I am a physical oceanographer with expertise in the dynamics of coastal, sub- and mesoscale ocean variability from Equatorial to Polar regions (e.g., Santana et al.,2018, 2019 and 2021). My focus is to improve our understanding of ocean variability observations, numerical modelling, and data assimilation (EnOI and 4D-Var) (e.g., Santana et al.,2020 and 2023). I work at the National Institute of Water and Atmospheric Research (NIWA), most specifically within the Coastal and Estuarine Group. At NIWA, my research targets at understanding past and future ocean conditions to increase society's resilience to extreme weather events. An example of my work is shown in the video below, where waves generated by a large storm hit the southeast coast of Aotearoa New Zealand. The waves were simulated using Wave Watch 3 forced by NIWA's atmospheric forecasting models.
Maps of Significant Wave Height in metres (Hsig, rainbow shade and white arrows) between 26th and 30th of June 2021. White arrows indicate te magnitude and direction of the wave height.Another example of my work is shown in the video below, where the impact of waves generated by the Tropical Cyclone Harold was studied using SWAN wave model forced by winds from the Tropical Cyclone wind generator (TCwindgen) and the European Reanalysis 5 (ERA5).
Left: maps of Significant Wave Height in metres (Hsig, rainbow shade and white arrows) and winds (black arrows) during Tropical Cyclone Harold. Right: timeseries at four different locations from the SWAN model forced by TCWindgen and ERA5. More work coming soon ... Can't wait? Get in touch via email rafacsantana@gmail.com or the platforms below:I started to study polar regions as a research fellow at The University of Auckland, where I worked on the Scale-Aware Sea Ice Project (SASIP). I targeted at understanding ocean-ice interactions around Antarctica using the sea-ice model neXtSIM. An example of neXtSIM's application is shown in the video below (credit: Nansen Environmental and Remote Sensing Center).
Sea ice concentration in Fram Strait simulated by the Lagrangian sea ice model neXtSIM. Credit: Nansen Environmental and Remote Sensing Center. Antarctic neXtSIM My collaborators and I have implemented an Antartic version of neXtSIM which has been thoroughly validated (Santana et al., in prep.). We compare two versions of neXtSIM in this study using a modified Viscous-Elastic-Plastic (mEVP - used in climate models) and a Brittle Bigham-Maxwell rheology (science of material deformation). In the the mEVP run, sea ice moves slowly and fails to represent observed mesoscale drift features (video below). The BBM run improves the representation of sea ice ice at any given day compared to the mEVP rheology, and is able to reproduce cyclonic features in sea ice drift forced by atmospheric events. This happens because the BBM run reproduces ice fractures more realistically (previous video) which facilitates the transport of sea ice. Daily Antarctic sea ice drift (km/h) from satellite observations (let), the modified Viscous-Elastic-Plastic (mEVP - centre) run, and the Brittle Bigham-Maxwell (right) run. These cyclones also break sea ice more effectively in the brittle model (BBM run) which generates more leads (linear fractures in sea ice). During winter, more sea ice tends to form in the BBM run compared to the mEVP run (video below). During the melting season, these leads might generate faster melting as broken ice / smaller parcels of ice tend to melt fast compared to larger parcels. This might be better reproduced in coupled ice-ocean models which is the focus of future research. 3-hourly Antarctic sea ice growth (m/day) from the modified Viscous-Elastic-Plastic run (mEVP - left), and the Brittle Bigham-Maxwell run (BBM - right).