43rd Field Season of North Cascade Glacier Climate Project

On July 23, 2026July 23, 2026 By mspeltoIn glacier climate change, glaciers salmon, Heat waves glacier melt, North Cascade GlaciersLeave a comment

**Lower Curtis Glacier terminus in 2025 with overall results of our work 1984-2025.**

2026 Field Season: For the 43rd consecutive summer we are heading into the field to measure and communicate the impact of climate change on North Cascade glaciers. This field season follows the 2021-2025 seasons that featured either historic heat waves and/or periods of extended warm weather. The heat led to a greater exposure of bare ice on glaciers with a higher albedo and greater density. The observed melt rates are 7-9 cm/day water equivalent during warm weather events vs 4-6 cm/day for snow surfaces. This led to substantial mass losses on North Cascade glacier for the five years of ~8m. This winter was poor and the summer will be hard on glaciers. This year we have provided support from Alpine Start, Marmot, Protect our Winters and Smartwool.

Science objectives: We will complete detailed measurements on 10 glaciers, three of which are part of the World Glacier Monitoring Service reference glacier network (48 glaciers globally), which have 30+ consecutive years of mass balance observations. This summer we will have an opportunity to assess the long-term ramifications of the 2021-2025 period of unprecedented mass balance losses and associated glacier changes, with detailed mass balance, crevasse depths and glacier surface elevation profiling. We also focus on the impact of diminishing glacier size on downstream runoff.

Art Objectives: We will collaborate with several artists who will join us for a portion of the field season. They will be able to create their own work about the landscape and the science or may join us for fieldwork and make plans for future artwork. We hope to use this art to share our research with a broader audience and highlight the beauty and importance of these places.

Communication Objectives: We will leverage the brands of our expedition sponsors and local organizations that we are building collaborations to focus on continued rapid glacier loss and the downstream effects. We will utilize a combination of artists and scientists to tell the story.

**Painting by Jill Pelto of the Nooksack watershed illustrating connections from glacier to the sea.**

Bios

Jill Pelto (she/her) is an artist and scientist from New England who grew up loving winter sports and trips to the mountains. She incorporates scientific research and data into paintings and prints to communicate environmental changes. 2025 was Jill’s 17th field season. She has coordinated an art gallery exhibit “Shaped by Ice” in Seattle in 2025 and in Winthrop, WA in 2026. She is excited about continuing to document the change in North Cascade glaciers that she has witnessed each of the last ten years —through science and art.

Mauri Pelto (he/him) has directed the project since its founding in 1984, spending more than 800 nights camped out adjacent to these glaciers. He is the United States representative to the World Glacier Monitoring Service. For 16years he has been author of the blog “From a Glacier’s Perspective”, and associate editor for three science journals. He is on the Science Advisory Board for NASA’s Earth Observatory. His primary position is Associate Provost at Nichols College, where he has been a professor since 1989. He either runs on trails or skis on alpine and cross country trails every day.

Ava Reynolds is a printmaker examining the relationship between environmental beauty and climate change in her work. Ava holds a B.A. in Global Sustainability and a B.A. in Studio Art from the University of Virginia (2020), and is in her first year at the Rhode Island School of Design, pursuing an MFA in Printmaking. She finds inspiration for her prints from organic forms, natural landscapes, and climate change data and seeks to use art as a medium to engage with a large audience about the impacts of climate change.

Shaina Dotson is a Seattle-based creative with a BFA in Metalsmithing whose hobbies include metal arts, fiber arts, and printmaking. She serves on the board of the Washington Alpine Club and instructs for their Basic Climbing Class, sharing her love of the mountains with new climbers. Shaina is an avid mountaineer who finds joy in exploring the forests, peaks, and wild places of Washington State. Her deep connection to the landscape, combined with a love of learning and giving back to her community, naturally drew her to this project. She looks forward to creating new work inspired by the glaciers of Washington and the research this project brings to light.

Rikki Held is an early-career scientist passionate about understanding Earth and climate systems and communicating science through film. Growing up on her family’s ranch in southeastern Montana and studying the adjacent river with USGS scientists sparked her interest in investigating the complex Earth systems in which we live. She earned her B.A. in Environmental Science at Colorado College and has conducted interdisciplinary research, taught high school biology and chemistry through the Peace Corps in Kenya, and communicated climate impacts through her climate advocacy work in Montana. In graduate school, Rikki aims to study glaciology and climate variability to better predict future change. She looks forward to learning from the scientists and artists involved in NCGCP and creating a short documentary on their inspiring work.

Abby Conner (she/her) is a water resources professional with a passion for connecting people to their local watersheds. She earned her M.S. in Civil Engineering from the University of Colorado and returned to the PNW, where she serves on the board of the Carkeek Watershed Community Action Project and volunteers with the Mountaineers. She looks forward to bringing her background in water resources to the NCGP and exploring the connections between North Cascade glaciers and the communities downstream.

Nina Adjanin (she/her) is an associate professor at Northwest Missouri State University. Her work integrates technology and immersive experiences to explore the intersection of education, extreme environments, and the impact of climate change on high mountains and polar regions. Beyond her academic work, Nina is an experienced high-altitude mountain guide and adventurer, with expeditions that have taken her to extreme environments around the world and shaped her interdisciplinary approach to research. Nina is thrilled to be joining this project documenting the changes in the North Cascade glaciers, bringing her background in extreme environments and climate change research.

Danielle Schlunegger-Warner is a multi-disciplinary artist working in sculpture, installation, and experimental digital photography, to celebrate the wonder of the natural world. After graduating from California College of Art with a BFA in Sculpture, she has fabricated and designed museum exhibits for over ten years and maintained an independent art practice including science communication projects. For NCGCP, Danielle plans to continue combining her art, science, and museum exhibit background. She will investigate how the rapidly changing glacial landscape of the Cascades can be seen through the lens of a microscope, intertwining field microscopy, image projection, and artistic observations illustrating impact of smallest forms of life the greater environment.

**Team on Rainbow Glacier in 2025 from left Katie Hovind, Caitlin Quirk, Claire Sianna Seaman, Jill Pelto and Margaret Kingston.**

2026 Schedule

July 28: Hike In Lower Curtis Glacier
July 29: Lower Curtis Glacier survey
July 30: Hike Out Lower Curtis/Hike in Ptarmigan Ridge
July 31: Sholes Glacier
Aug. 1: Rainbow Glacier
Aug. 2: Rainbow Glacier
Aug. 3: Hike out. Hike in Easton Glacier (Resupply in Bellingham WA)
Aug. 4: Easton Glacier
Aug. 5: Easton Glacier
Aug. 6: Squak Glacier
Aug. 7: Talum Glacier
Aug. 8: Hike out Hike in Columbia Glacier (resupply in Monroe WA)
Aug. 9: Columbia Glacier
Aug. 10: Hike out Columbia-Hike in Daniels
Aug. 11: Mount Daniels Survey
Aug. 12: Ice Worm-Hike out

North Cascade Glacier Climate Project Year of Glacier Preservation Observations

On April 11, 2026April 17, 2026 By mspeltoIn glacier climate change, Glacier Observations, glaciers salmon, North Cascade Glaciers

March 21, 2026 was World Day for Glaciers, telling this story is an ongoing four decades long project for us. The North Cascade Glacier Climate Project began in 1984 to identify the response of Washington’s North Cascade glaciers to climate change. The 2026 field season will mark our 43^rd year of observations.

