Firn Area Ratio an Emerging Metric for Glacier Mass Balance?

On February 11, 2022April 21, 2024 By mspeltoIn Glacier Observations

Columbia Glacier in 2015 viewed from the ridge above the glacier. The firn line is marked by blue dots. The age of the snow surface of 2015 and the firn surfaces of 2011-2014 are noted.

For an alpine glacier to be in equilibrium at the end of summer the glacier needs to be 50-70% covered in snow from the previous winter. This is the accumulation area ratio (AAR). AAR is a good measure of mass balance, which is why AAR is reported for WGMS reference glaciers. In recent years we have seen periodic strongly negative balance years that have removed all or nearly all of the snowpack from a glacier leaving an AAR of less than 10%, and considerable exposed firn. This typically occurs in assocation with a year that feature prolonged dry warm conditions in winter that limit snow accumulation or even reduce it, and/or summers with heat waves and extended warm periods that melt away the snowpack rapidly, particularly early in the melt season. This leads to exposure of firn, which is the snowpack retained from previous winters, hence more than a year old, but not yet glacier ice and significantly dirtier/darker than snow from the most recent winter. This firn melts more rapidly than snow, largely because it is darker. This leads to additional mass loss for the glacier. By the end of summer in strongly negative years we can see where the firn area boundary with glacier ice. This marks the region below which no accumlation has been retained in recent years, hence older ice is exposed. As such it delineates the multi-year accumulation area, the effective accumulation zone of the glacier. This would not be accuately determined from an simple average of annual AAR values. It is also readily visible in aerial or satellite imagery.

This scenario played out both in the Pacific Northwest in summer 2021 and in the Central Andes summer 2022. Pelto et al (2022) examine the impact of the heat waves on glacier runoff specifically. In New Zealand the 2022 NIWA annual snowline survey also indicate exposed firn below the annual snowline.

The blue dotted line on Columbia Glacier marks the accumulaiton zone for the 2011-2015 period, below that line no snow or firn was retained during that five year period. The is was a year of exceptional mass balance loss in the North Cascade Range (Pelto, 2018). Below is an example from Sholes Glacier in 2014 indicating the snow line in August and again in September now with a separte firn line apparent. Note the difference between the snowline for 2014 and the firn line for the 2011-2013 period. Below that point no firn has been retained.

Sholes Glacier snowline and firn line in August and September of 2014.

High negative balance years exposing significant firn areas at he surface have played out with increasing frequency in glaciated mountain regions from the North Cascade Range north through British Columbia to Alaska and across continents to the Alps, Canadian Arctic, Himalaya, and Andes. Glaciers where much of their snow cover is lost by mid-summer, then have the darker firn and ice exposed for enhanced ablation for the rest of the summer. There is no sunscreen they can apply for protection.

For Blackfoot and Jackson Glacier in Glacier National Park, Montana just one small area of snow remained on Blackfoot Glacier in early September of 2021. The area of firn on both glaciers is extensive nearly 50% of the glacier indicating overall an accumulation area of significant size. For Adams Glacier in late summer 2021 there is ~10% snowcover (A), while firn cover is 40% at the end of August.

In January 2022 the Central Andes of Argentina and Chile have experienced nearly complete snowcover loss on many glaciers. Volcan Overo, Argentina has four ice masses A-D with limited firn or remaining snowpack. Ice mass E has limited snowcover, but reasonable firn cover extent, not blue dots between firn and bare ice. On Olivares Beta and Gamma Glacier, Chile almost no snowcover remains from Winter 2021, the firn line is limited to the upper portion of both glaciers. This indicates less than 30% of the glacier is an accumulation zone during recent years. There is still six weeks left in the melt season to further reduce this area. The bare surfaces lasted from mid-January into late March leading to extensive mass loss.

For each of the glaciers illustrated here the firn area can be delineated accurately due to the glacier having a significant mass balance loss. The age of the firn cannot be determined without specific knowledge of the glacier or area, but for temperate alpine glaciers firn typically is converted to ice is 5-7 year

The snow cover (S) reamining on Jackston and Blackfoot Glacier in a Sentinel image by early September of 2021 is minimal. The firn area (F) in gray is more extensive.

Adams Glacier with areas of acccumulation (A) and firn (F) in a Sentinel image from Aug. 30, 2021. Green dots indicate the glacier boundary.

Olivares Beta and Gamma Glacier in Sentinel image, with ~10% snowcover remaining and 30% firn cover (blue dots) on January 20, 2022.

Olivares Beta and Gamma Glacier in Sentinel image indicating days of exposure at surface of firn and ice , March 26, 2022.

Volcan Overo, Argentina in January 13, 2022 Sentinel image, with negligible snowcover remaining in mid-summer and firn cover remaining on 30% of the Glacier E.

Volcan Overo in Sentinel image indicating days of exposure at surface of firn and ice , March 26, 2022.

Honeycomb Glacier (H) with evident firn lines below the annual snowline on Oct. 19, 2022 in a Sentinel image.

Kokanee Glacier 2021: slash and burn

On September 28, 2021April 22, 2024 By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations1 Comment

The southwest side of Kokanee Glacier from the ridge with Cond Peak at the Right and Sawtooth Ridge at center.

By Ben Pelto, PhD, UBC Mitacs Elevate Postdoctoral Research Fellow

Since 2013 I have been working on the Kokanee Glacier. Located just outside of Nelson in southeastern British Columbia (BC), the Kokanee Glacier is due north of the Washington-Idaho border. This work began as part of a five-year study of the cryosphere in the Canadian portion of the Columbia River. This project was carried out by the Canadian Columbia River Snow and Glacier Research Network — spearheaded by the Columbia Basin Trust. The glacier research, which included the Kokanee Glacier, was led by my former PhD supervisor at the University of Northern British Columbia Dr. Brian Menounos and myself. At the culmination of the project, we published a technical report, and a plain language summary of that report. When the five-year project officially ended in 2018, I learned of a BC Parks program called Living Labs, which offers funding for climate change research in BC Parks, particularly research which documents change and guides protected area management. With Living Labs funding in 2019-2021, I have kept the annual mass balance trips going — now a continuous nine-year record — and a winter mass balance trip in 2021. In conjunction with this, Brian Menounos has secured continued funding (continued from our 5-year project) from BC Hydro for LiDAR surveys of the glacier every spring and fall. These surveys are carried out by the Airborne Coastal Observatory team from the Hakai Institute.

During the 2021 spring trip, we found that the Kokanee Glacier had an average snow depth of 4.4 meters. Using snow density measurements collected with a snow-corer, we found that the winter balance for 2021 was 1.91 meters water equivalent (m w.e.). This value was lower than the 2013-2020 average of 2.18 m w.e. (Pelto et al. 2019).

Ali Schroeder probing snow depth on the Kokanee Glacier while Joel McBurney and Drew Copeland look on.

