GLIMS Update: GLIMS ASTER image coverage and research documentation
Jeffrey Kargel
jeffreyskargel at hotmail.com
Sun May 24 11:14:32 MDT 2009
Dear Gordon and all GLIMS participants,
Possibly a constructive way to go forward is to reissue a call for RC's to assess image acquisitions (good-quality scenes, low clouds); Gordon Hamilton and some others have been active in this activity in the past for the GLIMS project. For those who reported last year on this, you can either revise/update your stats, or not; I still have what you sent. For those who have never submitted such stats, you really should. It's for your benefit and that of GLIMS as a whole. We don't need thorough stats for all of a big RC, such as all of Greenland, but a representative selection would be good (not "cherry-picked" to achieve a desired statement of success or failure, but representative).
One way to go forward with nonpolar areas, which I have resisted til now, is to prioritize acquisitions according to what is actively being worked by GLIMS people, with glacier outlines being submitted or active work taking place that will result in GLIMS database entries. This has been a recurrent idea discussed, and always rejected, and I still resist the idea. The reason to resist it is, as many people have noted, there is a fundamental value in the glacier image archive, which will be used and is needed as part of the global satellite record ca. 2000. Until we have a complete archive with two-times repeat ASTER coverage (and one time for some glaciers), I cannot support the idea of prioritizing according to areas with active research. However, GLIMS participants might take this message as encouragement to become activists about pressing for improved image coverage. I have taken the JPL Mission Operations people off this email list to spare them the details of every message. But what I would like is for every GLIMS RC and highly active steward to send me a message telling me about ASTER's imaging success and failures (with stats), whether you're using ASTER imagery; and of course send Bruce Raup your glacier outlines, even for just some of your region. (They can be added to later.) Send me more paper titles and abstracts.
There is an ASTER Science Team meeting in Tokyo in a couple weeks, so info received before then will be more effective in assisting GLIMS than info received afterward; but any time, just send it.
Cheers,
Jeff Kargel
> Date: Sun, 24 May 2009 11:40:39 -0400
> From: gordon.hamilton at maine.edu
> To: jeffreyskargel at hotmail.com
> CC: tulaczyk at pmc.ucsc.edu; william.sneedjr at maine.edu; stearns at ku.edu; glims at flagmail.wr.usgs.gov; michael.j.abrams at jpl.nasa.gov; leon.maldonado at jpl.nasa.gov
> Subject: Re: GLIMS ASTER image acquisition planning
>
> Jeff--
>
> I am just back from East Greenland, so I am jumping into this discussion
> a bit late. Also, I will be heading back to Greenland in a few weeks, so
> regrettably I will not be at the team meeting in Kyoto. Slawek raises a
> very important point and it needs a thorough discussion.
>
> Examining the number of scene acquisitions per year over Greenland (and/or
> Antarctica) is a very crude way of determining the success of ASTER and/or
> GLIMS imaging in these incredibly important parts of the glacierized world.
> Bill just sent me a quick analysis of scene numbers/usability for the last
> few years over selected parts of Greenland. Sure, some years have a lot of
> image acquisitions (e.g., 400 scenes for the NE quadrant of Greenland in
> 2006) but the vast majority of these images are unusable for any kind of
> quantitative analysis, such DEM generation, velocity mapping, melt pond
> depth extraction, or margin mapping (e.g., for the same quadrant in 2006,
> only ~15 images out of the 400 were somewhat usable).
>
> A lot of the most important glaciers in Greenland (e.g., Kangerdlugssuaq,
> Helheim) have *no* useable images in recent years (2007, 2008), which means
> we have been unable to use ASTER to track the behavior of some of the key
> glaciers contributing to sea level rise (we have had much better success
> with ALOS data).
>
> The same is true for a lot of Antarctica outlet glaciers -- our recent work
> has relied on ALOS acquisitions to maintain data continuity.
>
> My own attempts at Greenland STARs have been a total bust. Maybe my requests
> were overrided by the GLIMS STAR?
