\log
The initial iteration of this file was provided by Tom Davinroy on 2
February 1994. Minor editorial revisions were made by RCI on that
date as well, and the file was put under sccs control.[RCI 2 February
1994] URL locations for related data were updated on 30 August 2000.[MAH
30 August 2000]
\doc
TITLE. Snowpack ablation in alpine couloirs: Mean data.
ABSTRACT. Lowering of the snowpack surface by ablation (melt) was
measured on a bimonthly basis within couloirs above the Green Lakes
and Isabelle Valleys during the summer months. One-inch diameter PVC
poles were driven into the snowpack to form vertical transects within
each couloir. The height difference (cm) between the top of each pole
and the snow surface was recorded. On the subsequent visit the new
height difference was recorded and the pole driven into the snow and
the reset height was recorded. Poles in a given transect were
relocated as necessary during the course of the season.
INVESTIGATOR. Tom Davinroy, INSTAAR, CB 450, University of Colorado,
Boulder, CO, 80309-0450, (303) 492-4815, tdavinro@culter.colorado.edu.
VARIABLES. ablation rate.
KEYWORDS. ablation rate, meltout, snowdepth, mean ablation, Meteorology and Climatology, hydrology.
LOCATION. Study sites were snow-accumulation zones within alpine
couloirs dissecting the flanks of Niwot Ridge and Kiowa Peak, above the
Green Lakes and Isabelle Valleys. Original data are stored at Research
Laboratory #1 (Room 179).
TIMING. begin 5 August 1992, end 23 September 1993, approximately
bimonthly.
CITATIONS. [1]Davinroy, T.C. 1994. Rates and controls of rock movement
through alpine couloirs, Colorado Front Range. M.S. thesis, University
of Colorado, Boulder. 161 pp.
COMMENTS. Isabelle couloir (I), located on the north side of Niwot
Ridge, 120 m northeast of D-1, descends to a large talus cone east of
Lake Isabelle. Chimney couloir (C), located on the south side of
Niwot Ridge, is the westernmost couloir of a prominent cliff band
immediately above Green Lake 1. Niwot couloir (N) is located on the
south side of Niwot Ridge, immediately above the west end of Green Lake
5. Kiowa couloir (K) is located immediately above the rock glacier on
the north face of Kiowa Peak (above Green Lake 5).
All data refer to vertical lowering of the snowpack surface
(cm or cm/day).
The unreduced data used to calculate these mean data can be found in
http://culter.colorado.edu:1030/exec/.extracttoolA?ablatraw.td
\type
statistical
\header
COL1. label=date (mm/dd/yy), type=string, units=none, missing value
indicator=, minimum=08/14/92, maximum=09/23/93, precision=
COL2. label=Julian date, type=integer, units=none, missing value
indicator=, minimum=, maximum=, precision=1
COL3. label=site, type=string, units=none, missing value indicator=,
minimum=, maximum=, precision=
COL4. label=number of days used for mean ablation calculation,
type=integer, units=days, missing value indicator=, minimum=1, maximum=,
precision=1
COL5. label=number of poles used for mean ablation calculation,
type=integer, units=none, missing value indicator=, minimum=1, maximum=,
precision=1
COL6. label=mean ablation, type=real, units=cm, missing value
indicator=, minimum=0.00, maximum=, precision=5.00
COL7. label=mean ablation rate, type=real, units=cm/day, missing value
indicator=, minimum=0.00, maximum=, precision=1.21
{*********************************************************************
If the data section below contains no data then you will need to
obtain permission from the investigator listed in the documentation
section of this file. If you have obtained permission or if the data
are already contained in this file, include the following
acknowledgment (in addition to an acknowledgment of the investigator)
in any published use of these data: "Logistical support
and/or data were provided by the Niwot Ridge Long-Term Ecological
Research project (NSF DEB 0423662) and the Mountain Research Station
(BIR 9115097)." Please send 4 reprints or high-quality copies of any
such publications to Todd Ackerman, NWT LTER data manager,
INSTAAR, CB 450, University of Colorado, Boulder, CO, 80309-0450.
The data contained in these files have many sources. Generally,
data collected prior to 1993 would have been subjected to quality
control standards imposed by the investigator. Data after 1992
were likely to have been manually entered and/or processed in the
NWT LTER central data management laboratory. Detailed information
on the quality control protocols and programs associated with any
data routed through the NWT LTER data management laboratory will
be supplied upon request. The user of these data should be aware
that, while efforts have been taken to ensure that these data are
of the highest quality, there is no guarantee of perfection for
the data contained herein and the possibility of errors exists.
If you encounter questionable data, please contact the NWT LTER
data manager (todda@culter.colorado.edu; (303) 492-4771) so that
the data can be corrected or qualified. Thus, these data should
be considered dynamic in that past data may be modified and future
data will be appended.
******************************************************************}
\data
08/14/92,227,Niwot,9,5,72.00,8.00
09/04/92,248,Niwot,21,5,78.40,3.73
09/04/92,248,Kiowa,30,4,92.50,3.08
09/05/92,249,Isabelle,18,5,82.00,4.65
09/11/92,255,Chimney,23,3,41.00,1.78
05/18/93,138,Isabelle,13,5,20.00,1.54
05/27/93,147,Isabelle,9,5,26.20,2.91
05/27/93,147,Chimney,8,3,42.67,5.33
06/03/93,154,Kiowa,7,3,17.33,2.48
06/03/93,154,Isabelle,7,5,22.00,3.14
06/17/93,168,Isabelle,14,3,44.00,3.14
06/23/93,174,Isabelle,6,5,19.40,3.23
06/24/93,175,Kiowa,21,3,38.00,1.81
06/24/93,175,Isabelle,1,1,5.00,5.00
06/25/93,176,Chimney,29,3,68.00,2.34
07/08/93,189,Niwot,14,6,17.00,1.21
07/08/93,189,Chimney,13,3,30.33,2.33
07/20/93,201,Niwot,12,6,66.67,5.56
07/20/93,201,Kiowa,26,4,77.75,2.99
07/21/93,202,Isabelle,27,4,82.25,3.05
07/21/93,202,Chimney,13,3,78.67,6.05
07/27/93,208,Isabelle,6,5,45.60,7.60
07/28/93,209,Niwot,8,5,42.40,5.30
07/28/93,209,Kiowa,8,4,20.00,2.50
08/04/93,216,Niwot,7,5,45.20,6.46
08/04/93,216,Isabelle,8,4,31.00,3.88
08/12/93,224,Kiowa,15,4,71.50,4.77
08/13/93,225,Niwot,9,5,45.60,5.07
08/16/93,228,Isabelle,12,4,33.25,2.77
09/10/93,253,Niwot,28,5,83.80,2.99
09/23/93,266,Niwot,13,5,33.10,2.55
09/23/93,266,Isabelle,38,4,49.50,1.30