Boundary-Layer Meteorology

, Volume 106, Issue 2, pp 283–295

Inter-annual Variability of Moisture Flux from the Prairie Agro-ecosystem: Impact of Crop Phenology on the Seasonal Pattern of Tornado Days

  • R. L. Raddatz
  • J. D. Cummine

DOI: 10.1023/A:1021117925505

Cite this article as:
Raddatz, R.L. & Cummine, J.D. Boundary-Layer Meteorology (2003) 106: 283. doi:10.1023/A:1021117925505


This study, through the inclusion of a simpleparameterization of the phenologicaldevelopment of spring wheat in evapotranspirationsimulations for 1988–2000, at a representativearid grassland and a representative transitionalgrassland site, delineated the inter-annualvariability of the seasonal moisture flux from theCanadian Prairie agro-ecosystem. Theagro-ecosystem's contribution to atmospheric boundary-layermoisture, at these representative sites, wasrelated to the seasonal pattern of tornado days in thegrassland eco-climatic zone for the averageyear, for a warmer/drier year and for a cooler/wetteryear. The following conclusions were drawn:(1) The moisture flux from the Prairie agro-ecosystemdisplays considerable inter-annualvariability due, in the main, to the rate andtiming of crop phenological development andassociated biophysical parameters, and (2) themoisture flux from the Prairie agro-ecosystemtranslates directly into changes in atmosphericboundary-layer moisture, which subsequentlyaffects the magnitude of the potential energyavailable for deep convection and the seasonalpattern of tornado days. For expansive agriculturalareas, representing the inter-annual variabilityof crop phenological development in land surfacemodels is critical to the successful simulationof the surface moisture flux, and thus thethermodynamic properties of the atmospheric boundarylayer. Therefore, it is of particularimportance to Prairie climate and climate change modelling.

Boundary-layer moistureCrop modellingEvapotranspirationLand-surface schemesSurface moisture fluxThunderstorms

Copyright information

© Kluwer Academic Publishers 2003

Authors and Affiliations

  • R. L. Raddatz
    • 1
  • J. D. Cummine
    • 1
  1. 1.Meteorological Service of CanadaPrairie & Northern Region, Environment CanadaWinnipegCanada