I co-direct the project as the science director, with Jill Pelto as the art director. We strive to create a diverse and collaborative portfolio of impactful observations connecting people to science through art and data publication. Our theory of change is that art has the power to inspire people by including the emotional context behind the science research. We seek collaborators who are passionate about contributing to and sharing this work. Here we reflect on some of the stories we have shared in the last 12 months that chronicle the rapidly melting reality of glaciers.

In April, 2025 the “Shaped by Ice” exhibit coordinated by Jill Pelto opened at the Slip Gallery in Seattle. This featured work from nine artists, eight of whom had been in the field with us and was the focus of a Seattle Magazine article.

In May we worked with Protect Our Winters to explore what the loss of glaciers, “Beyond the Ice” means for specific regions.

In June, High Country News focused on the use of art to preserve the legacy of glaciers, given the glaciers themselves are not being preserved.

In March through July we worked with the Global Glacier Casualty List to the tell the story of specific glaciers in the United States that are disappearing, including Ice Worm Glacier in the North Cascades, Darwin Glacier in the Sierra Nevada, Twins Glacier in Wyoming and Burroughs Glacier in Alaska.

In August our field season coincided with a Seattle Time report, on Melting Mountains in the Pacific Northwest means, that we collaborated on.

Joining us in the field on the Lower Curtis Glacier, Mount Shuksan was KING5 NBC-Seattle affiliate, led by Meteorologist Leah Pezzetti who backpacked with us into her first glacier. The logistical preparation for this by KING5 was thorough, and we provided guidance and support to them. The resulting feature was released while we were still in the field.

Upon returning to the trailhead from Lower Curtis Glacier a CBS Sunday Morning News team met us and travelled into the field with us to Sholes Glacier, Mount Baker. The overnight trip into the backcountry was a first for this news team and required extensive collaborative support. The results were shared just two weeks after the filming, and right after our field season.

We worked for a second year with Dan MacComb on a short film for the UN International Year of Glaciers’ Preservation called “Shaped by Ice”. This film published by Protect our Winters has been featured in tfour film festivals during 2025.

In January through February a second “Shaped by Ice” gallery event was held in at the Confluence Gallery in Twisp WA. This was spearheaded by Jill Pelto, Margaret Kingston, and Claire Waichler.

A poor winter snowpack will certainly lead to another year of extensive glacier loss across the Pacific Northwest and we will be there to observe it.

North Cascade Glacier Climate Project 2025 Field Season Summary: Year 42

On October 7, 2025October 8, 2025 By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations, glaciers salmon, North Cascade Glaciers

*Core field team in 2025 Emmett Elsom, Mauri Pelto, Jill Pelto and Caitlin Quirk*.

We hiked into North Cascade glacier to complete detailed observations for our 42nd consecutive year. These annual observations provide a detailed assessment of their response to climate change. For the third consecutive year North Cascade glacier on on average lost more than 2 m of glacier thickness. This cumulative loss of 7-8 m on most of the ranges glaciers that average 25-40 m in thickness represents 20% of their volume lost in just three years. On a few of the largest glaciers, such as those on Mount Baker that average 40-60 m in thickness the loss represents 12% of their volume lost.

The consequence is an acceleration of the collapse of the North Cascade glacier system. This landscape that has for long been shaped by ice is rapidly losing that glacier element. The rate of retreat for the glaciers we work on has accelerated so quickly that we are faced each year with changing terrain and new challenges. Beyond that, we are starting to really see the effect this retreat and the decrease in water has on the ecosystems both near the glaciers and further downstream. During the field season we love seeing the wildflowers, eating blueberries, and counting mountain goats. These are all parts of a habitat that is built around glaciers and snowpack. Seeing these shifts has been really difficult, but it helps to still return to these landscapes and continue to tell their stories through science and art. Below the story is told in images with captions by each of us who participated.

Two things that stood out during the 2025 field season were the strength of our collaborations, and the changing resources the glaciers are able to provide to the surrounding ecosystem. This visible change attracted the attention of KING5-Seattle NBC affiliate and CBS Morning News. At the bottom of this post the resulting footage is embedded. The film “Shaped By Ice” Jill and I worked on with Dan McComb has been a finalist in two recent film festivals, this footage also at bottom of this long read post.

*Working on Rainbow Glacier from left-Katie Hovind, Caitlin Quirk, Claire Seaman, Jill Pelto and Margaret Kingston*

We worked with two oil painters, one watercolor painter, one printmaker, two news film crews, a team of botanists, and more. The result of all these collaborations has led to so many great stories being created and shared about our collective work. It also meant our core group of field assistants had to be flexible to a changing group and the sometimes difficult and imperfect logistics that accompany that. -Jill Pelto

This photograph of an icefall at 2000 m (6700 ft) on the Easton glacier encompasses the wide range of emotions that I felt working on these glaciers this summer. The focal point of the picture is the wound inflicted upon the glacier by our changing climate. Bedrock and sediment creep through the gaping wound in the lowest icefall of the Easton, the opening visible for the first time in the project’s 42-year history. The place also holds a beauty, a sense of majesty that cannot be diminished by the tragic context of our work. The seracs at the top of the scene lean at impossible angles, destined to crash down onto the slope below, piercing the quiet of the snowy expanse in dramatic fashion. The dark annual layers in the glacier speak to the age of the ice, flowing down the flank of Mt. Baker over decades. The landscape has been a facet of my life for the past few years, as it falls upon the Easton Glacier route to the mountain’s summit. The icefall has always drawn me in as I pass, sparking a profound sense of wonder. It makes me deeply sad to see the beauty of such special places diminished, sad in a way that little else does. Over the past few years, I’ve come to like visiting these places to visiting an elderly loved one. While time may change them and even take them away from us, their beauty and meaning to me will hold true.-Emmett Elsom

How does being present in a place shape our understanding? To the left is a view of Sholes Glacier, complete with my on-site rendition. I can’t express how lucky I feel to have had the chance to experience these places first hand. To interact with a place by attempting to capture its likeness — paying attention to the negative space not only between the white snowpack and black exposed rock, but in the empty, carved-out area that used to be filled with ice. Experiencing the texture of the glacier under your feet, the cool air drifting off the snow, the good tired feeling of your body after physically traversing top to bottom. This is what you don’t get from a photo. To know places such as these is to love them and see their role in the world, and want to protect them. But so many never get the chance to understand them this way.-Claire Seaman

