New Article – Canada Water Agency

Canada Water Agency will help protect and sustain Canada’s water resources, say USask water scientists

USask News
September 29, 2020

The new Canada Water Agency—announced in the recent federal Throne Speech—is the first critical step toward transforming how water is managed across the country, said John Pomeroy, director of the University of Saskatchewan (USask)-led Global Water Futures (GWF) program.

Read the article here.

Professor David Male 1939-2020

The University of Saskatchewan hydrological community has lost one of the developers of hydrology at USask. Dr. David Male, a professor of Mechanical Engineering at USask, was one of the pioneers of the study of snow with seminal studies of snowmelt energetics, blowing snow transport, snow sublimation, infiltration into frozen soils and the development of hydrological models. Together with Professor Don Gray he edited and wrote parts of the 776 page Handbook of Snow: Principles, Processes, Management and Use in 1980 – still the most comprehensive book on snow and a key foundational book

Professor Male contributed a strong physics-based approach to the study of cold regions hydrology and emphasized the need for results to be based on firm physical principles and advanced experimentation and observations in outdoor environments. He was amongst the first to identify the major problems with solving the “energy equation” for snowmelt and then to offer solutions using coupled energy and mass budgets, dimensional analysis, turbulent transfer and radiative transfer theory. Working with Raoul Granger, Don Gray and Tom Brown, he deployed advanced instrumentation controlled by computers for snowmelt studies at remote sites in the early 1970s when this presented considerable technical challenges. He was active in all aspects of snow science from leading advanced field studies at the USask Division of Hydrology’s Bad Lake research site, to developing analytical solutions for mathematical problems, writing computer models, training students, and writing scientific papers and books.

Professor Male was a lead faculty member in the Division of Hydrology and his work at the University of Saskatchewan laid the foundation for USask’s development of cold regions hydrology and water security into current areas of institutional strength. He also made important contributions to the work of Environment Canada, National Research Council of Canada, American Geophysical Union, US Office of Hydrology (National Weather Service), Atomic Energy of Canada Limited, Saskatchewan Environment, Alberta Environment and other groups. Dr. Male was an excellent teacher who could explain difficult engineering concepts exceptionally clearly to his students. He will be remembered by his former students and colleagues not only as an exceptionally brilliant scholar who made formidable advances in science, but also as a very nice, warm, supportive and friendly person who welcomed and encouraged many into engineering, science and academia. Professor Male passed away in Saskatoon earlier this month, his full obituary can be found here.
Many of his publications can be found here.

New Article- The Future We Want, The UN We Need

By Robert W. Sandford,
Senior Fellow of the Centre for Hydrology and Global Water Futures Chair at United Nations University

Inter Press Service News Agency
September 24, 2020

As we reflect on this week and celebrate the United Nations’ rise in the war-ravaged world some 75 years ago, humanity is again being asked to lay the foundation for a new world.

As in 1945, we are asked to envision the world that emerges from a global catastrophe. Similarly, as well, in our post-pandemic world we will need to make not a partial but a full transformation, one in which human self-interest again aligns with planetary realities.

Such a global reset can produce universal benefits in the form of a healthier, more just, safer, kinder and more spirituality connected society.

Read this important article here.

Online Cutting Edge Lecture in Science: Freshwater Futures for Canada and the World

McGill University Free Zoom event
September 24, 6pm-7pm EDT (4pm-5pm CST)

Canada and the world are facing unprecedented water-related challenges. Climate warming and human actions are altering precipitation patterns, reducing snow levels, accelerating glacier melting, intensifying floods, and increasing risk of droughts, while pollution from population growth and industrialization is degrading water systems. With such unprecedented change, it is clear that the historical patterns of water availability are no longer a reliable guide for the future.

Join Dr. John Pomeroy, winner of the 2020 Miroslaw Romanowski Medal, for a free cutting-edge lecture in science that will delve into these issues. Dr. Pomeroy will present the results of his research and show how Canada can lead the world in forecasting, preparing for and managing water futures in the face of dramatically increasing risks.

Brought to you by the Redpath Museum.

