Lagrangian ocean analysis to study the physical mechanisms driving the processes occurring in the Greater Agulhas Current System

Speaker: 
Michael Hart-Davis

Seminar Date: 
13. August 2019 - 11:15 - 11:45

Lagrangian ocean analysis is a powerful way to study ocean processes from in-situ observations and numerical model simulations. As numerical modelling capabilities develop and physical mechanisms of the ocean are better understood, the importance of particle trajectory modelling continues to increase. Therefore, developing cross-disciplinary particle trajectory model applications for the Greater Agulhas System is highly relevant due to its potential contribution to scientific studies and operational applications.

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Physical and biogeochemical variability off Baja California (Mexico): insights from numerical NPZD ocean models

Speaker: 
David Rivas

Affiliation: 
CICESE

Seminar Date: 
30. August 2019 - 13:15 - 14:00

Physical-biogeochemical Nitrate-Phytoplankton-Zooplankton-Detritus (NPZD)
numerical models are used to study the variability of nutrients and
phytoplankton biomass in coastal waters off Baja California Peninsula, a
region of high socioeconomic importance located in the southern California
Current System. The focus of these analyses has been the effects of
interannual climatic anomalies. For example, the year 2006 was anomalously
warm and with low chlorophyll (Chl) levels, associated with warm phases of
El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation

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Explore dynamical information with Pseudo-orbit Data Assimilation

Speaker: 
HAILIANG DU

Affiliation: 
Durham University

Seminar Date: 
13. June 2019 - 11:00 - 12:00

Physical processes such as the weather are usually modeled using nonlinear dynamical systems. Traditional statistical approaches are found to be difficult to draw dynamical information from the nonlinear dynamics. This talk is focusing on exploring dynamical information with Pseduo-orbit data assimilation to address various problems encountered in analyzing and modeling nonlinear dynamical systems. The talk will start with solving an “impossible” challenge pointed out by Berliner (1991) when applying the Bayesian paradigm to state estimation in chaotic systems.

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Korea Satellite Remote Sensing of the Arctic

Speaker: 
Hyun-Cheol Kim

Affiliation: 
Korea Polar Research Institute (KOPRI)

Seminar Date: 
28. March 2019 - 15:00 - 15:30

Dr. Hyun-Cheol Kim is the director of Unit of Arctic Sea-Ice Prediction, Korea Polar Research Institute (KOPRI).
As a remote sensing scientist, he will give us a talk regarding the research activities of KOPRI.
After the seminar, NERSC and KOPRI will sign a MoU.

The challenge of bounded, non-Gaussian, non-linear and multi-scale variables

Speaker: 
Craig Bishop

Affiliation: 
School of Earth Sciences and ARC Centre of Excellence for Climate Extremes
University of Melbourne

Seminar Date: 
8. April 2019 - 11:00 - 12:00

Current state estimation or data assimilation techniques assume Gaussian uncertainties for both forecasts and observations. However, unbiased observations of bounded variables can be shown to have highly non-Gaussian uncertainties and observation error standard deviations that depend on the value of the unknown true state. In particular, the observation error variance of such observations must tend to zero as the unknown true state tends to zero.

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