Number of comments: 2
Comment by: Vasu Misra
September 11, 2015 - 1:01pm
Any of the 5 wet regimes that could explain the bimodal peaks in rainfall over Central America and western Caribbean. I would believe the first of the two bimodal peaks in May-June is too early for tropical-mid-latitude interaction to happen consistently?
Are you also implying that the absence of tropical-midlatitude interaction gives rise to "dry regime" types?
Comment by: Nicolas Vigaud
September 11, 2015 - 1:35pm
Greetings Vasu and thanks for your interest.
Dry regimes 2 and 4 seem to dominate the May-Nov period and be more frequent during Jul-Sep to the detriment of wet regimes 3, 6 and 5 most particularly, hence agreeing with a rainfall break. On the other hand, wet regime 3, at the beginning of the sequence we describe in the poster, seems to be more frequent for the second peak compared to May-Jun which actually supports your guess. To answer your second question, this same wet regimes 3-6-5 sequence displays tropical-midlatitude interactions in which easterly waves could be seen as seeds of convection transiting westwards which midlatitude westerly waves can cap, hook and sustain in their transition across the Caribbean basin. In this sense, the midlatitude component could be a necessary ingredient for the most rainfall-producing episodes but not all, i.e. regimes 1 most frequent during the first peak. On the other hand, dry regimes do not show similar wave-like pattern in the upper-troposphere, rather high pressure anomalies at surface and sustained subsidence, thus I do not think these results would imply the above. At this stage, I still need to fully examine the stratification of the circulation anomalies along the season and your input are well precious, thanks!
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