GLIMS Update: New WG on ASTER Imaging Priorities

Tue Dec 6 04:50:35 MST 2005

Dear Jeff,
I have been working on Baffin Island, Bylot Island initially and now 
looking at the southern regions. I have reported previously on the 
availability of ASTER imagery through Fiona Cawkwell, the RC for Canada, 
but she mentioned that it would be useful to send you information for the 
more recent acquisition.

Twenty-one images with 50% or less cloud cover were acquired between 10 
July and 10 Sept. 2005. Of these, 10 were good, usable images, the rest 
being cloudy over ice. One of these is from the Cumberland Peninsula and 
the remainder from Eastern Baffin Island.

The 2004 picture is summarized below because I think it provides useful 
information about the distribution of ASTER images. It is also typical of 
earlier years. Although a large number of scenes have been acquired, very 
few are clear-sky images with low snow cover (ie. taken between late July 
and early September).  Also, when clouds are present in part of a scene, 
they often cover the ice masses, hence the low number of good summer images.

ASTER 1A Imagery	East Baffin	Cumberland P.	Hall P.	Meta-Incog.P.
2004 (01/06 to 30/9)		161	60	15	7
Cloud Cover 60% or less	47	21 	3 	0
July to early Sept.		21	50	15	0	
Good images 			8	1	0	0
Earliest date of good image	20 July	26 August		

For the period 2000 to 2003, the number of usable images for Eastern Baffin 
Island is 5, for Cumberland Peninsula - 8, Hall Peninsula - 9 and Meta 
Incognita Peninsula - 0.

In summary, we have only 41 good ASTER images for the whole of Baffin 
Island. Any new acquisition used for mass balance purposes should be taken 
between late July and early Sept. I suspect cloud cover will always be a 
problem here.

Hope this helps. Good luck with your meeting.
Cheers,
Evelyn

--On 06 December 2005 03:38 +0000 Jeffrey Kargel 
<jeffreyskargel at hotmail.com> wrote:

