Positive Phase of PDO?
The first figure in the article on PDO shows positive phase and cites the original source, an article in Annu. Rev. Mar. Sci. But the figure in the source is very different. PDO is defined as the anomaly in the Pacific north of 20N. In the Wikipedia figure, the warm and cool areas are about equal, so the phase is closer to neutral rather than positive. I wanted to use it in a lecture, but it is not at all convincing. In the original article, the figure shows a clearly cool anomaly, hence a positive phase.
Hi,to me the two images looks very similar except for the different colors table(green is a positive anomaly into the original source vs orange in my image) and they should be similar because both are computed from the same dataset(HadISST) over a similar time period(1900-2008 vs 1900-2010) and likely with the same software(NCL); the anomaly over the north pacific is negative because the amplitude of the central pacific anomaly is greater than the positive one along the north american coast and per area ~62.5% of the north pacific have a negative anomaly.--Giorgiogp2 (talk) 20:09, 17 April 2014 (UTC)