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Bill and all GLIMSters,<div><br></div><div>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.</div><div><br></div><div>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.)</div><div><br></div><div>--Jeff<br><br>> Date: Sun, 24 May 2009 17:11:34 -0400<br>> From: william.sneedjr@maine.edu<br>> To: gordon.hamilton@maine.edu<br>> CC: jeffreyskargel@hotmail.com; tulaczyk@pmc.ucsc.edu; stearns@ku.edu; glims@flagmail.wr.usgs.gov; michael.j.abrams@jpl.nasa.gov; leon.maldonado@jpl.nasa.gov<br>> Subject: Re: GLIMS ASTER image acquisition planning<br>> <br>> Hi Gordon...welcome back....greetings to all others....<br>> <br>> I've finished looking at the 400 images from 2006. Bounding box for the<br>> search was UL: 83.59N & 38.45W and LR: 74.92N & 15.4W for the dates<br>> 01 June through 25 September.<br>> <br>> --- 266 images were above 80.0N.<br>> --- By my eye, 187 images had 80% or more cloud cover.<br>> --- 29 images were of the ice sheet as opposed to coastal glaciers and<br>> ice caps.<br>> --- 43 or more had heavy to light snow cover (no surprise given the<br>> starting date but they're of limited usefulness to me, anyway).<br>> --- 29 or more have an odd orangy-yellow tint. Non-GLIMS settings?<br>> Radiometric problems?<br>> <br>> Coverage of Peary Land and Kronprins Christian Land glaciers and<br>> ice caps seems pretty good. Sadly, the same can't be said for the large<br>> glaciers to the south. There is one decent image of Nioghalvfjerdsfjorden<br>> from 26 June and two others from mid/late July with considerable clouds<br>> but usable, as we've defined it. No images of Zachariae Isstrom. Two<br>> images of Storstrommen and part of L. Bistrup Brae from mid-June<br>> but with snow cover.<br>> <br>> Bottom line: a literal handful of images for 2006-2008 of these four <br>> large glaciers.<br>> <br>> For the years 2000-2005, my original search was confined to just<br>> Nioghalvfjerdsfjorden. (I should revisit these years to see what's<br>> available for the other three glaciers and the rest of this quadrant.)<br>> <br>> 2000: 4 images<br>> 2001: 2 images<br>> 2003: 11 (!!)<br>> 2004: 4<br>> 2005: 4<br>> <br>> ....see ya Tuesday....bill...<br>> <br>>> Jeff--<br>>><br>>> I am just back from East Greenland, so I am jumping into this discussion<br>>> a bit late. Also, I will be heading back to Greenland in a few weeks, so<br>>> regrettably I will not be at the team meeting in Kyoto. Slawek raises a<br>>> very important point and it needs a thorough discussion.<br>>><br>>> Examining the number of scene acquisitions per year over Greenland (and/or<br>>> Antarctica) is a very crude way of determining the success of ASTER and/or<br>>> GLIMS imaging in these incredibly important parts of the glacierized world.<br>>> Bill just sent me a quick analysis of scene numbers/usability for the last<br>>> few years over selected parts of Greenland. Sure, some years have a lot of<br>>> image acquisitions (e.g., 400 scenes for the NE quadrant of Greenland in<br>>> 2006) but the vast majority of these images are unusable for any kind of<br>>> quantitative analysis, such DEM generation, velocity mapping, melt pond<br>>> depth extraction, or margin mapping (e.g., for the same quadrant in 2006,<br>>> only ~15 images out of the 400 were somewhat usable).<br>>><br>>> A lot of the most important glaciers in Greenland (e.g., Kangerdlugssuaq,<br>>> Helheim) have *no* useable images in recent years (2007, 2008), which means<br>>> we have been unable to use ASTER to track the behavior of some of the key<br>>> glaciers contributing to sea level rise (we have had much better success<br>>> with ALOS data).<br>>><br>>> The same is true for a lot of Antarctica outlet glaciers -- our recent work<br>>> has relied on ALOS acquisitions to maintain data continuity.<br>>><br>>> My own attempts at Greenland STARs have been a total bust. Maybe my requests<br>>> were overrided by the GLIMS STAR?