Wednesday, October 3, 2018

Seasonal change

The second half of September at Quelccaya is typically characterized by increasing snowfall, as the dry season concludes. Cloudiness increases rapidly at this time of year, as evidenced and measured by sharply increasing longwave radiation receipt. Air temperature continues a steady increase into November.

These aspects of Quelccaya climate are illustrated by the 2 images below, acquired by Senitinel-2 only 5 days apart. On 27 September (upper image), fresh snow is evident at higher elevations of the Vilcanota, particularly on glaciers and eastern portions of this scene. By 2 October (through high thin clouds), fresh snow had ablated from the landscape (middle image). Lower elevations of Quelccaya Ice Cap also become snow-free, revealing the transient snowline (also see lower image).

Further evidence of this seasonal change in climate is provided by the lower image - an enlargement of yesterday's image - showing the apparent disappearance of ice cover from a marginal lake (circled). In July this ice was thick enough to support a person walking across the lake.


Friday, September 7, 2018

Return from fieldwork, forthcoming papers [updated]

August fieldwork was successful and fun, despite rather unstable weather. Considerable dry-season snow blanketed south-facing slopes and the entire glacier, yet little new snow occurred during our ~10 days at Quelccaya. The panorama above shows Boulder Lake and one lobe of the glacier where we have conducted observations since 2003; Lonnie Thompson has worked here since 1974. More photos and details of recent fieldwork will be posted in the next week or two.

A variety of new papers will soon be available, so look for links on this website. As indicated below, some are closer to publication than others...

[UPDATE 10/16] Yarleque, C., M. Vuille, D.R. Hardy, O.E. Timm, J. De la Cruz, H. Ramos, and A. Rabatel. Projections of the future disappearance of the Quelccaya Ice Cap in the Central Andes. 2018. Scientific Reports. To be freely available on 22 October from Nature!

Hardy, S.P., D.R. Hardy, and K. Castañeda Gil. Avian nesting and roosting on glaciers at high elevation, Cordillera Vilcanota, Peru. Accepted 20 Aug. for Wilson Journal of Ornithology.

Hurley, J.V., M. Vuille, and D.R. Hardy. On the interpretation of the ENSO signal embedded in the stable isotopic composition of Quelccaya Ice Cap, Peru. Submitted to JGR-Atmospheres.

Yarleque, C., M. Vuille, D.R. Hardy, O.E. Timm, and H. Ramos, Future projections of precipitation variability over the eastern Central Andes. Submitted to Frontiers.

Chadwell, C.D., D.R. Hardy, C. Braun, and H.H. Brecher. Thinning of the Quelccaya Ice Cap over the last thirty years. In revision/reorganization.

Hardy, D.R., R.S. Bradley, et al. The summit climate of Quelccaya Ice Cap. In preparation.

Thursday, August 9, 2018

More snow this week

As forecast by SENAMHI, the Vilcanota has received more snow. The Sentinel-2 image from yesterday shows snowcover surrounding Sibinacocha, as well as the area around the hamlet of Phinaya.

Tuesday, August 7, 2018

weather forecast: more of the same

The weather forecast for today and tomorrow from SENAMHI calls for rain and snow of moderate to strong intensity in the mountains, with hail expected above 3,000 m; wind gusts to 45 km/hr.

Quelccaya's location here is indicated by the red circle. "Danger Level 3"

And it appears the forecast was accurate, with restricted travel...


Saturday, August 4, 2018

August begins snowy

Sentinel-2 acquired an image of the Cordillera Vilcanota yesterday, 11 days since their previously-published image (via EO Browser)... and fresh snowcover is still widespread.

Compare these two identical scenes, from 3 August (upper) and the last time snowcover was restricted to the highest elevations, on 30 May (lower) - two months ago!

The community of Phinaya, where many alpaca and llama herders are based, is located within the red circle. During June and July, snowcover appears to have been only occasional at this elevation. The smaller red hexagon is the Quelccaya weather station location (5,680 m), illustrating that the transient snowline has remained below the glacier margin (approx. 5,300 m) since May.

Fieldwork begins in a week!

Wednesday, July 25, 2018

¡Tanta nieve! So much snow! [updated x2]

The snowy dry season of 2018 continues in the Cordillera Vilcanota. Yesterday's Sentinel-2 image (above) reveals a landscape blanketed by snow above 4500-4700 m. Quelccaya Ice Cap (lower right) is difficult to delineate, suggesting substantial accumulation at the margin. Hopefully our instrumentation continues to record hourly snowfall at the summit.

Note the variation in color of lakes just west of the glacier, surrounding the area of our camp (labeled). This reflects varying suspended sediment input, with relatively high concentrations apparently flowing into the Qori Kalis proglacial lake (north of camp); snow is accumulating, while also melting and delivering sediment to the lakes. The 'double' lake to the northwest of camp (and Sibinacocha) appear dark blue, as upstream wetlands (bofedales) filter sediment from freshly-exposed areas proximal to the glaciers.

We will be in the area during the second half of August, measuring snow and recovering weather station data. Fieldwork will occur later than normal, allowing an assessment of what appears to be an anomalous year. Although this snow will be beneficial to glacier mass balance, the toll on camelids (llama, alpaca) could be severe - without warming solar radiation typical of the dry season.

[UPDATE 7/26: A press release from SENAMHI* earlier this week (23 July) describes snowfall in the preceding 72 hours above 3,800 m in the Andes, accumulating to 20 cm. In conjunction with clouds, they warn of low temperatures and prolonged snowcover reducing food for livestock.

Gustavo Valdivia wrote yesterday learning details of the situation in the Cordillera Vilcanota. He received a call from the Phinaya community president, who described the situation as critical, because a lot of alpacas died in recent days. The local people agree that the weather is very unusual.

Press releases from SENAMHI can be found here (in Spanish), with a machine translation  here

*SENAMHI is The National Meteorology and Hydrology Service of Peru or El Servicio Nacional de Meteorología e Hidrología del Perú]

[UPDATE 7/27:  Today I learned from Bronwen Konecky (Washington University) that SENAMHI is making daily meteorological summaries available on their website. The closest station to Quelccaya - and one of their highest - is Sibinacocha, at ~4890 m (labeled on map above). These data show 11 mm of water equivalent precipitation on 21 July, followed by 5.9 on the 22nd. Since this automated station is located at the southern end of the lake, the image above suggests that considerably more snow fell at higher elevations. The regional nature of this event is demonstrated by daily totals from Sicuani (~3600 m, 45 km to the SW); very similar daily totals were recorded.

To access any SENAMHI data in Peru, go here, then use the "Seleccionar" button to select a District; zoom in on the map. Thanks, SENAMHI.]

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.