[GLIMS] Fwd: Glacier Mass Balance project
FUJITA, Koji
cozy at nagoya-u.jp
Wed Oct 12 00:13:17 MDT 2011
Dear Wendell and others,
Although I sent AA profiles of Nepalese glaciers to Wendell directly,
please mail me if somebody wants the data, which are used in a recent
paper (1).
I here put some comments.
It seems interesting idea commented by Roger, model comparison and/or
comparison of different meteorological inputs. However Wendell's focus
may be different from Roger's one. Anyhow, in my opinion, it does not
matter which model we use for mass balance of debris-free/ordinary
glaciers whereas it matters how we estimate precise (or plausible)
meteorological inputs. With respect to Himalayan glaciers, in turn, use
of Kathmandu data is NOT good idea because of urban effect (2). Without
precise/plausible meteorological inputs, we could not discuss optimized
parameters and/or their regional differences. Simple downscaling of
reanalysis global data seems to work well if observed data available
(3). Although a sophisticated approach is also important to discuss
cause of changing glaciers (4), I'm not sure whether such dynamic
downscaling gives realistic inputs over complicated terrain such as the
Himalayas. In any cases, observational data for validation is important.
As Adina commented, debris-covered glaciers require another approach.
Temperature index models cannot deal debris-covered glacier. Of course
we can optimize melt of ice beneath debris mantle even in temperature
index model but it is not based on physical processes. An idea of
'thermal resistance' is remotely sensed obtainable, simplified but
physically based approach to estimate debris thermal property and its
distribution (5). We recently show how this approach works well for a
debris-covered in the southeastern Tibet (6).
Regards,
Koji
(1) Fujita K, Nuimura T (2011) Spatially heterogeneous wastage of
Himalayan glaciers. PNAS, 108(34), 14011-14014.
http://www.pnas.org/content/108/34/14011
(2) Fujita K, Thompson LG, Ageta Y, Yasunari T, Kajikawa Y, Sakai A,
Takeuchi N (2006) Thirty-year history of glacier melting in the Nepal
Himalayas. JGR, 111, D03109.
http://www.agu.org/pubs/crossref/2006/2005JD005894.shtml
(3) Fujita K, Takeuchi N, Nikitin SA, Surazakov AB, Okamoto S, Aizen VB,
Kubota J (2011) Favorable climatic regime for maintaining the
present-day geometry of the Gregoriev Glacier, Inner Tien Shan.
The Cryosphere, 5(3), 539-549.
http://www.the-cryosphere.net/5/539/2011/tc-5-539-2011.html
(4) Mölg T, Kaser G (2011) A new approach to resolving
climate-cryosphere relations: Downscaling climate dynamics to
glacier-scale mass and energy balance without statistical scale linking.
J Geophys Res, 116, D16101.
http://www.agu.org/pubs/crossref/2011/2011JD015669.shtml
(5) Suzuki R, Fujita K, Ageta Y (2007) Spatial distribution of thermal
properties on debris-covered glaciers in the Himalayas derived from
ASTER data. Bull Glaciol Res, 24, 13-22.
http://www.seppyo.org/bgr/pdf/24/BGR24p13.pdf
(6) Zhang Y, Fujita K, Liu SY, Liu Q, Nuimura T (in press) Distribution
of debris thickness and its effect on ice melt at Hailuogou Glacier,
south-eastern Tibetan Plateau, using in situ surveys and ASTER imagery.
J Glaciol.
wendell Tangborn wrote (2011/09/18 11:59):
> To: Koji Fujita, Nagoya University
>
> From: Wendell Tangborn, HyMet Company
> Subject Glacier Mass Balance Project
>
>
> I am seeking collaborators and financial support for a project to calculate
> the historical and current mass balances of a small but statistically
> significant sample (about 0.12%) of the world’s 160,000 glaciers. Glaciers
> that have records of annual mass balance measurements are especially
> important to include in this study so that comparisons can be made with
> simulated annual balances. We would also like to include as many Himalayan
> glaciers as possible.
>
>
>
> * Project Purpose*
>
>
>
> The purpose of this project is to understand the cause of the rapid and
> unprecedented decline of the world’s glaciers during the past 3-5 decades,
> and determine if or how these losses are related to global climate change.
> It is incomprehensible that the public has not been more alarmed by the
> shrinkage and recent demise of so many glaciers, most of which have been in
> existence for 100,000 years or more. This project may at least increase an
> awareness that many of the earth’s glaciers may soon disappear.
>
>
>
> *Technical Approach*
>
>
>
> The PTAA (precipitation-temperature-area-altitude) glacier mass balance
> model that I developed will be used to accomplish the projects goals. This
> model uses only easily available daily temperature and precipitation
> observations at mostly low-altitude weather stations, plus the glacier’s
> area-altitude distribution. Both of these variables are inexpensive to
> acquire and readily available for many of the world’s glaciers. A unique
> feature of the model is its use of the glacier's surface configuration
> (area-altitude distribution) that has the glacier's climate history embedded
> in it.