<br>>><br>>> I am not sure I have any good solutions. Going back to the beginnings of<br>>> the GLIMS program, the idea of collecting at least one usable image of each<br>>> glacier on Earth for the ~2000-timeframe has largely been accomplished. A<br>>> lot of these images are ASTER scenes, but the availability of high-resolution<br>>> optical imagery has exploded since the days when the GLIMS idea was hatched,<br>>> so a lot of the scenes are non-ASTER images. My guess is that the existing<br>>> image archive is sufficient for a lot of GLIMS tasks (e.g., mapping changes<br>>> in snow/ice extent) -- the small size of many mid-latitude ice masses<br>>> necessitates the need for a long time record in order to detect change; in<br>>> these cases, annual coverage is not required. The polar regions are <br>>> different.<br>>> The changes are bigger and happening faster, and the consequences have global<br>>> implications. A lot of the really cool and high-profile science done by ASTER<br>>> has been in Greenland and Antarctica (I'm trying not to be biased here!), but<br>>> we have really been struggling to keep that science going with the current<br>>> acquisition plan.<br>>><br>>> Maybe we need to critically review the GLIMS objectives, see if the current<br>>> image archive (be it ASTER or any other easily-available high-resolution<br>>> imagery) is sufficient to meet that objective (and see where it does not meet<br>>> that objective), then re-assess what key science questions we want to be<br>>> trying to answer. The GLIMS idea is more than a decade old -- science has<br>>> evolved, and maybe other glaciological questions provide a better use of the<br>>> finite ASTER resource. Maybe not, but I think we need to take a close look<br>>> to be sure.<br>>><br>>> Okay, a long message, but I just wanted to echo Slawek's concerns.<br>>><br>>> -gordon<br>>><br>>><br>>><br>>> Quoting Jeffrey Kargel <jeffreyskargel@hotmail.com>:<br>>>><br>>>> Slawek,<br>>>> I offer this letter as an open message to the GLIMS community <br>>>> (responding to your message below) in a bid to enlist the GLIMS <br>>>> community's further help in evaluating the successes and failures <br>>>> of the GLIMS STAR in the Southern Hemisphere in 2009, with <br>>>> recognition that what elapsed there (successes and failures) is <br>>>> apt to be a model of what will happen this year in the Northern <br>>>> Hemisphere over the next few months. This is needed, while also <br>>>> recognizing that we need good Greenland coverage, as you are <br>>>> shooting for. Perhaps what we need is a one-year Greenland DAR <br>>>> that supplements the coverage expected from the GLIMS STAR by <br>>>> targeting possibly one-fifth of the Greenland coastline for <br>>>> multiple repeat imaging (that's in addition to the current plan to <br>>>> get one image on average of each part of the coastline over the <br>>>> course of the summer). I would need to know what one-fifth to <br>>>> cover with greater frequency, and then we could see how this idea <br>>>> fares with ASTER MIssion Operations.<br>>>> So far as what has actually been achieved for GLIMS STARs of <br>>>> non-Greenland/non-Antarctic glaciers, I can say we're still <br>>>> suffering. I don't know what it is, but there just seems to be a <br>>>> very minimum priority given to GLIMS, or there's some technical <br>>>> reason (the "exclusion zones" or whatever) that makes certain areas <br>>>> very difficult to image. There are lots of images of glaciers <br>>>> from 2008-2009, but the majority are global map or other images <br>>>> that have saturated snow. (Those work well for debris covered <br>>>> areas, so we don't discount the fact that we have those.) The <br>>>> Southern Hemisphere GLIMS STAR has completed its summer season a <br>>>> couple months ago, and the received images are fairly hit and miss <br>>>> according to a random assessment of a few areas done in Tucson <br>>>> and by some other GLIMS people; some really great images were <br>>>> received in Jan-Feb-Mar 2009, but many areas have had no coverage <br>>>> this year (or were attempted but were clouded out). So I am <br>>>> fairly apprehensive about this summer's northern hemisphere GLIMS <br>>>> STARs.