- 4301 Rickenbaker Causeway, Miami, Florida. 33149. 431-2
- 17864078827
Jhon Fredy Mojica Moncada
University of Miami, RSMAS, Faculty Member
- +PhD 2015 (Marine Science, Oceanography), Institute of Marine Science (ICM-CSIC); University of Barcelona. Barcelon... more+PhD 2015 (Marine Science, Oceanography),
Institute of Marine Science (ICM-CSIC); University of Barcelona. Barcelona - Spain.
+MSc 2011 (Oceanography and management of the marine environment),
University Politécnica of Catalunya; University of Barcelona. Barcelona - Spain.
+BSc 2007 (Physics), University Distrital Francisco José de Caldas. Bogotá. Colombia.
I got my PhD in 2015. working in strategies of processing and spectral analysis of seismic data to study dynamic processes in physical oceanography; I received the dissertation awarded Cum Laude. I worked as a physical oceanographer at the Institute of Marine Science (ICM-CSIC) in Barcelona, Spain. Aim: Mesoscale Ocean dynamics, gathering data in the Mediterranean, Atlantic and Pacific Ocean; characterizing processes and structures as internal waves, instabilities, turbulence, and mixing with different kinds of systems, such as CTD, XCTD, XBT, ADCP, and Moorings among others; and the Multichannel Seismic (MCS) System. The MCS is a new oceanographic acoustic technique used in Seismic Oceanography (SO). In 2017, I move to Abu Dhabi (UAE), to work at the Center for global Sea Level Change (CSLC) of New York University Abu Dhabi (NYUAD). My research work focused on ocean-glacier dynamics in polar regions, ice shelves' interactions, and their impacts in subtropical areas. I was particularly interested in characterizing the oceanic circulation and implications of sea level rise in polar areas at multiple scales and better understanding the mixing and diffusion processes and their temporal and spatial variability in Greenland Fjords and Antarctic ice shelves, located over the Amundsen, Weddell, and the Ross Sea, also the Antarctic peninsula. I have developed fieldwork in all these areas including the Arabic Gulf to describe and characterize the impacts of Sea-Level variation under the current scenario of Climate Change. In 2022, I move to Miami (US), to join the University of Miami and the Atmospheric Ocean Meteorologic Lab (AOML), a group part of the National Ocean and Atmospheric Agency (NOAA), as a Senior Research Associate. My aim is to support the Port Everglades Adaptive Management Moorings program as an Expert Information System. I oversee managing arrays of data buoys and sensors deployed in Port Everglades, Biscayne Bay, and the ocean around Florida to understand drivers of water quality and monitor turbidity during dredging operations.edit - Chris Kelble. NOAA Federal.edit
Research Interests:
Research Interests:
La circulacion oceanica de gran escala se encuentra relacionada con la pequena escala a traves de los procesos turbulentos, los cuales hacen posible el intercambio de energia cinetica. En equilibrio, el flujo de energia inyectado por el... more
La circulacion oceanica de gran escala se encuentra relacionada con la pequena escala a traves de los procesos turbulentos, los cuales hacen posible el intercambio de energia cinetica. En equilibrio, el flujo de energia inyectado por el forzamiento climatologico en el rango de produccion (macroescala) debe balancearse por los procesos de mezcla en el rango de disipacion (meso- y pequena escala). Alrededor de la frecuencia de Coriolis, el efecto cinematico dominante es el campo de los giros geostroficos, mientras que a mayores frecuencias y especialmente cerca de la frecuencia inercial, los movimientos estan dominados por la dinamica de las ondas internas, cuya propagacion en el oceano transfiere la energia a menores escalas a traves de procesos de dispersion y de interaccion onda-onda. Dependiendo de las condiciones oceanograficas, cuando las ondas internas rompen, generando como consecuencia, la transferencia de parte de su energia a las escalas mas pequenas mediante procesos de me...
Research Interests:
The Alboran Sea is a dynamically active region where the salty and warm Mediterranean water first encounters the incoming milder and cooler Atlantic water. The interaction between these two water masses originates a set of sub-mesoscale... more
The Alboran Sea is a dynamically active region where the salty and warm Mediterranean water first encounters the incoming milder and cooler Atlantic water. The interaction between these two water masses originates a set of sub-mesoscale structures and a complex sequence of processes that entail mixing close to the thermocline. Here we present a high-resolution map of the diapycnal diffusivity around the thermocline depth obtained using acoustic data recorded with a high-resolution multichannel seismic system. The map reveals a patchy thermocline, with areas of strong diapycnal mixing juxtaposed with others of weaker mixing. The patch size is of a few kms in the horizontal scale and of 10–15 m in the vertical one. The comparison of the obtained maps with the original acoustic images shows that vigorous mixing tends to occur in areas of internal wave instability, whereas mixing levels in more stable areas is lower. These results are also compared with others obtained usin...