With a below average winter balance, 2021 would need to feature a cool summer. Instead, multiple heat waves occured, with temperature records being broken across the province. Wildfires burned all over BC and the neighboring US states of Washington and Idaho, swamping the region in smoke for weeks on end. Rather than mitigate for a slightly-below-normal snowpack on the Kokanee, summer 2021 took a blow-torch to glaciers across the region.

We hiked into the Kokanee Glacier on September 12, stopping under a boulder to wait out proximal booms of thunder and flashes in the clouds. We got pelted with bursts of both hail and graupel, and soaked in the rain, before gingerly working our way up boulder field and talus that is climbers route up the Keyhole to the Kokanee Glacier. Like the satellite imagery had shown, there was no snow in sight on the glacier — bare ice only. Instead of my usual camp on the snow, we chose a climbers bivy site to set our tent.

Camp in the Keyhole — a total lack of snow forced us to skip camping on-glacier.

Stepping out onto the glacier, we immediately ran into difficult terrain, crevasse bridges of snow or firn had collapsed, leaving bedroom-width crevasses gaping open, necessitating an exercise in maze navigation. Our first stop was a stake at 2600 m which typically retains snow (50 to 100 cms), but this year had lost 1.6 meters. In fact, two stakes drilled at the site in 2015 and subsequently buried by snow had melted out, demonstrating that all snow/firn from the intervening years had been lost. This observation clued me in to the magnitude of melt to expect this year.

The first stake visited, showing 1.6 m of melt

Travel on the glacier was more challenging in spots, but overall faster, as the total lack of snow meant that most crevasse bridges were gone, requiring less probing of crevasse bridges and roped-travel. Later, using a satellite image from the dates of our visit, I mapped the retained snow cover, limited to two tiny patches high on the glacier’s east side. The accumulation area ratio (AAR), or the ratio of snow cover to bare ice/firn was <0.01, meaning that under 1% of the glacier was covered in snow.

The upper reaches of Kokanee Glacier to Cond Peak (2800 m) with no retained snow in 2021. Bare ice is exposed on the lower half of the image, and firn, or multi-year snow above

Near infrared-Red-Green 30 cm resolution ortho image of Kokanee Glacier from the Hakai Geospatial/ACO team on Sept. 2, 2021. Note how badly crevassed the glacier is, most crevasses are exposed with no retained snow. The white color and mottled appearance over the upper glacier is a skiff of overnight snow just a few centimeters thick that melted off the next day. Also note bare ice patches exposed under formerly perennial snow patches that have shrunk in recent years and now are disappearing.

Visiting the toe of the glacier, our lowest stake indicated just under 5 m of ice melt, double that of 2020. In May, this location had 3 m of snow; the combined melt of snow and ice (loss of winter snow and glacier ice) is termed the summer mass balance, and at this site was -6.2 m w.e., far higher than the usual -4 m w.e. I also noticed that much of the thin ice along the margin of the toe was gone, and a little rock nunatak (rock island) that appeared in 2015 (images below) became a bite out of the glacier rather than a island. We estimated that the toe experienced 60 m of retreat. Over the past 5 years, the Kokanee has lost an average of 16 m in length annually. Expecting to see above average thinning and retreat, I was still startled to see how diminished and thin the toe looked.

2015: a small hole forms in the glacier margin above the toe, Jesse Milner in the foreground

A week prior to my field visit, the Hakai Institute ACO team flew a LiDAR survey of the Kokanee Glacier as part of their work with Brian Menounos at UNBC. Comparing this year’s glacier surface with that from last year’s survey, Brian found a whopping 2.55 m of thinning. After mapping the glacier facies (ice/firn/snow) to represent on the density of the observed thinning, this equates to a glacier mass balance of -2.16 m w.e., higher than the previous record loss of -1.20 m w.e. in 2015.

LiDAR-derived height change 2020 to 2021 from 1 m resolution DEMs from Brian Menounos and the Hakai Institue ACO team. The black line is the 2021 glacier outline, note the bite out of the glacier above the toe to the NE corner of the glacier. Small red patches off-ice are seasonal snow patches losing mass. Points represent mass balance observation locations.

Kokanee Glacier terminus from 2015 to 2021. 140 meters of retreat for 23 m/yr. Data in the GIF are from Hakai Institute and Brian Menounos of UNBC ACO glacier surveys.

Back home, I crunched the numbers from our glaciological observations of mass balance (consisting of 14 ablation stakes this year) and calculated a mass balance of -1.97 m w.e. With Brian, I published a paper in 2019 (Pelto et al. 2019) comparing glaciological (field) and geodetic (LiDAR) mass balance estimates and found them to be similar — if some factors like snow and firn density were carefully considered. The small difference between estimates is likely due to timing (the LiDAR mass balance is from 8/26/2020 to 9/3/2021, while the field mass balance is 9/12/2020 to 9/13/2021), and that there was a skiff of fresh snow (likely 5-10 cms) on the glacier during the 2020 LiDAR survey.

Kokanee 2021 glacier mass balance. Blue dots are observations. The boxplots show the 100 m bins used to estimate glacier-wide mass balance (median line in black, mean dashed grey line). The grey bars depict the area of the glacier for each 100 m elevation-band

Seasonal and annual mass balance for Kokanee Glacier from LiDAR and glaciological measurements for each balance year from 2013 to 2021 with 2σ uncertainties.

In 2017, I visited the Kokanee Glacier to measure it’s ice thickness using ice-penetrating radar. I found that the glacier on average was 43 m thick using my measurements to tune a glacier model. I published these results in the Journal of Glaciology (Pelto et al. 2020). In the five years since that work, the glacier has lost over 4.8 m of total thickness. That equates to a loss of over 11% of its total volume. 2021 alone wasted away 6% of the glacier’s total volume — an eye-watering number for a single year.

Cumulative mass balance for Kokanee Glacier 2013-2021 from both field and LiDAR measurments. LiDAR-derived mass balance began in 2016.

The heat of 2021 was an outlier, but years like 2021 and 2015 take a toll on the glaciers. Currently, glaciers in western North America are losing around 0.75 m of thickness per year (according to my work in the Columbia Basin (Pelto et al. 2019) and work by Brian Menounos for all of western North America (Menounos et al. 2018)). The better years for Kokanee Glacier (2016 mass balance: +0.12 m w.e.) pale in comparison. That meager surplus was lost the very next year (2017).

Herein lies the issue, positive mass balance years in recent decades are not large enough to offset even average years; hot dry summers take years off the lifespan of glaciers across western North America.

Losing 6% of it’s total volume in 2021, the best we can hope for Kokanee Glacier is a few near-neutral or positive mass balance years to cover back up the exposed firn, to keep the glacier albedo from becoming too dark and increasing the rate at which ice can melt.

