Fieldwork is an essential component
of climate and glacier research, providing basic measurements as well as a foundation for theoretical and
modeling studies. Yes, fieldwork can be tremendously fun, sometimes even yielding
unexpected discoveries – yet it can also be difficult and dangerous. A successful
fieldwork campaign requires alignment of numerous components and factors; some
of these we can control, and others we must manage. For both categories, past
experience and planning is helpful. Sometimes though, the outcome also requires good luck.
After 20 prior trips to my
AWS on Kilimanjaro’s Northern Icefield, plans for October fieldwork came
together within only a couple weeks. Telemetry of data revealed technical
problems which could only be resolved by a visit to the station. However, budgetary
constraints dictated that this trip would need to be done differently. While recognizing that a lighter and faster approach would reduce the factors
we could control, and increase the required management of other factors, we
decided that the potential rewards of a brief visit to the station outweighed
the risks of this strategy. Supportive and generous collaborators* agreed to
make the visit possible.
Our quickly-hatched plan was
to acclimatize normally, and then in one day ascend the final 1000 meters,
undertake 4-6 hours of work, cross the summit caldera, and descend the other
side to rejoin our support team. Past experience on the mountain suggested to
all involved that the concept was reasonable –given just a few hours of
reasonable weather. For this trip, ‘reasonable’ weather meant conditions under
which an ascent of the Western Breach was safe (i.e., cold and dry), followed by a few
hours at the AWS without heavy snowfall, wind less than ~20 km/hr, and air
temperature above -5 °C or so; any sun would be a bonus. Once finished at the
station, we were confident about descending in almost any conditions.
Reasonable weather
prevailed through our first two days on the mountain, followed by conditions more typical
of the wet seasons (e.g., April-May). Warmth, rain, and wind appeared in the forecasts, and on day 3 became
our reality on the mountain, conditions increasingly at odds with both our work
needs and those required for the safety of all involved. Ascending in
wind-driven rain to Arrow Glacier camp below the Western Breach, there was
little ambiguity about what we were likely to encounter the following day –
which proved accurate, as illustrated below and revealed by telemetry from the AWS. That afternoon a consensus emerged: continuing with our plan would unacceptably compromise
safety, and that work at the AWS would almost certainly be impossible.
Disappointing? Absolutely.
Station problems remain unresolved, and the 18-year nearly-continuous record
may be compromised. In addition, not measuring and documenting the summit
glaciers will prevent assessing the response of anomalous accumulation during the
2018 long rains. Furthermore, any compromise on fieldwork goals is disappointing in
light of the carbon cost of traveling nearly 30,000 km. However, our decision
to retreat was correct, for in contrast to several other groups on the mountain,
we all returned safely.
Field scientists must fully
exploit observational and quantitative opportunities during every moment in the
field, and learn from every experience. This trip provided new insight into the
development of weather systems on Kilimanjaro. Valuable photographs and observations of
the slope glaciers were obtained, and new understandings were gained through
interactions with others on the mountain. More difficult to accept was something we already knew, the false economy of an ambitious undertaking in too-little time. Future fieldwork must allow adequate
time to accommodate difficult weather conditions, despite the higher
financial cost of extended fieldwork time on Kilimanjaro summit glaciers (e.g., extra
Park fees, staff salary premiums). Finally, the experience highlights the value
of high-elevation climate and glacier data, which should never be taken for
granted.
*Special thanks to Nicolas
J. Cullen at University of Otago (New Zealand), and Thomas Mölg at Friedrich-Alexander-University
(FAU) in Germany, for their encouragement and vital support!
Fig. 1. Timelapse of
clouds over Kibo, 24 Oct. at 13:30 (~1 sec interval). Wind speeds began increasing on the 23rd, and remained high for 3-4 days. Airflow throughout our time on the mountain was from just
south of east, as illustrated in Fig. 3 below.
Fig. 2. Kibo on 24 Oct. at
13:30 from near Karanga Camp. Although the mountain is quite snowy for
mid-October, snowcover decreased during the days prior, due to rain and a high
freezing level (note lack of fresh snow east of the Rebmann Glacier, on right-hand side of image).
Fig. 3. Airflow and
relative humidity at 500 hPa over east Africa and Kilimanjaro (green circle),
24 Oct. at 14:00. Cyan color indicates RH above ~95%; 49 km/hr equates to ~30 MPH, not a particularly high windspeed for a mountain summit, but difficult to work in when humidity is high (see riming in Fig. 4). Source:
earth.nullschool.net (c) 2018 Cameron Beccario.
Fig. 4. Summit scenes
early on 25 Oct., when apparently only 2 Norwegians and their guide reached the top. Photos courtesy of Dismas Kishingo, via Emanuel Mutta of SENE.
Fig. 5. Landsat 8 scene from 28 Oct. at 10:43 local time. Fresh snow on Kibo and
Mawenzi accumulated over the prior ~4 days, when AWS data show dropping air temperature and 20+ cm of accumulation.
Fig. 6. The proverbial calm after the storm. Kibo as seen from Moshi, 28 October at 08:00 (just prior to the Landsat image above).
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