GLIMS Update-GLIMS Miniworkshop and more

[Jeff Kargel]

Dear GLIMS colleagues and associates:

 
This GLIMS Update contains three major items:

1. New Zealand workshop reminder (note required abstract & registration).

2. New GLIMS publication, Remote Sensing of Environment.

3. GLIMS Tucson Miniworkshop summary, including an update on GLACE 2 (second
round-robin experiment) and further notes on required participation.

===============================================================
1. NEW ZEALAND WORKSHOP

We remind GLIMS participants and other interested colleagues about the next
major GLIMS workshop, to be held in New Zealand in February, 2006, with an
optional field trip to nearby glaciers of Mt. Cook. Abstracts and
registration are required by 30 November, 2005.  For the Second Announcement
and registration and abstract preparation/submission details, see:
http://www.geog.canterbury.ac.nz/research/antarctic/.

 

2. RSE paper (Kargel et al.)

A publication on selected science results of the GLIMS project is in press
with Remote Sensing of Environment (J.S. Kargel and 16 other GLIMS authors).
Those having ScienceDirect subscriptions can access the in-press article at:
http://authors.elsevier.com/sd/article/S0034425705002154

Lacking a subscription, only the abstract is available, but a pdf can be
sent upon request to Jeff Kargel.  The article will be made available also
on the GLIMS website upon the next website update;
http://www.glims.org/MapsAndDocs/ then "Technical Publications."

 

3. GLIMS MINIWORKSHOP SUMMARY

A GLIMS Miniworkshop was held 24-25 October at the University of Arizona,
Tucson.  Emphasized Alaskan glacier science, organization of an Alaska
Regional Center, and the GLACE II "round robin" experiment.


ATTENDEES:
  Armstrong, Richard
  Casey, Kimberly
  Dyurgerov, Mark
  Geissler, Paul
  Helm, Chris
  Khalsa, Siri Jodha Singh
  Kargel, Jeff
  Larsen, Chris
  Lee, Ella
  Molnia, Bruce
  Raup, Bruce
  Sneed, Bill
  Soltesz, Deborah

 
SCIENCE TALKS were given by:

Bruce Molnia (Alaskan glacier changes)

  - Showed numerous examples of ground and air photos indicating changing
    glaciers.
  
  - Mostly retreat over the last century, but some advancing glaciers.

  - Thinning below 1500 m elevation; no change or thickening above.

  - There were 100 tidewater glaciers 100 years ago; fewer than 40 now

  - The stagnant ice on Bering Glacier supports 100-year-old trees

Mark Dyurgerov (observations of the global glacier system)
  - Showed annual time series for mass balance of several regions in the
    world.  For some regions, he filled in time series values based on
    other regions. 
 
  - Some regions showed marked, abrupt changes in glacier mass balance
    trends starting exactly in 1988; other regions showed similar abrupt
    changes starting in the 1970's, 1980's, or 1990's.

  - Abrupt change in slope of mass balance vs time is a global phenomenon,
    but the event or onset of new slope occurred at different times in
    different regions.
 
  - Showed a temperature plot (latitude versus time) that showed:

        - 1988: clear shift to warmer global temps

        - 1991 (June): Pinatubo temporary cooling

        - 1993 on:  strong global warming

 
Kimberley Casey (working with Dorothy Hall, on SW Alaskan glaciers)

  - Working on glacier mapping in the national parks of the Kenai Peninsula
    and other parts of south-central and southwestern Alaska.

  - Between 1986 and 2002, there was a 3.62% decrease in glacier area in
    Katmai  National Park.
  

 
Bill Sneed (working with Gordon Hamilton, on Svalbard glaciers)

  - Showed about 8 snapshots of glacier front positions in Svalbard.
    (Though these are not closed polygons, it would be good to store this
    kind of information in GLIMS.)
 
  - Showed some maps of glacier surface flow-speed change occurring between
    two periods of glacier flow speed mapping.

