of the atmosphere. The entire southern hemisphere has not warmed in the month of December for seven decades.

    I don’t think that the environmental lobby is stupid. Rather, they are contriving. If its not the latter they must be exceedingly stupid. Perhaps the notion of renewable energy is evidence of the latter.

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    1. Nope. My data comes from the Kalnay et al reanalysis accessible here: https://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl Its compiled using many sources and cross checks via internal relationships as assessed in a computer program. Its designed to assist the effort to work out relationships and provide as reliable a history of a whole bank of relationships including the all important atmospheric relationships from the surface to the top of the atmosphere.

      Bob has diverse sources but I see a lot from KNMI Explorer.

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