Performance assessment of the database downscaled ocean waves (DOW) on Santa Catarina coast, South Brazil

Abstract

This work presents a validation of wave parameters from the new sixty years Downscaled Ocean Waves (DOW) reanalysis database. This study compares quantiles of the Gumbel distribution of Hs (significant wave height) and Tp (peak period) from simulated data with an 11 months' time series obtained from a buoy moored seaward on the Santa Catarina coast. Analysis by means of Gumbel distribution quantiles allows more weight to be given to the highest values of the time series, which are especially important in design projects. The statistical parameters used to verify the fit between the measured and the modeled data included: RMSE, BIAS, Scatter Index and Pearson Correlation Coefficient. Mean direction (θm) validation was conducted qualitatively. The database showed good fit of the mean conditions, especially Hs which was well reproduced by the wave model. Underestimation of Tp, related mainly to the low spatial and temporal resolution of wind data used to generate waves, highlights this general modeling problem. Based on calculated statistical parameters, DOW data were considered comparable to the values obtained by measurements; however, such data must be cautiously used for extreme events analysis and in areas of bimodal sea conditions, where major deficiencies in the database were observed.

Influência da orientação de praia na retração da linha de costa induzida por marés de tempestade: Armação e Canasvieiras, Ilha de Santa Catarina - SC

“…As ondulações mais frequentes de NE (Muler, 2012) não são confirmadas, dado que, para o SMC-Brasil foram modelados apenas ventos globais, que geram ondulações distantes da costa. Desta forma, os ventos locais e os processos de difração responsáveis pela formação de ondas incidentes de NE não são considerados (Silva et al 2014). A Figura 5B representa o histograma de altura de ondas modeladas para a posição do ponto DOW.…”

Brazil Wave Climate from a High-Resolution Wave Hindcast

“…For instance, in Brazil, [30] studied the coast of Ceará in the north, and [31,32] analyzed the waves along the southern region in Santa Catarina and Rio Grande do Sul, respectively. The longest analyses in Brazil were performed by [33,34] in the southern region of the country, and by [35] in the southeast. Other authors, including [36,37], exemplify the few studies covering the entire Brazilian coast, based on reanalysis data.…”

Climate-induced variability in South Atlantic wave direction over the past three millennia

“…The calibrated and validated Downscaled Ocean Wave (DOW) series consisting of 60 years (1948–2008) of reanalysis wave data at hourly resolution 25 , 39 , 57 was obtained from a virtual buoy (DOW point; 27.8°S, 41.9°W) selected at 111 m depth, proximal to the shelf-break (130 m). From the data series, 100 representative cases were selected using the Maxima Dissimilarity technique 58 for each 5° directional interval.…”

“…Over recent decades, the Subtropical South Atlantic wave climate approaching the South American coast has presented a frequent bimodal sea-swell configuration 21 – 25 , with the east (E) to south-southeast (SSE) sectors representing 80% of the wave climate 7 , 10 , 21 . The mean effective energy flux 26 reaching the study region has been largely influenced by waves generated in the mid- to high-latitudes (30–60°S and 40–70°W) of the South Atlantic basin (Fig.…”