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Quantitative Climate Science Seminar | Katja Fennel, Marine Carbon Dioxide Removal (mCDR): The good, the bad, and the ugly

Jenna Castanier — Mon, 07 Jul 2025 14:52:53 +0000

Quantitative Climate Science Seminar | Katja Fennel, Marine Carbon Dioxide Removal (mCDR): The good, the bad, and the ugly Jenna Castanier Mon, 07/07/2025 - 10:52

MC 5501

Speaker

Prof. Katja Fennel (Dalhousie University)

Title

Marine Carbon Dioxide Removal (mCDR): The good, the bad, and the ugly

Abstract

Approaches for a deliberate removal of CO2 from the atmosphere by manipulating the ocean's chemistry or ecosystems (also referred to as "marine Carbon Dioxide Removal" or mCDR) are rapidly gaining attention. None of the proposed approaches are currently technologically mature enough for deployment and significant research efforts are required. In this presentation, I will share general background and some personal thoughts about this rapidly developing field before diving into currently ongoing work on ocean alkalinity enhancement (OAE) in Halifax Harbour. OAE, the deliberate increase of ocean alkalinity, is an emerging technology that is considered comparatively scalable and promises to deliver durable carbon removal. A major challenge to the successful implementation of OAE (and any other mCDR technology) is the difficulty in reliably quantifying how much CO2 is being removed from the atmosphere and for how long. Observations are inherently sparse and therefore they alone cannot provide a comprehensive quantification of the effects of OAE. Numerical models are important complementary tools that can help guide fieldwork design, provide forecasts of the ocean state, and simulate the effects of alkalinity additions on the seawater carbonate system. I will describe a coupled circulation-biogeochemical model in a nested grid configuration that reaches a very high spatial resolution in Bedford Basin and model applications in support of OAE field work.

This event is part of the NSERC CREATE-funded Quantitative Climate Science summer school. More information about this initiative can be found at https://qcs-create2024.github.io/

Quantitative Climate Science Seminar | Laura Bianucci, High-resolution models of the nearshore ocean and their applications

Jenna Castanier — Mon, 07 Jul 2025 14:51:38 +0000

Quantitative Climate Science Seminar | Laura Bianucci, High-resolution models of the nearshore ocean and their applications Jenna Castanier Mon, 07/07/2025 - 10:51

MC 5501

Speaker

Dr. Laura Bianucci (Fisheries and Oceans Canada)

Title

High-resolution models of the nearshore ocean and their applications

Abstract

The coastal ocean is a dynamic, complex region where multi-scale processes interact and create conditions suitable for rich ecosystems. For instance, the combination of processes such as land and river runoff, local and remotely-forced upwelling, and wind and tidal mixing can bring nutrients to the surface waters, triggering high primary productivity rates. These coastal waters are also subjected to the direct impact of human activities like fishing, aquaculture farming, wastewater runoff, etc. These anthropogenic perturbations along with other pressures exerted by climate change can lead to negative effects in the coastal ocean (e.g., pollution, hypoxia, ocean acidification, sea level rise, etc.), which in turn can negatively affect ocean-dependent human activities. Since global and regional ocean models usually lack the necessary spatial resolution to fully represent many nearshore processes, there is a need for high-resolution coastal models to address some of these issues near shore. These coastal models can be used to understand the physical and biogeochemical drivers in different regions, how these processes can change in the future, and what the implications of these changes are. Furthermore, they can be useful tools to help inform the decision-making process of managers, regulators and the private sector alike. In this presentation, I will share some examples of high-resolution nearshore models developed at Fisheries and Oceans Canada (DFO) and their applications. Furthermore, I will take the opportunity to share my experience working as a scientist for the government of Canada.

