A seasonally lagged response to the NAO in the North Pacific

In this paper, we discuss the existence of a seasonally lagged response to the North Atlantic Oscillation (NAO) in the North Pacific region. In particular, we show that the spring sea level pressures and surface temperatures in the region are positively correlated with the sign of the NAO during the preceding winter. This response is identified in a number of long-term climate datasets including a Japanese tree ring time series that has been shown to be a proxy for spring temperatures in the North Pacific region. We identify two distinct mechanisms responsible for this lagged signal: one involving sea surface temperature anomalies in the North Pacific and the other involving Eurasian snow cover anomalies. We show that these anomalies develop during the winter and persist into the spring resulting in the observed lagged response.