Rainbow Glacier Fieldwork 8-7-2018

On April 9, 2020April 24, 2024 By mspeltoIn North Cascade Glaciers1 Comment

The video is of a single day of field work on Rainbow Glacier on 8-7-2018. This was our 702nd day of fieldwork during the project that began in 1984. On this day the field team consisted of Mariama Dryak, Erin McConnell, Jill Pelto and Mauri Pelto. Rainbow Glacier is a valley glacier on the northeast flank of Mount Baker, a stratovolcano and the highest mountain in the North Cascade Range, Washington. The glacier begins at a saddle at 2200 m sharing a divide with Mazama and Park Glacier. The glacier descends from the saddle through an icefall at 1950 m into the Rainbow Creek valley terminating at 1400 m. The consistent accumulation area extends from 1800 m to the saddle region above 1950 m. The glacier tongue features a deeply incised supraglacial stream channel. From 1984-2018 cumulative mass balance loss has exposed several bedrock knobs along the southern margin of the glacier.

Runoff from the glacier drains into Baker Lake, a reservoir for the Baker Dam hydropower facilities that have a generating capacity of 215 MW. Rainbow Glacier advanced during the 1950-1979 period building a terminal moraine. At the time of the first field season in 1984 the glacier was still in contact with this moraine. From 1984-2018 the glacier has retreated 620 m. In 2018 the mass balance was -0.53 m.

Terminus of Rainbow Glacier in 2018

Figure 1 is a map of the Rainbow Glacier indicating the mass balance measurement network.

Mass balance map of Rainbow Glacier in 2017 with mass balance isoline in m of water equivalent (Map by Ben Pelto)

36th Annual North Cascade Glacier Climate Project Field Season Begins

On July 29, 2019April 25, 2024 By mspeltoIn North Cascade Glaciers

Fieldwork includes terminus surveys, glacier runoff measurement and mass balance measurements

Field Season Begins August 1

Who we are? The North Cascade Glacier Climate Project (NCGCP) was founded in 1983 to identify the response of North Cascade glaciers to regional climate change, particularly changes in mass balance, glacier runoff and terminus behavior. This was prompted by the National Academy of Sciences listing this as a high priority and a personal appeal from Stephen Schneider. NCGCP is a field project that has a broader interdisciplinary scope and is the most extensive glacier mass balance field program in the United States. Two of the 41 reference glaciers in the world are in our network, and as of next year that will become three glaciers. We do this research cost effectively relying on no permanent camps, helicopter support or salary for the director. The field season includes no days off and each day is spent completing measurements on glaciers. The focus is on glacier mapping, mass balance measurement, terminus observations and glacier runoff monitoring. Each year we utilize several field assistants to complete the annual glacier surveys, with 2019 being the 36th field season. Our goal in choosing assistants is not to pick the most experienced, but the individuals who are capable and can benefit the most. We are a self-contained unit. Recently Hakai Magazine described our process well.

Why study glaciers in the North Cascades? Glaciers are one of the world’s best climate monitors and are a critical water resource to many populated glaciated regions. This is particularly true in the North Cascades where 700 glaciers yield 200 billion gallons of summer runoff and glaciers have lost 30 % of their area since 1980. These glaciers have lost 25-30% of their volume during the course of our study, three of our primary study glaciers have disappeared. We also monitor ice worms and mountain goats since we are in the same locations at the same time each year.

2019 Outlook: For North Cascade glaciers the accumulation season provides that layer of snow, that must then last through the melt season. A thin layer sets the glaciers up for a mass balance loss, much like a bear with a limited fat layer would lose more mass than ideal during hibernation. The 2019 winter season in the North Cascade Range, Washington has been unusual. On April 1 the retained snow water equivalent in snowpack across the range at the six long SNOTEL sites is 0.72 m, which is ~70% of average. This is the fifth lowest since 1984. The unusual part is that freezing levels were well above normal in January, in the 95% percentile at 1532 m, then were the lowest level, 372 m of any February since the freezing level record began in 1948. March returned to above normal freezing levels. As is typical periods of cold weather in the regions are associated with reduced snowfall in the mountains and more snowfall at low elevations. In the Seattle metropolitan area February was the snowiest month in 50 years, 0.51 m of snow fell, but in the North Cascades snowfall in the month was well below average. From Feb. 1 to April 1, snowpack SWE at Lyman Lake, the SNOTEL site closest to a North Cascade glacier, usually increases from 0.99 m to 1.47 m, this year SWE increased from 0.83 m to 1.01 m during this period. The melt season from May-Mid-July has also been warmer than average. This combination will lead to significant glacier mass loss in 2019, in one month we will report back on our measurements that will indicate just how negative.

2019 Field Team:

Clara Deck: is an earth scientist from Chicago with a passion for science communication, education, and outreach. She completed a B.A. in geology at the College of Wooster in Wooster, Ohio, where she began a journey in climatological research which led to a love for the cryosphere. In the summer of 2018, Clara contributed to glacial field work in the eastern Alaska Range, and was fascinated by the dynamic day-to-day changes in glacial features she was tasked with measuring. At the University of Maine, she is wrapping up her M.S. focused on numerical modeling of Antarctic ice shelf instabilities, but Clara’s favorite part of her college career has been sharing science with students as a teaching assistant. During her first visit to the North Cascades, she is excited to learn about ongoing glacial change and to explore accessible ways to share the findings with public audiences.

Abby Hudak is a native Floridian that has always had a deep calling to the mountains and frozen landscapes. Her passions revolve around understanding our changing climate and natural world which led her to attain a B.S. in Biological Sciences from the University of Central Florida. After starting her M.S. in Biological Sciences at Washington State University, she immediately indulged in snow sports and mountaineering in the Cascade Range. The beauty and vulnerability of these landscapes have driven her to expand her research interests to understanding aspects of the changing cryosphere. She is eager to intertwine her love for the Cascade Range and her desire to pursue scientific questions pertaining to climate impacts on alpine glaciers by working with the North Cascade Glacier Climate Project this summer.

Ann Hill, ever since she was a young child growing up in Minneapolis, Ann has been fascinated by ice and snow, however it wasn’t until her Sophomore year studying Geosciences at Skidmore College that she realized she could study ice as a career path. Consequently, during her junior year she traveled to Svalbard to gain hands-on experience studying and exploring glaciers. Determined to learn more, Ann spent a summer with the Juneau Icefield Research Program, which exposed her to glaciers that looked and behaved differently. In the fall, Ann will begin her M.S. in Earth and Climate Sciences at the University of Maine. Ann is thrilled to study the North Cascade glaciers to understand how their movement and characteristics compare to those she previously observed in Svalbard and Alaska.

Jill Pelto 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. Her multi-disciplinary work weaves visual narratives that reveal the reality of human impacts on this planet. She completed both her B.A. degrees in Studio Art and Earth and Climate Sciences and her M.S. focused on studying the stability of the Antarctic Ice Sheet at the University of Maine. She spent two field seasons at a remote camp in the southern Transantarctic Mountains to map glacial deposits and collect samples from them for dating. Jill will be joining the project for her 11th field season. 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 has directed the project since its founding in 1984, spending more than 700 nights camped out adjacent to these glaciers. He is the United States representative to the World Glacier Monitoring Service, author of the AGU blog “From a Glacier’s Perspective”, and associate editor for three science journals. His primary job is Dean of Academic Affairs at Nichols College, where he has been a professor since 1989.