 
Jeff Kargel (various topics)

  - ASTER coverage in Alaska (huge improvement over a year ago)

  - Glacier classification with some successful sample results applied to
    glaciers and glacier lakes

  - Model description explaining why classifiers do poorly in mapping
    Alaskan glacier lakes (high sediment input)

  - Collaborations with climate modelers

  - Outlined a climate explanation for glacier response complexity

 

Chris Larsen (elevation changes in Alaska from DEM comparisons)

  - Thickness changes between ~1941-to-1961 and SRTM (2000).  In Juneau
    Icefield, almost all glaciers have thinned, except Taku, which shows
    marked thickening over the entire glacier area.  Other thickening
    glaciers are highly localized and are concentrated geographically within
    the region.
        -- In regions that have shown thickening:  0.8 km^3 per year
        -- In regions that have shown thinning:  -11.7 km^3 per year

  - Variability is due to (1) special glacier dynamics of calving glaciers
    (tidewater and lacustrine), including processes involving calving and
    floating tongues, and (2) varying hypsometry.

  - Taku glacier's anomalous behavior is thought to be due to an old
    tidewater calving event, which drew down ice over the entire glacier,
    and now it is building up again.

 

Bill Manley (talk given in his absence by Molnia, on Alaska Range glaciers)

  - Looked at glacier changes in the central/eastern Alaska range as a
    function of various parameters, such as mean elevation, aspect, etc.

 

TECHNOLOGY UPDATES were given by:

 
Ella Lee (working w/Kargel on spectral classification of glaciers and lakes)

  - Described two algorithms based on bands 1 + 3 and bands 1 and band 3/4
    ratios designed to classify images using low quality, saturated images.

  - Gave sample output in a difficult region of Alaska where the
    classification has mixed results (as a contrast to Kargel's examples
    elsewhere that gave good results).

 
Paul Geissler (spectral classification in Alaska)

  - Did multispectral classification.  Identified misclassified parts,
    marked them as "unclassified", then filled these regions using a mode
    filter. 

  - Indicated a new direction for USGS classifier development.

 
Deborah Soltesz (GLIMSView)

  - Described some recent upgrades

  - Outlined future development work (debugging, addition of analysis
    modules, Š)

 

Bruce Raup (GLIMS Glacier Database and Web interface to it)

 
Chris Helm (GLIMS data submissions interface)

 
Siri Jodha Singh Khalsa (GLACE II -- more below)

 

 
GROUP DISCUSSION of strategies for funding an Alaskan Regional Center:

Views seemed to converge on:
   (1) A set of coordinated proposals in response to one of the anticipated
2006 NASA "ROSES" calls. (ROSES due out in January 2006; proposals will be
due later in the year).
   (2) Eventual organization into a coherent regional center consisting of
funded groups. 

Kargel suggests that if the structure/goals of the NASA ROSES announcement
allow, two types of GLIMS/Alaska proposals will be encouraged: (a) science
proposals keyed to a particular subregion or science task; (b) Alaska
regional center leadership.

 

GLACE II

 
On 24 Oct, Siri Jodha Singh Khalsa summarized the design and goals of the
second "Round-robin", or GLACE II (GLIMS Analysis Comparison Experiment),
which was previously announced on the GLIMS mailing list
(http://glims.colorado.edu/glace/).  The following morning, after receiving
a demo and tutorial on GLIMSView from Soltesz, participants used that tool
to manually digitize a small glacier in the GLACE II ASTER image (a glacier
not part of the main GLACE II experiment). They first digitized the
glacier boundaries looking only at the ASTER L1B image in RGB composite.
These results are being compiled as the "GLACE IIA" experiment, which
highlighted the ambiguity of discerning a glacier's edge when topographic
data are lacking.

Also ambiguous, when lacking topographic data, was delineation of the
ice-ice boundaries of adjacent glaciers in the accumulation zone.  Then,
Chris Larsen found the Google Earth representation of that area, and after
seeing the 3-D view, the participants re-digitized the boundaries again
using this new information; those results, which indicated much closer
convergence of glacier outlines, are being compiled as the "GLACE IIB"
experiment.  We discussed the results and their variability, and this
exercise highlighted the need to take advantage of topographic information
wherever possible.  The results of this exercise will be summarized in the
publication of the GLACE experiments, which is planned immediately following
the completion of GLACE II.

A hard deadline for further GLACE II analysis is 31 Dec 2005; a "soft
deadline" (desired, so results can be presented at the ASTER Science Team
meeting in December) is 20 November for those able to make that earlier
deadline.  

The GLIMS team leadership in Tucson and Boulder emphasizes (1) the
importance of completing the GLACE II experiment, and (2) of familiarizing
one's self with GLIMSView or of recent improvements in GLIMSView, which the
workshop participants recognized as a very handy and important tool kit.  We
expect at least one person from each regional center to complete GLACE II.

 
-- Jeff Kargel and Bruce Raup