SCIENTISTS CORNER

Here is a picture of me in 1987 hiking in Waimea Canyon State Park, Kauai.
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, Arizona at the Department of Hydrology and Water Resources at the University of Arizona.

I want to invite all of you to consider making soil moisture measurements. We are working on some new protocols that students at all grade levels can do (see below). Below, I will tell you why I am interested in your measurements, share with you some data from a site I am investigating and tell you how I got started in science.

First, congratulations to those of you who have begun to make soil moisture measurements. I am sure that you have discovered why this is the most difficult (and hopefully, interesting) GLOBE experimental protocol. Congratulations on your efforts!

I plan to use your soil moisture data in my research and to promote its use by other Earth scientists. There is no doubt you share my excitement about the GLOBE program and the prospect of collaborative research using this data.

I will use your GLOBE soil moisture measurements to help calibrate and validate the next generation of computer-based meteorological forecast and climate models, and to help interpret data obtained by Earth Resources satellites that estimate soil moisture. The calibration process involves turning instrument readings (often voltage) into physical measures such as cloud cover or soil moisture. Validation is the process of making sure that a calibrated signal is giving you the correct values (such as comparing radar precipitation measurements with raingauge measurements at your climate site).

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

I have two active research projects to study soil moisture in Southeast Arizona and Oklahoma. I am trying to understand the role soil moisture plays in the hydrologic cycle of arid and semiarid regions worldwide. One of the products of this investigation will be an atlas of seasonal soil moisture characteristics and soils around the world.

Below are several hotlinks to some related information. I encourage you to browse through each link, particularly my letter to you that tells you more about me and how I became a scientist. First, I want to make sure you are all aware of a data quality issue of utmost importance.

DATA QUALITY - IMPORTANT!

The soil moisture protocol calls for daily observations using four gypsum blocks and conversion of these meter readings to volumetric soil moisture. The calibration process takes time but MUST be done to minimize local soil differences that affect meter readings and allow comparison between sites. So far, most sites have been reporting meter readings to the GLOBE Student Data Server. The original intent of the protocol was to have this data accumulate in a field notebook until a calibration curve was produced and then use this conversion to report volumetric soil moisture. If you need to, please re-enter your calibrated data in place of raw meter measurements. Be sure to set the correct date (ie. the date the data was collected in the field).

If you would like to explore a developmental home page I have related to this project, follow this hyperlink . Have fun!

May each and every one of you have a Happy Holiday Season!

Jim Washburne 12/8/95

UA/GLOBE Science; Last updated: 12/08/95; Comments? globe@hwr.arizona.edu