Pacific-North American mode

The Pacific-North American (PNA) mode is an intrinsic pattern of atmospheric circulation that can be influenced by temperature anomalies in the tropical atmosphere, which are in turn driven by anomalies in tropical ocean surface temperatures. This mode is significant because it can affect atmospheric circulation over the Pacific and North America during autumn and winter.1

The PNA mode is one of the atmospheric patterns that can be influenced by ocean surface temperature anomalies. For example, warmer-than-normal ocean surface water in the Gulf of Alaska can lead to increased cyclone development in the following seasons. These ocean surface temperature anomalies can persist for extended periods, potentially serving as predictors for seasonal climate anomalies.1