> Fiona et al.:
>
> Thanks!  Good to have this kind of info (your msg below).  Thanks, too,
> to many others who have written on this matter.  (Good to know that GLIMS
> Updates actually are read; maybe this last couple days will increase
> readership!)  For those of you at Fall AGU, please remember that there
> will be a miniworkshop tomorrow (Tuesday) at 5:30-9:30 PM at the Hyatt at
> Fisherman's Wharf in the Kargel conference suite.  This issue at hand
> will be discussed.  Please consider staying afterward for refreshments.
>
> Your synopsis suggests that maybe we can leave imaging open for about
> July 10-August 10 for Greenland and get most of what we've been getting
> that is most useful.  The narrower window would reduce the number of
> images but those we get may be better.  If you can suggest other ideas,
> or take it subregion by subregion and suggest imaging windows that way,
> it would help.  But I have a better idea than this quick rush to
> decisions.
>
> We need a working group, "ASTER Himalayan, Alaskan, and Greenland GLacier
> Imaging Negotiations Group" (ASTER HAGGLING), with three teams, one each
> for the Himalaya/central Asia, for Alaska, and Greenland/High Arctic.  It
> doesn't need to be just GLIMS people, as the ASTER imaging is a wider
> community resource.  (This is always true.  We have never yet held a
> closed meeting.) We need solid data on ASTER imaging to date: results,
> failures, coverage, gaps, success-by-month results, success/failure as a
> function of gain settings, coverage by year data, info on other data
> sources, ideas on where we need to be in 3 years.  We need a set of
> users/advocates for that region.  Each teams needs to make a proposal for
> a revised ASTER imaging plan for their team's area; be prepared to haggle
> and winnow it back. I will moderate the whole group.  I need a leader for
> the Alaska team.  Mike Bishop is hereby volunteered for the Himalaya
> team.  I need a team lead for Greenland/High Arctic.  Each team needs
> team members in addition to the leader.  Each team puts their best foot
> forward with the view of increasing image acquisitions for Alaska and the
> Himalaya area, and maintaining imaging for the Greenland/High Arctic
> area.  I anticipate that eventually Greenland and Ellesmere imaging will
> be halved, and that's what I will push for and probably eventually insist
> on (unless ASTER Mission Ops gives us a higher quota.).  But we want that
> half to have improved quality on average.  And the increased Alaska and
> Himalaya region coverage also has to have improved quality over what has
> been acquired.
>
> I suggest that Bruce Raup, David Gaseau, and John Dwyer should assist the
> entire working group as communal resources.
>
> --Jeff K
>
>
>> From: Fiona Cawkwell <fiona.cawkwell at ualberta.ca>
>> To: luke.copland at uottawa.ca
>> CC: msharp at ualberta.ca, jeffreyskargel at hotmail.com,        Jeff
>> Kargel<jkargel1054 at earthlink.net>
>> Subject: Re: GLIMS Update: Global ASTER imaging reprioritization
>> Date: Mon,  5 Dec 2005 12:22:38 -0700
>>
>> Martin, Jeff, Luke
>>
>> Luke's assessment of the northern Ellesmere situation is correct - most
>> of  the
>> imagery available north of about 82.5N is either cloud covered or
>> relatively
>> early in the season (mid-June) when there is still considerable snow
>> cover  on
>> the ground - there is no Landsat coverage this far north so some ASTER
>> imagery
>> is better than nothing, but cloud-free summertime (July) imagery would be
>> better still, so I would certainly not advocate a reduction in image
>> acquisition of this region.
>>
>> As far as the rest of the QEI is concerned - there is one-time clear
>> ASTER coverage of most of the ice, the exception being parts of Devon
>> which are particularly susceptible to cloud cover and also Melville
>> Island (again due  to
>> cloud coverage). However there is very little (less than 10 good images)
>> level
>> 1B imagery available from the summers of 2004 and 2005 making detection
>> of change problematic, and I would certainly echo Luke's comments on the
>> need  for
>> a means of processing these data online or ourselves. I appreciate the
>> huge demand for images from other regions, but with ASTER being the only
>> good source
>> for the  northern polar regions and with a substantial baseline of data
>> from
>> 2000-2002 it would be a shame from a scientific viewpoint if this supply
>> of data were to be curtailed, particularly with the upcoming IPY.
>>
>> Fiona
>>
>>
>>> Hi Jeff & Martin,
>>>
>>> A quick search of the current ASTER database for northern Ellesmere
>>> shows that some images are available, but that many of these are
>>> cloud-covered. Hence the overall coverage is patchy - for example, I
>>> found clear scenes for Yelverton Inlet and Ayles Ice Shelf (western
>>> part of N. Ellesmere), but none for the Ward Hunt Ice Shelf to the east.
>>>
>>> Jeff - ASTER imagery provides a crucial resource for this region as it
>>> is the only available source of high resolution imagery since it is too
>>> far north for Landsat 7.
>>>
>>> Following on from John Dwyer's message, a big help would the ability to
>>> process L1A to L1B ourselves - either via an on-demand online interface,
>>> or via standalone Windows/DOS software. Of the scenes that are
>>> available, most haven't been processed to L1B yet.
>>>
>>> Cheers,
>>> Luke
>>>
>>> --
>>> Dr. Luke Copland
>>> Assistant Professor / Professeur Adjoint
>>> Department of Geography / Département de Géographie
>>> University of Ottawa / Université d'Ottawa
>>> 60 University
>>> Ottawa, Ontario K1N 6N5, Canada
>>>
>>> Tel: +1 613 562 5800 x1056
>>> Fax: +1 613 562 5145
>>>
>>>
>>>
>>
>>
>>
>> --
>> Dr Fiona Cawkwell
>> Post Doctoral Research Fellow
>> Department of Earth and Atmospheric Sciences
>> University of Alberta
>> Edmonton
>> Alberta, T6G 2E3
>>
>> tel. 780 492 7821
>> fax. 780 492 2030
>> fiona.cawkwell at ualberta.ca
>> http://www.ualberta.ca/~cawkwell/fiona_cawkwell.html
>
>

----------------------
EK Dowdeswell, Geographical Sciences
work: E.K.Dowdeswell at bristol.ac.uk
home: J.A.Dowdeswell at blueyonder.co.uk