The regression pattern of (a) TPT from MERRA data and (c) SST anomalies from HadISST data regressed on the PDO index (e). The PDO index is the leading PC of observed SST anomalies over the North Pacific (20°–70°N, 110°E–100°W) from the HadISST data for the period 1900–2014, with the seasonal cycle and the global mean removed. The PDO mode explains 27% of the variance of the SST anomalies. The thick black line in (e) represents the low-pass (6-year) filtered PDO index. The time series of TPTs are first low-pass filtered and then regressed onto the filtered PDO index. TPT anomalies are derived from the MERRA data. The black contour lines in (a) show the explained variance in percent, whereas stippling in (a) indicates the 95% significance level, with autocorrelation effects taken into account. (b,d,f) Same as (a,c,e), but for the Natural CESM experiment from 1955–2099. The right hand side number in (d) is the pattern correlation between (d,c). Maps were produced using licensed IDL (http://www.harrisgeospatial.com/ProductsandSolutions/GeospatialProducts/IDL.aspx), version 8.1.

Study finds: Middle atmosphere temperature in sync with the ocean PDO

Relationship between decadal variations in temperatures in the Pacific and the tropopause identified From the HELMHOLTZ CENTRE FOR OCEAN RESEARCH KIEL (GEOMAR) Water plays a major role for our planet not only in its liquid form at the surface. In the atmosphere too, it considerably affects our lives as well as weather and climate. Clouds and…

PDO3

Has the PDO flipped?

Guest post by David Middleton Cyclical changes in the Pacific Ocean have thrown earth’s surface into what may be an unprecedented warming spurt, following a global warming slowdown that lasted about 15 years. While El Niño is being blamed for an outbreak of floods, storms and unseasonable temperatures across the planet, a much slower-moving cycle…