New Journal Publication – Mountain Snowpack Prediction

Multi-scale snowdrift-permitting modelling of mountain snowpack

Vincent Vionnet, Christopher B. Marsh, Brian Menounos, Simon Gascoin, Nicholas E. Wayand, Joseph Shea, Kriti Mukherjee, and John W. Pomeroy

The Cryosphere,  Volume 15, Issue 2
February 17, 2021
DOI: https://doi.org/10.5194/tc-15-743-2021

Abstract
The interaction of mountain terrain with meteorological processes causes substantial temporal and spatial variability in snow accumulation and ablation. Processes impacted by complex terrain include large-scale orographic enhancement of snowfall, small-scale processes such as gravitational and wind-induced transport of snow, and variability in the radiative balance such as through terrain shadowing. In this study, a multi-scale modelling approach is proposed to simulate the temporal and spatial evolution of high-mountain snowpacks. The multi-scale approach combines atmospheric data from a numerical weather prediction system at the kilometre scale with process-based downscaling techniques to drive the Canadian Hydrological Model (CHM) at spatial resolutions allowing for explicit snow redistribution modelling. CHM permits a variable spatial resolution by using the efficient terrain representation by unstructured triangular meshes. The model simulates processes such as radiation shadowing and irradiance to slopes, blowing-snow transport (saltation and suspension) and sublimation, avalanching, forest canopy interception and sublimation, and snowpack melt. Short-term, kilometre-scale atmospheric forecasts from Environment and Climate Change Canada’s Global Environmental Multiscale Model through its High Resolution Deterministic Prediction System (HRDPS) drive CHM and are downscaled to the unstructured mesh scale. In particular, a new wind-downscaling strategy uses pre-computed wind fields from a mass-conserving wind model at 50 m resolution to perturb the mesoscale HRDPS wind and to account for the influence of topographic features on wind direction and speed. HRDPS-CHM was applied to simulate snow conditions down to 50 m resolution during winter 2017/2018 in a domain around the Kananaskis Valley (∼1000 km2) in the Canadian Rockies. Simulations were evaluated using high-resolution airborne light detection and ranging (lidar) snow depth data and snow persistence indexes derived from remotely sensed imagery. Results included model falsifications and showed that both wind-induced and gravitational snow redistribution need to be simulated to capture the snowpack variability and the evolution of snow depth and persistence with elevation across the region. Accumulation of windblown snow on leeward slopes and associated snow cover persistence were underestimated in a CHM simulation driven by wind fields that did not capture lee-side flow recirculation and associated wind speed decreases. A terrain-based metric helped to identify these lee-side areas and improved the wind field and the associated snow redistribution. An overestimation of snow redistribution from windward to leeward slopes and subsequent avalanching was still found. The results of this study highlight the need for further improvements of snowdrift-permitting models for large-scale applications, in particular the representation of subgrid topographic effects on snow transport.

Read the full article here.

 

New Water Towers Article in Chemistry and Industry Magazine

Water Towers Threatened

Anthony King
C&I Issue 12, 2020

“The earliest agricultural civilisations in the Middle East were built around managing mountain water supplies, holding back water to irrigate lowland areas. Mountain water is still critical in many regions. But it is increasingly threatened by the impacts of climate change.”

Read the C&I Article here: https://www.soci.org/chemistry-and-industry/cni-data/2020/12/water-towers-threatened

New Article – Alberta Coal Policy

Saskatchewan environmental groups welcome reinstatement of Alberta coal policy

Ryan Kessler, Global News
February 9, 2021

The Alberta government’s pledge to reinstate a ban on open-pit coal mining in a large section of the Rocky Mountains and foothills has alleviated some concern among Saskatchewan environmental groups.

The South Saskatchewan River receives 80 to 90 per cent of its water from runoff in the Rockies, according to Bob Halliday, board chair of Partners FOR the Saskatchewan River Basin.

“When you turn on a tap in Saskatoon, you’re actually drinking mountain water,” said Halliday, who is also a water resources consulting engineer.

On Monday, Alberta Energy Minister Sonya Savage said the province would reinstate the 1976 coal policy that was revoked last spring…..

 

Read the full article along with Dr. John Pomeroy’s comments here.

New CBC interview- Effects of coal mining on water quality

What effect could coal mining in Alberta have on water quality of Saskatchewan’s rivers?
Blue Sky with Garth Materie
CBCListen
February 4, 2021

A controversy is raging in Alberta over plans to allow open-pit coal mines on the eastern slopes of the Rockies. This could have an effect in Saskatchewan. Many of the rivers near the proposed mines eventually run into the Saskatchewan river system. This project has seen opposition from a wide range of groups including Indigenous communities and rancher/musician Corb Lund.

 

We spoke with Ian Urquhart, the Conservation Director for the Alberta Wilderness Association. We were also joined by John Pomeroy, the director of the Global Water Futures Project at the University of Saskatchewan and we heard from Garry Carriere, President of the Cumberland House Fisheries.

Listen to the episode at: https://www.cbc.ca/listen/live-radio/1-189-blue-sky

Read the corresponding CBC article:‘An abomination’: Sask. water expert warns of contamination following Alberta’s coal policy changes, by Mickey Djuric, CBC News, February 5, 2021

 

 

Centre Hydrologist Dr. John Pomeroy featured on The Weather Network

Snow laughing matter: Why you should never eat snow
Rachel Schoutsen
The Weather Network
February 1, 2021

Have you ever taken a bite out of winter? Eating snow may look harmless, however there could be thousands of elements in a single bite of snow. Auto emissions, bacteria, sea salts and nitrate are just the start!