This event is part of the NSERC CREATE-funded Quantitative Climate Science summer school. More information about this initiative can be found at https://qcs-create2024.github.io/

Quantitative Climate Science Seminar | Peter Crank, Microscale Urban Climate Modeling — pairing numerical modeling with the real world to promote healthy urban environments

Jenna Castanier — Mon, 07 Jul 2025 14:50:00 +0000

Quantitative Climate Science Seminar | Peter Crank, Microscale Urban Climate Modeling — pairing numerical modeling with the real world to promote healthy urban environments Jenna Castanier Mon, 07/07/2025 - 10:50

MC 5501

Speaker

Prof. Peter Crank (University of ��ݮ��Ƶ)

Title

Microscale Urban Climate Modeling — pairing numerical modeling with the real world to promote healthy urban environments

Abstract

Under climate change and growing urban populations, urban climatology is a growing field with many touchpoints with individuals, society, and the environment. Microscale numerical modeling provides researchers with unique tools to explore various urban design scenarios and their impact on the microclimate as well as on human health. Dr. Crank will explore how these models are used, evaluated, and validated through examples in hot climates like Phoenix and Singapore. He will also touch on how these models can be leveraged to support decision-making for healthy urban environments in hot climates but also in the Canadian context.

This event is part of the NSERC CREATE-funded Quantitative Climate Science summer school. More information about this initiative can be found at https://qcs-create2024.github.io/

Quantitative Climate Science Seminar | Andrea Scott, Fusing data for improved sea ice concentration estimates

Jenna Castanier — Mon, 07 Jul 2025 14:46:56 +0000

Quantitative Climate Science Seminar | Andrea Scott, Fusing data for improved sea ice concentration estimates Jenna Castanier Mon, 07/07/2025 - 10:46

MC 5501

Speaker

Prof. Andrea Scott (University of ��ݮ��Ƶ)

Title

Fusing data for improved sea ice concentration estimates

Abstract

Passive microwave sensors are a valuable tool for monitoring sea ice concentration in the Arctic. However, data from these sensors are known to have biases for thin ice, can be inaccurate when there is significant atmospheric moisture and have a high uncertainty in the marginal ice zone. Fusing passive microwave data with other sources of data can lead to improved results. In this talk we will discuss different data types and data fusion strategies as well as ways to quantify the uncertainty in the fused results. The focus will be on demonstrating the effectiveness of these tools for monitoring the marginal ice zone.

This event is part of the NSERC CREATE-funded Quantitative Climate Science summer school. More information about this initiative can be found at https://qcs-create2024.github.io/

Quantitative Climate Science Seminar | Carlos Pereira Frontado, Envisioning Future Technologies for Numerical Weather Prediction

Jenna Castanier — Mon, 07 Jul 2025 14:44:55 +0000

Quantitative Climate Science Seminar | Carlos Pereira Frontado, Envisioning Future Technologies for Numerical Weather Prediction Jenna Castanier Mon, 07/07/2025 - 10:44

DC 1302

Speaker

Dr. Carlos Pereira Frontado (Environment and Climate Change Canada)

Title

Envisioning Future Technologies for Numerical Weather Prediction

Abstract

Weather forecasting is undergoing a revolutionary transformation. At Environment and Climate Change Canada (ECCC), the Global Environmental Multiscale Model (GEM) has powered operational forecasts for the past few decades, but today's advances in artificial intelligence are fundamentally reshaping how we predict the atmosphere. As we begin this revolution, a natural path forward is to blend new data-driven insights with more established numerical methods for solving partial differential equations. At ECCC, breakthrough innovations like spectral nudging marry AI with classical numerics to boost accuracy, while we are simultaneously developing novel numerical schemes and a physics-informed AI framework, PARADIS, to push low-cost predictive skill even further. In this talk, we will present our hybrid forecasting vision, showcasing our work on high-order accurate numerical techniques and AI to deliver faster, more reliable weather forecasts that could help to save lives and protect our economy.