>
> I am not sure I have any good solutions. Going back to the beginnings of
> the GLIMS program, the idea of collecting at least one usable image of each
> glacier on Earth for the ~2000-timeframe has largely been accomplished. A
> lot of these images are ASTER scenes, but the availability of high-resolution
> optical imagery has exploded since the days when the GLIMS idea was hatched,
> so a lot of the scenes are non-ASTER images. My guess is that the existing
> image archive is sufficient for a lot of GLIMS tasks (e.g., mapping changes
> in snow/ice extent) -- the small size of many mid-latitude ice masses
> necessitates the need for a long time record in order to detect change; in
> these cases, annual coverage is not required. The polar regions are different.
> The changes are bigger and happening faster, and the consequences have global
> implications. A lot of the really cool and high-profile science done by ASTER
> has been in Greenland and Antarctica (I'm trying not to be biased here!), but
> we have really been struggling to keep that science going with the current
> acquisition plan.
>
> Maybe we need to critically review the GLIMS objectives, see if the current
> image archive (be it ASTER or any other easily-available high-resolution
> imagery) is sufficient to meet that objective (and see where it does not meet
> that objective), then re-assess what key science questions we want to be
> trying to answer. The GLIMS idea is more than a decade old -- science has
> evolved, and maybe other glaciological questions provide a better use of the
> finite ASTER resource. Maybe not, but I think we need to take a close look
> to be sure.
>
> Okay, a long message, but I just wanted to echo Slawek's concerns.
>
> -gordon
>
>
>
> Quoting Jeffrey Kargel <jeffreyskargel at hotmail.com>:
>>
>> Slawek,
>> I offer this letter as an open message to the GLIMS community
>> (responding to your message below) in a bid to enlist the GLIMS
>> community's further help in evaluating the successes and failures of
>> the GLIMS STAR in the Southern Hemisphere in 2009, with recognition
>> that what elapsed there (successes and failures) is apt to be a
>> model of what will happen this year in the Northern Hemisphere over
>> the next few months. This is needed, while also recognizing that we
>> need good Greenland coverage, as you are shooting for. Perhaps
>> what we need is a one-year Greenland DAR that supplements the
>> coverage expected from the GLIMS STAR by targeting possibly
>> one-fifth of the Greenland coastline for multiple repeat imaging
>> (that's in addition to the current plan to get one image on average
>> of each part of the coastline over the course of the summer). I
>> would need to know what one-fifth to cover with greater frequency,
>> and then we could see how this idea fares with ASTER MIssion
>> Operations.
>> So far as what has actually been achieved for GLIMS STARs of
>> non-Greenland/non-Antarctic glaciers, I can say we're still
>> suffering. I don't know what it is, but there just seems to be a
>> very minimum priority given to GLIMS, or there's some technical
>> reason (the "exclusion zones" or whatever) that makes certain areas
>> very difficult to image. There are lots of images of glaciers from
>> 2008-2009, but the majority are global map or other images that have
>> saturated snow. (Those work well for debris covered areas, so we
>> don't discount the fact that we have those.) The Southern
>> Hemisphere GLIMS STAR has completed its summer season a couple
>> months ago, and the received images are fairly hit and miss
>> according to a random assessment of a few areas done in Tucson and
>> by some other GLIMS people; some really great images were received
>> in Jan-Feb-Mar 2009, but many areas have had no coverage this year
>> (or were attempted but were clouded out). So I am fairly
>> apprehensive about this summer's northern hemisphere GLIMS STARs.
>> Greenland was one big area where GLIMS was going really well, and of
>> course that was a great thing. I just wish something like the
>> Greenland coverage we had year after year (several received
>> low-cloud scenes of most parts of the coast each year) would happen
>> just once in the lifetime of GLIMS for nonpolar glaciers; or even
>> just one good image per season (with GLIMS gains) of most glaciers
>> would be a great improvement. It just has not been achieved so far
>> in 9 years of ASTER. I realize that we have acquired lots of GLIMS
>> scenes over the life of ASTER, so I am not issuing an all-out
>> complaint, but certainly there remain serious inadequacies. I have
>> not done the analysis to see whether on average the Southern
>> Hemisphere did significantly better in 2009 than in other years
>> under the old STAR. I just know that there are quite a few
>> significant glaciers that were not imaged, and some that were imaged
>> had saturated snow (gains indicative of the global map program).
