This month we returned to Kilimanjaro's summit glaciers and automated weather stations, 14 months since our last visit (Aug. 2016). Yes, the changes were dramatic - everywhere we looked.
This post provides a few glimpses of the remaining ice, still incredibly
beautiful. Once an initial inspection is done on recovered AWS data, a
subsequent post will provide an overview.
Helping out on this fieldwork were Spencer and Chang'a (Fig. 1). This
was both of their first times on the mountain and both brought new
insights and questions, providing stimulating discussions during the
ascent and in camps. Dr. Ladislaus Chang'a is Director of Research and
Applied Meteorology at the Tanzania Meteorological Agency (TMA), and involved with the IPCC. He will
be coordinating our new data- and information-sharing collaboration with TMA,
hopefully as part of WMO's Global Cryosphere Watch.
As previous entries have mentioned, the past year has been drier than
normal at the summit. Decreased albedo has resulted in considerable
ablation of both vertical and horizontal surfaces. Indeed, ice loss at
the surface caused an unprecedented number of ablation stakes to melt
out, and the tipping of several instrument towers. With essential
support from our Summit Expeditions (SENE) crew (photos here and here),
the towers were reset after 4 nights camped at the summit (see Fig. 2
& 3) and everyone descended safely.
The Furtwängler Glacier provides one illustration of the speed with
which glaciers are shrinking on the mountain (Fig. 6). Since February
2000, when Henry Brecher determined the glacier area from aerial
photographs, more than 80 percent of this glacier has disappeared. A
brief historical perspective on this glacier is available here. The
linear rate of area decrease suggests that there will be nothing left of
the Furtwängler by 2025.
Many thanks to longtime collaborator Thomas Mölg for helping to support this fieldwork!
Figure 1. Spencer Hardy and Dr. Ladislaus Chang'a at Barafu Camp (4,670 m), our fifth night of the ascent.
Figure 2. Looking west over the Northern Icefield. Visible
instrumentation includes (left to right) a timelapse camera,
high-accuracy temperature and radiation measurement (Climate Reference
Network compatible), and the original AWS. Several ablation stakes are
faintly visible in the area around the instruments. See next image for
Figure 3. Northern Icefield instrumentation site at ~noon, looking
toward Uhuru Peak on left skyline (2 km distant). This cloud pattern
represents typical diurnal development, with convection to the south and
west, and rising up the Western Breach.
Figure 4. Detail of Northern Icefield surface near the AWS, with small
nieves penitentes formed since the 2017 long rain season. About 35 cm of
the ablation stake is exposed. Between the penitentes is new snow from
the previous evening. Also note the area of dirty ice to the right of
the stake; the character of all glacier surfaces on Kilimanjaro is
spatially heterogeneous and varies tremendously from year to year.
Figure 5. Rapidly shrinking, east-end remnants of the Northern
Icefield, likely once part of an ice body shown in image #95, here.
Figure 6. The view north from near Uhuru Peak. Northern Icefield in the
background, still 40+ meters thick, and the Furtwängler Glacier
(foreground); Reusch Crater sloping up to the right. The Furtwängler ice
area is 32 percent less than it was just two years ago (Sep. 2015). See
image #115 here for the same view in 2013.
Figure 7. The remaining ice of the former Eastern Icefield, ~1.5 km distant to the northeast.
Figure 8. Upper Deckens Glacier near Uhuru Peak, one remnant of the
former Southern Icefield. Compare with image #33 here from 2009, when
the Decken and Kersten Glaciers were still connected. The upper sections
of these dirty south-side glaciers provide dramatic evidence for the
processes of both sublimation and melt.
Figure 9. The upper Rebmann Glacier, not far from Stella Point. The
recent break-up here has been rapid, associated (in part) with marginal
lake formation and drainage; note several areas of buried ice. On the
right-hand side of the image, note how the ice stratigraphy more-or-less
parallels the slope, yet the ablation surface is nearly horizontal.
Selecting sites to obtain ice samples for age dating of these glaciers,
or for ice core drilling, is not a trivial issue.
Figure 10. Looking east from camp, just after sunset. One of the views which keeps us going back!