This field season I focused on exploring the once-barren foreland a glacier leaves behind. Studying the plants growing in the wake of the Easton Glacier made me reflect on the way life responds to these major changes. This photo of a bright monkeyflower cluster in the streambed of the nearby Sholes Glacier exemplifies this resilience and optimism to me. The Sholes, in the background, drains a lifeblood that will feed the watershed downstream into the Nooksack, supporting people, fisheries, and a whole riparian ecosystem. The eventual loss of glacial ice feeding the river will be catastrophic, yet the scarred space left behind will blossom with vegetation. Witnessing firsthand how staggering the extent of glacial retreat is can be overwhelming, but that bright patch of flowers stands as encouragement. Alone in an altered landscape, those flowers will pave the way for more to follow. Change is nuanced, and as we watch it occur we can change, sharing stories of the beauty of this environment supported by ice, and adapting our lives and policies in a way that can be the difference which keeps glaciers flowing.-Katie Hovind

As a backcountry skier and oil painter focused on winter landscapes of the North Cascades, the idea of painting glaciers in the field was a dream come true! I knew what we would see and learn about the health of our glaciers from the scientists would be highly emotional, but the power of these environments disappearing in our lifetimes is something my words fail to communicate how devastating that feels. During the study on Rainbow glacier I caught on film the moment a serac collapsed, loudly crashing, crumbling from a newly melted out rock knob down the mountain splitting into smaller and smaller pieces. It looked sickly as it broke before our eyes. Another unique experience was going into a teal, translucent, otherworldly ice cave. I have started 2 paintings to capture this vanishing environment. My goal is to assist the project in translating the study’s findings through landscape paintings that communicate the beauty of these places with titles that call attention to the retreating glaciers in the North Cascades. We all have a responsibility as humans to make individual changes to combat climate change and vote like fresh water and air depends on it, because it does. -Margaret Kingston

The pace of glacier change struck me hard this summer. Never before have humans lived with such a deglaciated Cascades mountain range. Not the settlers, not the fur trappers, not the first people who have been here for 13,000 years or more. Cultures and ecosystems spawned from the retreating edge of the Cordilleran Ice sheet into the Puget Sound area. Alpine glaciers fed streams, rivers, salmon, all kinds of human projects in Washington State. Our societies are shaped by the ice and now we are experiencing glaciers disappear.

I write this at the end of the 2025 hydrological year, waiting for winter snow to shelter the land I love in a cool white blanket. The devastation of the alpine glaciers has surfaced so frequently in conversation these last couple months. Those who have seen the mountains are alarmed as beds of ice they once knew to be hundreds of feet thick look shallow and frail, ice pitches that were once climbed are now grey gullies of rock, and volcanoes which have always been white are unnervingly gray and shrouded in smoke. The realities of climate change in the Northwest are clear.

It is a painful time to care about the glaciers of the Cascades. Witnessing the erosion of something so much older and bigger and impactful than myself is staggering. There is much action to be done in this new terrain but for now, I come back to this: I sit in the dying glaciers warm light as the sun rises, summon the deepest snowfall in years and tell the glacier that we care, that we were grateful for all the help watering our food and feeding our oceans and making sure our salmon had somewhere to live. We are here because of you. -Cal Waichler

Image description: This image shows a crevasse on the Easton Glacier of Mount Baker. The saturation is distorted because I shot this photo on 35mm and pre-exposed the film to light and heat to parallel the material effects of global warming on our glacier systems. The Easton glacier is a source of water for Baker Lake, which provides recreation and hydropower to the region. When I see this photo, I think of the impacts of glacial melt to water, energy, cultural, and economic resources in Washington. -Caitlin Quirk

*Columbia Glacier is one of sixty global reference glaciers*. *This summer it lost 5% of its volume.*

Lower Curtis Glacier continues to rapidly thin at the top of the glacier as well as at the terminus. The glacier retained additional avalanche accumulation, leading to a less negative balance than other glaciers.

*Rainbow Glacier is one of the sixty global reference glaciers. This year new bedrock began to emerge and expand in several icefalls, leading to serac fall.*

*Easton Glacier has retreated 700 m since 1990 and has a number of bedrock areas emerging in icefall up to 2500 m.*

*Lynch Glacier east and west side are separating. The upper basin did retain some snow in 2025.*

*Daniels Glacier lost all snowpack by the end of the summer and bedrock is quickly expanding amongst the glacier.*

The trajectory for most North Cascade glaciers is one of fragmentation. This is illustrated by Foss Glacier on the east flank of Mount Hinman, that we began observing annually in 1984 but stopped measuring as it fragmented. Foss Glacier from the top was a 1 km long and nearly 600 m wide glacier. In Sept. 2025 Cal Waichler captured view from the top with the two main fragments now less than 50 m wide and 300 m long.-Mauri Pelto

Leah Pezzetti KING5 meterologist hiked in with us to Lower Curtis Glacier.

The CBS team hiked into Sholes Glacier with us spending the night, and we had three generations of Pelto’s.

Sholes Glacier, WA and a Cascade of Ologies

On October 12, 2021April 22, 2024 By mspeltoIn climate change glacier retreat, glaciers salmon, North Cascade Glaciers

Watercolor painting of Sholes Glacier. The small figure is at the current terminus of the glacier, and the photo that inspired this painting was taken from where the glacier used to end about 35 years prior. By Jill Pelto

Sholes Glacier is on the northeast flank of Mount Baker, WA. We have spent the last 32 years completing detailed measurments on this glacier that has revealed a story of glacier mass balance loss, thinning, retreat, declining area, and a cascade of other consequences impacting other “ologies” beyond the glacier. If you are intrigued by many ologies, the Podcast by Allie Ward will be inspiring as it was to this title.

Sholes Glacier and stream gage station. We have constructed a rating curve for this station, that the Nooksack Indian Tribe maintains (Grah and Beaulieu, 2013).

The climatology of the region has shifted, with one key change being more frequent and intense heat waves. Glaciers and heat waves just are not compatible. Using daily maximum temperatures for the 1981-2021 period for Mount Baker from ERA5 temperature reanalysis, completed by Tom Matthews at Loughborough University, indicates that there have been 83 days where the maximum temperature exceeded 12°C, an average of 2 days/year. In the last five years there have been 22 days exceeding 12°C, over 4 days/year. There have been 16 days during 1981-2021 period when the maximum temperature exceeded 14°C, 75% (12) of these have been in the last five years.

Probing snow depth on Sholes Glacier in 2014, this is completed annually at a fixed network of over 100 locations.