>> Let me know whether you think the "one-fifth plan" will work
>> acceptably (plus an expected average of one summer image of the
>> other areas under the newly implemented STAR). We will need to do
>> something similar for Antarctica next austral summer.
>> --Jeff
>>
>>
>>> Date: Wed, 20 May 2009 13:26:45 -0700
>>> Subject: Re: US Mtg agenda
>>> From: tulaczyk at pmc.ucsc.edu
>>> To: Michael.J.Abrams at jpl.nasa.gov
>>> CC: kargel at hwr.arizona.edu
>>>
>>> Jeff,
>>>
>>> Let's talk about this. If at all possible, I would love to see more
>>> coverage of Greenland/Antarctica without subtracting from your focus
>>> on the smaller glacier systems.
>>>
>>> Cheers
>>>
>>> Slawek
>>>
>>> On 5/20/09, Michael Abrams <Michael.J.Abrams at jpl.nasa.gov> wrote:
>>>> Slawek,
>>>>
>>>> Could you also discuss this with Jeff Kargel before the meeting (He is
>>>> not attending). The GLIMS STAR was changed to reduce Greenaland
>>>> coverage. Not sure about antarctica.
>>>>
>>>> Michael Abrams
>>>> ASTER Science Team Leader
>>>> Group Supervisor, Land Surface Processes
>>>> NASA/Jet Propulsion Laboratory
>>>> Mail Stop 183-501
>>>> 4800 Oak Grove Dr.
>>>> Pasadena, CA 91109
>>>> 818-354-0937 FAX: 818-354-5148
>>>> michael.j.abrams at jpl.nasa.gov
>>>>
>>>>
>>>>
>>>>
>>>> Slawek Tulaczyk wrote:
>>>>> Dear Mike,
>>>>>
>>>>> Could we reserve time for a discussion on increased data acquisition
>>>>> over margins of Antarctica and Greenland?
>>>>>
>>>>> Cheers
>>>>>
>>>>> Slawek
>>>>>
>>>>> On Wed, May 20, 2009 at 10:29 AM, Michael Abrams
>>>>> <Michael.J.Abrams at jpl.nasa.gov> wrote:
>>>>>
>>>>>> attached is US Team meeting agenda for monday morning. let me know of any
>>>>>> changes/additions/etc.
>>>>>>
>>>>>> mike
>>>>>>
>>>>>> --
>>>>>> Michael Abrams
>>>>>> ASTER Science Team Leader
>>>>>> Group Supervisor, Land Surface Processes
>>>>>> NASA/Jet Propulsion Laboratory
>>>>>> Mail Stop 183-501
>>>>>> 4800 Oak Grove Dr.
>>>>>> Pasadena, CA 91109
>>>>>> 818-354-0937 FAX: 818-354-5148
>>>>>> michael.j.abrams at jpl.nasa.gov
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>
>>>
>>>
>>> --
>>> Professor Slawek Tulaczyk, Ph.D.
>>> Department of Earth and Planetary Sciences
>>> University of California, Santa Cruz, CA 95064, USA
>>> phone: 831-459-5207, fax: 831-459-3074, tulaczyk at pmc.ucsc.edu
>>
>> _________________________________________________________________
>> Hotmail® has ever-growing storage! Don’t worry about storage limits.
>> http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage1_052009
>
>
>
> --
> Gordon Hamilton, Assoc. Professor
>
> Climate Change Institute
> University of Maine, Orono, ME 04469
>
> gordon.hamilton at maine.edu
> 207-581-3446 (ph/voicemail)
> 207-581-1203 (fax)
_________________________________________________________________
Hotmail® has a new way to see what's up with your friends.
http://windowslive.com/Tutorial/Hotmail/WhatsNew?ocid=TXT_TAGLM_WL_HM_Tutorial_WhatsNew1_052009
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://nsidc.org/pipermail/glims/attachments/20090524/97987823/attachment.html>
More information about the GLIMS
mailing list