Tracking the Pacific Decadal Precession

• Published in: Journal of geophysical research. Atmospheres 2017-03, Vol.122 (6), p.3214-3227
• Main Authors: Anderson, Bruce T., Furtado, Jason C., Di Lorenzo, Emanuele, Short Gianotti, Daniel J.
• Format: Article
• Language: English
• Subjects: Anomalies; Approximation; Approximation methods; Atmosphere; Atmospheric circulation; Atmospheric models; Atmospheric pressure; Climate; Climate change; climate indices; Climate variability; Computer simulation; Data processing; decadal variability; Destabilization; Diagnosis; Drought; Ecosystems; Empirical analysis; ENVIRONMENTAL SCIENCES; Evolution; extratropics; Fires; Frameworks; Geophysics; Marine; Marine ecosystems; Mathematical models; Meteorology; Methods; Modes; Monitoring; North Pacific; Numerical models; Numerical simulations; Ocean models; Ocean-atmosphere interaction; Ocean-atmosphere system; Oscillations; Pacific Decadal Oscillation; Precession; Pressure anomalies; Real time; Socioeconomic factors; Standing waves; Tracking; Variability
• ISSN: 2169-897X; 2169-8996
• DOI: 10.1002/2016JD025962

Events of recent years—including extended droughts across California, record fires across western Canada, and destabilization of marine ecosystems—highlight the profound impact of multiannual to decadal‐scale climate shifts upon physical, biological, and socioeconomic systems. While previous research has focused on the influence of decadal‐scale climate oscillations such as the Atlantic Multidecadal Oscillation and the Pacific Decadal Oscillation/Interdecadal Pacific Oscillation, recent research has revealed the presence of a quasi‐decadal mode of climate variability that, unlike the quasi‐stationary standing wave‐like structure of the oscillatory modes, involves a progression of atmospheric pressure anomalies around the North Pacific, which has been termed the Pacific Decadal Precession (PDP). In this paper we develop a set of methods to track the spatial and temporal evolutions of the PDP within historical observations as well as numerical model simulations. In addition, we provide a method that approximates the time evolution of the PDP across the full period of available data for real‐time monitoring of the PDP. Through the development of these tracking methods, we hope to provide the community with a consistent framework for future analysis and diagnosis of the PDP's characteristics and underlying processes, thereby avoiding the use of different, and disparate, phenomenological‐ and mathematical‐based indices that can confound our understanding of the PDP and its evolution. Key Points An empirical method is developed to track the spatial and temporal evolutions of the Pacific Decadal Precession (PDP) An approximation to this method is developed to provide real‐time monitoring of the PDP Application of the method to ocean‐atmosphere models can assess whether they properly reproduce the observed PDP's characteristic evolution