Friday, January 11, 2013
Christmas snow
Here is how Kibo looked at about Christmas from near one of the Shira Camps. Unsettled weather and the snowlevel at roughly 4,500m (background photo courtesy SENE).
Monday, January 7, 2013
Snow, lightning
Kilimanjaro was wet through the second half of December, "crazy wet"
as characterized by Timba at Ahsante Tours. Telemetry from the
Northern Ice Field provides the evidence, with high humidity and
snowfall totaling 33.8 cm between 16 December and 3 January. The
days of
greatest accumulation were the 27th (4.9 cm), 30th (5.2 cm) and 2
January (5.5 cm). Although 5 cm is a moderate hourly rate in some
mountain regions, less than 4% of all days with snowfall on
Kilimanjaro are of this magnitude. Although such events do not add
much mass, they are disproportionally important in terms of raising
albedo and thus decreasing net radiation
receipt.
Snowfall on the glaciers is often rainfall lower on the mountain, and often much heavier than summit snowfall might suggest. Kilimanjaro precipitation is frequently associated with convection, particularly at this time of year, and at 12:30 PM on Wednesday (2 January), lightning struck a group that was approaching Lava Tower. The group leader Ian McKeever was killed and several other were burned. McKeever's FaceBook post the day before from Shira 2 camp mentioned "torrential rain all day", and the group's guide Said Makacha indicated that there was heavy rain during the hike to Lava Tower.
We have learned that 2 porters have also tragically died in recent days. At the moment it is unclear whether lightning, hypothermia, or another cause was responsible; condolences to the families of all 3 victims.
Lightning is not common on Kilimanjaro itself (e.g., zoom in with this Google Earth overlay showing lightning frequency), and deaths are quite rare - especially considering the number of people camped high on the mountain most nights . An article in the Tanzanian "Daily News Online Edition" recalls the previous incident in 1999, which occurred just a couple months before we began working on the mountain. The article quotes a National Park source suggesting the terrible idea that climbers take cover in caves (above 4,000 m) during rain, evidently not aware that the 1999 death occurred at Shira Caves, a short distance from where the death occurred this week.
While strikes may be infrequent, lightning is often visible at night from high on Kilimanjaro, and thunder has been heard while camped at the summit for fieldwork on the past two trips.
Can we learn anything from summit weather on 2 January that may help explain the tragic death(s)? Maybe. Wind direction on the Northern Ice Field blew steadily from the South beginning about midnight, at a bit lower speed than normal for the day. Southerly flow is relatively uncommon at our measurement site; wind is more typically from the East, which helps suppress convection above the mountain's western slopes (up which many climbers ascend). It is possible that light winds from the south, in conjunction with regional instability, aided the development of convection which led to the lightning strike.
On 4 January humidity decreased dramatically, the wind veered back to the East, and solar radiation measurements indicate generally clear conditions.
Snowfall on the glaciers is often rainfall lower on the mountain, and often much heavier than summit snowfall might suggest. Kilimanjaro precipitation is frequently associated with convection, particularly at this time of year, and at 12:30 PM on Wednesday (2 January), lightning struck a group that was approaching Lava Tower. The group leader Ian McKeever was killed and several other were burned. McKeever's FaceBook post the day before from Shira 2 camp mentioned "torrential rain all day", and the group's guide Said Makacha indicated that there was heavy rain during the hike to Lava Tower.
We have learned that 2 porters have also tragically died in recent days. At the moment it is unclear whether lightning, hypothermia, or another cause was responsible; condolences to the families of all 3 victims.
Lightning is not common on Kilimanjaro itself (e.g., zoom in with this Google Earth overlay showing lightning frequency), and deaths are quite rare - especially considering the number of people camped high on the mountain most nights . An article in the Tanzanian "Daily News Online Edition" recalls the previous incident in 1999, which occurred just a couple months before we began working on the mountain. The article quotes a National Park source suggesting the terrible idea that climbers take cover in caves (above 4,000 m) during rain, evidently not aware that the 1999 death occurred at Shira Caves, a short distance from where the death occurred this week.
While strikes may be infrequent, lightning is often visible at night from high on Kilimanjaro, and thunder has been heard while camped at the summit for fieldwork on the past two trips.
Can we learn anything from summit weather on 2 January that may help explain the tragic death(s)? Maybe. Wind direction on the Northern Ice Field blew steadily from the South beginning about midnight, at a bit lower speed than normal for the day. Southerly flow is relatively uncommon at our measurement site; wind is more typically from the East, which helps suppress convection above the mountain's western slopes (up which many climbers ascend). It is possible that light winds from the south, in conjunction with regional instability, aided the development of convection which led to the lightning strike.