This event is part of the NSERC CREATE-funded Quantitative Climate Science summer school. More information about this initiative can be found at https://qcs-create2024.github.io/

Quantitative Climate Science Seminar | Marek Stastna, Quantitative Climate Science: Adding Substance to a Phrase

Jenna Castanier — Mon, 07 Jul 2025 14:42:57 +0000

Quantitative Climate Science Seminar | Marek Stastna, Quantitative Climate Science: Adding Substance to a Phrase Jenna Castanier Mon, 07/07/2025 - 10:42

DC 1302

Speaker

Prof. Marek Stastna (University of ��ݮ��Ƶ)

Title

Quantitative Climate Science: Adding Substance to a Phrase

Abstract

Climate science has undergone rapid and transformative development in recent decades. Much of this progress has been driven by advances in computation, accompanied by an expanding range of applications and increasingly sophisticated ways of communicating climate concepts. Despite the deep historical ties between climate science and applied mathematics, those connections have frayed over the very period in which the field has grown most dramatically.

This disconnect is reflected in several ways: in the shifting content of graduate curricula, in the hiring challenges faced by our partners in the civil service, and in the current ambiguity surrounding the role of AI within the broader climate enterprise.

In this talk, I will present three examples of mathematical concepts that surface across different subfields of climate science. These will serve as entry points to explore both the opportunities and the obstacles — conceptual, notational, and practical — that arise when trying to bridge the gap between mathematical and climate science communities. I will make the case for a broader understanding of what constitutes "climate-related" research and argue for a thoughtful reassessment of the training we offer today's students, especially in light of what previous generations (my own included) were taught.

This event is part of the NSERC CREATE-funded Quantitative Climate Science summer school. More information about this initiative can be found at https://qcs-create2024.github.io/

Numerical Analysis and Scientific Computing Seminar | Jan Nordström, Skew-symmetric governing equations and boundary conditions for nonlinear initial boundary value problems: a general path to stability

Jenna Castanier — Fri, 04 Jul 2025 13:26:19 +0000

Numerical Analysis and Scientific Computing Seminar | Jan Nordström, Skew-symmetric governing equations and boundary conditions for nonlinear initial boundary value problems: a general path to stability Jenna Castanier Fri, 07/04/2025 - 09:26

MC 5501

Zoom (Please contact ddelreyfernandez@uwaterloo.ca for meeting link)

Speaker

Jan Nordström, Professor Emeritus in Computational Mathematics at the Department of Mathematics, Linköping University

Title

Skew-symmetric governing equations and boundary conditions for nonlinear initial boundary value problems: a general path to stability

Abstract

We first show that skew-symmetric formulations of the nonlinear terms in initial boundary value problems (IBVPs) leads to an energy rate in terms of surface integrals only. Next, we focus on the boundary conditions and present energy bounded strong and weak implementation procedures. The new boundary procedure generalizes the well-known characteristic boundary procedure for linear problems to the nonlinear setting. We exemplify the complete theory on a scalar skew-symmetric nonlinear IBVP including the linear advection and Burger’s equation. The scalar analysis is subsequently repeated for general nonlinear systems of equations and shown to hold for the shallow water, the incompressible and compressible Euler and Navier-Stokes equations and equations governing multi-phase flows in the volume of fluid setting. We conclude by indicating how the continuous analysis directly lead to nonlinear energy stability when using the SBP-SAT technique with summation-by-parts operators and weak boundary conditions.

Graduate Student Seminar | Adam Teixido-Bonfill, Observational entropy as a framework to derive thermodynamics

Jenna Castanier — Wed, 02 Jul 2025 13:34:32 +0000

Graduate Student Seminar | Adam Teixido-Bonfill, Observational entropy as a framework to derive thermodynamics Jenna Castanier Wed, 07/02/2025 - 09:34

Online (Email amgrad for the link)

Candidate

Adam Teixido-Bonfill | University of ��ݮ��Ƶ

Title

Observational entropy as a framework to derive thermodynamics

Abstract

Thermodynamics is one of the most successful theories in physics, built originally from empirical observations. However, its laws are expected to emerge from the underlying rules of classical and quantum mechanics. A key concept to form this connection is entropy, which plays apparently different roles depending on the context: in thermodynamics, it signals the direction of spontaneous processes, and in information theory, it quantifies uncertainty. At the microscopic scale, these roles can be linked.

