Dear Students,

Hi, my name is Jim Washburne and I am the GLOBE phase II scientist responsible
for soil moisture. I live and work in Tucson, AZ at the Department of
Hydrology and Water Resources at the University of Arizona but you can
find me on the web at: http://www.hwr.arizona.edu/globe/home.html

The purpose of this letter is to intorduce myself, welcome you to the
program, summarize how I see this data being used (don't let this limit
your ideas), review standard protocols and data quality and point out
some exciting program developments. The issue of data quality is very
important and almost every group reporting data at this point needs to
carefully review the information I will cover below.

First, I want to congratulate you on being among the first GLOBE schools
to work on soil moisture measurements. Undoubtedly you have discovered
why this is the most difficult (and hopefully, interesting) GLOBE
experimental protocol. Congratulations on your efforts to date!

I look forward to integrating your soil moisture data into the research
efforts of myself and others. There is no doubt you share my excitment
about the GLOBE program and the prospect of collaborative research using
this data. I know that many of you want to know:

	- what role I expect to play?
	- why this data is useful?
	- what are you going to do with it?
	- what do I get out of it?

I see my duties as:

	- improving and extending soil moisture protocols and activities,
	- monitoring overall soil moisture data quality,
	- encouraging as many schools as possible to participate in this,
	- promoting the use of GLOBE data to other scientists needing
	  surface soil moisture data,
	- mentoring individual school efforts and understanding, and
	- incorporating GLOBE data in my reseach.

My objective is to integrate your GLOBE soil moisture measurements
into other ongoing efforts to: 

   1) Help calibrate and validate the next generation of:

	- meteorological forecast and climate models, and
	- Earth Resources satellites that estimate soil moisture 

   2) Better understand the role of soil moisture in the land surface
      hydrologic cycle. 

   3) Better relate soil processes with water balance, plant growth and
      watershed / water supply issues. 

In general, by studying the correlation or agreement between models,
satellites and ground observations, scientists will be able to improve models
and measurement procedures - and this will lead to a better understanding
of the Earth Climate System. 

My research plans are still being formulated but can be summarized as:

- Developing regional-scale soil moisture data sets for model
  and satellite ground validation studies. In particular, I
  am focusing on SE Arizona/Mexico, Oklahoma, and Alabama/Tenn.
  I am working with NASA's Earth Observing System satellite teams
  to develop ground validation sites and evaluating the NWS/NMC
  eta forecast model in terms of near-surface fluxes, including
  soil moisture.

- Working with a NASA EOS InterDisciplinary Science team to better
  understand the role soil moisture plays in the hydrology of
  arid and semiarid regions worldwide.

- Produce an atlas of seasonal soil moisture characteristics and
  soils around the world.

DATA QUALITY

The present soil moisture protocol calls for daily observations of
a depth profile of four gypsum blocks and conversion of these meter
readings to volumetric soil moisture. The conversion or calibration
process is inexact, time consuming and may be time variable. It MUST
be done to minimize local soil differences that affect meter readings
and facilitate comparison between sites. To date, most sites have
been reporting meter readings to the Web data archive. The original
intent of the protocol was to have this data accumulate in a field
notebook until such time that a calibration curve was produced and
then only volumetric soil moisture would be reported. I propose the
following solution to this important data quality problem:

1) Modification of the Web input form to allow either meter or
volumetric soil moisture data to be recorded. Meter readings would
NOT be available through the data archive but would serve to flag
sites that were actively taking data. It will be the responsibility
of each GLOBE site to develop a calibration curve as before and then
re-enter the gravimetric equivalents on the Web input form. Only this
data will be available through the GLOBE data archive.

I recommend that the data acceptability window be set as follows:

Raw Meter reading: 0-100,
error message: Data outside acceptable range, check and re-enter.
UNITS=(meter reading) should be the default.

Calibrated Gravimetric soil moisture: 0-60,
error message for 60<x<=100: This value is high - change UNITS to meter
reading if that is the problem.
error msg for x<0 or x>100: Data outside acceptable range, check and re-enter.

2) Modification of the Web visualization maps to show a gray dot
indicating stations actively taking data and colored dots indicating
percent gravimetric soil moisture. This will satisfy a student's need
to see something related to their efforts in this protocol.

3) I would like each school that has or is developing a soil moisture
calibration curve to fax or post it to me ASAP so I can evaluate this
effort. Even if your curve is not finished - send it to me now so I
will have a snapshot of the calibration work to this date. I am at:

 Jim Washburne    Department of Hydrology and Water Resources 
                   University of Arizona,  Tucson, AZ 85721 
                   520 621-9944 (Off);   520 621-1422 (FAX) 

I expect to have access to the intermediate meter readings that are
being recorded and will be able to monitor your progress even before
the data makes it to the official data archive.

I will need to advise the data archive as to the proper classification
of the existing data in the archive. Last time I checked, only data
from the school in GA and VA looked like realistic gravimetric values,
the other 9 sites were meter readings.