Hi, my name is Jim Washburne. I am the scientist responsible for GLOBE
soil moisture measurements and I am located at the University of Arizona
in Tucson. I want to tell you why your participation in GLOBE is so
important to me and hundreds of other Earth scientists. My objective as a
Phase II scientist is to integrate your GLOBE soil moisture measurements
into other ongoing efforts to: 

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

2) Help calibrate and validate the next generation of:

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

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. Let me put these rather specific objectives in
perspective by comparing my work in global scale hydrology with earlier
scientific revolutions and try to transmit a sense of the place and
importance of your effort to Earth Science. 

As an undergraduate geology major in 1976, I was caught up in the
explosion of activity surrounding plate tectonics and its application to
centuries of careful, yet previously difficult to reconcile observations. Now,
as then, the same level of excitement is evident as a broad spectrum of
Earth scientists are attempting to study the Earth as one large but
interconnected system. This effort is made possible by ongoing
improvements in our ability to simulate Earth processes on computers and
to observe the Earth from satellites. 

Computer technology and, more importantly, our understanding of how to
model the atmosphere-ocean-land surface system is developing rapidly.
Equally important are rapid advances in satellite technology. NASA's
Mission To Planet Earth will radically improve the quality and quantity of
data gathered about our oceans, atmosphere and land surface cover when
the Earth Observing System launches the first in a series of Earth remote
sensing satellites in 1998. 

One activity scientists now are engaged in is making simulations of our
climate more realistic using computer codes called General Circulation
Models (GCM). Typically, these models run globally based on individual
grid squares on the order of one degree square. That is about 100 km on a
side or the size of some states. Now imagine changing your focus by powers
of ten. First to 10 km, the size of a small city. Then zoom down to 1 km, the
size of a small town. Finally zoom to 100 m, the size of a football field.
Realistically, this is the size area at which most land surface field studies
are done. Our dilemma is to relate what we can observe and model at this
field scale to what computers can simulate at GCM scales. This task is
immensely challenging and complicated but the rewards make it worthwhile.
Despite the cutting-edge nature of this challenge, it is a job that each and
every one of you can help with: 

     by monitoring one or more GLOBE sites, you will help scientists
     relate what is actually happening on the ground to what satellites and
     models can only approximate.