In terms of glaciology the result of the climate shift is that the glacier has lost 25-30% of its volume from 1990-2021. The terminus has retreated 155 m while the area has decreased by 25%. The changes have been most rapid in the last 8 years. The two years of largest mass loss were 2015 and 2021. We measure both melting (ablation) on the glacier and runoff from the glacier. This combination allows determination of the amount of glacier runoff. During 24 heat waves in the region from 2009-2021 mean daily ablation during the heat waves has ranged from 4.5-7.2 cm w.e./day (w.e.=water equivalent). The highest rate of 7.2 cm was during the June 26-July 1, 2021 period.

Sholes Glacier in 2015 exhibiting the darkening of the surface that occurs in high melt years, increasing melt rates. How much black carbon and algae is part of this darkening is the research of Alia Khan (WWU).

For a glacier to be in equilibrium or have a positive mass balance the majority of the glacier must be in the accumulation zone, snow covered at the end of the summer, that is an accumulation are ratio (AAR) greater than 50%. Pelto and Brown (2012) noted that for Mount Baker an AAR of 60% is required for a break even balance for the year. From 2013-2021 the average accumulation area ratio has been 35%. For Sholes Glacier if 50% of the glacier is exposed ice and firn in early August that increases mass loss. The ice and firn for the same weather conditions have a 30-40% higher melt rate than the snowpack. An early season heat wave strips the snow off earlier exposing the darker faster melting glacier surfaces for longer further increasing mass loss, note image above.

Sholes Glacier in 2021. The glacier has retreated 170 m from 1990-2021, the terminus in 1990 is approximately whre the goats are crossing the stream.

Hydrology downstream in Wells Creek and the North Fork Nooksack River is changing in part because of the changes in glacier runoff. Glacier runoff is a major source of streamflow during the summer low-flow season and mitigates both low flow and high water temperatures (Pelto, 2015). This is particularly true during summer heat waves, but this ability has been diminishing in the region (Moore et al 2020) For the last 37 summers we have been in the field monitoring North Cascade glaciers response to climate change including during heat waves (Pelto, 2018). In the last decade we have made synchronous observations of glacier ablation and stream discharge immediately below Sholes Glacier, Mount Baker (Pelto, 2015). This in conjunction with observed daily discharge and temperature data from the USGS stations on the ~6% glaciated North Fork Nooksack River (NFN) and the unglaciated South Fork Nooksack River (SFN), contrasts and quantifies the ameliorating role of glacier runoff on discharge and water temperature during 24 late summer heat wave events.

**Measuring discharge below Sholes Glacier in 2016.**

Sholes Glacier and ablation measurements on Sholes Glacier indicate daily ablation ranging from 5-6 cm/day, which for the NFN currently yields 9-11 cubic meters/second. This is 40-50% of the August mean discharge of 24 cubic meters/second, despite glaciers only covering 6% of the watershed. In the unglaciated SFN warm weather events generated a mean stream temperature change of +2°C, only 1 event in the NFN generated this rise and the mean was +0.7°C. Durng the June 2021 heatwave from June 21-29 maxium daily stream temperature in SFN warmed 3°C, vs 0.8°C for NFN. This illustrates that a greater proportion of snowmelt, which NFN recieves, has limited the temperature rise. Discharge rose at least 10% in 20 of the 24 events in the NFN with an average increase of 24%. In the SFN all 24 events led to a decreased discharge with an average decrease of 20%. The primary response to these summer heat waes is increased discharge in the heavily glaciated NFN, and increased stream temperature in the unglaciated SFN.

Discharge change during heat waves in South Fork (decreases) and North Fork Nooksack River (increases) above. Below temperature change during heat waves in South Fork (significant rise) and North Fork Nooksack River (small rise).

Glacier runoff is a product of glacier area and melt rate. Overall glacier runoff declines when area reductions exceed, ablation rate increases. This has already occurred in the NFN and now glacier runoff is declining (Pelto, 2015). The measured ablation rate is applied to glaciers across the NFN watershed, providing daily glacier runoff discharge to the North Fork Nooksack River. For the NFN glacier runoff production was equivalent to 34% of the total discharge during the 24 later summer heat wave events. As the glaciers continue to retreat the NFN will have a declining mitigation of heat waves for discharge and temperature and trend towards the the highly sensitive SFN where warm weather leads to declining streamflow and warming temperatures.

Aquatic ecology in glaciated watershed in turn is impacted. Glaciers are important in maintaining sufficient discharge and stream temperature that are critical for salmon in the North Fork Nooksack. Some cold-water trout and salmon species are already constrained by warm water temperatures and additional warming will result in net habitat loss (Isaak et al 2012). In the Fraser River and Thompson River, BC fish community thresholds were obsrved for mean weekly average temperatures of about 12°C and again above 19°C (Parkinson et al 2015). Below 12°C the community were characterized by bull trout and some cold water species, between 12°C and 19°C by salmonids and sculpins and above 19°C by minnows and some cold water salmonids (Parkinson et al 2015). These thresholds indicated small temperature changes can be expected to drive substantial changes in fish communities. During the 24 warm weather events noted in the North Fork only two events exceeded 12°C, while in the South Fork 15 of the events exceeded 19°C. This suggest that both rivers are near a threshold that could alter the fish community.

In the North Fork Nooksack the number of returning chinook is divided into natural and hatchery spawned salmon. The Chum and Coho salmon data for the Nooksack River during the 1999-2013 interval indicate there are two salmon population peaks for each species. The early peak is in 2002 and the second peak occurs in 2010 (Washington Dept. Fish & Wildlife, 2020). Overall numbers have not sustained an increase and remain endangered.

Ice Worm counts as the sunsets, 110 worms per square meter.

The climatology and glaciology has been difficult for ice wormology On the glacier itself ice worm population density surveys conducted annually indicate the density of ice worms has decreased since 2000 and that even 10 m beyond the edge of the glacier on snowpack they do not exist. This combined with the reduction in glacier area indicate population decline of ice worms.

In 2009 we observed the largest goat herd 62 goats (13 kids), some of them seen here below Sholes Glacier.

The climatology has been more favorable in terms of Goatology.We have conducted annual mountain goat surveys in the Ptarmigan Ridge-Sholes Glacier region each years since 1984. Populations stayed steady from 1984-2000, before rising dramatically through 2010. The difficult winters of 2011 and 2012 reduced the population, followed by a recovery up to 2021.

Three year running mean of mountain goat census conducted each summer while we are working on Ptarmigan Ridge, Sholes Glacier and Rainbow Glacier.

Observing Glacier Runoff Changes Under the Same Weather Conditions

On August 23, 2017April 28, 2024 By mspeltoIn glaciers salmon, North Cascade Glaciers

View of Sholes Glacier on August 8th in 2015 left and 2017 right. Note difference in ratio of snow surface to ice surface exposed.