<br>>>> Greenland was one big area where GLIMS was going really well, and <br>>>> of course that was a great thing. I just wish something like the <br>>>> Greenland coverage we had year after year (several received <br>>>> low-cloud scenes of most parts of the coast each year) would happen <br>>>> just once in the lifetime of GLIMS for nonpolar glaciers; or even <br>>>> just one good image per season (with GLIMS gains) of most <br>>>> glaciers would be a great improvement. It just has not been <br>>>> achieved so far in 9 years of ASTER. I realize that we have <br>>>> acquired lots of GLIMS scenes over the life of ASTER, so I am not <br>>>> issuing an all-out complaint, but certainly there remain serious <br>>>> inadequacies. I have not done the analysis to see whether on <br>>>> average the Southern Hemisphere did significantly better in 2009 <br>>>> than in other years under the old STAR. I just know that there <br>>>> are quite a few significant glaciers that were not imaged, and <br>>>> some that were imaged had saturated snow (gains indicative of the <br>>>> global map program).<br>>>> Let me know whether you think the "one-fifth plan" will work <br>>>> acceptably (plus an expected average of one summer image of the <br>>>> other areas under the newly implemented STAR). We will need to do <br>>>> something similar for Antarctica next austral summer.<br>>>> --Jeff<br>>>><br>>>><br>>>>> Date: Wed, 20 May 2009 13:26:45 -0700<br>>>>> Subject: Re: US Mtg agenda<br>>>>> From: tulaczyk@pmc.ucsc.edu<br>>>>> To: Michael.J.Abrams@jpl.nasa.gov<br>>>>> CC: kargel@hwr.arizona.edu<br>>>>><br>>>>> Jeff,<br>>>>><br>>>>> Let's talk about this. If at all possible, I would love to see more<br>>>>> coverage of Greenland/Antarctica without subtracting from your focus<br>>>>> on the smaller glacier systems.<br>>>>><br>>>>> Cheers<br>>>>><br>>>>> Slawek<br>>>>><br>>>>> On 5/20/09, Michael Abrams <Michael.J.Abrams@jpl.nasa.gov> wrote:<br>>>>>> Slawek,<br>>>>>><br>>>>>> Could you also discuss this with Jeff Kargel before the meeting (He is<br>>>>>> not attending). The GLIMS STAR was changed to reduce Greenaland<br>>>>>> coverage. Not sure about antarctica.<br>>>>>><br>>>>>> Michael Abrams<br>>>>>> ASTER Science Team Leader<br>>>>>> Group Supervisor, Land Surface Processes<br>>>>>> NASA/Jet Propulsion Laboratory<br>>>>>> Mail Stop 183-501<br>>>>>> 4800 Oak Grove Dr.<br>>>>>> Pasadena, CA 91109<br>>>>>> 818-354-0937 FAX: 818-354-5148<br>>>>>> michael.j.abrams@jpl.nasa.gov<br>>>>>><br>>>>>><br>>>>>><br>>>>>><br>>>>>> Slawek Tulaczyk wrote:<br>>>>>>> Dear Mike,<br>>>>>>><br>>>>>>> Could we reserve time for a discussion on increased data acquisition<br>>>>>>> over margins of Antarctica and Greenland?<br>>>>>>><br>>>>>>> Cheers<br>>>>>>><br>>>>>>> Slawek<br>>>>>>><br>>>>>>> On Wed, May 20, 2009 at 10:29 AM, Michael Abrams<br>>>>>>> <Michael.J.Abrams@jpl.nasa.gov> wrote:<br>>>>>>><br>>>>>>>> attached is US Team meeting agenda for monday morning. let me <br>>>>>>>> know of any<br>>>>>>>> changes/additions/etc.<br>>>>>>>><br>>>>>>>> mike<br>>>>>>>><br>>>>>>>> --<br>>>>>>>> Michael Abrams<br>>>>>>>> ASTER Science Team Leader<br>>>>>>>> Group Supervisor, Land Surface Processes<br>>>>>>>> NASA/Jet Propulsion Laboratory<br>>>>>>>> Mail Stop 183-501<br>>>>>>>> 4800 Oak Grove Dr.<br>>>>>>>> Pasadena, CA 91109<br>>>>>>>> 818-354-0937 FAX: 818-354-5148<br>>>>>>>> michael.j.abrams@jpl.nasa.gov<br>>>>>>>><br>>>>>>>><br>>>>>>>><br>>>>>>>><br>>>>>>><br>>>>>>><br>>>>>>><br>>>>>>><br>>>>>><br>>>>><br>>>>><br>>>>> --<br>>>>> Professor Slawek Tulaczyk, Ph.D.<br>>>>> Department of Earth and Planetary Sciences<br>>>>> University of California, Santa Cruz, CA 95064, USA<br>>>>> phone: 831-459-5207, fax: 831-459-3074, tulaczyk@pmc.ucsc.edu<br>>>><br>>>> _________________________________________________________________<br>>>> Hotmail® has ever-growing storage! Don’t worry about storage limits.<br>>>> http://windowslive.com/Tutorial/Hotmail/Storage?ocid=TXT_TAGLM_WL_HM_Tutorial_Storage1_052009<br>>><br>>><br>>><br>>> -- <br>>> Gordon Hamilton, Assoc. Professor<br>>><br>>> Climate Change Institute<br>>> University of Maine, Orono, ME 04469<br>>><br>>> gordon.hamilton@maine.edu<br>>> 207-581-3446 (ph/voicemail)<br>>> 207-581-1203 (fax)<br>> <br>> <br>> <br>> -- <br>> william a. sneed<br>> climate change institute<br>> university of maine, orono, ME, 04469 USA<br>> 207-581-1491<br>> william.sneedjr@maine.edu<br></div><br /><hr />Hotmail® goes with you. <a href='http://windowslive.com/Tutorial/Hotmail/Mobile?ocid=TXT_TAGLM_WL_HM_Tutorial_Mobile1_052009' target='_new'>Get it on your BlackBerry or iPhone.</a></body>
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