Mesoscale Monitoring of Soil Moisture Across a Statewide Network

Authors: ILLSTON, BRADLEY - UNIV OF OKLAHOMA; BASARA, JEFFERY - UNIV OF OKLAHOMA; Fisher, Daniel; ELLIOTT, RONALD - OKLAHOMA STATE UNIV; FIEBRICH, CHRISTOPHER - UNIV OF OKLAHOMA; CRAWFORD, KENNETH - UNIV OF OKLAHOMA; HUMES, KAREN - UNIV OF IDAHO; HUNT, ERIC - UNIV OF OKLAHOMA

Submitted to: Journal of Atmospheric and Ocean Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/25/2007
Publication Date: 2/1/2008
Citation: Illston, B.G., Basara, J.B., Fisher, D.K., Elliott, R., Fiebrich, C.A., Crawford, K.C., Humes, K., Hunt, E. 2008. Mesoscale Monitoring of Soil Moisture Across a Statewide Network. Journal of Atmospheric and Ocean Technology. 25(2):167-182.

Interpretive Summary: Sensing devices to measure soil moisture conditions were installed as part of an automated network of 116 remote, meteorological stations across Oklahoma. Because the need for soil moisture observations extended beyond the scientific community to potential customers focused on agriculture, water resources, and natural resource policy, the system was designed to meet as many needs as possible without sacrificing data quality. The sensing devices were calibrated to report soil moisture levels in terms of water potential, and were installed at multiples depths below the soil surface. Data quality assurance techniques were applied to the observations to flag suspicious or erroneous measurements. Data from the sensor network were used to analyze the annual cycle and temporal characteristics of soil moisture, revealing four distinct soil moisture phases (moist plateau, transitional drying, enhanced drying, and recharge).

Technical Abstract: Soil moisture is an important component in many hydrologic and land-atmosphere interactions. Understanding the spatial and temporal nature of soil moisture on the mesoscale is vital to determine the influence that land surface processes have upon the atmosphere. Sensing devices to measure soil moisture conditions were installed as part of an automated network of 116 remote, meteorological stations across Oklahoma. Laboratory and field methods were used to calibrate the sensors, and to report soil moisture levels in terms of water potential. At each site, sensors were installed at multiples depths below the soil surface. Soils were analyzed, and soils data were used to estimate soil-water retention properties at each site. Water-potential values from the sensors were then converted to water-content values using the estimated retention curves. Data quality assurance techniques were applied to the observations to flag suspicious or erroneous measurements. Data from the sensor network were used to analyze the annual cycle and temporal characteristics of soil moisture, revealing four distinct soil moisture phases (moist plateau, transitional drying, enhanced drying, and recharge).