Reconstructed July temperatures since AD 1800, based on a tree-ring chronology network in the Northwest Pacific region, and implied large-scale atmospheric-oceanic interaction

•July temperature was reconstructed for the NW pacific region using tree-ring network.•The reconstruction model demonstrated satisfactory predictive skills.•Our study is the first reconstruction for spatial climate information in the region.•The reconstruction showed generally good agreements with other studies.•Our study suggests a large scale atmospheric-oceanic interaction in the region.

We present a large-scale dendroclimatic reconstruction of July temperatures from 42-52°N to 140-145°E in the Northwest Pacific region for the period from 1800 to 1996. A multiple regression model with principal components (PCs) of a tree-ring chronology network was used for the reconstruction, which accounted for 31.7% of the temperature variance in the calibration period (1901-1996). The reconstructed spatially-averaged July temperatures show large fluctuations, which are comparable to previously published dendroclimatic reconstruction of spring temperatures in northeast Asia. It also shows stable relationships with other datasets, notably sea surface temperatures (SSTs) in a wide area of the North Pacific and the Pacific Decadal Oscillation (PDO), indicating atmospheric-oceanic interaction in the Northwest Pacific region since AD 1800.