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Recent developments in satellite processing tools allow low-cost, fast and automatic processing of a large amount of information from Earth observation, enhancing the capability of detecting coastal changes from space at different temporal scales. Some works have assessed the quality of these data and applied it to detect coastal evolution locally, most of them focusing on mid-term and long-term changes in the coastline. In this work, we evaluate the capability to monitor changes in coastal morphology at various temporal and spatial scales using 1D (coastlines) and 3D (bathymetry) satellite-derived data obtained from site-specific processing methods. Local characteristics were included in several phases of the development of the satellite products used here: i) geolocated very high resolution images from each pilot site were used in the coregistration process to enhance geolocation accuracy in images from different missions, ii) different spectral indices were tested at each pilot site to obtain more reliable detection of the coastline at all sites and iii) measured topobathymetry data were used to obtain datum-based satellite shorelines and bathymetry. The accuracy and skill of those satellite products were assessed at several pilot sites in Spain. The results indicated high horizontal accuracy (RMSE < pixel size), with errors on the order of half of the pixel size (RMSE = 5.0 m and for Sentinel-2 and 18.8 m for Landsat5). Furthermore, the coastlines used here presented errors comparable to those obtained from the widely used open-source tool CoastSat. Time-series analysis using satellite-derived shorelines showed that coastal change processes can be detected at several temporal and spatial scales, such as short-term erosion and accretion events on a small beach, seasonal beach rotation, and long-term trends at local and regional scales. However, the results from satellite-derived bathymetry indicated that the quantitative assessment of the coastal morphology with 3D products is still limited. Some in situ measurements are necessary to obtain satellite data that represent site-specific conditions. However, the quantity of this auxiliary in situ measurements required to obtain reliable time series of satellite derived shorelines and bathymetry is significantly lower than the quantity required by traditional monitoring methods. The results are discussed, highlighting the gaps that need to be filled in the future so that satellite-derived products can be used in usual coastal change monitoring practices. • We assess the capability to monitor coastal changes with 1D and 3D satellite data. • Local characteristics are included in the development of the satellite data. • Coastal changes are detected at several temporal and spatial scales. • Long-term shoreline change in local and regional scales, and seasonal beach rotation are successfully detected. • Storm-induced erosion is monitored although cloud cover affects data availability. [ABSTRACT FROM AUTHOR]

ABSTRACT Changes in climate in the South Atlantic region and adjacent regions have been described in numerous works using projections from global climate models from CMIP5 and CMIP6. This paper presents an evaluation of the ability of these models to reproduce the atmospheric circulation patterns (weather types) and their seasonal and inter‐annual variability. The analyses are performed based on the probability of occurrence of weather types in the historical period and in future projections. The scatter index and the relative entropy are the statistical parameters used to evaluate the models' performance in the historical period. Future projections consist of RCP2.6, 4.5 and 8.5 scenarios for the CMIP5 models and the SSP126, 245, 370 and 585 scenarios for the CMIP6 and are assessed at different time intervals: short term (2015–2039), mid‐term (2040–2069) and long term (2070–2100). The performance of projections is measured by analysing their consistency, that is, based on the similarity between projections of the same scenario in different models. The results show that the reproduction of the probability of occurrence of historical weather types and their seasonal and interannual variability was better performed by ACCESS1‐0, HadGEM2‐ES, HadGEM2‐CC, CMCC‐CM and MPI‐ESM‐P when assessing the models from CMIP5, and by HadGEM3‐GC31‐MM, ACCESS‐ESM1‐5, ACCESS‐ CM2 and MRI‐ESM‐P when assessing the models from CMIP6. As for future projections, only the BESM‐AO2‐5, GFDL‐ESM4 and HadGEM3‐GC31‐MM models showed inconsistency in one or more scenarios. [ABSTRACT FROM AUTHOR]

A field campaign was undertaken at Somo beach in northern Spain, with the aim of understanding the processes involved in the generation of low frequency swash. Taking the parameterization presented in earlier studies as a starting point, a novel empirical model was defined based on a database which included datasets from Somo beach and from 9 other experiments. This new parameterization was obtained by relating the horizontal cross-shore component of the infragravity swash to the foreshore slope and the morphodynamic beach state through the non-dimensional fall velocity parameter. The role of previous sea states when determining the morphodynamic beach state was also assessed. A strong correlation between low frequency oscillations and the morphology of the beach was verified, resulting in a substantial improvement over existing infragravity swash predictions proposed in the literature. [ABSTRACT FROM AUTHOR]

