Turbulent Heat Flux Reconstruction in the North Pacific from 1921 to 2014

Abstract

 The turbulent heat flux is the main passageway for air–sea interactions. However, due to lack of long-term observations for the turbulent heat flux, it is difficult to investigate the mechanisms of coupled ocean-atmosphere variabilities, such as the Pacific Decadal Oscillation. We here reconstructed the long-term turbulent heat flux in the North Pacific for the period 1921–2014 based on observations in the International Comprehensive Ocean-Atmosphere Data Set–International Maritime Meteorological Archive. The sea surface temperature, air temperature, wind and humidity were used to reconstruct the turbulent heat flux using the Coupled Ocean–Atmosphere Response Experiment (COARE3.5) algorithm. The modified Fisher–Tippett distribution was employed to calculate the turbulent heat flux at each grid square, and then the missing values were further derived based on data interpolating empirical orthogonal functions (DINEOF). The reconstructed turbulent heat flux was shown to be in accordance with the commonly used short-term heat flux datasets. This reconstruction is further examined by comparison with the long-term data of twentieth century reanalysis from European Center for Medium-range Weather Forecasts twentieth century reanalysis (ERA-20C) and the 20th Century Reanalysis (20CR) dataset from National Oceanic and Atmospheric Administration. It displays a good agreement with the ERA-20C both in spatial and temporal scales, but some differences from the 20CR. By these examinations, the reconstructed turbulent heat flux can well reproduce the main features of the air-sea interaction in the North Pacific, which can be used in studies of the air-sea interaction in the North Pacific on multidecadal timescales.