ASP Summer Colloquium & Workshop


Every year, the Advanced Study Program hosts a summer colloquium designed for graduate students on subjects that represent new or rapidly developing areas. The colloquium brings together experts from NCAR and the community at large together with a small group of 25-30 graduate students.

In 2021, the Advanced Study Program Summer Colloquium will be on the topic of "The Science of Subseasonal to Seasonal (S2S) Predictions". The event will be held virtually and will consist of live (and lively!) lectures and debates in the morning (9:00 AM - 12:30 PM Mountain Daylight Time / UTC-7) followed by guided hands-on application of S2S diagnostic tools in the afternoons.

This colloquium is intended for advanced graduate students whose expertise includes atmospheric and adjacent sciences. It will feature lectures from domestic and international experts on the fundamental processes leading to S2S predictability such as the Madden-Julian Oscillation, sudden stratospheric warmings, and atmospheric interactions with the ocean, the land and cryosphere.


In recent years there has been increasing interest to improve predictions on the subseasonal to seasonal timescale. It bridges the prediction gap between weather and climate and forecasts on this timescale are highly sought after by the energy, water management, agriculture, and other sectors for decision making. This timescale is challenging because it poses the limit of predictability from initializations (predictability of the first kind) and predictions are only skillful under certain conditions.

Expected Outcome

This colloquium will provide attendees with an integrated conceptual understanding of earth system processes that influence S2S predictions, numerical modeling, initialization strategies, ensemble configuration and applications of S2S-predictions. Attendees will also gain hands-on experience by applying probabilistic verification and process-based S2S diagnostics to numerical simulation output as well as implement and test machine learning methods for S2S predictions. Each tutorial will present its findings at the end of the summer colloquium or as part of the virtual scientific workshop.

Scientific workshop

As part of the colloquium a virtual scientific workshop will take place in the week of Aug 2-6, 2021. The workshop provides an opportunity for the lecturers and additional invited speakers to present their latest work in this fast moving field. Students are invited to attend and are expected to give a short presentation on their tutorial work on the last day.

A second in-person workshop will be held in the summer of 2022 (date TBD) in Boulder to which colloquium participants will have preferred access.


To make the colloquium as interactive as possible, we will have a number of lively “debates”. For the debates, we ask two or more lecturers to present arguments of two opposite sides of a topic, independently - or somewhat exaggerated - from their own scientific opinion. Here the “exaggerated” view part is emphasized as we want the debates to be opportunities for students to see divergent views and scientific argumentation rather than focus on the differentiated scientific opinions of the individual scientist.

List of debates:

  1. Is the atmosphere on S2S timescales a chaotic system or not?
  2. Dynamical vs statistical forecast are (links to nonlinear/linear)
  3. Team land vs team ocean vs team stratosphere - which is the dominant source of S2S predictability?
  4. Team tropics vs team midlatitudes - which forces which?
  5. Team tropics vs team polar - which forces the midlatitudes?
  6. There is/isn’t decadal/interannual modulation of S2S predictability
  7. ML can/cannot help with the understanding of physical processes

How To Apply


To start the new application process, you will need to provide the following information:

* If you applied for the 2020 summer colloquium, the letters of reference can be uploaded without change


  • All application information needs to be submitted by March 15, 2021, by midnight MST
  • All Adviser recommendation letters need to be received by March 22, 2021, by midnight MST

Event Details

Date & Location

Colloquium Dates: July 12-23 2021

Workshop Dates: August 2-6 2021

Location: Virtual

Colloquium Trello Board
Workshop Trello Board

Organizing Committee

  • Judith Berner, NCAR
  • Aneesh Subramanian, CU Boulder

Scientific Organizing Committee

  • Yaga Richter, NCAR
  • Elizabeth Barnes, Colorado State University
  • Donata Giglio, CU Boulder
  • Neena Mani Josph, IISER Pune - India
  • Arun Kumar, NOAA/CPC
  • Kathy Pegion, GMU
  • Carolyn Reynolds, NRL
  • Sam Shen, SDSU
  • Yuhei Takaya, JMA-MRI Japan
  • Frederic Vitart, ECMWF
  • Duane Waliser, JPL/CalTech
  • Chidong Zhang, PMEL/NOAA

Event Contact

Event Sponsors