Validation of improved significantwave heights from the Brown-Peaky (BP) retracker along the East Coast of Australia

Abstract

Improved significantwave heights (SWHs) along the east coast ofAustralia have been estimated using the parameters resolved by a Brown-peaky (BP) retracker through reprocessing of three years of Jason-1 altimetric waveforms. The BP-estimated SWHs are validated against eight waverider buoys along the coast, and compared with the SWHs estimated by the standard four-parameter maximum likelihood estimator (MLE4). When assessing 1 Hz coastal SWHs for distances from 12 km to the coast, mean standard deviations (STDs) of BP SWHs vary fromca. 0.5mto 0.9m, while those ofMLE4 SWHs increase from ca. 0.6 m to ca. 2.3 m, indicating a dramatically drop in the quality ofMLE4-derived SWHs at the coast. The BP retracker has retrieved ca. 80% of 1 Hz coastal SWHs, which are more than those (ca. 50%) by the standardMLE4. The validation of 1Hz SWHs is performed by calculating the along-altimeter-track pointwise bias, STD and correlation coefficient between altimetry and buoys. The results showthatwithin 30 km off the coast the BP dataset has better agreement with buoy's wave heights than the SGDRMLE4 dataset in terms of the BP's small absolute biases and STDs, as well as high correlation coefficients.