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.