Southern Hemisphere Planetary waves indices

What are Complex Empirical Orthogonal Functions

Complex Empirical Functions (cEOF) are an extension of Empirical Orthogonal Functions that can describe wave-like modes of variability which vary both in amplitude an phase.

cEOFs of the Southern Hemifphere Circulation

In our paper (ref upcoming) we describe the first two cEOFs of the zonally asymmetric circulation of the Southern Hemisphere.

The leading cEOF describes a wave-1 pattern and the variations in the direction of the climatological mean. The second cEOF describes a wave-3 pattern active only in the Western Hemisphere, also known as the Pacific-South American Pattern (PSA, Mo and Paegle (2001)).

Figure 1: Spatial patterns for the two leading cEOFs of SON geopotential height zonal anomalies at 50 hPa and 200 hPa for the 1979 – 2019 period. The shading (contours) corresponds to 0º (90º) phase. Arbitrary units. The proportion of variance explained for each mode with respect to the zonal mean is indicated in parenthesis.

Get the data

You can grab the monthly indices for the 1979 – 2018 period as used in ref in this Zenodo repository

Real-time indices will be available in this website momentarily.

How to cite

If you use this data on your research, please cite it with

Citation forthcoming

References

Mo, Kingtse C., and Julia N. Paegle. 2001. “The Pacific Modes and Their Downstream Effects.” International Journal of Climatology 21 (10): 1211–29. https://doi.org/10.1002/joc.685.