Sholes Glacier is at the headwaters of Wells Creek in North Fork Nooksack River watershed in Washington. We have been measuring the mass balance of this glacier annually since 1990 and runoff in detail since 2012 (Pelto, 2015). Glacier runoff in this watershed during late summer frequently provides more than a third of all runoff for the watershed, this occurred on 37 days in 2015 and 19 days in 2016. This water is critical for local hydropower, irrigation and fall salmon runs. We measure glacier runoff all summer long directly at a stream gage 150 m from the glacier. We also measure ablation directly on the glacier. The amount of runoff is dependent on the area exposed for melting, glacier area in this case, the melt rate which is largely determined by temperature and the surface type, snow and ice having different melt rates.

A typically reliable method to calculate glacier runoff is a degree day model. This model is based solely on daily observed temperature and the glacier surface type. The degree day melt rate factor for snow and for ice are different. Based on 27 years of ablation measurements on the glacier the melt factors for snow is 0.0045 m w.e. d^-1C^-1and for ice 0.0060 m w.e. d^-1C^-1which falls within the range of temperate glacier observations (Hock, 2003). If you multiply this result by the area of the glacier the glacier runoff is determined.

For a specific day the determination of runoff looks like:

Glacier Runoff=( 14 C * 0.0045 m w.e. d-1C-1)(550,000 m2) + (14C*0.0060 m w.e. d-1C-1)(100,000m2)

This equals 43,000 m3 for the day or 0.5 m3/second from Sholes Glacier. In fact our measurement of discharge on this day was 41,330 m3 and the observed melt rate was within 5% of the calculated amount. In August the average streamflow in the North Fork Nooksack at the USGS gage is 22 m3/second. We have observed that ablation rates on Sholes Glacier are consistent with those on other glaciers in the watershed. For the watershed as a whole the glacier runoff on this particular day would be 9.4 m3/second or ~40% of mean daily August runoff provided by glacier melt.

It has been interesting in the case of the Sholes Glacier to observe how different the runoff rate/volume is for the same weather conditions depending solely on changes in snow and ice cover area. Note in the images above from 2015 and 2016 the change in the percent of the glacier that is snowcovered. Also note the difference below from 2014 and 2017. Given the same weather conditions the melt rate formula suggest that ice covered areas will yield 33% more runoff. This in fact has been the case with observed runoff on a 14 C day in 2015 yielding 30% more runoff than on the a 14 C day in 2017. The difference is no ice exposed in 2017 and 85% of the glacier area being bare ice on the observed day in 2015. The change during a melt season as indicated by snowcover change in 2016 from August 16th to Sept. 8th, illustrates the importance of understanding the changing distribution of snow and ice on the glacier on a weekly basis for determining glacier runoff.

On 8/8/2014 the glacier was 85% snowcovered

On 8/8/2015 the glacier was 15% snowcovered

On 8/8/2016 the glacier was 97% snowcovered

On 8/8/2017 the glacier was 100% snowcovered

View of Sholes Glacier on August 8th in 2014 left and 2016 right. Note difference in ratio of snow surface to ice surface exposed.

**Jill Pelto and Andrew Hollyday measuring flow below Sholes Glacier.**

Pete Durr Probing snowpack on Sholes Glacier

2016 Field Season Results-North Cascade Glacier Climate Project

On October 14, 2016October 14, 2016 By mspeltoIn climate change glacier retreat, Glacier Observations, glaciers salmon

For Mount Baker, Washington the freezing level from January-April 20 was not as high as the record from 2015, but still was 400 m above the long term mean. April 1 snowpack at the key long term sites in the North Cascades was 8% above average. A warm spring altered this, with April being the warmest on record. The three-four weeks ahead of normal on June 10th, but three weeks behind 2015 record melt. The year was poised to be better than last year, but still bad for the glaciers. Fortunately summer turned out to be cooler, and ablation lagged. Average June-August temperatures were 0.5 F above the 1984-2016 mean and 3 F below the 2015 mean. The end result of our 33rd annual field season assessing glacier mass balance in the North Cascades quantifies this. Our Nooksack Indian Tribe partners again installed a weather and stream discharge station below Sholes Glacier.

The primary field team consisted of myself, 33rd year, Jill Pelto, grad student UMaine for the 8th year, Megan Pelto, Chicago based illustrator 2nd year, and Andrew Hollyday, Middlebury College. We were joined by Tom Hammond, NCCC President 13th year, Pete Durr, Mount Baker Ski Patrol, Taryn Black, UW grad student and Oliver Grah Nooksack Indian Tribe. The weather during the field season Aug. 1-17th was comparatively cool.

Mass Balance: Easton Glacier provides the greatest elevation range of observations. On Aug 2, 2016 the mean snow depth ranged from 0.75 m w.e. at 1800 m to 1.5 m w.e. at 2200 m and 3.0 m w.e. at 2500 m. Typically the gradient of snowpack increase is less than this. There was a sharp rise in accumulation above 2300 m. This is the result of the high freezing levels. The mass balances observed fit the pattern of a warm but wet winter. The high freezing levels left the lowest elevation glaciers Lower Curtis and Columbia Glacier with the most negative mass balance of approximately 1.5 m. The other six glaciers had negative balances of -0.6 to -1.2 m. This following on the losses of the last three years has left the glaciers with a net thinning of 6 m, which on glaciers averaging close to 50 m is a 12% volume loss in four years. We anticipate with that this winter will be cooler and next summer the glaciers happier. We will back to determine this.

Snowpack loss from Aug. 5-Sept. 22 is evident in the pictures below on Sholes Glacier. Detailed snow depth probing, 112 measurements, of the glacier on August 5th allows determination of ablation as the transient snow line traverses probing locations from Aug. 5. GPS locations were recorded along the edge of blue ice on each of the dates. Ablation during this period was 2.15 m.

Terminus Change: We measured terminus change at several glaciers and found that a combination of the 2015 record mass balance loss and early loss of snowcover from glacier snouts in 2016 led to considerable retreat since August 2015. The retreat was 25 m on Easton Glacier, 20 m on Columbia Glacier, 20 m on Daniels Glacier, Sholes Glacier 28 m, Rainbow Glacier 15 m, Lower Curtis Glacier 15 m. The main change at Lower Curtis Glacier was the vertical thinning, in 2014 the terminus was 41 m high, in 2016 the terminus seracs were 27 m high. The area loss of the glaciers will continue to lead to reduced glacier runoff. We continued to monitor daily flow below Sholes Glacier which allowed us to determine that in August 2016 45% of the flow of North Fork Nooksack River came from glacier runoff. This is turns has impacts for the late summer and fall salmon runs.

Thirty-third Annual North Cascade Glacier Climate Project Field Season Underway

On July 31, 2016May 2, 2024 By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations, glaciers salmon, North Cascade Glaciers4 Comments

Base Map of the region showing main study glaciers, produced by Ben Pelto.

