New Journal Article – future changes in land cover and hydrological cycling across the interior of western Canada

Summary and synthesis of Changing Cold Regions Network (CCRN) research in the interior of western Canada – Part 2: Future change in cryosphere, vegetation, and hydrology

DeBeer, C. M., Wheater, H. S., Pomeroy, J. W., Barr, A. G., Baltzer, J. L., Johnstone, J. F., Turetsky, M. R., Stewart, R. E., Hayashi, M., van der Kamp, G., Marshall, S., Campbell, E., Marsh, P., Carey, S. K., Quinton, W. L., Li, Y., Razavi, S., Berg, A., McDonnell, J. J., Spence, C., Helgason, W. D., Ireson, A. M., Black, T. A., Elshamy, M., Yassin, F., Davison, B., Howard, A., Thériault, J. M., Shook, K., Demuth, M. N., and Pietroniro, A.

Hydrology and Earth System Sciences, Volume 25, Issue 4
April 9, 2021

This article examines future changes in land cover and hydrological cycling across the interior of western Canada under climate conditions projected for the 21st century. Key insights into the mechanisms and interactions of Earth system and hydrological process responses are presented, and this understanding is used together with model application to provide a synthesis of future change. This has allowed more scientifically-informed projections than have hitherto been available.

The interior of western Canada, like many similar cold mid- to high-latitude regions worldwide, is undergoing extensive and rapid climate and environmental change, which may accelerate in the coming decades. Understanding and predicting changes in coupled climate–land–hydrological systems are crucial to society yet limited by lack of understanding of changes in cold-region process responses and interactions, along with their representation in most current-generation land-surface and hydrological models. It is essential to consider the underlying processes and base predictive models on the proper physics, especially under conditions of non-stationarity where the past is no longer a reliable guide to the future and system trajectories can be unexpected. These challenges were forefront in the recently completed Changing Cold Regions Network (CCRN), which assembled and focused a wide range of multi-disciplinary expertise to improve the understanding, diagnosis, and prediction of change over the cold interior of western Canada. CCRN advanced knowledge of fundamental cold-region ecological and hydrological processes through observation and experimentation across a network of highly instrumented research basins and other sites. Significant efforts were made to improve the functionality and process representation, based on this improved understanding, within the fine-scale Cold Regions Hydrological Modelling (CRHM) platform and the large-scale Modélisation Environmentale Communautaire (MEC) – Surface and Hydrology (MESH) model. These models were, and continue to be, applied under past and projected future climates and under current and expected future land and vegetation cover configurations to diagnose historical change and predict possible future hydrological responses. This second of two articles synthesizes the nature and understanding of cold-region processes and Earth system responses to future climate, as advanced by CCRN. These include changing precipitation and moisture feedbacks to the atmosphere; altered snow regimes, changing balance of snowfall and rainfall, and glacier loss; vegetation responses to climate and the loss of ecosystem resilience to wildfire and disturbance; thawing permafrost and its influence on landscapes and hydrology; groundwater storage and cycling and its connections to surface water; and stream and river discharge as influenced by the various drivers of hydrological change. Collective insights, expert elicitation, and model application are used to provide a synthesis of this change over the CCRN region for the late 21st century.

Read the full article here.

New journal publication – SPADE

Meteorological observations collected during the Storms and Precipitation Across the continental Divide Experiment (SPADE), April–June 2019

J.M. Thériault, S.J. Déry, J.W. Pomeroy, H.M. Smith, J. Almonte, A. Bertoncini, R.W. Crawford, A. Desroches-Lapointe, M. Lachapelle, Z. Mariani, S. Mitchell, J.E. Morris, C. Hébert-Pinard, P. Rodriguez, and H.D. Thompson

Earth System Science Data, Volume 13, Issue 3
March 24, 2021

The continental divide along the spine of the Canadian Rockies in southwestern Canada is a critical headwater region for hydrological drainages to the Pacific, Arctic, and Atlantic oceans. Major flooding events are typically attributed to heavy precipitation on its eastern side due to upslope (easterly) flows. Precipitation can also occur on the western side of the divide when moisture originating from the Pacific Ocean encounters the west-facing slopes of the Canadian Rockies. Often, storms propagating across the divide result in significant precipitation on both sides. Meteorological data over this critical region are sparse, with few stations located at high elevations. Given the importance of all these types of events, the Storms and Precipitation Across the continental Divide Experiment (SPADE) was initiated to enhance our knowledge of the atmospheric processes leading to storms and precipitation on either side of the continental divide. This was accomplished by installing specialized meteorological instrumentation on both sides of the continental divide and carrying out manual observations during an intensive field campaign from 24 April–26 June 2019. On the eastern side, there were two field sites: (i) at Fortress Mountain Powerline (2076 m a.s.l.) and (ii) at Fortress Junction Service, located in a high-elevation valley (1580 m a.s.l.). On the western side, Nipika Mountain Resort, also located in a valley (1087 m a.s.l.), was chosen as a field site. Various meteorological instruments were deployed including two Doppler light detection and ranging instruments (lidars), three vertically pointing micro rain radars, and three optical disdrometers. The three main sites were nearly identically instrumented, and observers were on site at Fortress Mountain Powerline and Nipika Mountain Resort during precipitation events to take manual observations of precipitation type and microphotographs of solid particles. The objective of the field campaign was to gather high-temporal-frequency meteorological data and to compare the different conditions on either side of the divide to study the precipitation processes that can lead to catastrophic flooding in the region. Details on field sites, instrumentation used, and collection methods are discussed. Data from the study are publicly accessible from the Federated Research Data Repository at (Thériault et al., 2020). This dataset will be used to study atmospheric conditions associated with precipitation events documented simultaneously on either side of a continental divide. This paper also provides a sample of the data gathered during a precipitation event.

