DATA FORMAT DESCRIPTION
-----------------------
This file describes the format of the field data submitted as
supplementary material to the publication:

M.A. Werder, T.V. Schuler and M. Funk, Short term variations of
tracer transit speed on Alpine glaciers, The Cryosphere, 2010

Please cite this publication if you use any of this data.  All the
data is published under the Creative Commons Attribution 3.0 License
(http://creativecommons.org/licenses/by/3.0), copyright M.A. Werder
and M. Funk.


NETCDF FORMAT
-------------
All the data is provided in the binary netcdf 3.0 format
(http://www.unidata.ucar.edu/software/netcdf/).  If you do not know
how to use this format the easiest way might be to use the 'ncdump'
tool (included in all netcdf distributions) to generate an ASCII file
dump.  The layout of the data mostly follows the CF 1.4 Metadata
conventions (http://cf-pcmdi.llnl.gov/).

The Python program 'easy_plot.py', included with these files, can be
used to plot the data.


ALL DATA
--------
All data shares the following global attributes:
* name
* copyright_licence
* institution
* source - what kind of measurement
* references - Reference to this publication

All data shares the following variable attributes:
* units:  units of the variable quantity
* long_name: A descriptive name

Time variable has
* units = "days since 0000-12-31 00:00:00 +2:00" 
* calendar = "proleptic_gregorian"
(This corresponds to the time description used by the Python Matplotlib
plotting library.)


TRACER
------
Files: Ur_063.nc - Ur_076.nc

All tracer experiments were done using Uranine dye injected into
moulin M4, which has a total transit distance of 6500m.  The
proglacial stream has a transit distance of 1250m.

Global attributes:
* amount - injected tracer in litre of solution
* arrived - time of peak concentration
All attributes beginning with cxt were obtained by fitting the CXTFIT
model, the ones ending in _err give the absolute error band.  If NaN
are given for beta and omega, the CXTFIT curve only fitted the rising
limb of the breakthrough curve.
* cxt_D - dispersion
* cxt_beta - fraction of mobile water
* cxt_omega - exchange coefficient 
* cxt_rsqr - R-squared goodness of fit parameter
* cxt_v - transit speed

* inj_date - date of injection
* inj_time - time of injection
* t_englacial - residence time in glacier (seconds)
* t_proglacial - residence time in proglacial stream (seconds)
* v_englacial - transit speed in glacier (m/s)
* v_proglacial - transit speed in proglacial stream (m/s)


LAKE DISCHARGE
--------------
File: Lake_discharge.nc

BOREHOLE WATER LEVEL
--------------------
File: BH1.nc

* location - location given in Swiss Grid coordinates
* borehole_depth - depth of borehore. Error +/- 15m
* sensor_depth - depth of pressure sensor in borehole. Error +/- 10m

AIR TEMPERATURE
---------------
File: AWS.nc

* location - location given in Swiss Grid coordinates


OTHER DATA
----------

* The proglacial discharge data was provided by Grande Dixance SA
  (www.grande-dixence.ch).

* If you would like to work with other field data not included here
  please contact Martin Funk at the VAW, ETH Zurich, Switzerland.
