Mediterranean climate regions rainfall data

I don't know if anyone is interested in this, but I was looking at 
some climatological data and decided to play around with plotting 
some rainfall data from "mediterranean" areas around the world and 
see how they compare. I picked a representative location from each 
place (and ended up hopping all the way around the Mediterranean 
basin) and noticed a few interesting things. Maybe this can provide 
some insight into why plants from some of these regions tolerate or 
require conditions that sometimes frustrate people who try growing 
them in one of the other "mediterranean" areas. Maybe not...

I have created a PDF file (readable with the free Adobe Acrobat 
Reader <http://www.adobe.com/products/acrobat/readstep2.html>) of one 
of the plots I made which I have attached.

Anyway, a few things I noticed were:

1. The Perth area and Adelaide area of Australia and the Cape Town 
area of South Africa have much wetter summers than the other 
mediterranean areas. However, so does the region from Marseille, 
France to Rome, Italy. This was a surprise to me. It was also 
interesting to see that Marseille and Rome both have their peak 
maximum rainfall in October (mid-autumn) rather than mid-winter like 
everywhere else, even though their peak minimum rainfall occurs in 
mid-summer (July, or January for the southern hemisphere).

2. The mid-highland areas on the dry side of the Hawaiian islands of 
Maui and Lanai seem to have a temperature and rainfall profile that 
to my eyeball looks just like any other recognized mediterranean 
climate region. (Although their peak minimum rainfall seems to occur 
one month earlier than everywhere else.) I suspected this after 
having seen all the banksia and protea and eucalyptus growing at that 
elevation in Maui. I wonder if there are any other islands or 
highland areas in the subtropics with similar conditions that are 
also effectively mediterranean. (This would give us "six" 
mediterranean climate regions in the world...)

3. Other than the 6 month shift and the higher summer rainfall in 
Australia, I was surprised to see that Perth and Beirut, Lebanon have 
almost identical monthly rainfall patterns. I wouldn't have guessed 
that those two places were so climatically similar.

4. This isn't shown in the plot, but I was surprised at how very 
rapidly the "mediterranean" pattern disappears as one moves away 
towards the northeast or east from Cape Town, South Africa, or 
towards the north, northwest, or west from the French Riviera into 
areas that aren't mediterranean---unlike the analogous situation in 
California and Baja California, or in Chile, or in the Perth and 
Adelaide areas of Australia, or in the rest of the Mediterranean 
basin, (or as one heads north from Cape Town), where the rainfall 
pattern gradually merges into a different climate rainfall pattern 
(most often a desert-like one).

5. Based on the rainfall patterns for different parts of New Zealand 
that are easily available, I can't understand why they can grow so 
much mediterranean climate stuff there so easily. Auckland, 
Wellington, and Christchurch are all much wetter year-round than the 
"standard" mediterranean regions.

Anyway, I hope a few people find the plot useful.

Medit.pdf

-- 
--Lee Poulsen
Pasadena area, California, USDA Zone 9-10
wlp@radar-sci.jpl.nasa.gov
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