A modified cressman interpolation method applied to process total nitrogen data in Bohai surface waters

A modified Cressman interpolation (MCI) method was proposed to study the total nitrogen (TN) data in Bohai surface waters, based on the distribution of Bohai routine monitoring stations.The pollution concentration station data features two idealized distributions.The twin experiments suggest reduced interpolation biases using MCI method, compared to the traditional Cressman, Kriging and Local Polynomial (LP) method.In practical experiments, cross validation scheme was applied to evaluate the interpolation biases.Bohai Surface TN concentration was recalculated following MCI method for four quarters in 2009 and 2010, providing an improved dataset for Bohai pollution investigation.