Schedule

Aug. 1: Arrive Hike into Easton Glacier

Aug. 2: Easton Glacier survey

Aug. 3: Easton Glacier survey

Aug. 4: Hike out Hike in Lower Curtis Glacier

Aug. 5: Lower Curtis Glacier Survey

Aug. 6: Hike out Lower Curtis Glacier Hike in Ptarmigan Ridge

Aug. 7: Sholes Glacier

Aug. 8: Rainbow Glacier

Aug. 9: Hike out- Coleman Glacier survey

Aug. 10: Hike in Columbia Glacier

Aug. 11: Columbia Glacier survey

Aug. 12: Columbia Glacier survey

Aug. 13: Hike out Columbia Hike in Mount Daniels

Aug. 14: Ice Worm Glacier survey

Aug. 15: Lynch and Daniels Glacier survey

Aug. 16: Hike out

35th Annual Field Season Monitoring North Cascade Glaciers Preliminary Assessment

On August 20, 2018April 27, 2024 By mspeltoIn North Cascade Glaciers

We monitor the response of North Cascade glacier to climate change and the consequent impacts for water resources and the ecosystem, as illustrated here by Megan Pelto and Jill Pelto.

For the 35th consecutive year I headed to the North Cascade Range, Washington to monitor the response of glaciers to climate change. During the course of this study we observed several of the glaciers we monitor disappear. Two of the glaciers we monitor are now part of the 42 glaciers comprising the World Glacier Monitoring Service reference glacier network, where annual mass balance has been assessed for more than 30 years consecutively.

The 2018 winter season featured relatively normal snowpack despite a winter of wide temperature fluctuations, Feb freezing levels 400 m below the mean and December 500 m above the mean. Summer melt conditions featured a high freezing levels in May, normal freezing levels in June and high levels in July (NA Freezing Level tracker). The summer melt season through Aug. 20th has been exceptionally warm and dry, which has also helped foster forest fires. The melt rate during the August field season was 35% above normal.

We assessed the mass balance of eight glaciers. All eight will have significant negative mass balances in 2018. Retreat was measured on six of the glaciers where the terminus was exposed, all had retreated since 2017.

Sholes Glacier Runoff Monitoring Location in early August 2018

This year the field team consisted of:

Mariama Dryak, UMaine graduate student quantifying iceberg melt rates and meltwater fluxes around the Antarctic Peninsula using satellite imagery. She is the US national committee representative for the Association of Polar Early Career Scientists, co-chair of USAPECS and helps coordinate the USAPECS blog. Mariama is also the creator and editor of an environmental advocacy blog Let’s Do Something BIG., which highlights the need for effective science communication and the need for greater diversity in the earth sciences.

Erin McConnell, UMaine graduate student, who is studying ice core stable isotope records from the Eclipse Icefield, St. Elias Range, Yukon.She has written about the equal importance of communicating science and the science itself..

Jill Pelto, UMaine graduate student studying paleoclimate records recording past ice sheet changes in the Transantarctic Mountains and an artist, joining the field team for the 10th year. Her work has taken her to Antarctica, New Zealand and Falkland Islands and has been widely featured by Earth Issue, The Smithsonian, and Edge Effects.

Mauri Pelto, Nichols College academic dean, World Glacier Monitoring Service Representative and director of the North Cascade Glacier Climate Project . I am heading into the North Cascades for the 35th year. The results will from this year will be promptly published with the AGU From a Glaciers Perspective Blog and the North Cascade web site. A video encapsulation of the field year will also be developed as in past years. Putting the long term record in perspective was the 2018 Water publication on the long term mass balance record.

Observing snowpack thickness retained in August on Rainbow Glacier

Mapping terminus of Lower Curtis Glacier

Terminus of Columbia Glacier with evident forest fire smoke haze.

Easton Glacier Icefall at 2500 m, indicating a typical 2.25 m thick accumulation layer.

Alpine Glacier-BAMS State of the Climate 2017

On August 1, 2018April 27, 2024 By mspeltoIn glacier climate change

Global alpine glacier annual mass balance record of reference glaciers submitted to the World Glacier Monitoring Service, with 2017 continuing the trend of significant negative mass balance.

The Bulletin of the American Meteorological Society: State of the Climate 2017 has been published. Since 2008 I have written the chapter on alpine glaciers.

The World Glacier Monitoring Service (WGMS)record of mass balance and terminus behavior (WGMS 2017) provides a global index for alpine glacier behavior. Glacier mass balance is the difference between accumulation and ablation, reported here in mm of water equivalence. Mean annual glacier mass balance in 2016 was −847 mm for the 37 long-term reference glaciers and −761 mm for all 140 monitored glaciers. Of the reporting reference glaciers, only one had a positive mass balance. Preliminary data reported to the WGMS in 2017 from Austria, Canada, China, France, Italy, Kazakhstan, Norway, Russia, Switzerland, and United States indicate that 2017 will be the 38th consecutive year of negative annual balances with a mean loss of −1036 mm for 29 reporting reference glaciers, with three glacier reporting a positive mass balance (http://wgms.ch/latest-glacier-mass-balance-data/).

The ongoing global glacier retreat is currently affecting human society by raising sea levels, changing seasonal stream runoff, and increasing geohazards (Huss et al. 2017a). Huss and Hock (2018) indicate that approximately half of 56 glaciated watersheds globally have already passed peak glacier runoff. Rounce et al. (2017) identify the widespread expansion of glacier lakes due to retreat in Nepal from 2000 to 2015, which pose a glacier lake outburst flood hazard. Glacier retreat is a reflection of strongly negative mass balances over the last 30 years (Zemp et al. 2015). Marzeion et al. (2014) indicate that most of the recent mass loss, 1991–2010, is due to anthropogenic forcing.

The cumulative mass balance loss from 1980–2016 is −19.9 m, the equivalent of cutting a 22-m thick slice off the top of the average glacier . The trend is remarkably consistent from region to region (WGMS 2017). WGMS mass balance based on 41 reference glaciers with a minimum of 30 years of record is not appreciably different from that of all glaciers at −19.1 m. The decadal mean annual mass balance was −228 mm in the 1980s, −443 mm in the 1990s, −676 mm for 2000s, and –896 mm for 2010–17 (WGMS 2017). The declining mass balance trend during a period of retreat indicates alpine glaciers are not approaching equilibrium and retreat will continue to be the dominant terminus response.

