DCMIP-2025:
Overview and Schedule 

The Dynamical Core Model Intercomparison Project (DCMIP-2025) and Summer School will highlight the newest modeling techniques for global climate and weather models. It will be held at Mesa Lab of the National Center for Atmospheric Research (NCAR) in Boulder, CO, from June/2-6/2025 and will emphasize high-resolution non-hydrostatic modeling approaches and Machine Learning (ML) emulators as overarching themes. The objectives of the DCMIP-2025 Summer School are (1) to teach a group of about 50 multi-disciplinary students and postdocs how today’s and future atmospheric models and their dynamical core are or need to be built, (2) to shed light on the skill and realism of machine learning emulators for atmospheric fluid flows, and (3) to use idealized test cases to expose selected model design choices in simplified modeling frameworks. A particular focus of the idealized tests will explore the impact of topography on the circulation.
The summer school includes mornings lectures and hands-on modeling activities in the afternoon. The focus will lie on the three non-hydrostatic dynamical cores (Spectral Element, MPAS, FV3) that are available via NCAR’s Community Earth System Model (CESM) with its Community Atmosphere Model (CAM). The exploration of the ML emulators for General Circulation Models includes Google’s GraphCast and NVIDIA’s FourCastNet. DCMIP-2025 thereby continues the DCMIP-2008, DCMIP-2012 and DCMIP-2016 model intercomparison and summer school series. The DCMIP-2025 event is supported by the National Science Foundation (NSF), NOAA, and NSF NCAR. The available funding will support the travel, lodging, food, and local transportation expenses of the selected participants.

This hands-on summer school is based on morning lectures and afternoon modeling projects with the CESM dynamical cores as well as selected ML-based GCM emulators like GraphCast and FourCastNet. We will form 8 small groups that will be guided by modeling mentors. In particular, we will form two groups each for the CAM dynamical cores. The latter are the Spectral Element (SE), FV3 (Finite Volume model on the cubed-sphere), and Model for Prediction Across Scales (MPAS) dynamical cores. In addition, we will form two groups that focus on ML emulators such as Google's GraphCast and NVIDIA's FourCastNet. All participants will utilize a shared Wiki online workspace (this Google site)
https://sites.google.com/umich.edu/dcmip-2025

to share information and discuss the modeling results before, during, and after the event and create a collaborative spirit.

All morning lectures will be presented in the Main Seminar Room at the NCAR Mesa Lab (1850 Table Mesa Dr, Boulder, CO 80305). All afternoon hands-on modeling sessions take place in the Mesa Lab Library.

The DCMIP-2025 schedule is shown below (all times are for the Mountain Time (MT) zone):

The DCMIP lectures will be available during the DCMIP-2025 week via the live stream: https://www.youtube.com/@NCAR_CGD/streams
Recordings will also be made available after the DCMIP-2025 week via the YouTube channel: https://www.youtube.com/@NCAR_CGD

Sunday June/1/2025:
Travel day, all participants travel to Boulder, Colorado,
Check-in at the Embassy Suites Hotel (2601 Canyon Blvd, Boulder, CO 80302) or at your accommodations (if self-paid)

Monday June/2/2025

7:50-8am bus (from CU Boulder) pickup from Embassy Suites hotel (bus leaves at 8am sharp)
8:30am - 9:00 Lecture 1: Welcome and logistics (Christiane Jablonowski (UM) and Peter Lauritzen (NCAR))

9:00am - 10:00am Lecture 2: Overview of General Circulation Modeling, scales, and dynamical cores (Adam Herrington, NCAR)

10:00am-10:30am coffee break

10:30am - 11:30am Lecture 3: Overview of Machine Learning (ML) Approaches, use of ML in atmospheric science for weather and climate (William Chapman, NCAR)

11:30am-12:45pm Lecture 4: Introduction to the Hands-on component of DCMIP and the DCMIP-2025 test cases (Timothy Andrews, Owen Hughes, Nicholas Androski, Christiane Jablonowski (all UM), and Joshua Elms, Indiana University)

12:45pm-1:45pm lunch break

1:45pm-3:15pm hands-on session 1

3:15pm-3:45pm afternoon break

3:45pm-5:15pm hands-on session 2

5:20-5:30pm bus pickup at the Mesa Lab (bus leaves at 5:30pm sharp)

Tuesday June/3/2025

7:50-8am bus pickup from Embassy Suites hotel (bus leaves at 8am sharp)
8:30am - 9:00 Lecture 5 (Short Course): DCMIP visualization options & Python scripts (Timothy Andrews and Anthony Chen, UM)

9:00am - 10:00am Lecture 6 (Design of Dynamical Cores): Equation Sets and Computational Grids (Christiane Jablonowski, UM)

10:00am-10:30am coffee break

10:30am - 11:30am Lecture 7 (Design of Dynamical Cores): Horizontal discretizations, advection, and grid staggering options (Owen Hughes, UM)

11:30am-12:00pm Lecture 8: Idealized Assessments of GCM ML Emulators (Gregory Hakim, University of Washington, remote presentation)

12:00pm-12:20pm Lecture 9: Perspective from NVIDIA: ML weather forecast emulators (David Hall, NVIDIA)

12:20pm-12:40pm Lecture 10: Perspective from Google: ML weather forecast emulators (Dmitrii (Dima) Kochkov, Google Research) 

12:40pm-1:40pm lunch break

1:40pm-3:15pm hands-on session 3

3:15pm-3:45pm afternoon break

3:45pm-5:15pm hands-on session 4

5:20-5:30pm bus pickup at the Mesa Lab (bus leaves at 5:30pm sharp)

