GLIMS ASTER image acquisition planning

Mon May 25 11:22:04 MDT 2009

Bill and all GLIMSters,
Thanks.  Just what we need.  You might consider preparing 1 or 2 or 3 ppt slides summarizing this.  I can take your tabular data and prepare a nice slide, but if you have something that is map or image-based, that would be good to supplement the numbers.
I'd like to present this at an ASTER STAR Committee meeting in a couple weeks.  (I won't be at the meeting, but I'll give a presentation to Mike Abrams to present for us.)
--Jeff

> Date: Sun, 24 May 2009 17:11:34 -0400
> From: william.sneedjr at maine.edu
> To: gordon.hamilton at maine.edu
> CC: jeffreyskargel at hotmail.com; tulaczyk at pmc.ucsc.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
> 
> Hi Gordon...welcome back....greetings to all others....
> 
> I've finished looking at the 400 images from 2006.  Bounding box for the
> search was UL: 83.59N & 38.45W  and LR: 74.92N & 15.4W for the dates
> 01 June through 25 September.
> 
> --- 266 images were above 80.0N.
> --- By my eye, 187 images had 80% or more cloud cover.
> --- 29 images were of the ice sheet as opposed to coastal glaciers and
>       ice caps.
> --- 43 or more had heavy to light snow cover (no surprise given the
>      starting date but they're of limited usefulness to me, anyway).
> --- 29 or more have an odd orangy-yellow tint. Non-GLIMS settings?
>      Radiometric problems?
> 
> Coverage of Peary Land and Kronprins Christian Land glaciers and
> ice caps seems pretty good. Sadly, the same can't be said for the large
> glaciers to the south. There is one decent image of Nioghalvfjerdsfjorden
> from 26 June and two others from mid/late July with considerable clouds
> but usable, as we've defined it. No images of Zachariae Isstrom.  Two
> images of Storstrommen and part of L. Bistrup Brae from mid-June
> but with snow cover.
> 
> Bottom line: a literal handful of images for 2006-2008 of these four  
> large glaciers.
> 
> For the years 2000-2005, my original search was confined to just
> Nioghalvfjerdsfjorden. (I should revisit these years to see what's
> available for the other three glaciers and the rest of this quadrant.)
> 
> 2000:  4 images
> 2001:  2 images
> 2003:  11 (!!)
> 2004:  4
> 2005:  4
> 
> ....see ya Tuesday....bill...
> 
>> 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
>>>
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>>
>>
>>
>> -- 
>>  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)
> 
> 
> 
> -- 
> william a. sneed
> climate change institute
> university of maine, orono, ME, 04469 USA
> 207-581-1491
> william.sneedjr at maine.edu

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