AbstractModulation of tropical cyclone (TC) genesis by Madden-Julian Oscillation (MJO) has been quantitatively diagnosed by using climatological Genesis Potential Index (GPI). Analysis of TC genesis during November-April of 1979-2014 indicates the most effective factors controlling intraseasonal TC genesis are 850hPa relative vorticity (ζr850,) weighted by the Coriolis parameter, fζr850, and 500hPa vertical motion (ω500). The total vertical wind shear and maximum potential intensity are unimportant, and the role of 600hPa relative humidity is highly represented by ω500. The MJO modulates TC genesis primarily through changing low-level vorticity induced by its Rossby wave gyres and meridional shears of equatorial zonal winds. A new Intraseasonal GPI (ISGPI) is proposed to quantify MJO’s modulation of TC genesis. The ISGPI significantly improves representation of intraseasonal variation of TC genesis in the tropics and in each sub-region of southern Indian Ocean, Australian monsoon and South Pacific. In the hot spots of southern hemisphere TC genesis zone, the probability of TC genesis can differ by a factor 5-19 due to MJO modulation. The results suggest that the large-scale factors controlling TC genesis may vary with different time scales and the climatological GPI may not be quite applicable for diagnoses of climate variability and future change of TC genesis potential. To simulate realistic impacts of MJO on TC genesis, the general circulation models must reproduce not only realistic eastward propagation but also the MJO low-level circulation structure. Application of the new ISGPI may have a large potential to improve dynamical sub-seasonal prediction of TC genesis.
Journal of Climate – American Meteorological Society
Published: Mar 2, 2017
It’s your single place to instantly
discover and read the research
that matters to you.
Enjoy affordable access to
over 12 million articles from more than
10,000 peer-reviewed journals.
All for just $49/month
Read as many articles as you need. Full articles with original layout, charts and figures. Read online, from anywhere.
Keep up with your field with Personalized Recommendations and Follow Journals to get automatic updates.
It’s easy to organize your research with our built-in tools.
Read from thousands of the leading scholarly journals from SpringerNature, Elsevier, Wiley-Blackwell, Oxford University Press and more.
All the latest content is available, no embargo periods.
“Hi guys, I cannot tell you how much I love this resource. Incredible. I really believe you've hit the nail on the head with this site in regards to solving the research-purchase issue.”Daniel C.
“Whoa! It’s like Spotify but for academic articles.”@Phil_Robichaud
“I must say, @deepdyve is a fabulous solution to the independent researcher's problem of #access to #information.”@deepthiw
“My last article couldn't be possible without the platform @deepdyve that makes journal papers cheaper.”@JoseServera