On 4 January humidity decreased dramatically, the wind veered back to the East, and solar radiation measurements indicate generally clear conditions.
Thursday, December 13, 2012
Ten years for the US Climate Reference Network
Congratulations to the USCRN program on the first decade of operations!
Some of the equipment on the UMass Kilimanjaro weather station is compatible with that of the U.S. Climate Reference Network (USCRN), which NOAA's National Climatic Data Center (NCDC) began 10 years ago. We chose to incorporate elements of their system at our site as a result of the extensive testing and characterization they carried out. A nice overview of all USCRN aspects and prospects is contained in the Early Online Release of a paper titled "U.S. Climate Reference Network after One Decade of Operations: Status and Assessment." The paper will appear in a future issue of the Bulletin of the American Meteorological Society, and is freely available now from this link.
To stay updated on further developments of the USCRN, follow NCDC on Twitter: @NOAANCDC
Some of the equipment on the UMass Kilimanjaro weather station is compatible with that of the U.S. Climate Reference Network (USCRN), which NOAA's National Climatic Data Center (NCDC) began 10 years ago. We chose to incorporate elements of their system at our site as a result of the extensive testing and characterization they carried out. A nice overview of all USCRN aspects and prospects is contained in the Early Online Release of a paper titled "U.S. Climate Reference Network after One Decade of Operations: Status and Assessment." The paper will appear in a future issue of the Bulletin of the American Meteorological Society, and is freely available now from this link.
To stay updated on further developments of the USCRN, follow NCDC on Twitter: @NOAANCDC
Tuesday, November 13, 2012
Media communication: no margin for error
Yesterday, the website Live Science - a "trusted and provocative source for highly accessible science... news" - re-published scrambled elements of a NASA Earth Observatory article about Kilimanjaro glaciers. The result is anything but trustworthy, and provocative only in the sense that the information is confusing and only partially accurate. How did this happen?
The story begins innocently enough. Kimberly Casey from NASA Goddard Space Flight Center collaborated on recent Kilimanjaro fieldwork. We all enjoyed having her along, she adapted well to the altitude and proved physically strong, and at the summit she independently undertook a number of different measurements. Once back at Goddard, she took the initiative to request a new NASA EO-1 image of the mountain, which was acquired with perfect timing (see previous blog entry). With such a cool image, the Earth Observatory office reached out to her about featuring it as an Image of the Day. Great!
The EO article took shape over a couple days last week. Kimberly was provided with considerable information regarding what I, as project PI, felt was most important and valuable about the new satellite image, and this material was passed along to EO editors. Following one opportunity to review a draft, the article then went live: Kilimanjaro's Shrinking Ice Fields.
To the credit of EO, the image provides a timely update on Kilimanjaro ice retreat. The text is interesting, and more-or-less consistent with published understandings. However, the article missed an opportunity to present evidence for recent and important changes in the pattern of ice extent, which we provided. Instead, the piece closes with an observation that the Northern Ice Field has (finally) divided into 2 parts -- a process underway since sometime between 1976 and 1989, and of no physical significance.
In summary, the concluding emphasis of the EO article is not what us as scientists felt was most noteworthy, but is instead an easy-to-grasp bit of trivia.
In the first 5 days, the article has had over 20,000 views. As a NASA product, the EO website has considerable credibility and deservedly so; EO images provide fascinating, timely glimpses of our dynamic planet.
Enter Live Science, a brand of the TechMediaNetwork. With a monthly visitation of 5.3 million and 250,000 FaceBook likes, one might expect the company to insure that their content is accurate and helpful. Apparently not though, for this new story is chock-full of mistakes and confusion. Indeed, the article mentions glaciers that do not even exist!
Most distressing about such over-simplified blurbs by Popular Media is that they confuse the public, while undermining the credibility of hard-working scientists eager to get their results disseminated accurately. In this case, with their large readership and the iconic status of Kilimanjaro, statements such as "The major cause of the ice loss is a matter of debate" are sure to fan the flames of climate-change denialism and obscure what we've learned about Kilimanjaro's glaciers in the past decade of observations, measurements and modeling. No, the proximal causes of ice loss on Kilimanjaro are not still in dispute; lack of snowfall is the problem!
For scientists, the message here is to insist that journalists get the details and the emphasis of your original story exactly correct. Thereafter, expect any errors, omissions, or ambiguities to propagate.
Anyone wishing to read an overview on Kilimanjaro glaciers can start here, and for a synopsis of a decade's worth of research this document will be essential; within it are all the references needed to better understand the processes and uncertainties.
