IT does not reflect badly at all, by the self admission of Willard Miller (Satellite communication, ST 5/4/15) that as a mariner when he “studied a bit of meteorology” he “never heard of the Madden Julian Oscillation (MJO)”.
This is correct as the oscillation did exist but was only clearly defined and understood much later in a scientific publication in 1971, and to date, it is still not even fully understood nor used fully by all meteorologists.
The MJO is not a day-to-day forecasting tool similar to a weather map. Nor would you note it in an upper air atmospheric weather chart analysis. These waves are hemispheric scale with varying amplitudes and frequency, and can only be delineated and understood using general circulation computer models.
The MJO is a large-scale coupling between atmospheric circulation and tropical deep convection. A synoptic meteorologist may use this information for him to understand whether we are in a suppressed or an enhanced phase which may have a bearing on his understanding of the thermodynamics of the atmosphere.
Information on the phase of the MJO is one of the many other forecasting aids that a meteorologist will use in his day-to-day career as a specialist tool and laymen will not necessarily hear about the MJO often.
Like all fields of science, meteorology is a very well understood science, and fields like satellite meteorology, radar meteorology, synoptic meteorology, thermodynamic, and dynamic meteorology, very well understood.
However like any other evolving sciences, similarly in atmospheric sciences, some of the large-scale circulation systems, wave energetics and its tele-connections, and linkages are still being fully understood.
Also included are issues of Southern Oscillation, El Nino, La Nina, Hadley Circulation and the Walker Circulation -all these issues and their anomalies, reversals, linkages which are responsible for our natural variability of weather and climate on a global and hemispheric scale are still only now being fully understood. These can aid in long range weather and climate forecasting.
Atmospheric waves in our upper atmosphere moving from the west to east around our globe, with varying amplitudes and frequency, in the form of troughs or ridges, helping with either cyclonic or anticyclonic vorticity advection to the lower surface levels, which either help form, enhance or suppress surface high or low pressure and thus good or bad weather can be explained by these upper air waves.
The MJO is just one of the many contributing factors in weather forecasting, and not an exclusive factor or tool. The MJO is the largest element of the intra-seasonal (one-three month) variability in the tropical atmosphere. It was discovered in 1971 by Ronal Madden and Paul Julian of the American National Center for National Research (NCAR).
Unlike a standing pattern like the El Nino Southern Oscillation (ENSO), the MJO is a travelling pattern that propagates eastward at approximately four to eight miles per second through the atmosphere above the warm parts of the Indian and Pacific oceans. This overall circulation pattern manifests itself most clearly as anomalous rainfall, enhanced convective activity, and thunderstorms.
The MJO is characterised by an eastward progression of large regions of both enhanced and suppressed tropical rainfall, observed mainly over the Indian and Pacific oceans.
The wet phase of enhanced convection and precipitation is followed by a dry phase where thunderstorm activity is suppressed.
As far as other issues raised by Willard Miller (ST 5/4/15), it should be made clear that no tropical cyclones can form 5-7 degrees latitudes of either sides of the Equator. This means that in the areas either side of the Equator bound by latitudes 5-7 degrees north and latitudes 5-7 degrees south, no cyclones can form.
Further no cyclones can traverse and cross from one hemisphere to the other, crossing the Equator. No such notion is suggested in the article “It’s God or Science” (FT 30/3/15, Dr Sharma), either. TC Bavi was always in the Northern Hemisphere and TC Pam in the Southern Hemisphere, and no suggestion is made in the article that they crossed the Equator.
In the tropics, the normal type of analysis of upper weather maps similar to the higher latitudes fails, and a streamline analysis is used for tropical upper air atmospheric analysis.
Streamline analysis is simply a line drawn through — in parallel to the manner of the flow of the air — which clearly shows the inflows, outflows, convergence and divergence of the airflow in the upper atmosphere. This acts as a good guide to the behaviour of the tropical cyclone systems on of the surface levels.
For TCs Bavi and TC Pam, it was clear from upper atmospheric streamline analysis, that these systems were clearly not only feeding and sustaining each other, but also responsible for each other’s movement; stalling TC Pam 1300 km north-northwest of Fiji near latitude 10-12 degrees South, where it was able to build up strength to a category five.
Discussion and explanation of all aspects of the science of tropical cyclone genesis, dynamics, climatology, and forecasting is not possible within the confines of a newspaper, but it is highly appreciated that both daily newspapers were able to cover fully a fairly technical contribution by me, without any objections.
I appreciate the questions raised by Willard Miller (FT 5/4/15) and agree that there was a typo error, the N for North should have read S for latitude South. The typo error was mine and I take full responsibility for it.
* The views expressed are that of the author and not of this newspaper.
