Summer School for Inverse Modeling of Greenhouse Gases (SSIM-GHG) 2025
Motivation
Rising concentrations of CO2 and CH4 are the driver of climate change and reflect a complex mix of natural and human sources and sinks. For example, plants and oceans absorb about half of human CO2 emissions every year, slowing the progression of climate change. Tracking progress to combat climate change requires good quality understanding of sources and sinks and underlying processes, which come from a variety of complex modeling tools that help scientists calculate the exchanges of CO2 and CH4 at the Earth’s surface from atmospheric data. This workshop, supported by the newly-established US Greenhouse Gas Center, aims to develop a future workforce skilled at using existing tools as well as building their own tools to understand sources and sinks of greenhouse gases.
Workshop goals
The goal of the workshop is to present and provide guidance and instruction of the state of the art in atmospheric data assimilation techniques needed to support current and future GHG observing systems. This includes different flux estimation techniques for GHGs, and retrieval techniques for estimating atmospheric GHGs from space-based and surface-based remote sensing platforms.
Sponsors





Presentations
Note: Some videos are concatenated across multiple speakers***
Week One:
Student Homework to be reviewed before Summer School
Instructors: Michael Bertolacci and Sean Crowell
| Speaker | Title/Slides and/or Notebooks | Video |
|---|---|---|
| Michael Bertolacci | Linear Algebra and Probability | Linear Algebra and Probability |
| Michael Bertolacci | Linear Models | Linear Models |
| Michael Bertolacci | Bayesian Linear Models | Bayesian Linear Models |
Jupyter Notebook by Sean Crowell | Jupyter Notebooks (Python) Please read the README | NA |
Background/Intro – Tuesday, July 8th
Instructors: Scott Denning, Sean Crowell, Gretchen Keppel-Aleks, Andy Jacobson
| Speaker | Title | Video |
|---|---|---|
| Lucas Estrada, Betsy Farris, Jess Lyons | “How to survive Summer School” | Surviving Summer School |
| Scott Denning | Global Carbon Cycle: CO2 | Carbon Cycle: CO2 |
| Lori Bruhwiler | Global Carbon Cycle: CH4 | Carbon Cycle: CH4 |
Andy Jacobson | In-situ Observations | |
| Sean Crowell | Satellite Observations | Remote Sensing |
Atmospheric Transport and Bayesian Matrix Inversion Methods – Wednesday, July 9th
| Speaker | Title | Video |
|---|---|---|
| Scott Denning | Atmospheric Transport Modeling | Atmospheric Transport |
| Hannah Nesser | Batch Inversion Intro | Batch Inversions |
| Hannah Nesser | Jacobian/Sensitivity Matrix Intro | Jacobians/Sensitivity |
| Michael Bertolacci, Sourish Basu | Prior Flux and MDM Covariances | Covariances |
Bayesian Matrix Methods / Plume Methods – Thursday, July 10th
| Speaker | Title | Video |
|---|---|---|
| Hannah Nesser | Inversion Diagnostics | Diagnostics |
| Sean Crowell | Plume Methods | Plume Methods |
Ensemble Kalman Filter Methods- Friday, July 11th
| Speaker | Title | Video |
|---|---|---|
| Andy Jacobson | L Curve Digression (Diagnostics) | L_curve |
| Andy Jacobson, Abhishek Chatterjee (lost second half) | Kalman Filtering Techniques | Kalman Filtering |
Week Two:
4DVAR/Variational Methods – Monday, July 14
| Speaker | Title | Video |
|---|---|---|
| David Baker | Variational Methods | Variational Methods |
| Sourish Basu | Variational Example | Variational Example |
Trace Gas Retrievals – Tuesday, July 15
| Speaker | Title | Video |
|---|---|---|
| Chris O’Dell | GHG Retrievals Part I | Retrievals |
| Rob Nelson | GHG Retrievals Part II | Retrieval Toy Problem |
LPDM Methods I and METEC Field Trip – Wednesday, July 16
| Speaker | Title | Video |
|---|---|---|
| Dien Wu | Regional Inversion Introduction | Regional Inversions |
| Dien Wu | Lagrangian Methods | Lagrangian Methods |
| Ben Hmiel | Colorado AQ Perspective GHG | Application CO DPHE |
| Anna Hodshire | METEC and COBE | Facilities |
Field Trip to Niwot Ridge, CO (facilitated by NOAA-GML), Wednesday, June 19
LPDM Methods II – Thursday, July 17
| Speaker | Title | Video |
|---|---|---|
| Kim Mueller | Engineering a Regional Inversion | Eng Regional Inversion Part I Eng Regional Inversion Part II |
| Hannah Nesser | Boundary Conditions | Boundary Conditions |
Resources
Q&A
Toy Example Code
Code for the toy examples presented in class can be found at the following link: https://github.com/US-GHG-Center/ssim-ghg