 

Watch the interview at: https://www.theweathernetwork.com/ca/news/article/why-you-should-not-eat-snow

Centre Hydrologist discusses melting glaciers on CBC news

Melting ice and glaciers could lead to water crisis
Tashauna Reid, CBC News
January 28th

A new study finds that ice is disappearing around the globe at an alarming rate and glaciers represent a significant amount of ice loss. Researchers in Canada say the retreat of glaciers will have major impacts on water security in Canada.

Watch the video here: https://www.cbc.ca/player/play/1849913411823

 

New Journal Article – Snow Model Intercomparison

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 A. Semenov, Tatiana Smirnova, Ulrich Strasser, Sean Swenson, Dmitry Turkov, Nander Wever, and Hua Yuan

Bulletin of the American Meteorological Society, Volume 101, Issue 1
January 14, 2021
https://doi.org/10.1175/BAMS-D-19-0329.1

Abstract
Twenty-seven models participated in the Earth System Model–Snow Model Intercomparison Project (ESM-SnowMIP), the most data-rich MIP dedicated to snow modeling. 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 modeling issues identified by previous snow MIPs arose: albedo is a major source of uncertainty, surface exchange parameterizations 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 behavior 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.

New Journal Article – Snow cover duration

Snow cover duration trends observed at sites and predicted by multiple models

Richard Essery, Hyungjun Kim, Libo Wang, Paul Bartlett, Aaron Boone, Claire Brutel-Vuilmet, Eleanor Burke, Matthias Cuntz, Bertrand Decharme, Emanuel Dutra, Xing Fang, Yeugeniy Gusev, Stefan Hagemann, Vanessa Haverd, Anna Kontu, Gerhard Krinner, Matthieu Lafaysse, Yves Lejeune, Thomas Marke, Danny Marks, Christoph Marty, Cecile B. Menard, Olga Nasonova, Tomoko Nitta, John Pomeroy, Gerd Schädler, Vladimir Semenov, Tatiana Smirnova, Sean Swenson, Dmitry Turkov, Nander Wever, and Hua Yuan

The Cryosphere, Vol 14, Issue 12
December 21, 2020
https://doi.org/10.1002/hyp.13986

Abstract:
The 30-year simulations of seasonal snow cover in 22 physically based models driven with bias-corrected meteorological reanalyses are examined at four sites with long records of snow observations. Annual snow cover durations differ widely between models, but interannual variations are strongly correlated because of the common driving data. No significant trends are observed in starting dates for seasonal snow cover, but there are significant trends towards snow cover ending earlier at two of the sites in observations and most of the models. A simplified model with just two parameters controlling solar radiation and sensible heat contributions to snowmelt spans the ranges of snow cover durations and trends. This model predicts that sites where snow persists beyond annual peaks in solar radiation and air temperature will experience rapid decreases in snow cover duration with warming as snow begins to melt earlier and at times of year with more energy available for melting.

Read the full article here.

New Article- What Canada’s melting glaciers tell USask researchers

Chris Morin
University of Saskatchewan News
Jan 8, 2021

It may seem unfathomable, but these masses of ice are melting at an alarming rate. Canadian glaciers have shrunk 15 per cent since 1985, and estimated glacier loss in the Rockies could rise to 100 per cent by the end of the century, according to University of Saskatchewan (USask) hydrology PhD candidate Caroline Aubry-Wake.

One of the areas that Aubry-Wake conducts research at is the Peyto Glacier in Banff National Park and the Athabasca Glacier in Jasper National Park. It’s an area that’s a cause for alarm—not just the immediate region, but also those areas downstream—and a look at the region’s rapid ice loss makes this clear.

Read the full article at: https://news.usask.ca/articles/research/2021/what-canadas-melting-glaciers-tell-usask-researchers.php

New Journal Article – Isotope analysis of subalpine forest water sources

A δ18O and δ2H stable water isotope analysis of subalpine forest water sources under seasonal and hydrological stress in the Canadian Rocky Mountains

Lindsey E. Langs, Richard M. Petrone and John W. Pomeroy

Hydrological Processes
Volume 24, Issue 26
December 18, 2020
https://doi.org/10.1002/hyp.13986

Abstract:
Subalpine forests are hydrologically important to the function and health of mountain basins. Identifying the specific water sources and the proportions used by subalpine forests is necessary to understand potential impacts to these forests under a changing climate. The recent “Two Water Worlds” hypothesis suggests that trees can favour tightly bound soil water instead of readily available free‐flowing soil water. Little is known about the specific sources of water used by subalpine trees Abies lasiocarpa (Subalpine fir) and Picea engelmannii (Engelmann spruce) in the Canadian Rocky Mountains. In this study, stable water isotope (δ18O and δ2H) samples were obtained from S. fir and Engelmann spruce trees at three points of the growing season in combination with water sources available at time of sampling (snow, vadose zone water, saturated zone water, precipitation). Using the Bayesian Mixing Model, MixSIAR, relative source water proportions were calculated. In the drought summer examined, there was a net loss of water via evapotranspiration from the system. Results highlighted the importance of tightly vadose zone, or bound soil water, to subalpine forests, providing insights of future health under sustained years of drought and net loss in summer growing seasons. This work builds upon concepts from the “Two Water Worlds” hypothesis, showing that subalpine trees can draw from different water sources depending on season and availability. In our case, water use was largely driven by a tension gradient within the soil allowing trees to utilize vadose zone water and saturated zone water at differing points of the growing season.

Read the full article here.