Exceptional glacier melt was noted across the European Alps, leading to high snowlines and contributing to large negative mass balance of glaciers on this continent (Swiss Academy of Sciences 2017). In the European Alps, annual mass balance has been reported for nine reference glaciers from Austria, France, Italy, and Switzerland. All had negative annual balances: exceeding −1000 m with a mean of −1664 mm. This continues the pattern of substantial negative balances in the Alps that continue to lead to terminus retreat. In 2016, in Switzerland 94 glaciers were observed: 82 retreated, 7 were stable, and 5 advanced (Huss et al. 2017b). In 2016, Austria observed 90 glaciers: 87 retreated, 2 were stable, and 1 advanced; the average retreat rate was 14 m (Fischer 2017).

In Norway and Svalbard, terminus fluctuation data from 36 glaciers with ongoing assessment, indicates that in 2016 32 retreated, 3 advanced, and 1 was stable. The average terminus change was −12.5 m (Kjøllmoen, 2017). Mass balance surveys with completed results are available for nine glaciers; seven of the nine had negative mass balances with an average loss of −80 mm w.e.

In western North America data have been submitted from eight reference glaciers in Alaska and Washington in the United States, and British Columbia in Canada. Seven of the eight glaciers reported negative mass balances with a mean loss of −1020 mm. Winter and spring 2017 had above-average snowfall, while ablation conditions were above average. In Alaska mass losses from 2002 to 2014 have been −52 ± 4 gigatons yr⁻¹, as large as any alpine region in the world (Wahr et al. 2016).

In the high mountains of central Asia four glaciers reported data from China, Kazakhstan, and Nepal. All four were negative, with a mean of −674 mm. This is a continuation of regional mass losses, such as reported by King et al. (2017) who found for 2000–15 the mean annual mass balance of 32 glaciers in the Mount Everest region was −520 ± 220mm.

Landsat image from 8/19/2017 illustrating the snowline on Mont Blanc glaciers with one month left in the melt season (M=Mer de Glace, A=Argentière, S=Saleina, L=Le Tour, T=Trient)

Canadian Columbia River Basin Winter 2016-2017: A Late Rally

On August 14, 2017April 28, 2024 By mspeltoIn Glacier Observations, Uncategorized

Guest Post by Ben Pelto, PhD Candidate, UNBC Geography, pelto@unbc.ca

As the summer ticks by and the fall glacier field season approaches, I’ve realized that I never put out a winter 2016-2017 synopsis, so, like the snowfall this year, it’s arrived late.

May 2017, Jesse Milner of the ACMG on the Nordic Glacier in front of the “meteor strike” a newly exposed rock face that spalls ice regularly. Photo by Ben Pelto.

Story of the winter

The winter began with an extremely warm November, featuring temperatures 2-5˚C above normal, with greater than average precipitation generally delivered via Pacific storm cycles. Arctic air masses moving south across BC dominated December, with a complete reversal of temperature to well below average temperatures (Figure 1), and drier conditions. By January 1^st the BC River Forecast Center announced that the Columbia River Basin was at 80-88% of normal snowpack (Figure 2).

Figure 1. Maximum temperature anomaly for December 2016. Note Columbia Basin (SE BC) roughly 3˚C below normal (Pacific Climate Impacts Consortium).

Figure 2. January 1^st snow survey data from the BC River Forecast Center. The Columbia River Basin is comprised of the Upper Columbia, East Kootenay, and West Kootenay Basins, which range from 80-88% of normal.

March and April brought cool and moist unstable conditions, leading to a significant increase in snowpack across southern BC, delaying the onset of the melt season by about two weeks. Snowpack measures for the basin were over 100% of normal for the first time of the winter; by May 1^st, the Columbia Basin was at 115% of normal to the north and 135% in the south (Figure 3). By the first week of May, most regions had transitioned into the melt season, though at low to mid-elevations (below 1500 m) much of the snow had already melted.

Figure 3. May 1^st snow survey data from the BC River Forecast Center. The Columbia River Basin is comprised of the Upper Columbia, East Kootenay, and West Kootenay Basins, which ranged from 115 to 137% of normal.

Questions of alpine snowpack conditions

A trend seen over the past few winters is minimal to no snow at lower elevations with significant snow remaining higher, and it’s a pattern expected to continue in an era of rising temperatures leading to both rain on snow, and melt events through the winter. Unfortunately, current measurements, including the network of 70 automatic snow weather stations (ASWS) across the province, are all located at or below 2000 m. This leaves the alpine largely un-sampled. Rising temperatures may well be increasing the balance gradient of winter snow accumulation; that is, there will be a greater rate of change (increase) in snowpack with elevation than previously experienced, though data for this shift is lacking.

Our glacier research program

This information gap of alpine snowpack across BC is being addressed within the context of our glacier mass balance network funded by the Columbia Basin Trust. Each year we have been studying a series of five glaciers across the Basin, which from north to south are the Zillmer Glacier (Valemount), Nordic Glacier (northern boundary of Glacier National Park), Illecillewaet Glacier (Parks Canada, Rodgers Pass, Glacier National Park), Conrad Glacier (Golden, northern boundary of Bugaboo Provincial Park), and the Kokanee Glacier (Nelson, Kokanee Glacier Provincial Park). For more background see previous posts here and here.

Our spring field season consists primarily of snow depth measurements and snow density measurements, used to determine the snow water equivalent (SWE) retained on each glacier at the winter’s end. We also conduct GPS surveys of the glacier height, which we use to account for any surface height change between field visits, and the subsequent airborne laser altimetry surveys (LiDAR)of each glacier and the surrounding area that we’re conducting every spring and fall for the five years of the project.

May 2017, Pulling the ground penetrating radar up the Kokanee Glacier to measure ice thickness. The Kokanee is 20-80 m thick, averaging around 30-40 m. Photo by Rachael Roussin.

Our LiDAR data allows us to calculate snow depth by comparing a fall LiDAR-derived digital elevation model (DEM) to our spring DEM. Off-glacier, the fall DEM represents bare earth, and on glacier, the glacier surface at the end of the melt season. The spring DEM thus captures the fall surface height plus the winter snowpack. The difference in height between the two is taken to be accumulated snow. While our manual snow depth and density surveys of the five study glaciers are incredibly valuable data, our LiDAR surveys cover roughly 10% of the Columbia Basin glacier area, a more than three-fold increase. This expanded footprint allows a better picture of alpine snowpack across the province at elevations largely un-sampled; highly important to downstream concerns such as spring flooding and snow available for summer streamflow.

Fires and Floods

Dramatic swings of weather patterns characterized the 2016-2017 winter, with snowpack well below average in February and early March for the province. By the end of April, snowpack across the Columbia Basin and southern half of the province had rebounded to average or record levels depending upon location with Vancouver and the lower mainland receiving significant snowfall to much fanfare.