RSVP for this event here in order to receive the Zoom link.

John Pomeroy to speak at GW4 Water Security Alliance online conference

Knowledge Flow – Building Bridges between Science & Community

28-30 September, 2020

A team of PhD students from across the GW4 are leading an exciting new conference. Working with the WSA and The Flow Partnership, their event will bring together practitioners working with communities across the world, and researchers, working in fields spanning climate change, water scarcity and resource management, flood risk and policy, to explore this vital ‘knowledge flow’.

View more information here.



New Article- Snow Modelling Issues

Scientific and human errors in a snow model intercomparison

Cecile B. Menard; Richard Essery; Gerhard Krinner; Gabriele Arduini; Paul Bartlett; Aaron Boone; Claire Brutel-Vuilmet; Eleanor Burke; Matthias Cuntz; Yongjiu Dai Bertrand Decharme; Emanuel Dutra; Xing Fang; Charles Fierz; Yeugeniy Gusev; Stefan Hagemann; Vanessa Haverd; Hyungjun Kim; Matthieu Lafaysse; Thomas Marke; Olga Nasonova; Tomoko Nitta; Masashi Niwano; John Pomeroy; Gerd Schädler; Vladimir Semenov; Tatiana Smirnova; Ulrich Strasser; Sean Swenson; Dmitry Turkov; Nander Wever; Hua Yuan

Bulletin of the American Meteorological Society 1-46
September 9, 2020

Twenty-seven models participated in the Earth System Model – Snow Model Intercomparison Project (ESM-SnowMIP), the most data-rich MIP dedicated to snow modelling. Our findings do not support the hypothesis advanced by previous snow MIPs: evaluating models against more variables, and providing evaluation datasets extended temporally and spatially does not facilitate identification of key new processes requiring improvement to model snow mass and energy budgets, even at point scales. In fact, the same modelling issues identified by previous snow MIPs arose: albedo is a major source of uncertainty, surface exchange parametrizations are problematic and individual model performance is inconsistent. This lack of progress is attributed partly to the large number of human errors that led to anomalous model behaviour and to numerous resubmissions. It is unclear how widespread such errors are in our field and others; dedicated time and resources will be needed to tackle this issue to prevent highly sophisticated models and their research outputs from being vulnerable because of avoidable human mistakes. The design of and the data available to successive snow MIPs were also questioned. Evaluation of models against bulk snow properties was found to be sufficient for some but inappropriate for more complex snow models whose skills at simulating internal snow properties remained untested. Discussions between the authors of this paper on the purpose of MIPs revealed varied, and sometimes contradictory, motivations behind their participation. These findings started a collaborative effort to adapt future snow MIPs to respond to the diverse needs of the community.

Read the full article here.



Software developed by Centre for Hydrology researcher, Chris Marsh, featured in StarPhoenix and USask articles

Young Innovators: U of S software helps predict floods and freshwater supplies

Federica Giannelli
Star Phoenix, September 13, 2020

“Predicting snowmelt in the mountain headwaters of the world’s major rivers is now vastly more accurate due to a new University of Saskatchewan computer simulation model that can improve forecasts of downstream river flow — an innovation that will improve water management in the face of a changing climate.

“Our software has predicted the high snowpacks that occurred in the Rockies this year and the low snowpacks of previous years — useful for forecasting floods and droughts,” said U of S post-doctoral fellow Chris Marsh, who developed the model as part of his PhD project supervised by hydrologists John Pomeroy and Howard Wheater.”

Read the full article here.

The article is also available here.