From President Reagan to President Obama each August since 1984 I have headed to the North Cascade Range of Washington to measure the response of glaciers to climate change. Specifically we will measure the mass balance of nine glaciers, runoff from three glaciers and map the terminus change on 12 glaciers. The data is reported to the World Glacier Monitoring Service. Three glaciers that we have monitored annually have disappeared since 1984.

In 2016 for Mount Baker, Washington the freezing level from January-April was not as high as the record from 2015, but still was 400 m above the long term mean. The snowpack on June 1st was three weeks behind last year’s record melt, but still three to four weeks of head of normal. July has been exceptionally cool reducing this gap. With all the snow measurement stations losing snowcover by July 1, the gap is uncertain until we arrive on the glaciers. This will not be a good year, but will be a significant improvement over last year, likely more in the 2012 or 2013 category. Each location is accessed by backpacking in and camping in tents.

We will first travel north to Mount Baker and the Easton Glacier, we will be joined by Oliver Lazenby, Point Roberts Press. We will then circle to the north side where I expect we will be joined by Jezra Beaulieu and Oliver Grah, Nooksack Indian Tribe. Jen Lennon from the Sauk-Suiattle Tribe and Pete Durr, Mount Baker Ski Patrol are also planning to join us here. When we head into Columbia Glacier Taryn Black from U of Washington will join us. The field team consists of Mauri Pelto, 33^rd year, Jill Pelto, UMaine for the 8^th year, Megan Pelto, 2^nd year, and Andrew Hollyday, Middlebury College. Tom Hammond, 13^th year will join us for a selected period.

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Aug.   1: Hike into Easton Glacier.
Aug.   2: Easton Glacier
Aug.   3: Easton Glacier
Aug. 4: Hike Out Easton Glacier, Hike in Ptarmigan Ridge
Aug.   5: Sholes Glacier
Aug.   6: Rainbow Glacier
Aug.   7: Sholes Glacier and/or Rainbow Glacier
Aug. 8: Hike out and into Lower Curtis Glacier
Aug. 9: Lower Curtis Glacier
Aug. 10: Hike out Lower Curtis Glacier- Hike in Blanca Lake Mail Pickup Maple Falls, WA 98266
Aug. 11: Hike in Columbia Glacier
Aug. 12: Columbia Glacier
Aug. 13: Hike out Columbia Glacier; Hike in Mount Daniels
Aug. 14: Daniels and Lynch Glacier
Aug. 15: Ice Worm Glacier
Aug. 16: Ice Worm Glacier, Hike out Mount Daniels-Hike out

Harris Glacier Retreat, Kenai Fjords, Alaska

On June 14, 2016May 2, 2024 By mspeltoIn alaska glacier retreat, glacier climate change, Glacier Observations, glaciers salmon

Landsat images of Harris Glacier from 1986 and 2015. The red arrow indicates 1986 terminus location, yellow arrow the 2015 terminus position. The orange arrow indicates a key eastern tributary and the pink arrow a smaller eastern tributary.

Harris Glacier flows from the northwest corner of the Harding Icefield, Alaska and it drains into Skilak Lake. The glaciers that drain east toward are in the Kenai Fjords National Park, which has a monitoring program. Giffen et al (2014) observed the retreat of glaciers in the region. From 1950-2005 all 27 glaciers in the Kenai Icefield region examined are retreating. Giffen et al (2014) observed that Harris Glacier (A Glacier) retreated 469 m from from 1986-2005. Here we examine Landsat imagery from 1986-2015 to illustrate the retreat of this glacier and other upglacier changes. The glacier supplies meltwater to Skilak Lake which is a critical salmon habitat for the Kenai. Chinook Salmon spawn on a section of the Kenai River between Kenai Lake and Skilak Lake. With Skilak Lake being the resulting home for ninety percent of the salmon fry for the Kenai River, and with the most of any nursery in the Cook Inlet area. Escapements of chinook in the Kenai River exceed 50,000 annually in two runs (Heard et al 2007).

In 1986 the glacier extended to an elevation of 590 m, on the east side of the glacier there were two smaller tributaries reaching the glacier at the orange and pink arrow. By 2015 the terminus had retreated 600 m from 1986. The eastern tributary at the pink arrow had detached from the main glacier. The tributary at the orange arrow still reaches the main glacier, but the blue ice extent after joining the glacier has diminished significantly. Below is a closeup of the terminus from 1996 and 2015 illustrating a 225 m retreat and associated thinning. It is also interesting to note the prominent ash layer has shifted little. This suggests the terminus area is relatively stagnant. There is no active crevassing in the lower 1 km suggesting retreat will be ongoing. In 1989 the snowline is at 975 m whereas in 2014 the snowline is at 1125 m. This higher snowline is too high to maintain the glacier. The snowline in 2015 was again above 1100 m, though it is lower in the mid-August image at 1050 m. The retreat of this glacier is less than neighboring glaciers such as Grewingk, Pederson and Bear Glacier that have calving termini.

Landsat images from 1989 and 2014, with the snowline indicated by purple dots.

Terminus of Harris Glacier in Google Earth images from 1996 and 2015. Margin with purple dot, purple arrow indicates 1996 terminus lcoation, with a 225 m retreat by 2015. Note the prominent ash layer

Shamrock Glacier, Alaska Loses Terminus Tongue

On February 28, 2016May 2, 2024 By mspeltoIn alaska glacier retreat, glacier climate change, Glacier Observations, glaciers salmon

Shamrock Glacier comparison in 1987 and 2014 Landsat images. Red arrow 1987 terminus, yellow arrow 2014 terminus, purple arrows upglacier thinning and purple dots the snowline. The terminus tongues extending into the lake has been lost.

Shamrock Glacier flows north from the Neacola Mountains into Chakachamna Lake in the Lake Clark National Park of Alaska. This lake is transited by several species of salmon, mainly sockeye, heading into spawning areas upriver. The lake had been the site of a proposed hydropower plant, that would not have required building of a dam, but this project is currently not being developed. The National Park Service completed a Southwest Alaska Network mapping project that identified the changes of glaciers in the region. Lake Clark NP has 1740 glaciers which have lost 12% of their total area from 1950 to 2009 (Loso et al, 2014). Here we examine Landsat imagery from 1987 to 2014 to identify recent change of Shamrock Glacier.

July 2015 image looking across Shamrock Lake to Shamrock Glacier, taken by Jerry Pillarelli, note he has many more gorgeous images of area. The trimline on the far side of the glacier between sediment and vegetation indicates the 1950 margin. There is an elevation step several hundred meters inland of the terminus indicating Shamrock Lake will expand little.