The late and cool spring saved the snow season, but also led to flooding across the province, particularly throughout the Okanogan and around Kelowna. As the wildfire season began in earnest, sandbags were still in place in Kelowna to protect properties against flooding from Okanogan Lake, which remained above full pool by 38 cms on July 10^th. Wildfire crews had been tasked with fighting the flooding, and were removing many sandbags as lake levels began to fall before heading off to respond to escalating fires. The flooding began following a rapid warm-up combined with heavy rainfall that led to extreme avalanche risk and activity, with highway closures along the Trans-Canada and Icefields Parkway.

The record snowpack across the southern-most Columbia Basin such as around Nelson, BC, has long since disappeared, with Nelson implementing water restrictions to attempt to cut water usage by 50% in response to the rapidly diminishing snowpack which feed the town’s water supplies.

Forest fires have been raging over the province, burning an area larger than Prince Edward Island, in what is the worst fire season in BC since 1958. Forest fire impact on glaciers is largely unknown, as soot and ash from the fires may raise albedo, but smoke clouds reflect incoming solar radiation. One thing is for certain however, should the fires cloud the skies during our field season, spending 24 hours a day in fire smoke makes for a tough go.

Team members at the foot of a recent avalanche preparing to head up to the Nordic Glacier in the first week of May 2017. Photo by Alex Bevington

Outlook

With our fall field season (August 19-September 21) only a week away, it will be an interesting time to observe how our study glaciers across the Columbia Mountains fared over this roller coaster of a year. After a cold, dry start to the winter, a late rally in March and April delayed the start of the melt season and raised snowpack to well above average across the Columbia Basin. A hot, dry summer led to flooding in May, and now wildfires in June-August, which reversed snowpack levels to below-average at most elevations. Satellite images of the study glaciers show rapidly rising snow lines, as above-average snow packs are reduced to average to below-average across most glaciers, with only the Kokanee Glacier appearing set for a possible positive mass balance year.

How do you get out? Jesse Milner at the bottom of a 5.5 m deep snow pit, which we use for sampling snow density. Nordic Glacier. Photo by Alex Bevington.

The field research is funded by the Columbia Basin Trust, with BC Hydro providing funds for the LiDAR surveys, and addition research support from the Natural Sciences and Engineering Research Council of Canada and the Canada foundation for innovation. The author is a supported by a Pacific Institute for Climate Solutions Fellowship and a scholarship from the University of Northern British Columbia.

State of Alpine Glaciers in 2016-Negative for 37th Consecutive Year

On February 17, 2017May 1, 2024 By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations

Figure 1. Global Alpine glacier annual mass balance record of reference glaciers submitted to the World Glacier Monitoring Service.

Each year I write the section of the BAMS State of the Climate on Alpine Glaciers. What follows is the initial draft of that with a couple of added images and an added paragraph.

The World Glacier Monitoring Service (WGMS) record of mass balance and terminus behavior (WGMS, 2015) provides a global index for alpine glacier behavior. Globally in 2015 mass balance was -1177 mm for the 40 long term reference glaciers and -1130 mm for all 133 monitored glaciers. Preliminary data reported to the WGMS from Austria, Canada, Chile, China, France, Italy, Kazakhstan, Kyrgyzstan, Norway, Russia, Switzerland and United States indicate that 2016 will be the 37^th consecutive year of without positive annual balances with a mean loss of -852 mm for reporting reference glaciers.

Alpine glacier mass balance is the most accurate indicator of glacier response to climate and along with the worldwide retreat of alpine glaciers is one of the clearest signals of ongoing climate change (Zemp et al., 2015). The ongoing global glacier retreat is currently affecting human society by raising sea-level rise, changing seasonal stream runoff, and increasing geohazards (Bliss et al, 2014; Marzeion et al, 2014). Glacier mass balance is the difference between accumulation and ablation. The retreat is a reflection of strongly negative mass balances over the last 30 years (Zemp et al., 2015). Glaciological and geodetic observations, 5200 since 1850, show that the rates of early 21st-century mass loss are without precedent on a global scale, at least for the time period observed and probably also for recorded history (Zemp et al, 2015). Marzeion et al (2014) indicate that most of the recent mass loss, 1991-2010 is due to anthropogenic forcing.

The cumulative mass balance loss from 1980-2015 is -18.8 m water equivalent (w.e.), the equivalent of cutting a 21 m thick slice off the top of the average glacier (Figure 2). The trend is remarkably consistent from region to region (WGMS, 2015). WGMS mass balance based on 40 reference glaciers with a minimum of 30 years of record is not appreciably different from that of all glaciers at -18.3 m w.e. The decadal mean annual mass balance was -228 mm in the 1980’s, -443 mm in the 1990’s, –676 mm for 2000’s and – 876 mm for 2010-2016. The declining mass balance trend during a period of retreat indicates alpine glaciers are not approaching equilibrium and retreat will continue to be the dominant terminus response. The recent rapid retreat and prolonged negative balances has led to some glaciers disappearing and others fragmenting (Figure 2)(Pelto, 2010; Lynch et al, 2016).

Below is a sequence of images from measuring mass balance in 2016 in Western North America from Washington, Alaska and British Columbia. From tents to huts, snowpits to probing, crevasses to GPR teams around the world are assessing glacier mass balance in all conditions.

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Much of Europe experienced record or near record warmth in 2016, thus contributing to the negative mass balance of glaciers on this continent. In the European Alps, annual mass balance has been reported for 12 glaciers from Austria, France, Italy and Switzerland. All had negative annual balances with a mean of -1050 mm w.e. This continues the pattern of substantial negative balances in the Alps continues to lead to terminus retreat. In 2015, in Switzerland 99 glaciers were observed, 92 retreated, 3 were stable and 4 advanced. In 2015, Austria observed 93 glaciers; 89 retreated, 2 were stable and 2 advanced, the average retreat rate was 22 m.

In Norway, terminus fluctuation data from 28 glaciers with ongoing assessment, indicates that from 2011-15 26 retreated, 1 advanced and 1 was stable. The average terminus change was -12.5 m (Kjøllmoen, 2016). Mass balance surveys with completed results are available for seven glaciers; six of the seven had negative mass balances with an average loss of -380 mm w.e.

In western North America data has been submitted from 14 glaciers in Alaska and Washington in the United States, and British Columbia in Canada. All 14 glaciers reported negative mass balances with a mean loss of -1075 mm w.e. The winter of and spring of 2016 were exceptionally warm across the region, while ablation conditions were close to average.

In the high mountains of central Asia five glaciers reported data from Kazakhstan, Kyrgyzstan and Russia. Four of five were negative with a mean of -360 mm w.e. Maurer et al (2016) noted that mean mass balance in the eastern was significantly negative for all types of glaciers in the Eastern Himalaya from 1974-2006.

Figure 2. Landsat images from 1995 and 2015 of glaciers in the Clephane Bay Region, Baffin island. The pink arrows indicate locations of fragmentation. Glaciers at Point C and D have disappeared.

Recent Climate Change Impacts on Mountain Glaciers – Volume

On January 12, 2017May 1, 2024 By mspeltoIn glacier climate change, Glacier Observations

Landsat Image of glaciers examined in the Himalaya Range: Chapter 10 that straddles a portion of Sikkim, Nepal and Tibet, China. Notice the number that end in expanding proglacial lakes.

