Fall 2026 UTIG Seminar Series: Denis Felikson

Fall 2026 UTIG Seminar Series: Denis Felikson

by Denis Felikson · View the channel on PSI

Life & Natural Systems Earth Sciences & Geography RBEarth sciences
🎙 Denis Felikson 👥 605 📅 October 19, 2026 ⏱ 62 min 👁 26 📄 science communication 🧭 2026-10-20
Available in: English (current) Français

Keywords

sea level projectionsice sheet modelsGRACEISMIP6model weighting

Summary

Denis Felikson presents a seminar at UTIG on narrowing uncertainties in future sea-level rise projections using satellite observations. He begins by highlighting that while 2050 projections are relatively certain, uncertainties grow significantly by 2100, driven mainly by ice sheet dynamics. He introduces the concept of model weighting or Bayesian calibration to compare model ensembles with satellite data. Using GRACE and GRACE Follow-On mass change observations, he demonstrates how models can be evaluated by both ice-sheet-wide mass change and spatial patterns, noting that some models get the total right for wrong reasons due to compensating errors. He also discusses the use of additional metrics like velocity and surface elevation change, which yield different posterior distributions. The talk underscores the importance of developing better metrics and accounting for biases in observations, such as those from surface mass balance models. He concludes by emphasizing the growing body of literature on this approach and the need for continued research to reconcile results across different observational constraints.

162 words

Critical Evaluation

Value of the Information & Strength of the Argument

The presentation provides substantial value by clearly articulating a methodological approach to constrain sea-level projections—an area of high societal relevance. The argumentation is solid, grounded in existing literature and satellite data, and acknowledges limitations such as the influence of surface mass balance biases. The speaker effectively uses visual aids (graphs, maps) to support his points, and the discussion of compensating errors is particularly insightful. The reasoning is logical and progresses from problem identification to proposed solutions, though it stops short of delivering a definitive reconciled estimate, which is appropriately framed as ongoing work.

Scientific Rigor, Source Quality, Title Accuracy

The scientific rigor is high, with the speaker citing authoritative sources such as the IPCC AR6, ISMIP6, and GRACE mission data. The talk is internally consistent and transparent about the caveats and uncertainties in both observations and models. The title accurately matches the content, as the entire talk is dedicated to using satellite observations to narrow projection uncertainties. However, the presentation does not provide detailed references or URLs, so the audience must rely on the speaker’s credibility and prior publications for source verification. The lack of a peer-review process for the talk itself is a minor caveat.

205 words

Title / Content Match

The title accurately reflects the talk's focus on using satellite observations to narrow uncertainties in sea-level projections.

Quality & Reliability

8/10

The talk is delivered by a NASA research scientist with extensive experience in satellite remote sensing and ice sheet modeling. The content is well-structured, references official sources like IPCC AR6 and ISMIP6, and presents a balanced view of uncertainties and limitations. However, it is a seminar presentation rather than a peer-reviewed publication, and some conclusions are preliminary.

Key Moments

Markers derived by PSI from the transcript: the creator did not define chapters.

Cited Sources

  • IPCC AR6 Sea Level Change Chapter — Mentioned as the baseline for global and regional sea level projections and their uncertainties.
  • ISMIP6 (Ice Sheet Model Intercomparison Project for CMIP6) — Referenced as the multi-model ensemble used in AR6 for ice sheet contributions.
  • GRACE and GRACE Follow-On — Satellite missions mentioned as sources of mass change observations for the ice sheets.

Contribution & Novelties

The talk contributes to the emerging field of using satellite observations to calibrate ice sheet model ensembles, offering a clear explanation of model weighting techniques and the importance of spatial pattern evaluation. It highlights the issue of compensating errors and the need for multiple observational metrics.

Pour aller plus loin :

  • IPCC AR6 — The Sixth Assessment Report, which includes sea level projections and deep uncertainty discussions.
  • ISMIP6 — Ice Sheet Model Intercomparison Project providing multi-model ensembles for ice sheet contributions.
  • NASA Sea Level Change Team — Official portal with data and resources on sea level change, including satellite observations and projections.

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Radar Profile

The radar profile shows a balanced performance with high scores in information quality, technical level, and reliability, while information quantity is slightly lower, reflecting the talk's focused scope rather than a broad survey. The strong technical and reliability scores indicate a data-driven, expert presentation.

Reliability 8/10