October fieldwork!

We were back on the glaciers for fieldwork in October! As previously reported (here), the pandemic and logistical issues prevented us from visiting since February 2020, and although 'automated', our weather stations on the ice are not self-maintaining. Over the course of the ensuing three years, problems and damage occurred - so one of our objectives last month was to remove weather instrumentation and mass balance stakes. With tremendous help from the porters and staff of Summit Expeditions (SENE), we were successful. The next step is examining data we recovered, and evaluating options to continue measurements with new instrumentation!

Doug Hardy (UMass), Mike Winkler (GeoSphere Austria), and Emily Collier (Univ. Innsbruck). 

Click on any image to enlarge:

Fig. 1 (above): Kibo and 5,000 meters of relief, from Moshi. Preparing to head up again was very exciting, first time in over 3 years!

Fig. 2 (above): Our first task, led by Emily and her newly-funded research, was exploring the Kilimanjaro Mountain Club archives - in search of historical observations pertaining to the impacts of Tropical Cyclones on Kilimanjaro precipitation.

Fig. 3 (above): Morning of day two, a favorite view on the Umbwe Trail. These southern slopes were once covered by the Southern Icefield. Only fragments remain today, including sections of the Kersten Glacier (center).

Fig. 4 (above): Umbwe route passes through a recently-burned area below Barranco Camp, one of several new fire scars seen on this trip.

Fig. 5 (above): Diamond Glacier, Breach Icicle, and fragments of the Balletto Glacier. The icicle is larger than in 2020* due to meltwater drainage from above. Also note extensive rockfall onto the Balletto. (*2020 image here.)

Fig. 6 (above): Mike and Emily above Karanga Camp. Kersten Glacier remnants are visible above Mike, and the Rebmann Glacier is above Emily; between them is the vanishingly meager Decken Glacier ice.

Fig. 7 (above): Team member Mathayo Melio, preparing fresh greens (Kale) at Barafu Camp.

Fig. 8 (above): Late afternoon at Barafu, where multiple helicopter pickups are now occurring daily - typically to expedite the descent of wealthy clients.

Fig. 9 (above): Wishful thinking. Simon is testing whether he can transmit a message directly from his brain through this cable. Kilimanjaro Park authorities are testing whether they can string fiber optic cable along the trails for tourists to post on Instagram. We had no success with either. Increasing rockfall and debris flows on the mountain could make unprotected fiber maintenance difficult...

Fig. 10 (above): Riming on the Uhuru sign, as the weather clears. Northern Icefield in the distance.

Fig. 11 (above): Furtwängler Glacier from above. Since 2020 the area has decreased by seventy percent (yes, in 3 yearss); the glacier's demise is imminent.

Fig. 12 (above): Upper Kersten Glacier, October 2017; find the weather station. Zoom in, as this is a panorama. Then find the relatively thick, clean stratum and compare it's position to that in 2023 (next image).

Fig. 13 (above): Kersten Glacier upper margin, where thinning and lateral retreat continue. Where is the weather station? Occasional collapses of the wall and a marginal meltwater lake has been noted for 20+ years. However, compare the thick, clean ice layer position here with that 2017 (prior image) or in 2014, 9 years ago (with Will Gadd for scale).

Fig. 14 (above): Mike investigating ice blocks where the Kersten Glacier margin most-recently collapsed. Find the weather station (we couldn't either).

Fig. 15 (above): The largest remaining fragments of the former Eastern Icefield. The right-hand block is featured in the Red Bull film.

Fig. 16 (above): Northern Icefield margin, just west of camp. Note person for scale, just right of center - and the interesting basal stratigraphy.

Fig. 17 (above): Wonderful textures photo taken by Mike.

Fig. 18 (above): Northern Icefield margin, looking west toward camp. Compare to this similar view in February 2000.

Fig. 19 (above): Northern Icefield again... but the northern margin. As evident here, in next image, and elsewhere - the ice is fracturing to a greater extent than previously seen.

Fig. 20 (above): A fresh, curious collapse feature at the Northern Icefield margin. An ice layer associated with ponded and frozen supraglacial meltwater can be seen at the top of the fracture. These have been occasionally observed on Kibo's glaciers, always frozen at the surface.

Fig. 21 (above): A portion of AWS being carried through penitentes on the Northern Icefield. These particularly-large penitentes made walking difficult!

Fig. 22 (above): The AWS tower being carried back across the crater toward Uhuru Peak, 23 years after being brought up!

Fig. 23 (above): Doug, Emily, and Simon - along with about 20 other team members - prepare for a tree-planting ceremony honoring climate research on the mountain.

