North Pacific Index (NP) Monthly Time-series
Describes North Pacific Variability
Correlation of 20CRV3 January SLP with the NP Index. (center Plot and label). Created with the Atmospheric WRIT Correlation Tool.
Times-series from the WRIT Time-series Plotting Tool (center this)
Description
The North Pacific Index (NP index or NPI) is the area-weighted sea level pressure over the region 30°N-65°N, 160°E-140°W. The NP index is defined to measure interannual to decadal variations in the atmospheric circulation. The dominant atmosphere-ocean relation in the North Pacific is one where atmospheric changes lead changes in sea surface temperatures by one to two months. However, strong ties exist with events in the tropical Pacific, with changes in tropical Pacific SSTs leading SSTs in the north Pacific by three months.Temporal Coverage
- Monthly values: 1899/01 to present
- Update Status: Monthly
Data Notes
- Units: mb
- Missing data value: -999.0
Time-series List
- NP: Standard PSL Format, CSV, NetCDF (What is standard format?)
Usage Restrictions
- None
Caveats
- None
Related Time-series
Links
Original Source
- Index is calculated at PSL using code supplied by NCAR.
Time-series source dataset(s)
- Data is obtained from NCAR's Monthly Northern Hemisphere Sea-Level Pressure Grids, continuing from 1899 (ds010.1)
Citation
- For dataset, see NCAR webpage.
References
- Trenberth and Hurrell (1994), Climate Dynamics 9:303-319