AWS fieldwork images

A small selection of weather station images have been posted here, illustrating current instrumentation, the atmospheric conditions during fieldwork, and the glacier surface at the end of September. Mass balance for horizontal surfaces of the Northern Ice Field was positive this year (Oct. 2011 - Sept. 2012).

Additional fieldwork images will be posted soon. Credit for above photo:  K. Casey, NASA

Furtwängler Glacier update

Furtwängler Glacier (foreground) and the Northern Ice Field on 27 September 2012, as seen from just west of Uhuru Peak. Although the mass balance on Furtwängler's horizontal surfaces was slightly positive for 2011/12, shrinkage of the glacier continues due to recession of the vertical walls.

Recent recession of the Furtwängler is well documented by annual GPS surveys. These reveal that although continuous, the rate of recession is not constant. For example, with an extended period of snowcover in the crater during the past year, area only decreased by ~3%. However, over the past 5 years, ice extent has decreased ~35%, and since the Feb. 2000 air photos renewed interest in Kilimanjaro's glaciers, 59% of the ice area has disappeared. In conjunction with ~6-7 meters of thinning since 2000, the loss of ice volume is considerably greater!

To view the Furtwängler Glacier in greater detail, two GigaPan panoramas are available. The western portion is here and embedded below, and clicking through will provide a link to another GigaPan of the eastern portion (also available here).

Five days at the summit

We are just back from fieldwork on the summit glaciers, concentrating on the Northern Ice Field. After 4 nights on top for some of us, we accomplished most of our objectives. Thermal imaging was unfortunately postponed yet again, due insufficient time for export control paperwork. Nonetheless, this was a fun group and everyone adapted well to the altitude. Fieldwork did present a few surprises which will be detailed later.

Below are a couple images from the trip. The first illustrates a small portion of the mountain's largest glacier, showing automated weather stations on the upper surface and our camp in the foreground. For late in September, considerable snowcover was present on the glacier and patchy elsewhere within the crater.

The lower image demonstrates why high-elevation observations are so valuable in helping to understand tropical, mid-tropospheric climate. The stratification visible in the image - sharp, spatially uniform, and persistent - is often present in northern Tanzania at a varying altitude. For reference, the distant peak (Mt. Meru) reaches over 4,500m -- and on this day was still not within the free atmosphere! Virtually all climate stations in the region are yet another 2,000 to 3,000m lower in elevation; they simply cannot accurately represent conditions high on the mountain. Two AWS currently operate on the Northern Ice Field, as shown. During this trip a 4-component net radiometer was added to the left-hand station, which will improve the accuracy of our radiation measurements. Also shown (within red circles) are 3 of the NIF ablation stakes, installed to help track gains and losses of mass at the glacier surface.

August ablation - mostly

Ablation of the snow-covered Northern Ice Field during August proceeded more-or-less at the July pace, with a net surface lowering of ~20 cm. One small snowfall event on ~27 August (~3 cm) brightened the surface and retarded ablation for about a week. For the 11 months since our last fieldwork, ~40 cm of accumulation remains, which could result in a positive balance for 2011-12 at the AWS site.

We depart for fieldwork next week. One of our tasks will be to assess the spatial variability of last year's accumulation on the summit glaciers. This promises to be a fun trip, as we will be a group of 6 interesting people - representing 4 different countries - and accompanied by the-one-and-only Simon Mtuy. Discussions in the dining tent will likely continue each night until our teeth are chattering from the cold!

Remembering Emmanuel Mtui

The Kilimanjaro community lost a kind person and a strong leader on July 31st, when Emmanuel Mtui was tragically killed in a vehicle accident on the Marangu-Rombo road. He lived in Mbahe, not far from Park Headquarters and the Marangu Gate, and leaves behind his wife and 5 children. Emmanuel worked for years as a Senior Guide at Summit Expeditions & Nomadic Experience (SENE). His leadership style was subtle, yet tremendously effective - orchestrating his trips almost as if by remote control. With pride, attention to detail, and a sense of humor, Emmanuel carefully looked after his staff and clients alike. He will be missed by all who had the good fortune to know him.

Anyone wishing to make a donation to Emmanuel's family may send a personal check made out to Summit Expeditions and Nomadic Experience with "Emmanuel Mtui" in the "for" line. The SENE US office is at: 1808 Riverside Ave S. Suite 208 Minneapolis, MN 55454. More photos of Emmanuel are posted here, and comments may be made on the SENE facebook page.

Summit snowcover - late July

Recent posts have detailed the extent of snowfall during the 2012 Long Rains, which included a couple atypical events during June. Below are some images from the summit taken at the very end of July, snowing snowcover on the crater rim and within the crater.  Imagine the effect of this snowcover on energy exchanges at the crater surface, when perhaps only 30% of the intense incoming solar radiation is absorbed rather than roughly 80% without snow. The effect on people climbing the mountain is likewise severe, exposing skin to radiation from all directions; big sunhats offer protection only from incoming sun!

These images were shot by Peter Greig during a reconnaissance climb for the project Wings Of Kilimanjaro (WoK). In early 2013 a large number of pilots will paraglide and hang-glide off the top while raising a substantial amount of money for Tanzanian charities. Additionally, their goal is to "reinforce the universal need for humanity, compassion and generosity inherent in all of us". More photos from the reconnaissance are available on facebook.

Image captions:

1. late afternoon in the crater, with Uhuru Peak to the left and the Furtwängler Glacier to the right
2. nearing Uhuru Peak, showing snowcover on the ridge above the southern glaciers
3. morning within the crater, walking East between Furtwängler Glacier and the descent from Stella Point; note some topographic shading here
4. looking North across the crater from high on Uhuru Peak; "crater camp" is visible in the foreground by the Furtwängler Glacier fragments, with the Northern Ice Field in the distance. At this time of year, when the sun is in the northern hemisphere, north-facing slopes such as those above crater camp are the first to become snow free.

Peter Greig photo, Wings Of Kilimanjaro

Peter Greig photo, Wings Of Kilimanjaro

Peter Greig photo, Wings Of Kilimanjaro

Peter Greig photo, Wings Of Kilimanjaro

June & July weather

A summary of the previous month's weather at Kilimanjaro's summit is typically posted (here) within the first few days of each month. This year the June synopsis didn't make it in time, due to travel for other fieldwork. As usual though, the temperature fell slightly and the average humidity dropped relative to May, but two other reasons made the month noteworthy. First, June saw a net increase in the glacier surface height. Although the net change was only +4 cm, this was the first June in which accumulation was greater than ablation. In comparison - now that the dry season is underway - lowering during July amounted to ~16cm.

Also in June 2012, the daily maximum of incoming solar radiation was on average lower than in any month of the past 10 years. June irradiance is always relatively low of course, being at 3°S latitude, yet the new record this year is likely due to both greater cloud cover than normal - and to snow on the radiometer dome.