This January a book I authored has been published by Wiley. The goal of this volume is to tell the story, glacier by glacier, of response to climate change from 1984-2015. Of the 165 glaciers examined in 10 different alpine regions, 162 have retreated significantly. It is evident that the changes are significant, not happening at a “glacial” pace, and are profoundly affecting alpine regions. There is a consistent result that reverberates from mountain range to mountain range, which emphasizes that although regional glacier and climate feedbacks differ, global changes are driving the response. This book considers ten different glaciated regions around the individual glaciers, and offers a different tune to the same chorus of glacier volume loss in the face of climate change. There are 107 side by side Landsat image comparisons illustrating glacier response. Several examples are below: in each image red arrows indicate terminus positions from the 1985-1990 period and yellow arrows terminus positions for the 2013-2015 period, and purple arrows upglacier thinning.

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There are chapters on: Alaska, Patagonia, Svalbard, South Georgia, New Zealand, Alps, British Columbia, Washington, Himalaya, and Novaya Zemlya. If you are a frequent reader of this blog you will recognize many of the locations. This updates each glacier to the same time frame. The book features 100 side by side Landsat image pairs illustrated using the same methods to illustrate change of each glacier. The combined efforts of the USGS and NASA in obtaining and making available these images is critical to examining glacier response to climate change. The World Glacier Monitoring Service inventory of field observations of terminus and mass balance on alpine glaciers is the another vital resource. The key indicators that glaciers have been and are being significantly impacted by climate change are the global mass balance losses for 35 consecutive years documented by the WGMS. The unprecendented global retreat that is increasing even after significant retreat has occurred in the last few decades (Zemp et al, 2015). Last, the decline in area covered by glaciers in every alpine region of the world that is documented by mapping inventories such as the Randolph Glacier inventory and GLIMS ( Kargel et al 2014)

Landsat Image of glaciers examined in the Svalbard: Hornsund Fjord Region: Chapter 6.

Landsat Image of glaciers examined in the South Georgia Island: Chapter 5.

Landsat Image of Mount Baker glaciers examined in the North Cascades, Washington: Chapter 8.

Landsat Image of glaciers examined in the Southern Alps of New Zealand S: Chapter 11.

Canadian Columbia Basin Glacier Fall 2016 Field Season

On December 28, 2016May 1, 2024 By mspeltoIn Canada glacier retreat

Guest Post by Ben Pelto, PhD Candidate, UNBC Geography, pelto@unbc.ca

Figure 1. An illustration of the glacier mass balance sum. Mass balance is equal to the amount of snow accumulation and the amount of ice melt over time. Traditionally, this is reported as annual mass balance (how much mass a glacier gained or lost in a particular year) and is reported in meters water equivalent (mwe).

The Columbia Basin Glacier Project is studying the mass balance of several glaciers in western Canada to assess their ‘health’ over time (Figure 1) using field-based measurements and remote sensing. This work is funded by the Columbia Basin Trust and BC Hydro. During the fall season of 2016, we visited our four study glaciers in the Columbia Mountains (Figure 2). These form a transect from south to north: the Kokanee Glacier (in the Selkirk Range), Conrad Glacier (Purcell Range), Nordic Glacier (Selkirk Range), and Zillmer Glacier (Premier Range). We also visited Castle Creek Glacier and the Illecillewaet Glacier with Parks Canada. This post is an overview of the field season and some preliminary results for 2016.

If you are interested in our main research objectives and methods, you can see the abstract from my recent talk at the American Geophysical Union conference and a video of an accompanying press conference (my piece starts at 18 minutes) with Gerard Roe (University of Washington) and Summer Rupper (University of Utah) titled: Attributing mountain glacier retreat to climate change. More information can be found in the November 29^th episode of the Kootenay Co-op radio program Climate of Change (start at 34 minutes).

Figure 2. Map of the Columbia River Basin in Canada. Our six study glaciers are marked by red stars. Other glaciers are in light blue (from the Randolph Glacier Inventory) and major rivers and lakes are in dark blue.

Our research consists of both field work and remote sensing. The fieldwork involves manually measuring the amount of snow that accumulates and ice that melts on each glacier at the start (spring) and end (fall) of each melt season (Figure 3). This gives us a mass balance measurement for individual glaciers but is very labor intensive (even if the views are great!). The remote sensing portion of the project is conducted using aerial laser altimetry (Figure 4). To conduct the laser altimetry we mount a Light Detection and Ranging (LiDAR) unit to the bottom of a fixed-wing aircraft and fly surveys of the glaciers twice each year. This creates two 3-Dimensional models of each glacier, one for the spring and one for the fall. When we subtract the spring model from the fall model, we are left with the thickness change of the glacier, and can thus derive mass change. We are still developing this method as a means of measuring more glaciers each year than could be achieved in the field.

Figure 3. To measure ablation (ice melt) we use ablation stakes drilled into the glacier in fall so that the top is flush with the ice surface. The following year, we visit the stakes to measure how much ablation has occurred during the summer, and then drill them in again to record the next year’s melt. In fall 2015, the top of this stake in the terminus of Nordic Glacier was flush with the ice surface, so it has lost nearly 3 meters of ice thickness (photo by Micah May).

Figure 4. Kokanee Glacier elevation change map showing the difference in glacier elevation between September 2015 and September 2016. The difference can be used to calculate glacier mass loss. The glacier (black outline) flows from the bottom of the page to the top, so the terminus of the glacier lost the most mass whereas the middle reaches are net neutral and the upper reaches gained mass. Non-ice areas (e.g. rock) are white because there was no elevation change. The blue and red patches outside the glacier are changes in seasonal snow patches and fresh snow deposited in depressions after a small storm at the time of the 2016 survey.

The year of 2015 was a record for glacier melt across western North America. By contrast, 2016 resulted in slightly negative mass balance for our study glaciers. This means that on average the glaciers we studied lost far less mass in 2016 than in 2015 (and 2014, see Figure 5).

Figure 5. The Conrad Glacier terminus in 2014 (on the left) and 2016 (on the right). Between 2014 and 2016, the terminus of this glacier retreated by 75 m (yellow arrows) and the glacier also thinned markedly. The visibility of the rock band in the center of the image shows this thinning of the ice (red arrows). Also note the orbital crevasses (green arrow), which formed due to the collapse of ice caves along the margin. These ice caves formed in 2014 and 2015 as the surrounding exposed rock warmed (via solar heating) and melted the ice margins from below, and subsequently collapsed in 2016.