In 1987 Shamrock Glacier had receded from a terminal moraine in Chakachamna Lake that it had terminated on in the 1950’s map. The new proglacial lake was less than 500 m across. The snowline was at 1200 m. In 2000 seen below the snowline was at 1350 m, and the terminus had narrowed more than it had retreated. By 2014 the terminus had retreated 900 m leaving the new Shamrock Lake within Chackachamna Lake. The new Shamrock Lake has an area of 4 square kilometers. This is the majority of the loss in glacier area since 1950 as well. In 2014 the snowline is quite high at 1450 m. A snowline that is consistently above 1300 m will drive continued retreat. Thinning upglacier is evident with expanded bedrock areas adjacent to the glacier margin above 1200 m at the purple arrows, indicating the snowline has been consistently higher than this. The retreat is similar to other glaciers in the region South Sheep Glacier, Sovereign Glacier and Fourpeaked Glacier. With the glacier retreating out of the lake basin soon, the rate of retreat should decline.

2000 Landsat image

2013 Image of Shamrock Glacier, Shamrock Lake and Chakachamna Glacier.

Murchison Glacier, New Zealand Rapid Retreat Lake Expands 1990-2015

On January 14, 2016May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, glaciers salmon, New Zealand glacier1 Comment

Murchison Glacier change revealed in Landsat images from 1990 and 2015. The red arrow indicates 1990 terminus location, the yellow arrow indicates 2015 terminus location and the purple arrow indicates upglacier thinning.

Murchison Glacier is the second largest in New Zealand. The glacier drains south in the next valley east of Tasman Glacier and terminates in a lake that is rapidly developing as the glacier retreats. The lower 6 km section is debris covered, stagnant, relatively flat and will not survive long. There was not a lake in the 1972 map of the region. In 1990 the newly formed lake was limited to the southeast margin of the terminus . From 1990 to 2015 the terminus has retreated 2700 m. A rapid retreat will continue as 2010, 2013 and 2015 imagery indicate other proglacial lakes have now developed 3.5 km above the actual terminus. These lakes are glacier dammed and may not endure but do help increase ablation, and in the image below show a glacier that is too narrow to provide flow to the lower 3.5 km. The demise of the lower section of this glacier will parallel that of Tasman Glacier. The expanding lake will continue to enhance the retreat in part by sub-aqueous calving noted by Robertson et al (2012) on nearby glaciers. The increased retreat has been forecast by the NIWA and Dykes et al (2011). The glacier still has a significant accumulation area above 1650 m to survive at a smaller size. The ongoing retreat is triggered by warming and a rise in the snowline in the New Zealand Alps observed by the NIWA. Notice the changes upglacier indicated at the purple arrows above, where tributary flow has declined, bedrock areas in accumulation zone have expanded and the snowline is higher. Gjermundsen et al (2011) examined the change in glacier area in the central Southern Alps and found a 17% reduction in area mainly from reductions of large valley glaciers such as Murchison Glacier.

Terminus reach of Murchison Glacier in Google Earth images from 2007 and 2013. Note expansion at pink arrow on the terminus lake and the development of proglacial lakes 3.5 km upglacier at blue arrows.

The Feb. 2011 earthquake near Christchurch led to a major calving event of a portion of the rotten stagnant terminus reach of the Tasman Glacier. There was no evident calving event from Murchison Glacier.This has led to increased exposure of bedrock high on the glacier and reduction of tributary inflow noted at purple arrows.

Murchison Glacier drains into Lake Pukaki,a along with Hooker, Mueller and Tasman Glacier, where water level has been raised 9 m for hydropower purposes. Water from Lake Pukaki is sent through a canal into the Lake Ohau watershed and then through six hydropower plants of the Waitaki hydro scheme: Ohau A, B and C. Benmore, Aviemore and Waitaki with a combined output of 1340 MW. Meridian owns and operates all six hydro stations located from Lake Pūkaki to Waitaki. Reductions in glacier area in the watershed will lead to reduced summer runoff into the Lake Pukaki system. Below the Benore Dam is pictured,. Interestingly salmon have been introduced into the Waitaki River system for fishing near its mouth. Benmore Lake itself is an internationally renowned trout fishing spot, providing habitat for both brown trout and rainbow trout.

Google Earth Image with Benmore Dam in foreground and Benmore Lake. This hydropower system is fed by a canal from Lake Pukaki which in turn is fed by Murchison Glacier.

Visualizing Glacier Melt Impacts

On September 4, 2015May 2, 2024 By mspeltoIn glacier climate change, Glacier Observations, glaciers salmon, North Cascade Glaciers1 Comment

Key questions emerge from the summer of 2015 in the Pacific Northwest glacier basins. That can both be visualized and quantified.

With record temperatures and minimum flows in most rivers in the Cascade Range during July and August of 2015, a key question was how much did glaciers contribute in basins that are glaciated? Note the water pouring off the glacier and the lack of snowcover in the first few minutes of the video.

You can examine flow per unit watershed area as a first order observation. In the unglaciated South Fork discharge was 0.5 cfs/square mile, rising to 0.7 cfs/square mile in the lightly glaciated Skykomish River and 4.3 cfs/square mile in the heavily glaciated North Fork Nooksack. For a more direct measure we measured ablation from July 29 to August 17th in the North Fork Nooksack and Skykomish River basin. With the Nooksack Tribe we also measured discharge below glaciers in the North Fork but those recorders are still deployed in the field.

Because the glaciers had mostly ice, not snow at the surface, melting was enhanced. We found in the Skykomish Basin that glacier runoff was 45 CFS versus a mean discharge of 375 CFS , this is 12% of the total flow despite covering only 1.3 % of the basin. In the North Fork Nooksack glacier runoff was 340 CFS versus total flow of 460 CFS, this is 74% of the total flow though only 6.1 % of the basin has glacier cover. In both cases the glaciers contributed a river flow percentage 12 times greater than the percent of basin area they cover. With a substantial loss in glacier area occurring this summer, next year glacier runoff for the given climate conditions will be reduced. Given this higher flow the glacier fed streams offer less stressful conditions this summer to salmon.

How much did glacier runoff water temperature amelioration?

In the South Fork Nooksack without glaciers stream temperature was above 20 C on eight days between Aug.1 and Aug. 20. In the North Fork Nooksack with glacier contribution, the stream temperature peaked at 13-14 C.

With the early loss of snowcover and exposure of the underlying ice, how are glacier ice worms impacted? In the video note ice worms featured in the first minute in a glacier filled crevasse.

These worms live on snow algae primarily, which would seem to be in short supply in a summer with limited snowpack on the glaciers. How well can they survive being on the glacier ice for extended periods? For the 21st year we conducted ice worm population surveys. The numbers were the lowest we have seen at 175-250 ice worms per square meter, but it should be next year when the full impact would be evident.

How much glacier area will be lost? Note the visual of terminus retreat.
The summer is not over, but our observations indicate a 5-7 % volume loss will occur. This should be approximately equaled by area loss. Hopefully good satellite imagery in September will provide a specific answer. The Aug. 17th Landsat image is excellent. Retreat just this summer has been 40 m on Easton Glacier, 32 meters on Columbia Glacier, 25 meters on Sholes Glacier and 30 meters on Lower Curtis Glacier.