Gomes da Silva, P.; Dalinghaus, C.; González, M., Gutiérrez, O., Espejo, A., Abascal, A.J., and Klein, A.H.F., 2016. Estimating flooding level through the Brazilian coast using reanalysis data. In: Vila-Concejo, A.; Bruce, E.; Kennedy, D.M., and McCarroll, R.J. (eds.), Proceedings of the 14th International Coastal Symposium (Sydney, Australia). Journal of Coastal Research, Special Issue, No. 75, pp. 1092 - 1096. Coconut Creek (Florida), ISSN 0749-0208. This paper presents an estimative of coastal flooding level values distribution along the Brazilian coast by using reanalysis data and by simulating wave propagation with Snell approximation. The coast was divided into 24 zones and flooding levels series were calculated for each one. Mean and extreme distribution show higher flooding levels occurring in northern coast (3 m higher than beaches in central coast) followed by the southern coast (1 m higher than central coast). High values obtained on north region were associated with greater tidal elevations (maximum values > 3 m) while higher values in south were related to greater wave heights and higher storm surge elevations (∼2 m and >7 m respectively). A comparison between beach types were also conducted and demonstrate higher values of flooding levels during reflective conditions (0.3 m higher for a specific beach condition), as a result of the runup model applied. Although simplifications were used to calculate this large scale variation of the flooding level along the coast, the results partially presented here can be of large usefulness in pre-design phases of coastal projects and in preliminary risk analysis. [ABSTRACT FROM AUTHOR]

A hybrid method is applied to generate a high‐resolution regional downscaling of atmospheric conditions to the southern coast of Brazil. The method consists of applying a principal component analysis to daily fields of the sea level pressure (SLP) data from the NCEP‐CFSR reanalysis. A cluster analysis (K‐means) is then applied to the 87 principal components that explained 95% of the variance of the time series. Daily atmospheric conditions were clustered into 36 weather types which represent the most predominant conditions observed in the study area. The estimated weather types were able to represent the major atmospheric systems affecting local climate, including the cyclones and anticyclones that are usually present in this region. Then, we applied the numerical Ocean‐Land‐Atmosphere Model (OLAM) to dynamically downscale the atmospheric condition that is closest to the centroid of each cluster. The model was set with a global grid and a refining approach with 6 km grid spacing over the coastal region of south Brazil. This approach allowed us to represent simultaneously the planetary waves and the local mesoscale systems, and their mutual interactions. The results provided new high‐resolution atmospheric fields for the coastal region and showed that the model was capable of resolving the major local mesoscale features. The main advantage of applying such a method is in reducing the number of numerical simulations (lower computational cost) at the same time it represents the totality of the atmospheric conditions observed in the study area. The final results consist in detailed information of the local climate that can be related to injuries to the coastal area and thus is useful to support decision‐makers. [ABSTRACT FROM AUTHOR]

Wave runup is one of the most critical parameters contributing to coastline flooding and shoreline change. Many formulas have been developed to empirically predict wave runup characteristics. However, large errors are still associated to these estimates, feeding a debate on the best approach to describe runup through simple parameterizations. In this work we present a comprehensive review on runup, setup and swash empirical models. We use a large database of field measurements to verify the predictive capability of recent formulas, addressing possible sources of variability. We identify the effect of the nearshore bathymetry as an important factor missing in empirical predictors and examine this issue through an analysis of runup simulated with the SWASH model over different barred and linear bathymetries. The details of the submerged beach profile affect estimates, especially with respect to setup values. The lack of standardization in measuring, post-processing and sharing runup data, limits the application of previous published databases on new analysis. We list a set of recommendations that can be used as guidelines for new measurements to broaden the applicability of the datasets in future studies. Finally, we discuss the remaining questions that still need to be further explored. [ABSTRACT FROM AUTHOR]

In this work we present an analysis of the effect of the processes related to beach morphodynamic state on high frequency (incident band) swash oscillations. The effect of wave reflection and saturation on swash oscillations was assessed based on new field data measured under different morphodynamic conditions on the northern coast of Spain. Data measured under more reflective conditions indicated the occurrence of a cross-shore partial standing structure, a process which was observed earlier using laboratory and numerical data. Part of the dataset data showed saturation in accordance to limits between reflection and saturation established in previous works. The new measured data was added to a large database compiled from previous works, and, assuming the hypothesis that the reflection and saturation processes are related to the beach state, a new parameterization was established to calculate the incident swash under different morphodynamic conditions. Our results indicate that the role of the foreshore slope and wave steepness varies according to the morphodynamic beach state. The proposed formula showed a reasonable correlation with measured data ( ρ 2 =0.56 and RMSE = 0.41 m), and improvements in S i n c predictions were observed for all beach types when compared to existing formulas. • The role of the processes related to the beach morphodynamic on indent swash was explored based on new field measurements. • Saturation and reflection processes were verified through commonly used parameters. • The exact limit above which saturation begin to occur is not clear in data measured on natural beaches. • A new parameterization to estimate the incident swash was determined based on the relationship between swash saturation and beach morphodynamics. • The correlation between measured and calculated values showed improvement in incident swash estimations in comparison to previous formulas. [ABSTRACT FROM AUTHOR]