Ensenada Center for Scientific Research and Higher Education

About: Ensenada Center for Scientific Research and Higher Education is a facility organization based out in Ensenada, Mexico. It is known for research contribution in the topics: Population & Nonlinear system. The organization has 1934 authors who have published 3733 publications receiving 63115 citations.

River nutrient loads and catchment size

Abstract: We have used a total of 496 sample sites to calibrate a simple regression model for calculating dissolved inorganic nutrient fluxes via runoff to the ocean. The regression uses the logarithms of ru ...

Suggested Integral Analysis for Chaos-Based Image Cryptosystems

Abstract: Currently, chaos-based cryptosystems are being proposed in the literature to provide confidentiality for digital images, since the diffusion effect in the Advance Encryption Standard (AES) algorithm is weak. Security is the most important challenge to assess in cryptosystems according to the National Institute of Standard and Technology (NIST), then cost and performance, and finally algorithm and implementation. Recent chaos-based image encryption algorithms present basic security analysis, which could make them insecure for some applications. In this paper, we suggest an integral analysis framework related to comprehensive security analysis, cost and performance, and the algorithm and implementation for chaos-based image cryptosystems. The proposed guideline based on 20 analysis points can assist new cryptographic designers to present an integral analysis of new algorithms. Future comparisons of new schemes can be more consistent in terms of security and efficiency. In addition, we present aspects regarding digital chaos implementation, chaos validation, and key definition to improve the security of the overall cryptosystem. The suggested guideline does not guarantee security, and it does not intend to limit the liberty to implement new analysis. However, it provides for the first time in the literature a solid basis about integral analysis for chaos-based image cryptosystems as an effective approach to improve security.

Farallon slab detachment and deformation of the Magdalena Shelf, southern Baja California

Abstract: [1] Subduction of the Farallon plate beneath northwestern Mexico stalled by ∼12 Ma when the Pacific-Farallon spreading-ridge approached the subduction zone. Coupling between remnant slab and the overriding North American plate played an important role in the capture of the Baja California (BC) microplate by the Pacific Plate. Active-source seismic reflection and wide-angle seismic refraction profiles across southwestern BC (∼24.5°N) are used to image the extent of remnant slab and study its impact on the overriding plate. We infer that the hot, buoyant slab detached ∼40 km landward of the fossil trench. Isostatic rebound following slab detachment uplifted the margin and exposed the Magdalena Shelf to wave-base erosion. Subsequent cooling, subsidence and transtensional opening along the shelf (starting ∼8 Ma) starved the fossil trench of terrigenous sediment input. Slab detachment and the resultant rebound of the margin provide a mechanism for rapid uplift and exhumation of forearc subduction complexes.

Data assimilation in ocean models

Abstract: This review covers recent advances in applying data assimilation techniques to problems in physical oceanography. The introduction and appendices provide the non-specialist reader with background in ocean circulation and observing methods. The 4D variational assimilation approach is covered in depth showing how model - data misfits can be minimized using Lagrange multipliers in an unconstrained variational problem. Applications to modelling tropical Pacific temperatures, sea surface heights and circulation in the North Atlantic, and tomographic (sound travel time) data are all presented. The use of variational methods for deriving average climatological circulation patterns is also described as well as applications to error growth during numerical forecasting. The paper then focuses on three important topics in physical oceanography, the evolution of ocean mesoscale eddies in middle latitudes, the development of El Nino events in the tropical Pacific, and the evolution of ocean surface waves. Recent improvements in data acquisition and modelling in these areas mean that data assimilation is practical and is providing new insights and forecasting capabilities to varying degrees. Results using a variety of assimilation techniques are presented, concluding with a forward look to a time when routine forecasting of ocean developments will be possible with important implications ranging from understanding climate change to fishing and pollution control.