Observational entropy (arXiv:2008.04409) is a proposal that received renewed attention with the aim to make this link explicit. This proposal consists of defining entropy in terms of what an observer can actually measure, incorporating the idea of coarse-graining due to limited resolution. A recent generalization allows to account for known constraints on the state of the physical system (arXiv:2503.15612). This formulation unifies most previous entropy definitions under a common framework.

In this talk, I will introduce observational entropy and its generalizations, and outline how they offer a promising route to derive the laws of thermodynamics from first principles.

Graduate Student Seminar | Einar Gabbassov, From Quantum Errors to Stochastic Dynamics: Unravelling Open Quantum Systems

Jenna Castanier — Thu, 26 Jun 2025 20:32:12 +0000

Graduate Student Seminar | Einar Gabbassov, From Quantum Errors to Stochastic Dynamics: Unravelling Open Quantum Systems Jenna Castanier Thu, 06/26/2025 - 16:32

MC 6460

Candidate

Einar Gabbassov | University of ��ݮ��Ƶ

Title

From Quantum Errors to Stochastic Dynamics: Unravelling Open Quantum Systems

Abstract

Open quantum systems are quantum systems that interact with an external environment and exhibit dynamics fundamentally distinct from those of isolated, unitary evolution. These interactions give rise to decoherence and dissipation, which are crucial for understanding quantum technologies and the limits of quantum information processing.

In this talk, I will introduce the mathematical framework used to describe such systems, with a focus on Lindblad master equations, which govern the averaged evolution of open quantum systems. I will then present their stochastic unravellings via stochastic Schrödinger equations, offering a trajectory-based perspective that connects the ensemble dynamics to individual realizations.

To make this connection intuitive, I will introduce the essentials of stochastic (Itô) calculus, which underpins the formulation of these stochastic differential equations. Along the way, we will examine basic quantum channels that model common errors such as dephasing, relaxation, and depolarization, and explore how these channels give rise to both deterministic and stochastic dynamical descriptions.

The talk is designed to be accessible to a general mathematics audience, with an emphasis on the interplay between operator theory, probability, and quantum physics.

Graduate Student Seminar | Einar Gabbassov, Adiabatic Dynamics of Entanglement

Jenna Castanier — Thu, 26 Jun 2025 20:26:32 +0000

Graduate Student Seminar | Einar Gabbassov, Adiabatic Dynamics of Entanglement Jenna Castanier Thu, 06/26/2025 - 16:26

MC 6460

Candidate

Einar Gabbassov | University of ��ݮ��Ƶ

Title

Adiabatic Dynamics of Entanglement

Abstract

In the world of quantum computing, entanglement is a powerful resource. Our research investigates how entanglement behaves during a special kind of quantum process called 'adiabatic evolution,' where a quantum system slowly transforms from one state to another. We've discovered that entanglement isn't just changing randomly; instead, it's precisely 'woven' and re-woven at specific points during this evolution, almost like threads in a fabric. These crucial points are known as 'avoided energy level crossings,' where the system's energy levels approach each other closely but don't quite touch.

This weaving process has significant implications for the speed at which we can perform adiabatic quantum computations. We found that the more efficiently entanglement needs to be manipulated (which happens at very 'narrow' avoided crossings), the slower the quantum computer must operate to maintain accuracy. Intriguingly, the amount of entanglement that builds up during a quantum computation is directly related to how 'rugged' or complex a quantum problem's energy landscape is. This provides new insights into why some quantum problems are inherently harder than others, and could offer fresh perspectives on where the 'quantum advantage' truly comes from. Our work offers new tools to precisely control and study entanglement in adiabatic quantum computation.