NP Index is the area-weighted sea level pressure over the region 30N-65N, 160E-140W.

Time Interval: Monthly
Time Coverage: 1899 to 2006
Update Status: Periodically updated

Get Data:

NP: Standard CDC Format (What is standard format?)
NP: Original

Source:
Data is from NCAR/CGD at http://www.cgd.ucar.edu/cas/jhurrell/indices.data.html#npmonl
References:

1. Trenberth and Hurrell (1994), Climate Dynamics 9:303-319

This page hosted by: NOAA ESRL Physical Sciences Division Document maintained by Cathy Smith (cathy.smith@noaa.gov) Updated: Sep 27, 2007 10:50:19 MDT http://www.cdc.noaa.gov/Pressure/Timeseries/NP/index.html