Is the poleward migration of the maximum intensity of cyclones a result of tropical expansion or are there some other contributing factors?

Question

In the recently published article by Kossin et al. (Nature, 2014, dx.doi.org/10.1038/nature13278), they show that there is a trend toward poleward migration of the location of tropical cyclone (hurricanes and typhoons) maximum intensity in most areas of the world.

Their proposed explanation focuses on the tropical expansion (the increasing area of the world where tropical phenomena is observed has expanded in time). Is there some alternative explanation for the poleward migration of the hurricanes?

The shift seems to be occurring in the Pacific and Indian Oceans but not in the Atlantic. How can we explain that difference?

Answer 1

You will find the full text of Jim Kossin's migration paper here. http://www.ssec.wisc.edu/~kossin/articles/nature13278.pdf In it he describes his findings only as an empirical observation. He does state that the migration is consistent with tropical expansion but he does not attribute the migration to the expansion. In fact he does not get into the subject of attribution at all. Perhaps attrbution will be the subject of a future paper. You may wish to check his list of publications from time to time to see if he has written an attribution paper. His (vey impressive) publication list may be found at http://www.ssec.wisc.edu/~kossin/pubs.html