FALL 2026
Fridays at 11:00 am, Rosenstiel School Auditorium / Virtual Auditorium
Aug 21: NO SEMINAR
Aug 28: NO SEMINAR
Sep 04: NO SEMINAR
Sep 11: NO SEMINAR
Sep 18: NO SEMINAR
Sep 25: Drs. Dan Collins and Emerson LaJoie
NOAA / NWS / NCEP Climate Prediction Center, Riverdale Park, MD
Guests of Marybeth Arcodia, Department of Atmospheric Sciences
Accessing Sources of Predictability for
Subseasonal-to-Seasonal (S2S) Climate Prediction
Recording Available at COMPASS ON DEMAND
Predictability of climate on S2S timescales emerges in dynamical models from fundamental physical principles on the grid scale to the extent that they describe large-scale sources of predictability. For example, climate phenomena such as the El Nino Southern Oscillation (ENSO) and Madden Julian Oscillation (MJO) are known sources of predictability at this timescale. However, dynamical models are imperfect in their description of the climate system, limiting their prediction skill, relative to theoretical predictability limits. Statistical methods have long been applied to both optimize the extraction of information from dynamical model forecasts, and to make statistical predictions from relationships between current and future states of the climate system, without explicitly describing physics. While artificial intelligence (AI) systems are being developed to extend these concepts, extracting potentially nonlinear information from large multivariate datasets, currently applied forecast tools generally use linear statistical methods and are limited in their consideration of state-dependent predictability, i.e. forecasts of opportunity. This talk describes some of the methods currently employed by the National Weather Service / Climate Prediction Center to access predictability from statistical and dynamical models, as well as methods to combine or consolidate models. The skill and limitations of these forecast systems, as well as the potential for development of new forecast tools, will be discussed.
Oct 02: NO SEMINAR
Oct 09: NO SEMINAR (Rosenstiel School faculty meeting)
Oct 16: Student Seminars CALENDAR LINK
Christina Schuler (ATM)
Coupled Variability in the Gulf Stream-Nash System in a High-Resolution Coupled Model
The intensity and position of the North Atlantic Subtropical High (NASH) and the Gulf Stream play prominent roles in determining the trajectory of North Atlantic tropical cyclones (TCs). However, the impact of the Gulf Stream on NASH variability and consequent feedback mechanisms is less understood. This research analyzes the coupled dynamics between the Gulf Stream and the subtropical high by incorporating 850-hPa geopotential height, sea surface temperature (SST), and zonal and meridional ocean current velocities. Maximum covariance analysis (MCA) is employed to identify dominant modes of ocean–atmosphere variability among these fields. Regression analyses paired with statistical significance testing provide confidence whether there is a physical connection between oceanic and atmospheric variables. The results suggest that a stronger subtropical gyre (with an amplified western boundary current) leads to an enhanced meridional SST dipole (warm north and cold south) in the North Atlantic and intensified northward heat transport. Moreover, there is statistical significance for both SST and 850-hPa regression analyses from the model dataset. However, that significance lessens or is not present from the observational estimates due to the signal-to-noise ratio decreasing for smaller sample sizes. We additionally hypothesize that an increase in northward heat transport reinforces the NASH, amplifying the likelihood for straight-moving cyclones. Future research using modeling experiments will test this potential positive feedback mechanism.
Stephen Casey (OCE)
Michael Perez (ATM)
Oct 23: Student Seminars CALENDAR LINK
Abigail McDonnell (ATM)
Samuel Ephraim (MPO)
Shanna Chamhitt (ATM)
Oct 30: Reserved for visitors of Siyuan Wang, ATM
Nov 06: NO SEMINAR (SUSTAIN event in Auditorium)
Nov 13: Katrina Simi CALENDAR LINK
Department of Ocean Sciences, Rosenstiel School
(1-hour OCE student seminar)
Nov 20: Victoria Pizzini CALENDAR LINK
Department of Ocean Sciences, Rosenstiel School
(1-hour ATM student seminar)
Nov 27: NO SEMINAR (Thanksgiving Recess)
Dec 04: Snigdha Samantaray CALENDAR LINK
Department of Atmospheric Sciences, Rosenstiel School
(1-hour MPO student seminar)
Feb 12: NO SEMINAR (Parents Council in Auditorium)