Read more here.

New journal publication: human-water systems

Conceptualizing Cascading Effects of Resilience in Human–Water Systems

Li Xu, Feng Mao, James S. Famiglietti, John W. Pomeroy, Claudia Pahl-Wostl

Multisystemic Resilience: Adaptation and Transformation in Contexts of Change
March, 2021
DOI: 10.1093/oso/9780190095888.001.0001

People and water interact over time and across space as coupled systems. Investigating the resilience of such coupling should take a multisystemic approach to address not only the resilience in different human and water systems, but also the interrelationship between their resilience processes. Based on the three framings of resilience in the coupled human–water context (i.e., social resilience, hydrological resilience, and socio-hydrological resilience), a conceptual framework is proposed for understanding the cascading effects of resilience along a chain of resilience change across systems and scales. The authors use a case example from a drainage basin in the Canadian Prairies to exemplify this framework and demonstrate how a change in the resilience of one system can exert an impact on the resilience of another, in socio-hydrological systems that are under the influence of both human activities and climate change.

Read the full article here.

New Journal Publication – Atmospheric boundary layer dynamics over glaciers

Icefield Breezes: Mesoscale Diurnal Circulation in the Atmospheric Boundary Layer Over an Outlet of the Columbia Icefield, Canadian Rockies

Conway, J.P., Helgason, W.D., Pomeroy, J.W., Sicart, J.E.

Journal of Geophysical Research – Atmospheres, Volume 126, Issue 6
February 13, 2021

Atmospheric boundary layer (ABL) dynamics over glaciers mediate the response of glacier mass balance to large‐scale climate forcing. Despite this, very few ABL observations are available over mountain glaciers in complex terrain. An intensive field campaign was conducted in June 2015 at the Athabasca Glacier outlet of Columbia Icefield in the Canadian Rockies. Observations of wind and temperature profiles with novel kite and radio‐acoustic sounding systems showed a well‐defined mesoscale circulation developed between the glacier and snow‐free valley in fair weather. The typical vertical ABL structure above the glacier differed from that expected for “glacier winds”; strong daytime down‐glacier winds extended through the lowest 200 m with no up‐valley return flow aloft. This structure suggests external forcing at mesoscale scales or greater and is provisionally termed an “icefield breeze.” A wind speed maximum near the surface, characteristic of a “glacier wind,” was only observed during night‐time and one afternoon. Lapse rates of air temperature down the glacier centerline show the interaction of down‐glacier cooling driven by sensible heat loss into the ice, entrainment and periodic disruption and warming. Down‐glacier cooling was weaker in “icefield breeze” conditions, while in “glacier wind” conditions, stronger down‐glacier cooling enabled large increases in near‐surface temperature on the lower glacier during periods of surface boundary layer (SBL) disruption. These results raise several questions, including the impact of Columbia Icefield on the ABL and melt of Athabasca Glacier. Future work should use these observations as a testbed for modeling spatio‐temporal variations in the ABL and SBL within complex glaciated terrain.

Read the full article here.

New Article – Saskatchewan Wetlands

Peiris: Saskatchewan wetlands at critical point, protection policy needed

Sarath Peiris
The Star Phoenix
February 18, 2021

It’s astounding that Saskatchewan still doesn’t have a comprehensive policy to manage and preserve its wetlands, which have been steadily drained since the early 1900s to accommodate agriculture. More than 50 per cent of these invaluable sites have now disappeared while the rest are under threat.

With half of Canada’s arable land, Saskatchewan should be the leader in acting to preserve wetlands that provide a wide array of environmental services such as serving as wildlife habitats and carbon sinks, producing pollinators, recharging aquifers, purifying water, retaining nutrients, mitigating flooding, contributing to soil health, and providing water security in a drought-prone province.

Read the full article here.

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

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:

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

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

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: