North Pacific Gyre Oscillation (NPGO) Index in the CESM Large Ensemble
NPGO website and observational data: http://www.oces.us/npgo
NCAR/CISL LENS NPGO data location: /glade/p/work/rbrady/NPGO/
Python Code: https://github.com/bradyrx/public_code/blob/master/NPGO_Index.py
- Regrid SST to a 1x1 degree (360x180) global map for each ensemble member.
- Deseasonalize and detrend SST to produce SSTa. This is done by removing the ensemble mean at each grid cell at each time step.
- Subset the Northeast Pacific over 180-110W and 25-62N.
- Compute the EOF of the JFM (winter) seasonal means, taking the second mode as the NPGO.
- Project monthly SSTa back onto EOF2 to reconstruct a monthly time series of NPGO.
- Di Lorenzo, Emanuele, et al. "North Pacific Gyre Oscillation links ocean climate and ecosystem change." Geophysical Research Letters 35.8 (2008).
- Di Lorenzo, Emanuele, and Nathan Mantua. "Multi-year persistence of the 2014/15 North Pacific marine heatwave." Nature Climate Change 6.11 (2016): 1042-1047.
- Joh, Y., and E. Di Lorenzo. "Increasing coupling between NPGO and PDO leads to prolonged marine heatwaves in the Northeast Pacific." Geophysical Research Letters 44 (2017).