Wednesday, July 11, 2018

BBC Glacier Bird filming

During our April/May 2016 fieldwork, we were joined by a BBC Natural History Unit crew. Their objective was to film White-winged Diuca Finches nesting on the glacier, a breeding behavior unknown among all other bird species. The project timing was fraught with uncertainty, for only 2 other active Diuca nests had ever been observed, and the 2015-16 El Niño event considerably impacted Quelccaya climate (overview here of a manuscript now out for review). Foremost in our minds was whether we could find active nests to film, when we arrived in April.

Fortunately, our timing was perfect; we observed all stages of breeding behavior, and successfully installed a remote camera at one of the nest sites. After a year in production the segment aired on BBC as part of an episode on the Andes, in the series Mountain: Life at the Extreme. Links to the BBC series are here and here.

This month, BBC Glacier Bird footage will premiere in the United States on PBS. The series takes a new name, Kingdoms of the Sky, with a new presenter, but otherwise appears identical: a three-part documentary "revealing the extraordinary animals and remarkable people who make a home on the iconic mountain ranges of the world - Rockies, Himalaya and Andes." The three episodes will initially air on Wednesday evenings, beginning with The Rockies on July 11 at 9 PM EDT. Himalaya premieres one week later on July 18, and Andes premieres on July 25.

The PBS series website is here, and DVDs can be pre-ordered now.

At the moment, the Glacier Bird segment can be viewed from the right-hand side of the series homepage. Click on "Meet the Bird that Nests Inside Glaciers" to see the first-ever footage of Diuca speculifera nestlings.

Even better is an 8-minute, behind-the-scenes look at Quelccaya filming, available from PBS here. Images from that clip are included above and below.

Our extended fieldwork with BBC in April 2016 was good fun, and provided new observations of Diuca and other high-elevation species. Please check our website for the Glacier Bird, and stay tuned for a new publication (still in review; contact us for a synopsis of the paper, or a pre-print).

Friday, July 6, 2018

Still Snowy - Quelccaya and beyond

The Cordillera Vilcanota remains snowy, as illustrated by the Sentinel-2 image above from 4 July. Snowcover at high elevations, on south-facing slopes, and on glaciers has changed very little over the past month. At Quelccaya Ice Cap, bare ice is exposed only at the lowest elevations of outlet glaciers (e.g., Qori Kalis, on west side).

Extensive snowcover on the glacier is keeping the albedo high, minimizing mass loss... at least for the moment.

Quelccaya is not alone in being unseasonally snowy this year. For example, in the Karakoram Mountains (Pakistan) climbing teams on mountains such as K2 are finding dangerous avalanche conditions due to heavy snowfall, during the core climbing season. More details can be found here.

Kilimanjaro is also unusually snowy for July, the result of above-average accumulation during the March-May wet season.

In Northeast Greenland, the winter of 2018 brought twice as much snow as the long-term average, and snowcover into early July remains so extensive that Sanderlings and other shorebirds may not even attempt nesting this year. The late snow is having large consequences for the ecosystem.

Finally, snow on portions of the Greenland Ice Sheet is resulting in the "least surface ice loss in decades". As Jason Box notes via Twitter (@climate_ice), these persistent extremes in patterns of atmospheric circulation are an expected signature of climate change.

Friday, June 15, 2018

June snow

Several snowfall events during the first half of June have kept the landscape snowy at Quelccaya this year. In the 14 June image above (ESA Sentinel-2, bands 4,3,2) lingering snow is visible below 4,900 m in shaded locations.

Typically the dry season is underway by mid-June, often with snow only on the glacier. This year, the relatively-bright fresh snow is keeping the albedo low, reducing energy input and ablation of the glacier surface.

Despite the current situation, evidence indicates that recession of the ice margin is accelerating. Planning is underway for fieldwork in the next few months, when snowcover on the glacier will be measured and AWS data since July 2017 will be recovered. We're anxious to document 2017-18 La Niña accumulation!

Tuesday, May 15, 2018

Snowcover update & ice retreat

Quelccaya Ice Cap currently remains largely blanketed by snowcover, excepting the very lowest ablation zone (e.g., Qori Kalis outlet glacier). The GIF above contains only 2 images; the snowy scene without red annotation was acquired last week (10 May 2018). Contrast 2018 snowcover on the glacier with that 2 years earlier, at the end of March 2016.

These images show a portion of the ice cap's western margin. We have visited this area at least annually since 2003, witnessing continuous retreat of the margin and changes in all of these proglacial lakes.

