A methodology for estimating the response of the coastal ocean to meteorological forcing: A case study in the Bohai Bay

Abstract. The sea level (SL) variations at the coastal ocean result from multiscale processes and are substantially contributed by the SL changes due to the meteorological forcing. In this study, a new methodology, named as IBR, is developed to estimate the response of the coastal ocean to meteorological forcing. The response is taken as the combination of the static ocean response calculated using the inverted barometer formula and the dynamic ocean response estimated using the multivariable linear regression involving atmospheric pressure and wind component at the dominant wind orientation. The dominant wind orientation is determined based on the averaged values of the magnitude squared coherences between the adjusted SL and wind at every wind orientation.

The IBR is implemented to estimate the response of the coastal ocean at two stations, E1 and E2 in the Bohai Bay, China. The analysed results indicate that at both E1 and E2, the adjusted SLs are related more to the regional wind, which is the averaged value in the Bohai Bay of the 10 m wind in the ERA-Interim data, than to the local wind; the dominant regional wind orientation is 75°. The estimated response using IBR with the regional meteorological forcing is much closer to the observed values than other methods, including the classical inverted barometer correction, the dynamic atmospheric correction, the multivariable linear regression and the IBR with local forcing, demonstrating that IBR with regional forcing have the best skill in estimating the response. The large deviations between the observed values and the estimated values using IBR with the regional meteorological forcing are mainly due to the remote wind, which is not considered in the IBR. This case study indicates that the IBR is a feasible and relatively effective method to estimate the response of the coastal ocean to the meteorological forcing.