Wednesday June/4/2025

7:50-8am bus pickup from Embassy Suites hotel (bus leaves at 8am sharp)

8:30am - 9:30am Lecture 11 (Design of Dynamical Cores): Vertical coordinates, vertical staggering, vertical boundary conditions, and conservation properties (David Randall, CSU)

9:30am - 10:00 Lecture 12 (Short Course): The Design Aspects of the MPAS dynamical core (David Randall, CSU)

10:00am-10:30am coffee break

10:30am - 11:30am Lecture 13 (Design of Dynamical Cores): Temporal discretizations (Peter Bosler, Sandia Labs)

11:30am-12:30pm Lecture 14 (Design of Dynamical Cores): Dissipation properties (Christiane Jablonowski, UM)

12:30-12:40pm: Group photo, Mesa Lab staircase

12:40pm-1:40pm lunch break

1:40pm-3:15pm Lecture 15: Physics-Dynamics Coupling: grids, time-split versus process split,accuracy (Peter Lauritzen, NCAR)

3:15pm-3:45pm afternoon break

3:45pm-4:15pm Lecture 16: The Design Aspects of the SE dynamical core (Mark Taylor, Sandia Labs)

4:15pm-4:45pm Lecture 17: The Design Aspects of the U.K. Met Office dynamical core LFRIC (Thomas Bendall, U.K. Met Office)

5:20-5:30pm bus pickup at the Mesa Lab (bus leaves at 5:30pm sharp)

Thursday June/5/2025

7:50-8am bus pickup from Embassy Suites hotel (bus leaves at 8am sharp)
8:30am - 9:00 Lecture 18 (Short Course): The Design Aspects of the FV3 dynamical core (Christiane Jablonowski, UM)

9:00am - 9:30 Lecture 19 (Short Course): Programming paradigms, parallel computing concepts for GCMs, and parallel performance aspects (Mark Taylor, Sandia Labs)

9:30am - 10:00 Lecture 20 (Short Course): Design of coupled weather and climate models, technical aspects of the coupling, coupling frequency, coupling software (David Lawrence, NCAR)

10:00am-10:30am coffee break

10:30am - 12:30pm hands-on session 5

12:30pm-1:30pm lunch break

1:30pm-3:15pm hands-on session 6

3:15pm-3:45pm afternoon break

3:45pm-5:15pm hands-on session 7

5:20-5:30pm bus pickup at the Mesa Lab (bus leaves at 5:30pm sharp)

Friday June/6/2025

7:50-8am bus pickup from Embassy Suites hotel (bus leaves at 8am sharp)
8:30am - 9:00 Lecture 21 (Short course): Model hierarchies and the CESM Simpler Models Framework, international MIPs (Isla Simpson, NCAR)

9:00am - 10:00am Lecture 22: Overview of Physical Parameterizations  (Richard Neale, NCAR)

10:00am-10:30am coffee break

10:30am - 11:30am Lecture 23: Inside the CESM Factory: Model Development and Tuning (Cecile Hannay and Brian Mederios, NCAR)

11:30am-12:30pm Lecture 24: Prospects & frontiers: Variable-resolution, high-resolution and ultra-high-resolution (cloud system permitting) weather and climate modeling, ML (Colin Zarzycki (Penn State University) and Travis O'Brien (Indiana University)

12:30pm-1:30pm lunch break

1:30m-3:00pm hands-on session 8: Finalize presentations, optional: short after-lunch hike behind the Mesa Lab

3:00pm-3:30pm afternoon break

3:30pm-5:30pm Presentations Mesa Lab Main Seminar Room, about 15 minutes per group (8 groups)

5:45pm-8pm Farewell BBQ, Tree Plaza

7:50-8pm bus pickup at the Mesa Lab (bus leaves at 8pm)

9pm optional: meet downtown at Avanti (Food and Beverage Court, 1401 Pearl St, Boulder, CO 80302), meet on the rooftop terrace (25-minute walk from the hotel)

Saturday June/7/2025

Travel day, participants check out of the hotel (by 11am) and travel back home

DCMIP-2025 will enable the participants to describe and judge selected design choices for the dynamical cores of General Circulation Models (GCMs). The participants will learn how to configure, modify, run, and analyze simple configurations of the NCAR Community Earth System Model (CESM) with a particular focus on its Community Atmosphere Model (CAM). This will be accomplished via the use of idealized test cases. Furthermore, basic Machine Learning (ML) ideas will be conveyed to enable simple benchmarks of selected ML emulators for GCMs.

DCMIP-2025 will shed light on the

• differences between hydrostatic/nonhydrostatic and shallow-atmosphere/deep-atmosphere equation sets, and the selection criteria for the dry equation sets

• advective and flux-form of the transport (advection) equation and desirable physical properties of numerical schemes for advection: monotonicity and positive-definiteness

• various horizontal grids such as latitude-longitude, cubed-sphere, icosahedral, hexagonal, variable-resolution grids

• horizontal and vertical grid staggering options like the so-called A, B, C, D, E, and Z grids, as well as the Lorenz and Charney-Philips grids

• choice of the vertical coordinate in GCMs and the treatment of topography

• general characteristics of numerical schemes for the spatial discretization: spectral, finite element, finite volume and finite difference schemes

• general characteristics of numerical schemes for the temporal discretization: implicit versus explicit, semi-Lagrangian, one-step methods, multi-step methods

• accuracy and stability of numerical methods

• typical diffusion mechanisms in GCMs

• idealized test cases for the dynamical cores of GCMs

• Machine Learning concepts and ML emulators for GCMs