Impact of a possible local wind change on the wave climate in the upper Río de la Plata

Abstract

The aim of the present work is to give a quantitative assessment of the change in mean wave parameters in the upper Río de la Plata (RDP) by considering a possible change in local winds. A statistical analysis of the sea and swell in the outer RDP, as well as the computation and analysis of their propagation and transformation throughout the intermediate and upper regions, reveal that refraction, shoaling and friction effects diminish wave heights by 94.9%. Consequently, the predominant wave climate in the upper RDP could only be described considering wind waves generated locally (sea). The present wave climate (directional wave heights and periods) in the upper RDP is estimated by the hindcasting methodology based on 10-year statistics of winds measured at 'Aeroparque Jorge Newery' meteorological station. A possible future scenario is sketched for which wind frequencies and intensities for the easterly directions are respectively 30% and 10% higher than the present values. The results for the upper RDP show that mean easterly wave heights will increase by 0.12 m (13%) relative to present values (0.90 m) and their frequencies will increase by 30% (from 18.4 to 23.9%), producing larger total heights. Therefore, the coast of Buenos Aires city will be more frequently exposed to wave effects, giving rise to intensified associated littoral processes. The mean period for easterly waves will not change significantly (less than 4%, from 5.3 to 5.5 s). The results obtained are a first approximation to the problem, suggesting that within the upper RDP the wave climate is very sensitive to the predicted change in the wind field.

Global change effects on biogeochemical processes of Argentinian estuaries: An overview of vulnerabilities and ecohydrological adaptive outlooks

“…The Argentinian Patagonia is likely to experience changes below the global mean, up to $30% in the southern extreme, while the Pampa region will experience changes above the global mean up to $10% in the northern extreme (Perrette et al, 2013). The northern coastal area of the Pampa is more frequently exposed to higher levels of wave energy and coastal erosion; this trend is consistent with regional climate change and sea-level rise (Dragani and Romero, 2004;Fiore et al, 2009;Codignotto et al, 2012). The Holocene sea-level fluctuations in the Bahía Blanca estuary indicate that relatively short perturbations in global climate could have more important consequences than heretofore recognised (Gómez et al, 2005).…”

Modeling the Suspended Sediment Transport in a Very Wide, Shallow, and Microtidal Estuary, the Río de la Plata, Argentina

“…Because the wave data available are not directional, the direction of wave propagation was assumed to be equal to the direction of wind. This condition is characteristic within the RdP Estuary, where waves are mainly local (Dragani & Romero, 2004). Since the wave gauge was located at the intermediate region of the RdP Estuary, Torre Oyarvide, it is possible that the empirical relationship overestimates wave height in the upper estuary and underestimates it in the exterior estuary.…”

Nonlinear Interaction Between the Tide and the Storm Surge with the Current due to the River Flow in the Río de la Plata

“…For the analysis of interactions, we followed the terminology introduced by Wolf (1978), and applied in several papers (e.g., Bijlsma 1986;Bernier and Thompson 2007;Zhang et al 2010;Idier et al 2012;Dinȧpoli et al 2020c). Wind waves inside the estuary are usually locally generated (sea) because both short and long swell coming from the Continental Shelf are strongly attenuated by refraction and bottom friction within the FTZ of the RdP (Dragani and Romero 2004). Significant wave heights and periods are relatively low (0.52 m and 3.3 s, respectively) and wave breaking does not often occur (Dragani and Romero 2004); therefore wave-induced setup can be considered negligible for this analysis.…”

“…Wind waves inside the estuary are usually locally generated (sea) because both short and long swell coming from the Continental Shelf are strongly attenuated by refraction and bottom friction within the FTZ of the RdP (Dragani and Romero 2004). Significant wave heights and periods are relatively low (0.52 m and 3.3 s, respectively) and wave breaking does not often occur (Dragani and Romero 2004); therefore wave-induced setup can be considered negligible for this analysis. This way, the water level (η W L ) is considered to be the algebraic sum of (i) the pure tide or surge level (η T /η S ); (ii) the pure river discharge elevation (η R ); and (iii) the residual elevation due to the nonlinear interactions (η I ), so that, Eq.…”