>
>
> The PTAA model has been successfully applied to several dozen glaciers in
> Alaska and the Pacific NW, and was also tested on one glacier in the
> Himalayas. Several peer-reviewed scientific papers and three MS thesis that
> are based on the PTAA model have been published and can be viewed at:
> http://glacierchange.org/2011/06/the
> ptaa-glacier-mass-balance-model/<http://glacierchange.org/2011/06/the%20ptaa-glacier-mass-balance-model/>
>
> The PTAA FORTRAN program and all auxiliary programs will be turned over to
> the organization or group that agrees to manage and support this
> project. HyMet
> will be available to assist in setting up and running the model and other
> programs.
>
> Initial tasks
>
>
>
> 1. Select approximately 200 glaciers (5-10 for each mountain range) on
> the basis of available DEM data and proximity to long-term (50-60 years)
> weather stations
> 2. Tabulate area-altitude distribution from the DEM for each glacier
> 3. Collect daily temperature and precipitation observations at 2-3
> weather stations for each glacier located 300 km or less from the glacier.
> There will likely be some overlap so that one weather station will be
> tested for several glaciers.
> 4. Reconstruct missed observations of weather data using HyMet programs
> designed for this purpose
> 5. Revise PTAA computer program to incorporate all selected glaciers, AA
> profiles and associated weather data
>
> Project Goals
>
>
>
> 1. Calibrate the PTAA model for each glacier to find the minimum
> calibration error and optimum values for the mass balance coefficients
> 2. Apply the optimum coefficients to produce daily mass balance results
> for the period of record to determine average snow accumulation, snow and
> ice ablation, mass balance and runoff as a function of altitude, equilibrium
> line elevations, daily lapse rates, historical annual balances and other
> variables for the period of record (50-60 years). Tabulate and organize all
> calculated variables into files.
> 3. Relate historical mass balances to global temperature anomalies of
> maximum and minimum temperatures compiled by the Hadley Climate Center, and
> to the changes in concentration of atmospheric carbon dioxide measured at
> Mauna Loa to determine the cause of the recent and widespread glacier
> decline.
> 4. Develop a simplified, dynamic glacier model using the mass balance
> results thatl demonstrates how the climate, glacier mass balance, glacier
> surface configuration (AA profiles), glacier flow and bed erosion are
> interrelated.
>
> *The final product of the Glacier Mass Balance project will be a detailed
> accounting of most of the daily variables that produce a glacier's mass
> balance, a task that would require a dozen glaciologists to do manually in
> the field for a single glacier for one year. We are planning to do this for
> 200 glaciers for 50-60 years and will continue a mass balance measurement
> program into the future..
> *
> *Questions we will attempt to answer based on PTAA model results
> for 200 glaciers.*
>
> *
> *1. What are the physical mechanisms that link the historical climate,
> glacier bed erosion, a glacier’s surface configuration (AA profile), the
> current weather and a glacier’s mass balance?
> 2. How do these mechanisms change with time and what are their
> implications for climate change?
> 3. How has the correlation between the annual mass balances of
> two-hundred glaciers changed with time?
> 4. The south-facing glaciers in the Wrangell Range in Alaska have an
> ablation rate 3 times greater than the north-facing glaciers. How does the
> model determine this without glacier orientation being used in the model?
> 5. Can debris-cover thickness be estimated from the difference in mass
> balance between debris-covered and clean glaciers?
>
> 6. Are Himalayan glaciers loing mass more rapidly than other glaciers?
> 7. What is the relationship between global temperature anomalies
> collected by the Hadley Climate Center and glacier mass balances?
> 8. What is the relationship between changes in the concentration of
> atmospheric carbon dioxide and glacier mass balances?
> 9. How does glacier altitude, latitude and size influence the average
> mass balance?
>
> 10. What is the relationship between global heat waves in 2003, 2007 and
> 2010 and glacier mass balances?
>
>
> *Estimated time and labor to complete*
>
> * *
>
> Two or three experienced people working full time could complete the Initial
> Tasks in 10-12 months. The tasks identified in the Project Goals would also
> require another 10-12 months without number 4, which could need another year
> or more.
>
> *Koji,*
> **
> *Would it be possible to get the area-altitude distributions for these three
> glaciers? Are there other weather stations in Nepal (besides Kathmandu)
> with records of historical meteorological observations?*
>
> *Your recently published paper in PNAS is very interesting and timely.*
> **
> *Regards*
> **
> *Wendell*
> **
> Wendell Tangborn
> HyMet
> 13629 Burma Rd SW
> Vashon Island, WA 98070
> 206 567 4077
> hymet01 at gmail.com
> www.hymet.com
>
--
Koji Fujita
cozy at nagoya-u.jp
http://www.cryoscience.net/
Associate Professor
Graduate School of Environmental Studies, Nagoya University
F3-1(200), Chikusa-ku, Nagoya 464-8601, Japan
c/o Hydrospheric-Atmospheric Research Center 403
+81-52-789-3479:phone
+81-52-789-3436:fax
藤田耕史
名古屋大学・大学院環境学研究科・准教授
〒464-8601 名古屋市千種区不老町F3-1(200)
地球水循環研究センター403
052-789-3479:phone
052-789-3436:fax
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