Fig. 24 (above): Final preparations for a feast celebrating safe and successful fieldwork! Much of this food was grown right on Simon's farm.
 

Kibo Weather Stations - 23 years later

Our team is just back from difficult-but-stimulating fieldwork on summit glaciers, documenting Kibo's climate. Initial instrumentation at our weather station was installed in February 2000, then gradually supplemented and expanded. The configuration by 2013 is shown above. After near-annual maintenance and observation visits through 2017, we visited the stations for a Red Bull film in 2020 and then could not get back during the pandemic. Fieldwork in 2022 was foiled by bureaucratic miscommunication. By September of 2023, negative mass balance resulted in tipping and damage of equipment - the extent of which will soon be revealed by analysis of recorded data.

All the hardware, instrumentation, and ablation stakes have now been removed from the mountain and the National Park. As will be detailed in subsequent posts here, this was accomplished despite delays in departure, followed by high winds and riming precipitation. Removing everything required multiple trips to the summit by our accompanying crew, as well as an additional 19 porters to move equipment down the mountain.

We dedicate our 2023 mission to the hundreds of porters who have been essential to the success of this research since February 2000. They did the hard work transporting everything up - and then down - 5,000 meters of elevation, keeping us cheerful (most of the time) and productive. Perhaps most impressively, they were integral to a perfect safety record through the entire study. On this latest trip, we crossed paths with numerous porters from past trips, and spent time with one who was along on trip #1 back in February 2000; today he continues working as a respected mountain and safari guide. Also this month, one porter introduced himself as the son of a favorite porter, not yet born when his dad started helping. Asante sana to all the porters, guides, cooks, drivers, and support staff who have been involved - from Keys Hotel, Marangu Hotel, and since 2006, Summit Expeditions and Nomadic Experience (SENE).

2023 team:  Doug Hardy (UMass), Mike Winkler (GeoSphere Austria), and Emily Collier (Univ. Innsbruck)

September fieldwork!

With great anticipation, I'm planning to be back on Kibo's glaciers next month. After 17 years of frequent observations and measurements, circumstances beyond my control have foiled research efforts in recent years. Never take high-elevation glacier fieldwork in National Parks for granted! Chief among the issues were a major storm (October 2018), postponement of two consecutive collaborative trips (July & December 2019), a collaborative-and-fun glacier visit with limited time and deep snow (February 2020), the pandemic (2 years), and most recently - failure to get above 2200 m due to logistical/permitting difficulties (September 2022). Phew... I'm ready to get back up there!

Extensive fieldwork and AWS service was conducted in October 2017, including repairs at the station and documenting changes to summit glaciers. Accompanying us on this trip - to the Roof of Africa - was Dr. Ladislaus Chang'a, currently the Acting Director of Tanzanian Meteorological Authority.

Conditions are currently very dry at the summit. Meager high-elevation precipitation during the 2023 long rains (March-May) resulted in no snow accumulation within the caldera as the dry season began in June. By then, any snowcover remaining on glacier surfaces was continuing to thin, although without telemetry or observations, recent changes in surface mass balance remain speculative. Through June, July, and August, isolated patches of snow on Kibo's flanks have been ablating, as shown in the timelapse below - from very little, to almost none!

During this next visit, extensive glacier photography will help us better understand changes at the Northern Icefield (compare with image above). Lesser Penck Glacier (compare with image below), Furtwängler Glacier (compare with image above), and what remains of the Southern Icefield (compare with image below). Glacier images from this October will be posted here after fieldwork.

September and October fieldwork will have two objectives. The first task will be to recover AWS data from the station, extending the weather record which began over 23 years ago. These data are being stored in memory on-site, even if power to the station has been lost. In addition, the weather stations and ablation stakes (photo below) will be removed from the mountain. Both stations tipped over last year, ending the interval of high-quality measurements. Continuing a trustworthy climate record would require replacing instruments and electronics, along with sufficient funding and dedicated personnel willing to perform regular inspections and service.

Stay tuned for updates!

 

Northern Icefield weather stations, and adjacent stakes to measure ablation

Lesser Penck Glacier extent, 1930 to 2008 - continuously shrinking

Southern Icefield, 2003 (GoogleEarth image)

Stable weather at the summit

Two months into the 2022 dry season - roughly halfway through - the extent of snowcover has remained remarkably constant. The animation below runs from 12 June through 27 July at a five-day interval (22 July not shown due clouds).