Spring arrived around four weeks earlier than normal this year, as we noted in our spring report, with the melt season commencing near the start of April instead of the start of May. At the beginning of April, the 2015-2016 winter had resulted in average snowpack in the northern half of the Columbia Basin and above-average snowpack in the southern half. However, early hot temperatures during April then led to early melt instead of a slow increase in snow throughout the rest of the spring. By mid-April, the snowpack across the entire basin had dropped to under 50% of the normal amount. One caveat here is that province-wide snow monitoring includes many measurements at around 2000 m, but very few above this elevation. Most glaciers in the Columbia Basin lie above 2000 m elevation, so our understanding of the snowpack affecting these glaciers is limited. While there are no long term records for higher elevations in the basin, our data, and discussions with local ski guides and lodge operators, suggests that the snowpack was probably around average during winter 2015-2016 until April.

Our measurements indicate that overall, the 2015-2016 winter resulted in a snowpack that was only 7% lower than the 2014-2015 winter. Why, then, was 2015 a year of substantial mass loss in the Columbia Basin but 2016 only a slightly negative year? The answer is that temperature difference has a far greater impact in this region than the amount of snow accumulation. In our region, at the elevation where glaciers are located (generally above 2000 m), the variability in snowfall year to year is far smaller than the variability in annual temperatures. Temperatures have risen over the Canadian portion of the Columbia River Basin by 1.5°C over the past century, more than double the global rate according to the Columbia Basin Trust. Due to rising temperatures, above-average snowpack is needed just to break even in a typical year. Thus, in order to have a positive mass balance year, you need above average snowfall and below average temperatures.

The summer of 2016 featured average to slightly above average temperatures (Figure 6), with a cooler-than-average July. This is in contrast to the last two years, which both featured well-above-average temperatures through the melt season. Precipitation was also about average over the basin during the summer months (Figure 7). The basin began with a roughly average alpine winter snowpack, experienced an early and hot spring, slightly warmer-than-average summer temperatures, and average precipitation. The combination of these factors led to a slightly negative mass balance overall for our glaciers in 2016: those in the north lost around 0.5 mwe and those in the south stayed around neutral or even slightly gained mass.

Figure 6. Summer (June/July/August) mean daily maximum temperature anomaly for British Columbia in 2016. The red ellipse highlights the Columbia Basin, where temperatures were average to slightly above average (data from the Pacific Climate Impacts Consortium).

The 2016 trend was likely due, in part, to the prevailing position of the jet stream in the 2015-2016 winter. The northerly position of the jet stream, and persistent ridge over the Pacific Northwest, led to warmer winter temperatures over the southern part of the Columbia Basin but also more moisture and concentrated storm tracks (calcification: while accumulation variability resulting from winter weather patterns may have played a role in the north-south trend, the magnitude of mass change (small loss) was controlled by melt season temperatures). My favorite location to observe the jet stream in winter is from the California Region Weather Server at San Francisco State University. There have been many discussions of the jet stream behavior and its influence on winter weather in this region (here’s a simple overview from NOAA). The north-south trend was observed in 2015 as well, but in reverse, with the glaciers in the south experiencing greater mass loss.

Figure 7. Summer (June/July/August) precipitation anomaly for BC. Red ellipse highlights the Columbia Basin. Columbia Basin precipitation was net average to slightly below average for summer 2016 (Pacific Climate Impacts Consortium).

Well-above-average snowfall and well-below-average spring, summer and fall temperatures would be needed for any of the Columbia Basin glaciers to gain substantial mass. This has happened just twice over the past 20 years, as recorded by the North Cascades Glacier Climate Program in the North Cascades of Washington, just southwest of the Columbia Basin. During the winter of 1999, Mt. Baker set the record for most snowfall ever recorded in the US at 1140 inches (or 2900 cm, yes…29 meters!), leading to average glacier mass gain of over 1 meter water equivalent (mwe). The winter of 2011 also featured above average snowpack, and in combination with a cool and cloudy summer, led to below-average melt and a positive mass gain of over 1 mwe. Unfortunately, closer to the Columbia Basin, the Peyto, Place and Helm Glaciers of British Columbia, have never reported a mass gain of 1 mwe since Geologic Survey of Canada records began for those glaciers in the 1960s and 1970s.

The take home points:

In 2016, glaciers in the Columbia Basin experienced a slightly negative mass balance year. There was slight mass gain in the south (less than +0.25 mwe) and moderate mass loss in the north (around -0.5 mwe).
At present, an average year still results in moderate glacier mass loss in the Columbia Basin. Either above-average snowpack or below-average temperatures are needed during the melt season for a neutral mass change. A combination of both is required for the glaciers to gain mass.

If you want to see what our fieldwork looks like in practice, see my video from the spring field season.

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.

World Glacier Monitoring Service 30th Anniversary

On September 8, 2016May 2, 2024 By mspeltoIn climate change glacier retreat, glacier climate change, Glacier Observations

The numbers on the left y-axis depict quantities of glacial mass loss from the WGMS and sea level rise, and the suns across the horizon contain numbers that represent the global increase in temperature, coinciding with the timeline on the lower x-axis From Jill Pelto

The World Glacier Monitoring Service (WGMS) celebrated 30 years of achievement last week. I have had the privilege of being the United States representative to the WGMS and was an invited speaker for the Jubilee held in Zurich, Switzerland along with Matthias Huss, Wilfried Haeberli, Liss Marie Andreassen and Irene Kopelman. This post examines the important role that WGMS has and continues to serve under the leadership of Michael Zemp. The organization has been compiling, homogenizing and publishing data on glacier fluctuations and mass balance primarily from 1986-2013. WGMS remains the leading organization for the collection, storage and dissemination of information on the fluctuations of alpine glaciers. The resulting standardized collection of alpine glacier data that is archived by WGMS, is also leading to analysis efforts that otherwise would be hampered by limited data and lack of homogeneity to the data. Glaciers are recognized as one of the best climate indicators. Mass balance data is the best parameter to measure on glaciers for identifying climate change, because of its annual resolution. The core of the WGMS data set has been frontal variations, which indicate longer response to climate as well as dynamic changes. The key data set today provided by WGMS are the reference glaciers.

This set of glaciers has a 30-year continuous record of annual mass balance measured in the field, and each glacier also has geodetic verification. This mass balance data set is featured on the Global Climate Dashboard at NOAA. I report the mass balance of two reference glaciers Lemon Creek Glacier in Alaska and Columbia Glacier in Washington. Today the field based work is being increasingly supplemented and supplanted by remote sensing methods. This data sets indicates a period of sustained mass balance loss, and glacier retreat that Zemp et al (2015) using WGMS data noted as historically unprecedented. The most recent compilation publication is the Global Glacier Change Bulletin.

This data set is of particular value during this period of climate change and is already chronicling the disapperance of a number of glaciers in the data set. Glacier loss is not a process that has been well documented. The WGMS data set can be enriched by more data from expanding monitoring, reporting data from archives and simply adding the submission of data as a step in the research process for those monitoring alpine glaciers. The video of my presentation looking at 33 consecutive years of field work and sharing this data after compilation with the WGMS is below. The slides below are from the Jubilee presentations.

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