Number and energy of cyclones and anticyclones

  1. How many cyclones and anticyclones are there in the northern hemisphere compared to the southern hemisphere, on a typical day of the year.Is the energy of cyclones/anticyclones in the north greater than the energy of the cyclones/anticylones in the south? How do the numbers of cyclones/anticyclones vary over a period of decades?
     
  2. jcsd
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  3. jamalmunshi

    jamalmunshi 8
    Gold Member

    This is a really great question but it is such a vast question that it would be difficult for anyone to post a comprehensive response. Perhaps a collection of regional responses may eventually add up to sufficient data for you to see the kind if pattern that you are looking for. Most tropical cyclone activity consist of (1) the Atlantic hurrianes, (2) the Pacific typhoons, (3) the Australian cyclones, and (4) the Indian Ocean cyclones. I can contribute some information about the Indian Ocean where there are two cyclone seasons that peak in May and October. I did a study of total cyclone intensity in the Indian Ocean for the period 1998-2014 and found no statistically significant trends although I did find a very sigfinficant amount of cyclone energy consistent with high sea surface temperature and favorable wind patterns throughout the period except for a couple of quiet years including the very quiet 2012 seasons - both May and October. I posted my findings online and would be grateful for your comments if any.
    http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2586947
     
  4. jim hardy

    jim hardy 5,021
    Science Advisor
    Gold Member
    2014 Award

  5. D H

    Staff: Mentor

    Some basic rules of thumb:
    • The northern hemisphere gets hammered much harder than does the southern hemisphere.
      The Southern Ocean creates a lot of wind sheer that militates against cyclone formation.
    • The Pacific Ocean gets hammered much harder than do the Atlantic or the Indian Oceans.
      The Pacific is big.
    • The western Pacific Ocean gets hammered hardest of all.
      The Pacific is very, very big.
    Taiwan, Okinawa, southeast Asia: They get hammered, hammered hard, and nowhere else compares. I recently traveled to Okinawa. The buildings there are concrete bunkers. They know how to protect themselves against typhoons.

    Here's a nice image that illustrates things:

    [​IMG]
     
  6. Just my guess, but I think the likely reason for why there is on average less intense storm activity in the southern hemisphere, is because there is less land.
    The presence of land greatly influences the flow direction of sea and air currents causing air masses with very different characteristics to often form boundaries,
    Those boundaries, (fronts), are regions where a lot of potential energy is available to be converted into kinetic energy, particularly in the form of convection, which is necessary for the formation of storm systems.
    Also other phenomena such as warm moist air being cooled leads to condensation of water vapour resulting in rain.
     
    Last edited: Apr 19, 2015
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