Long-range atmosphere-ocean forecasting in support of undersea warfare operations in the western north Pacific

Abstract

Skillful long-range forecasts of acoustic variables have the potential to be very useful in planning Navy undersea warfare operations. Our study assessed the potential to predict sonic layer depth (SLD) in the western north Pacific at lead times of one to several months. We conducted correlations between SLD and remote climate system variables, and identified a high potential for skillful long-range forecasts of SLD in the western north Pacific using sea surface temperature in equatorial and south Pacific as predictors. We used tercile matching and composite analysis forecast (CAF) methods to develop hindcasts and forecasts of SLD based on SST predictors at lead times of one to four months. Our forecast verification metrics show that the resulting long lead probabilistic forecasts are a clear improvement over presently available long term mean climatology products. We also used conditional compositing techniques to create mean and environmental threshold probability products based on the long lead forecasts. Our results indicate that the support of USW operations by the Navy meteorology and oceanography community could be improved by the use of advanced climate data sets, climate analysis, and long-range forecasting methods.