Research Interests:
Research Interests:
Research Interests: Geology and Geophysical
The Alboran Sea is a dynamically active region where the salty and warm Mediterranean water first encounters the incoming milder and cooler Atlantic water. The interaction between these two water masses originates a set of sub-mesoscale... more
The Alboran Sea is a dynamically active region where the salty and warm Mediterranean water first encounters the incoming milder and cooler Atlantic water. The interaction between these two water masses originates a set of sub-mesoscale structures and a complex sequence of processes that entail mixing close to the thermocline. Here we present a high-resolution map of the diapycnal diffusivity around the thermocline depth obtained using acoustic data recorded with a high-resolution multichannel seismic system. The map reveals a patchy thermocline, with areas of strong diapycnal mixing juxtaposed with others of weaker mixing. The patch size is of a few kms in the horizontal scale and of 10–15 m in the vertical one. The comparison of the obtained maps with the original acoustic images shows that vigorous mixing tends to occur in areas of internal wave instability, whereas mixing levels in more stable areas is lower. These results are also compared with others obtained usin...
Research Interests:
Research Interests:
Research Interests: Geology and Geophysical
Research Interests:
Research Interests:
Research Interests:
In the western Antarctic Peninsula one of the areas the highest warming in the southern hemisphere has been identified. To characterize this tendency, we selected the Lange Glacier (LG) on King George Island, to evaluate: 1) LG surface... more
In the western Antarctic Peninsula one of the areas the highest warming in the southern hemisphere has been identified. To characterize this tendency, we selected the Lange Glacier (LG) on King George Island, to evaluate: 1) LG surface temperature and dynamics using stakes with temperature data loggers; 2) LG submerged thickness and sea parameters through bathymetry (BT) and 29 CTD stations in front of LG; 3) glacier front (GF) using BT and a Digital Elevation Model (DEM); 4) change in GF position using DEM and historical data of GF width; 5) Calving flux (QC). Our findings showed 85 % of temperatures were above the 0 °C melting point (mean = 5.0 ± 5.2 °C). The stakes had an average ice loss of 9.3 ± 1.3 cm. The LG mean dynamics was 8.8 ± 1.5 m (0.40 ± 0.70 m/day), corroborated by Sentinel-1 satellite images (Offset Tracking = 0.43 ± 0.01 m/day). An intrusion of external waters warmer in the LG bay was identified, which destabilizes the water column due to convection processes. Our findings together indicated a continuous glacial melt that increases its dynamics due to the increase in temperature, with a contribution of fresh water to the Admiralty Bay. Based on historical results and this study, the LG retracement was estimated in 2,492 m between 1956 and 2019.
Research Interests:
Con el fin generar conocimiento sobre la fauna marina antartica, se realizo la caracterizacion de los organismos componentes del zooplancton hasta el nivel taxonomico mas detallado posible. Se determino la biomasa, la riqueza de especies... more
Con el fin generar conocimiento sobre la fauna marina antartica, se realizo la caracterizacion de los organismos componentes del zooplancton hasta el nivel taxonomico mas detallado posible. Se determino la biomasa, la riqueza de especies y su distribucion horizontal; los cuales se relacionaron con las variables oceanograficas colectados para cada estacion (temperatura, oxigeno disuelto y salinidad superficiales); obteniendo informacion de los parametros oceanograficos que influyen en la distribucion, presencia, ausencia y densidades del zooplancton, las muestras y los datos fueron colectados durante el verano austral antartico en enero de 2015, en el Estrecho de Gerlache, Peninsula Antartica, en el marco de la Primera Expedicion Cientifica de Colombia a la Antartica “EXPEDICION CALDAS”. Para ello se realizaron arrastres superficiales con red de zooplancton tipo bongo de 200 µm, entre los 30 y 50 m de profundidad en la columna de agua, en los 20 puntos de muestreo de la grilla prop...