New Article- Water flow through snow water resources research

Simulation of Preferential Flow in Snow With a 2‐D Non‐Equilibrium Richards Model and Evaluation Against Laboratory Data

Nicolas R. Leroux, Christopher B. Marsh, John W. Pomeroy
Published August 10, 2020
Water Resources Research, Volume 56. Issue 9, Pages 1-11


Recent studies of water flow through dry porous media have shown progress in simulating preferential flow propagation. However, current methods applied to snowpacks have neglected the dynamic nature of the capillary pressure, such as conditions for capillary pressure overshoot, resulting in a rather limited representation of the water flow patterns through snowpacks observed in laboratory and field experiments. Indeed, previous snowmelt models using a water entry pressure to simulate preferential flow paths do not work for natural snowpack conditions where snow densities are less than 380 kg m−3. Because preferential flow in snowpacks greatly alters the flow velocity and the timing of delivery of meltwater to the base of a snowpack early in the melt season, a better understanding of this process would aid hydrological predictions. This study presents a 2‐D water flow through snow model that solves the non‐equilibrium Richards equation. This model, coupled with random perturbations of snow properties, can represent realistic preferential flow patterns. Using 1‐D laboratory data, two model parameters were linked to snow properties and model boundary conditions. Parameterizations of these model parameters were evaluated against 2‐D snowpack observations from a laboratory experiment, and the resulting model sensitivity to varying inputs and boundary conditions was calculated. The model advances both the physical understanding of and ability to simulate water flow through snowpacks and can be used in the future to parameterize 1‐D snowmelt models to incorporate flow variations due to preferential flow path formation.

Read the full article here.


New Article- Warm-air entrainment and advection during alpine blowing snow events

Nikolas O. Aksamit and John W. Pomeroy
Published: September 1, 2020
The Cryosphere, volume14, issue 9, pages 2795–2807


Blowing snow transport has considerable impact on the hydrological cycle in alpine regions both through the redistribution of the seasonal snowpack and through sublimation back into the atmosphere. Alpine energy and mass balances are typically modeled with time-averaged approximations of sensible and latent heat fluxes. This oversimplifies nonstationary turbulent mixing in complex terrain and may overlook important exchange processes for hydrometeorological prediction. To determine if specific turbulent motions are responsible for warm- and dry-air advection during blowing snow events, quadrant analysis and variable interval time averaging was used to investigate turbulent time series from the Fortress Mountain Snow Laboratory alpine study site in the Canadian Rockies, Alberta, Canada, during the winter of 2015–2016. By analyzing wind velocity and sonic temperature time series with concurrent blowing snow, such turbulent motions were found to supply substantial sensible heat to near-surface wind flows. These motions were responsible for temperature fluctuations of up to 1 ∘C, a considerable change for energy balance estimation. A simple scaling relationship was derived that related the frequency of dominant downdraft and updraft events to their duration and local variance. This allows for the first parameterization of entrained or advected energy for time-averaged representations of blowing snow sublimation and suggests that advection can strongly reduce thermodynamic feedbacks between blowing snow sublimation and the near-surface atmosphere. The downdraft and updraft scaling relationship described herein provides a significant step towards a more physically based blowing snow sublimation model with more realistic mixing of atmospheric heat. Additionally, calculations of return frequencies and event durations provide a field-measurement context for recent findings of nonstationarity impacts on sublimation rates.

Read the full article here.

John Pomeroy consultant on award-winning Canadian author’s newest book

Author Leona Theis discusses Dr. Pomeroy’s contribution in this interview.

A&S: What is the research process like for your books? For example, you collaborated with USask scientist and alumnus Dr. John Pomeroy (BSC’83, PHD’88) for part of your new book. 
LT: For each of Sylvie’s lives, I wanted to connect with the spirit of the year it was set in—1974, 1979, 1984, etc. To do this I watched news clips, movie clips, and music videos. For example, the OJ Simpson chase plays a role, real and metaphorical, in one chapter. I watched and rewatched videos of the chase to remind me of the public mood that day and the way people were so caught up in the chase itself, in a bizarre, voyeuristic way. Another form of “research” consisted of sifting in a concentrated way through my own memories associated with specific years.
In some of her lives, Sylvie seems slow to grow into the responsibilities of adulthood. I wanted her, in later chapters, to take a more mature approach and to make connections between her own choices and the larger world. When we encounter her in the final chapter, she’s a grandparent concerned about environmental degradation and, wanting to play some part for the better, she returns to school as a grad student. She earns a place working on a research project modelled on Dr. Pomeroy’s work at Fisera Ridge in Kananaskis Country…