Upcoming fieldwork

I haven't been on the mountain for 11 months now, and am anxious to get back. Telemetry indicates that the rate of ablation during the current dry season has been unprecedented in the 10-year record - which is somewhat perplexing. Snow accumulation began on the glaciers within a few weeks of our October 2009 fieldwork and continued without much interruption until the very end of May, bringing a net accumulation of 70 cm to the Northern Ice Field. Ablation then began, and although measurements from the two sensors differ, most of this snow appears to have now ablated. Visiting the glaciers will allow evaluation of the extent to which melting, evaporation, and superimposed ice formation is responsible.

So, we depart later this month for the summit glaciers with an ambitious program and a collaborative team, including personnel from the Univ. of Massachusetts, Innsbruck University, and NASA JPL. Simon Mtuy and Summit Expeditions are again providing logistical support on the mountain. One of my objectives will be to add reference-quality instrumentation developed by the U.S. CRN (Climate Reference Network), establishing the first CRN station outside the Americas. Operating CRN instruments alongside those which have been on Kilimanjaro since February 2000 will provide an intercomparison with which the long-term data can be adjusted. Measuring air temperature in that environment, on snow and with solar radiation typically exceeding 1,200 W/m^2, is far more difficult than might be expected.

Accompanying work at the weather station will be measurement of how ablation on the glacier has varied spatially, while NASA team members investigate microbiological diversity in the ice. And we're optimistic about getting some dates soon on ice samples collected last October. Stay tuned!

-Doug Hardy, UMass Geosciences

Science journalism

Christopher Reddy of Woods Hole Oceanographic Institution has an opinion piece in the August 25th Wall Street Journal, pertaining to media coverage of the Deepwater Horizon's subsurface oil plume. Although the situation is arguably more complex and important than the Kilimanjaro retreating glacier story, I find it to be an interesting analog in terms of scientist's differing findings, their interaction with journalists, and how the story is conveyed by the media. Reddy suggests that "...it is incumbent on scientists and journalists to keep the results in perspective" [especially those which are preliminary] "and refrain from veering into misleading waters."

Two new publications

This week, two new papers add to our knowledge of Kilimanjaro's glaciers.  Georg Kaser is first author on "Is the decline of ice on Kilimanjaro unprecedented in the Holocene?" published (appropriately enough) in The Holocene.  The paper sets forth a hypothesis that the glaciers may be only hundreds of years old, rather than 11,700 - as detailed in the only other paper published on the matter (Thompson et al., 2002).  A link to this new paper, as well as the 2002 paper in Science, are provided to the right.  The quest for definitive dates on the ice is underway!

A second new paper is primarily the work of Ph.D. student Michael Winkler (Innsbruck), and published in Erdkunde (in English). "Land-based marginal ice cliffs: focus on Kilimanjaro" will be of interest to anyone familiar with - or intrigued by - the unique vertical walls of Kilimanjaro glaciers. The paper is also available from our publications link.

Dry season underway

As typically the case, the beginning of June marked the transition from accumulation to ablation on the Northern Ice Field. Two sensors are used to measure changes in surface height, and while one indicates less than 5 cm of ablation the other shows 20-25 cm (with the average being -11.5 cm). In both cases the decrease is more-or-less continuous through the month.

Whimpy Long Rains

Telemetry from the Northern Ice Field suggests that the Long Rains ended at the end of May, consistent with previous years. Snowfall frequency was fairly regular, beginning with a relatively large event in March (see this entry), but net accumulation was only 10-15 cm. This is quite a contrast to the Short Rains of November to mid-January which netted 45-50 cm of accumulation on the glacier.

The dry interval between the rains this year was centered on February, as is typically the case. It extended from mid-January to the March snowfall mentioned above, yet included 2-3 multi-day snowfall events of 5-10 cm.

In summary, as of today (mid-June) snow depth on the Northern Ice Field is ~60 cm.

Kilimanjaro returns to PNAS

Back in November, we published a paper in Proceedings of the National Academy of Science (PNAS) which documented changes in ice-covered area on Kilimanjaro since February 2000 (see blog entry with link to paper). Collaborators at the University of Innsbruck had a different perspective on a few elements of the paper, so wrote a Letter to the Editor. Together with our response, the letter was published online April 21st in PNAS Early Edition, and both will remain there until appearing in print.

The Mölg et al. letter is also available here, and the Thompson et al. response is here.

As an active collaborator with all authors involved, I would like to point out that such discussion - in scientific literature - is normal, healthy scientific discourse. This is how the process is supposed to work, and this is one way in which science advances! Our correspondence does not demonstrate uncertainty about whether Kilimanjaro's glaciers are shrinking, or whether they are likely to disappear with a few decades, or whether global warming is likely driving recent shrinkage; we are all in complete agreement on these tenets! Nor do the letters reveal some fundamental divide between research groups. In both cases, dedicated researchers are simply articulating nuanced perspectives gained from varying combinations of arduous fieldwork, laboratory analysis, and/or computer modeling. Given the short history of quantitative measurements from Kilimanjaro, both groups are attempting to make sense of climate-glacier interactions that all agree are complex. Everyone involved is dedicated to developing a better understanding of the mountain's fascinating glaciers.

-Doug Hardy, UMass Geosciences

Singing at the summit

Here are a few audio recordings from the cook tent, by the singing crew of October 2009 (above). Only those who ascend slowly with good equipment are capable of such joyful singing at nearly 6,000 meters. Thanks to everyone at Summit Expeditions!

• cook tent track #1
• cook tent track #2
• cook tent track #3
• In Mbahe, track A
• In Mbahe, track B
• In Mbahe, track C