Research Interests:
Research Interests:
The Intergovernmental Panel on Climate Change concludes that glaciers are sensitive indicators of climate change. Numerous studies have detected changes in the cryosphere during the last decades, where the thickness of the ice has... more
The Intergovernmental Panel on Climate Change concludes that glaciers are sensitive indicators of climate change. Numerous studies have detected changes in the cryosphere during the last decades, where the thickness of the ice has decreased due to temperature increase, causing melting ice and sea-level rise. Antarctica is one of the greatest areas of interest due to its sensitivity and implications of warming over the cryosphere. Particularly, the Antarctic Peninsula and adjacent islands are areas where the greatest regional warming of the Southern Hemisphere has been identified. We selected the Lange Glacier on King George Island, Antarctica, in order to characterize the implications of Southern warming, from to description its dynamics, glacier front, temperature, melting and calving flux. Three temperature data loggers were installed in bamboo stakes at 200m distance each, and 200m from the north side on the surface of the glacier, which worked by 10 min for 22 days in the austra...
Research Interests:
Part of the kinetic energy that maintains ocean circulation cascades down to small scales until it is dissipated through mixing. While most steps of this downward energy cascade are well understood, an observational gap exists at... more
Part of the kinetic energy that maintains ocean circulation cascades down to small scales until it is dissipated through mixing. While most steps of this downward energy cascade are well understood, an observational gap exists at horizontal scales of 10 3 –10 1 m that prevents characterizing a key step in the chain: the transition from anisotropic internal wave motions to isotropic turbulence. Here we show that this observational gap can be covered using high-resolution multichannel seismic (HR-MCS) data. Spectral analysis of acoustic reflectors imaged in the Alboran Sea thermocline shows that this transition is likely caused by shear instabilities. In particular, we show that the averaged horizontal wave number spectra of the reflectors vertical displacements display three subranges that reproduce theoretical spectral slopes of internal waves (λ x > 100 m), Kelvin-Helmholtz-type shear instabilities (100 m > λ x > 33 m), and turbulence (λ x < 33 m), indicating that the whole chain of events is occurring continuously and simultaneously in the surveyed area.
This work explores a method to recover temperature, salinity, and potential density of the ocean using acoustic reflectivity data and time and space coincident expendable bathythermographs (XBT). The acoustically derived (vertical... more
This work explores a method to recover temperature, salinity, and potential density of the ocean using acoustic reflectivity data and time and space coincident expendable bathythermographs (XBT). The acoustically derived (vertical frequency >10 Hz) and the XBT-derived (vertical frequency <10 Hz) impedances are summed in the time domain to form impedance profiles. Temperature (T) and salinity (S) are then calculated from impedance using the international thermodynamics equations of seawater (GSW TEOS-10) and an empirical T-S relation derived with neural networks; and finally potential density (q) is calculated from T and S. The main difference between this method and previous inversion works done from real multichannel seismic reflection (MCS) data recorded in the ocean, is that it inverts density and it does not consider this magnitude constant along the profile, either in vertical or lateral dimension. We successfully test this method on MCS data collected in the Gulf of Cadiz (NE Atlantic Ocean). T, S, and q are inverted with accuracies of dT sd 50:1 C, dS sd 50:09, and dq sd 50:02kg=m 3. Inverted temperature anomalies reveal baroclinic thermohaline fronts with intrusions. The observations support a mix of thermohaline features created by both double-diffusive and isopycnal stirring mechanisms. Our results show that reflectivity is primarily caused by thermal gradients but acoustic reflectors are not isopycnal in all domains.
Recent work has shown that Full Waveform Inversion could be suitable to extract physical properties such as sound speed (c), density (), temperature (T), and salinity (S) from the weak impedance contrasts associated with the ocean’s... more
Recent work has shown that Full Waveform Inversion
could be suitable to extract physical properties such as
sound speed (c), density (), temperature (T), and salinity
(S) from the weak impedance contrasts associated with the
ocean’s thermohaline fine structure.The seismic inversion
approaches proposed so far are based on the iterative inversion
of c from multichannel seismic data, while the rest
of parameters (T, S, and ) are determined in a second
step using two equations of state and a local T-S empirical
relationship. In this work, we present an alternative to this
approach. Using 1-D synthetic seismic data, we demonstrate
that the direct full waveform inversion of T and S
using adjoint methods is feasible without the use of any
local T-S relationship and that the models of physical properties
obtained with this approach are far more accurate
than those inferred from
could be suitable to extract physical properties such as
sound speed (c), density (), temperature (T), and salinity
(S) from the weak impedance contrasts associated with the
ocean’s thermohaline fine structure.The seismic inversion
approaches proposed so far are based on the iterative inversion
of c from multichannel seismic data, while the rest
of parameters (T, S, and ) are determined in a second
step using two equations of state and a local T-S empirical
relationship. In this work, we present an alternative to this
approach. Using 1-D synthetic seismic data, we demonstrate
that the direct full waveform inversion of T and S
using adjoint methods is feasible without the use of any
local T-S relationship and that the models of physical properties
obtained with this approach are far more accurate
than those inferred from