Although mass loss continues, the low rate of ablation suggests cold and dry conditions at the summit, supported by the lack of convective clouds seen on these images. With such weather conditions, sublimation is the predominant mechanism of ablation, requiring eight times more energy per unit mass lost.

Typically, an increase in atmospheric moisture marks the transition between the dry season and short rains, yet for much of eastern Africa the pattern has been disrupted in recent years. David Nash details the current and forecast situation in a short article for The Conversation.

We will be back on the mountain in September! After a 2-year COVID hiatus, we are eager to observe the glaciers, recover meteorological data - and provide a new perspective on Kilimanjaro climate variability and change (stay tuned)!

 

What Will Gadd learned on top of Kilimanjaro

Red Bull today released a fantastic new Will Gadd film, shot with a full crew during our pre-COVID February trip. The finished product (45 minutes) is about extreme sport, but also about the science of Kilimanjaro glaciers and climate change; it is well worth watching.

Will was a joy to work with - as eager to learn and share knowledge as he is to climb ice - and clearly articulates the responsibility we all have to reduce our carbon impact. Red Bull deserves major credit for broadening the scope of their productions. And, the stuff is tasty!

Director Tom Beard and the KEO Films crew did a wonderful job of editing, and eagerly accepted ideas to insure an accurate result.

Access the film here:  <https://redbull.com/thelastascent> or here.

 

 

Stable weather returns [updated]

February weather on Kilimanjaro is often characterized by a dry interval, between the Short Rains of approximately Nov/Dec, and Long Rains within the Mar/Apr/May time period. As noted previously, the Short Rains brought considerable rain to the mountain this year, with snow up high, beginning in early October. That wet period appears to have ended.

The upper image from 2 February shows patchy snowcover on the upper 1000 meters of the mountain's south side, as viewed from above Moshi (Simon Mtuy credit). Distinguishing remnants of the former Southern Icefield from snowcover is difficult here.

The second image above was acquired today by the ESA Sentinel-2 satellite, revealing continuous snowcover within the summit caldera, and on the upper slopes. The stable-weather cumulus clouds visible here appear only slightly more extensive than those on the day before (top image).

Although telemetry of data from the Northern Icefield (NIF) weather station is not currently available (budget constraints), several recent reports from climbers confirm what the images depict. On 23 January, collaborator Sarah Konrad visited the NIF and measured a mean snowdepth of ~0.60 m around the weather station. Shortly thereafter (28 Jan.), Simon was above the Western Breach in the Furtwängler Glacier area, reporting "almost one meter of snow."

Images below show Simon's camp at Arrow Glacier on the 27th, looking south across the Western Breach, and a Furtwängler Glacier remnant near Crater Camp (Sarah Konrad credit). Finally, a photo of the NIF weather station from Sarah reveals that the equipment is overdue for a "service visit". Fortunately, planning is underway to visit the station later this month!

[UPDATE 02/04:  Our friend Timba keeps close tabs on Kilimanjaro weather from Moshi, in the interest of safety for the many guides and porters working on the mountain. It was Timba who inspired our analysis of how tropical cyclones might influence snowfall on the mountain (Collier et al., 2019).

Timba wrote today, emphasizing how wet the region has been in recent months, especially at the end of September and through most of October 2019. As he points out, this is the time when the Indian Ocean Dipole (IOD) was very strongly positive, a water temperature pattern associated with heavy rain in eastern Africa - and bushfires in Australia (read more here and here).

So, has stable weather really returned to Kilimanjaro? Although the IOD has returned to a neutral pattern, older friends of Timba's equate the current rainfall pattern with that of Oct. 1988 to June 1989 - when the two rainy seasons merged into one long wet season.]
 

19 years on the Northern Icefield

This week marks 19 years since AWS measurements began on Kilimanjaro's Northern Icefield (NIF). With enthusiastic help from our Tanzanian crew, Mathias Vuille and I installed a tower into the ice and connected the electronics. Remarkably, the same datalogger continues measurement and control functions, and the same solar panels continue to provide power. Most sensors have been swapped out for recalibration or replacement, yet the original barometric pressure sensor continues reliable measurements every hour.

Ice ablation since 2000 has substantially reduce the areal extent of all glaciers on the mountain. However, this portion of the NIF has "only" thinned by ~5 meters, because the low surface gradient retards meltwater runoff - which then refreezes in place as superimposed ice. Other portions of the NIF, and other glaciers, have thinned more dramatically. For example, ice no longer remains at February 2000 drill sites on the Furtwängler and Decken Glaciers, which were 9.5 and ~20 m thick at the time (respectively).

Wild weather on the mountain

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).

18 years!