Previous Seminars

Creating a Madden-Julian oscillation (MJO) without convection

Speaker: 
Dr Jun-Ichi Yano
Affiliation: 
Meteo France
Seminar Date: 
12. July 2018 - 12:15 - 13:00

The Madden--Julian oscillation (MJO), a planetary--scale eastward propagating coherent structure with periods of 30--60 days, is a prominent manifestation of intraseasonal variability in the tropical atmosphere.
It is widely presumed that small--scale moist cumulus convection is a critical part of its dynamics.
However, the recent results from high--resolution modeling as well as data analysis suggest that the MJO may be understood by dry dynamics to a leading--order approximation.

Particle trajectory modelling for improved understanding of the South African shelf sea meso- and submesoscale variability and applications in operational oceanography

Speaker: 
Michael G. Hart-Davis
Affiliation: 
Institute for Coastal and Marine Research, Nelson Mandela University, Port Elizabeth, South Africa
Seminar Date: 
5. July 2018 - 12:30 - 13:30

This seminar will focus on previous work done in collaboration with the Nansen Environmental and Remote Sensing Center as well as the planned working being done at NERSC and throughout the M.G. Hart-Davis master thesis.

Impact of Winter Storms in a Thinner Arctic Sea-ice Regime

Speaker: 
Polona Itkin
Affiliation: 
Norwegian Polar Institute
Seminar Date: 
5. June 2018 - 10:00 - 11:00

The integrative effects of increased winter storm activity in the Arctic's Atlantic sector were studied using a collection of field observations and analyses. In early 2015, during the six-month N-ICE2015 expedition in the pack ice north of Svalbard, we observed a chain of events in the atmosphere-ice-ocean system that was triggered by several powerful winter storms. Our unique, interdisciplinary observations show that these winter storms entail significant effects that last much longer than the short-lived storm events themselves.

On the ongoing development of a new rheological model for a better representation of the drift and deformation of sea ice

Speaker: 
Véronique Dansereau
Affiliation: 
Centre National de la Recherche Scientifique - Institut des Sciences de la Terre, Grenoble, France, and Nansen Environmental and Remote Sensing Center, Bergen, Norway
Seminar Date: 
4. June 2018 - 11:00 - 11:30

Dansereau, V.*, Weiss, J., Saramito, P., Rampal, P., Bouillon, S., Olason, E.

Introductory Course On Statistical Modeling Of Extreme Values

Speaker: 
Hans Wackernagel
Affiliation: 
Equipe de GEOSTATISTIQUE - MINES ParisTech - PSL
Seminar Date: 
31. May 2018 - 10:15 - 1. June 2018 - 15:00

Extreme value theory is based on different principles than those
of conventional statistics as it is designed to study and model
exceptional events rather than the average characteristics of
natural phenomena.

This two-day introductory course will start by presenting
exploratory tools to analyze the behavior of extreme values in
geophysical data. This will help to motivate the basic principles
of the statistical modeling of extreme values and the
distributions that characterize them. The two common approaches
for assessing the risk of extreme events at a given level, i.e.

Study of the Kuroshio intrusion events by the identified paths into the South China Sea using an improved synthetic method

Speaker: 
Dazhi Xu
Affiliation: 
Visiting Scholar from South China Sea Marine Prediction Center, Guangzhou China
Seminar Date: 
28. May 2018 - 13:00 - 13:45

Originating from the North Equatorial Current (NEC), the Kuroshio is the strongest ocean current in the northwest Pacific, which is characterized by high temperature, high salinity, narrow band, and large flow velocity and its variable rate. When passing by the Luzon Strait (LS), a branch of the Kuroshio flows into the South China Sea (SCS) and affects the circulation and temperature-salinity structure in the SCS.

Ocean Acoustic Tomography in the North Atlantic

Speaker: 
Brian Dushaw
Affiliation: 
Nansen Center, Bergen, Norway
Seminar Date: 
15. May 2018 - 13:00 - 14:00

An objective mapping exercise was used to assess the resolution capabilities of ocean acoustic tomography in combination with Argo floats. Basis functions for a basin-wide area are derived from a covariance computed using an ocean state estimate. As is demonstrated by the formal uncertainty estimates from this computation, Argo and tomography are complementary measurements. In several examples, each separately gives results with comparable uncertainty, while when both are employed, uncertainties are reduced by O(50%).

Tutorials on data assimilation

Speaker: 
Patrick N. Raanes
Affiliation: 
NORCE / NERSC
Seminar Date: 
7. May 2018 - 10:00 - 12:00

NERSC is a world leader in data assimilation (DA) using the ensemble Kalman filter (EnKF). As a "farewell" seminar, Patrick N. Raanes will give some tutorials on the subject. The tutorials (i) provide a hands-on introduction; (ii) use Python, but are accessible for Matlab users; (iii) have already been used for two (and counting) short courses given at NERSC; (iv) have been developed alongside the underlying DA package (DAPPER), in part with internal, basic funding.

Note: Bring your laptops! (fear not: we'll not install anything)

Evolutions of the Arctic MFC in an evolving CMEMS 2018-2021.

Speaker: 
L. Bertino
Affiliation: 
NERSC
Seminar Date: 
20. March 2018 - 11:15 - 12:00

The Copernicus Marine Services (CMEMS) have kicked off their second phase for the period Jan-2018 to Mar-2021. The Arctic MFC, like other elements of CMEMS, has ambitious plans for modeling, assimilation of new Copernicus observations for forecasts and reanalyses and data dissemination. This presentation aims at keeping you updated with the main changes and discuss how NERSC can make the best out of the Copernicus programme.

Seasonal to decadal prediction skill in "our" region of Norwegian Climate Prediction model

Speaker: 
Climate Dynamics and Prediction (Yiguo Wang)
Seminar Date: 
6. March 2018 - 11:15 - 11:45

Recently it has been demonstrated that the slow fluctuations of the climate can be predicted up to a decade in advance in region such as in the North Atlantic. Prediction of near-term climate changes is of great interest to stakeholders e.g., fisheries, energy, shipping, farming, and insurance sectors. The Bjerknes Centre has developed climate prediction capability (the Norwegian Climate Prediction Model, NorCPM) that makes use of existing observations to control the internal variability of the climate that drives these slow fluctuations.