- Doug Hardy
The story begins innocently enough. Kimberly Casey from NASA Goddard Space Flight Center collaborated on recent Kilimanjaro fieldwork. We all enjoyed having her along, she adapted well to the altitude and proved physically strong, and at the summit she independently undertook a number of different measurements. Once back at Goddard, she took the initiative to request a new NASA EO-1 image of the mountain, which was acquired with perfect timing (see previous blog entry). With such a cool image, the Earth Observatory office reached out to her about featuring it as an Image of the Day. Great!
The EO article took shape over a couple days last week. Kimberly was provided with considerable information regarding what I, as project PI, felt was most important and valuable about the new satellite image, and this material was passed along to EO editors. Following one opportunity to review a draft, the article then went live: Kilimanjaro's Shrinking Ice Fields.
To the credit of EO, the image provides a timely update on Kilimanjaro ice retreat. The text is interesting, and more-or-less consistent with published understandings. However, the article missed an opportunity to present evidence for recent and important changes in the pattern of ice extent, which we provided. Instead, the piece closes with an observation that the Northern Ice Field has (finally) divided into 2 parts -- a process underway since sometime between 1976 and 1989, and of no physical significance.
In summary, the concluding emphasis of the EO article is not what us as scientists felt was most noteworthy, but is instead an easy-to-grasp bit of trivia.
In the first 5 days, the article has had over 20,000 views. As a NASA product, the EO website has considerable credibility and deservedly so; EO images provide fascinating, timely glimpses of our dynamic planet.
Enter Live Science, a brand of the TechMediaNetwork. With a monthly visitation of 5.3 million and 250,000 FaceBook likes, one might expect the company to insure that their content is accurate and helpful. Apparently not though, for this new story is chock-full of mistakes and confusion. Indeed, the article mentions glaciers that do not even exist!
Most distressing about such over-simplified blurbs by Popular Media is that they confuse the public, while undermining the credibility of hard-working scientists eager to get their results disseminated accurately. In this case, with their large readership and the iconic status of Kilimanjaro, statements such as "The major cause of the ice loss is a matter of debate" are sure to fan the flames of climate-change denialism and obscure what we've learned about Kilimanjaro's glaciers in the past decade of observations, measurements and modeling. No, the proximal causes of ice loss on Kilimanjaro are not still in dispute; lack of snowfall is the problem!
For scientists, the message here is to insist that journalists get the details and the emphasis of your original story exactly correct. Thereafter, expect any errors, omissions, or ambiguities to propagate.
Anyone wishing to read an overview on Kilimanjaro glaciers can start here, and for a synopsis of a decade's worth of research this document will be essential; within it are all the references needed to better understand the processes and uncertainties.
- Doug Hardy
Thursday, November 8, 2012
Glacier images - September 2012
Two additional GigaPans are also now posted. One provides a perspective on the Kersten Glacier upper margin, which is the view climbers to Uhuru Peak are most familiar with. The other is a wide-angle view of the Reusch Crater. These compliment 2012 GigaPans of the Furtwängler Glacier and Northern Ice Field.
In conjunction with these glacier images, have a look at a valuable new satellite image of the mountain. This was acquired by the Advanced Land Imager (ALI) on the EO-1 mission, just 4 weeks after our fieldwork, at the request of NASA collaborator Kimberly Casey. The timing of this acquisition is quite fortuitous, showing less seasonal snow present than during our fieldwork, yet prior to an early-November snowfall event as the Short Rains got underway.
Previous Earth Observatory stories illustrate patterns of decreasing ice extent, and this latest image reveals that the most dramatic changes are occurring on the south side. Compare, for example, this new image with the 2004 ISS image provided by EO here. Although the Northern Ice Field split has been underway since the 1980s, fragmentation of the Southern Ice Field has been most pronounced in the past year or two. Thanks to Kimberly for arranging acquisition of this latest satellite image!
Monday, November 5, 2012
Seasonal change
Kilimanjaro's extended dry season appears to be coming to a close, based on AWS measurements via telemetry. About 20 cm of horizontal glacier surface ablation occurred between the time of our fieldwork visit at the end of September, terminated by a couple days of snowfall on 11 and 12 October. This event brought ~6 cm of accumulation; after mid-October there was essentially no change in the surface height.
The monthly mean weather for October is available here. As expected going into November, mean air temperature is increasing, along with humidity. A snowfall event during the first few days of November suggests that the short rains will be underway soon.
The monthly mean weather for October is available here. As expected going into November, mean air temperature is increasing, along with humidity. A snowfall event during the first few days of November suggests that the short rains will be underway soon.
Friday, October 26, 2012
AWS fieldwork images
Additional fieldwork images will be posted soon. Credit for above photo: K. Casey, NASA
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