Aug. 17 Landsat image. Arrows indicate areas where we observed rapid area loss of glacier ice this summer.

Kokanee Glacier Spring 2015 Assessment, British Columbia

On June 15, 2015May 3, 2024 By mspeltoIn Canada glacier retreat, glacier climate change, Glacier Observations, glaciers salmon

Guest Post by Ben Pelto

Kokanee Glacier is located in the Selkirk Mountains of southeastern B.C., 30 km northeast of Nelson in Kokanee Glacier Provincial Park. Kokanee Glacier drains into the Joker Lakes, the uppermost of which are turquoise due to glacier flour input. Joker Creek carries the water downstream, eventually feeding into the Kootenay Lake and the Kootenay River, which flows to meet the Columbia River in Castlegar, B.C. In the last few years a decline in the number of fish inventoried in feeder streams to the lake caused cancellation of the Fishing Derby in 2015. The Meadow Creek spawning channel usually supports 500,000 to one million kokanee spawners, declined to less than 200,000 annually. In fall 2014, their numbers were down to 60,000. A drop of snow melt from this glacier also would pass through 16 hydroelectric facilities before reaching the ocean.

Kokanee Glacier looking west towards camp. April 20th, 2015 Photo: Ben Pelto

A research team from the University of Northern British Columbia and the University of Calgary began visiting the glacier each spring and fall beginning in 2013. Fall access to the glacier is via the Gibson Lake trailhead, which is a 7.5 km hike to Kaslo Lake and the new Kokanee Glacier Cabin (Slocan Chief cabin is only 1 km farther up the trail, but is no longer in use as a backcountry cabin). Spring access is via helicopter under a research permit. The Kokanee Glacier is north-facing and extends from 2800 meters at the summit of Kokanee Peak, to 2230 m where it terminates in an unnamed lake. This lake is a recent addition to the Joker Lakes, due to glacier retreat in the past two decades. The Kokanee Glacier covers about 1.7 km2.

Contour map of the Kokanee Glacier, with the uppermost Joker Lake. Approximate current terminus position purple-dashed line. Oval indicates new proglacial lake.

Our spring visit to the glacier documented snowpack deposited during an anomalously warm winter, as shown in the image below from the North American Freezing Level Tracker. The tracker is run by Idaho State University and estimates freezing levels based on the NCEP/NCAR Global Reanalysis, which is determined every six hours. Freezing level is the elevation where air temperature is 0°C at a given time. Freezing levels are important to mountain hydrology and determine whether precipitation falls as rain or snow, the elevation of the rain/snow line, whether the ground is frozen when snow falls in the autumn, the efficiency of snowpack accumulation through the winter (melt events, rain on snow), the internal temperature of the snowpack (which drives melt and metamorphosis of the snowpack), and the length of snow free season at a given elevation. What is immediately apparent is that freezing levels were elevated throughout the accumulation season, which generally begins in late September. Freezing levels were highest relative to the median in the key winter months of January through March. Local skiers and ski guides complained of rain during many storms, which reached to or near the mountain tops and left poor skiing conditions.
Estimated freezing levels for Kokanee Glacier for July 2014 to June 2015 North American Freezing Level Tracker

The Redfish Creek snow pillow is the nearest snow pillow site (see below), and is located 7 km southeast of the glacier at 2086 m. The Kokanee Glacier extends from around 2230 m to 2800 m so the snow pillow site may not accurately represent the amount and type of precipitation on the glacier. Regardless, this winter featured a fairly average snowpack, generally hovering above the mean SWE (snow water equivalent), which is calculated from 2001, when the gauge was installed, to present. A precipitous drop in SWE marked an early and strong start to the melt season, with maximum snowpack coinciding with our visit (April 19-21, 2015), roughly two weeks ahead of the usual SWE maximum date (in the first week of May) as seen by the purple line.

Redfish Creek snow pillow site of the B.C. River Forecast Center for 2014-2015.

The primary goal of our trip was to assess winter accumulation. Our measurements consisted of probing snow depth and digging snow pits. We took 80 probe measurements at 20 locations, and dug two snow pits, one at 2475 m and one at 2675 m. While snow depth was lowest near the terminus at 3 to 3.5 m, there was no correlation between elevation and accumulation from 2300 m and above, which accounts for a majority of the glacier area. Above 2300 m, snow depth ranged from 4.3 to 6.3 m with an average of 4.8 m.

Probing snow depth on the Kokanee Glacier, April 20th, 2015. Photo: Alison Criscitiello.

Our measurements revealed that this year’s snow pack was a dense one, likely due to mid-winter melt events, rain-on-snow events, and increased temperature during snow events. Given that snowpack was low across B.C. in the winter of 2014-2015, it would have been reasonable to assume that the glacier fared poorly. However, the winter balance was precisely halfway between the healthy winter balance of 2013 and the weak winter balance of 2014. Our data indicate that freezing levels played a large role in this year’s snowpack for the Kokanee Glacier given that the surrounding region is below 50% of normal snowpack, yet the glacier is much closer to normal as it was still above even the high 2015 winter freezing levels. Given our limited sample size, with this being the third measured winter accumulation, it is beyond the scope our data to assess how close to or far from normal this winter’s snowpack was for the Kokanee Glacier.

Standing on the glacier looking down valley, we observed that bare ground began around 1800 m where there should have still been a couple meters of snow. This highlighted the stark contrast between high and low elevations. Clearly, rain dominated below 1800 m this winter. This winter may be a potential model for the immediate future climate, where increased winter temperatures lead to a higher snowline, lower snowpack at lower elevations, and near average snowpack at higher elevations. Given the early start to fire season in B.C. and the Yukon, similar winters will come at a high cost for fire fighting, forest productivity, and water resources.

View looking west from Kokanee Glacier April 19, 2015. Approximate snow line yellow dashed line ~1800 m. Red J indicates location of uppermost Joker Lake. Red T is just beyond the terminus, which cannot be seen due to the slope. Photo: Ben Pelto

4.5 m deep snow pit at 2675 m on the Kokanee Glacier, April 20th, 2015. Photo: Alison Criscitiello.

The B.C. River Forecast Center releases a monthly snow report, and stated that temperatures in the Kootenay Region, where the Kokanee Glacier is located, were 3 to 5°C above average. The image below shows that by May 1, snowpack was 67% of average. The June 1st map has all but three sub-regions of B.C. exhibiting less than 50% of normal snowpack, with the West Kootenay region at 30% of normal. The result will be less snowpack across southern BC this summer. At the end of August last year there was considerable bare ice and firn exposed on Kokanee Glacier, this year we anticipate even more upon our return at the end of the melt season. Of course the snow report is critical for hydropower in BC. For the Kokanee Glacier, meltwater goes through a series of hydropower dams on the Kootenay River.