The red ellipses on the 2016 image highlight two areas where margin retreat is clearly evident. Our GPS measurements up through 2017 at the lower section indicate a retreat rate of 10-15 m/year. At the small red circle by the larger lake, the area of bedrock near the circle has expanded, and only a small portion of the glacier still extends into the lake (contrast 2013). Throughout our years of fieldwork in the area we have observed ice calving into this lake, which began forming in ~1985 (Thompson et al., 2013). Within the next year or two the glacier will no longer reach the lake.

One consequence of Quelccaya margin retreat and thinning is loss of suitable nest sites for the "Andean Glacier Bird" (White-winged Diuca-Finch, Idiopsar speculifer; formerly Diuca speculifera). Until the mid-2000s the area near the lower ellipse supported a relatively high density of nests, built directly on the ice (Hardy and Hardy, 2008 and here). As ice at this margin thinned and became less steep, the area was abandoned for nesting. More recently, the area near the small circle has been used for nesting (e.g., 2014 oblique photo of margin at the lake), but as the ice becomes thinner the birds will need to move up in elevation to find suitable, steep ice slopes. Furthermore, the Glacier Bird is not the only bird species impacted by ice recession; a new manuscript detailing this is currently in review (and available upon request). 

Ref:  Thompson, L.G., E. Mosley-Thompson, M.E. Davis, V.S. Zagorodnov, I.M. Howat, V.N. Mikhalenko, and P.-N. Lin. 2013. Annually resolved ice core records of tropical climate variability over the past ~1800 years. Science, vol. 340, 945-950. 10.1126/science.1234210

Tuesday, April 3, 2018

Vilcanota wet season

Image above:  A portion of the Cordillera Vilcanota, including Nevado Ausangate (upper left), Sibinacocha (the big lake), and Quelccaya Ice Cap on 31 March 2018 (Sentinel-2 image).

Our ~15 years of measurements reveal clear relationships between ENSO and climate at Quelccaya. A detailed documentation of these is nearly ready for submission, primarily authored by collaborator John Hurley and titled "ENSO variability of Quelccaya Ice Cap d18O”

Our understanding of Quelccaya's response to ENSO will be further refined when we are able to examine accumulation resulting from the ongoing La Niña event (2017-18). Since last September, negative sea surface temperature anomalies have persisted in the east-central equatorial Pacific. These SST anomalies have been slightly more negative than last year, which followed very warm anomalies associated with the 2015-16 El Niño.

Quantifying the timing and properties of this newest accumulation cannot occur until we visit the weather station, since our data telemetry system failed in 2017. However, satellite imagery suggests that snowfall has been considerable this year. The image above provides the first relatively-clear view of the glacier and surrounding terrain in several months. In this ESA Sentinel-2 "natural-color" image (bands 4, 3, and 2), glaciers and higher peaks are entirely snow covered, and a dusting of snow is visible on terrain west and south of Quelccaya.

Greater detail can be seen in the cropped image below, showing only Quelccaya - and revealing that glacier ice is not exposed even at the lowest elevations (~5,200 m).

Finally, the GIF image at the bottom shows the Sentinel-2 EO Agriculture composite product, on approximately 1 April of the past 3 years. Note in particular the vegetation color difference between the El Niño year 2016, and the next two wet seasons during cold phase ENSO events. Also, there appears to be more snow around the glacier margin this year than in April of 2017. Our ENSO paper will document such ENSO variabilty at the summit of Quelccaya, in terms of snowfall seasonality, the vapor initial d18O values, and air temperature.

Tuesday, November 21, 2017

2017 dry season - towards the end

Satellite imagery from earlier this month show that the 2017-2018 accumulation season began sometime within the past month. The image above from 2 October shows a familiar snowline pattern, as ablation continued. We won't know exactly when accumulation began at the summit until our next visit to the AWS, as telemetry was not restored during July fieldwork. Will there be a La Niña signal in accumulation this year?

Friday, September 8, 2017

Glacier Bird on BBC

The final episode of BBC TWO's new documentary series about mountains will air at 9 pm on 13 September, featuring a variety of sequences filmed in the Andes.

Among the Andes sequences will be a segment filmed at Quelccaya, as described above. Several wonderful "behind the scenes" clips have been produced for the Glacier Bird film, one of which is here (hopefully available soon in North America). A link to the page above, with an embedded clip, is here.

Since the time of filming - just last year - science has moved forward:  we have discovered a second species of bird which also nests on the glacier (Hardy et al., submitted to Wilson Journal of Ornithology), and Glacier Bird's taxonomic classification has changed from Diuca speculifera to Idiopsar speculifer. The common name in English remains White-winged Diuca-Finch, but this too may change because the bird is not a Diuca-Finch!

For those not in the UK, the series will be broadcast in North America by PBS at a later date.