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United States Department of Agriculture

Agricultural Research Service

Title: Atmospheric Scales of Biotic Dispersal

Authors
item Westbrook, John
item Isard, S. -

Submitted to: Agricultural and Forest Meteorology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 19, 1999
Publication Date: N/A

Interpretive Summary: Many insects, spores, and fungi disperse in the air, but are often undetected before they infest or infect crops and animals. Recent advances in meteorological instrumentation systems are providing new insight into various scales of airborne dispersal of insects and other organisms. For example, lidar systems have identified small-scale atmospheric convection over agricultural fields which might be important in the airborne spread of spores, fungi, and flightless insects, spiders, and mites. Also, the tracks of instrumented weather balloons have indicated nightly insect flight paths between agricultural production regions that were 400 kilometers apart in south central Texas. Further, output from a single (NEXRAD) Doppler weather radar has been used to estimate the amount, speed, and displacement direction of aerial concentrations of organisms over an area of more than 1,000 square kilometers. Development of applications for these new meteorological instrumentation systems will help producers, extension agents, and regulatory agencies estimate the spread of agricultural pest insects and diseases for use in areawide pest management decision-making.

Technical Abstract: Recent advances in meteorological technologies and techniques are providing new insight into microscale, mesoscale, and macroscale aerobiological processes. For example, Lidar systems have identified microscale characteristics of atmospheric turbulence over agricultural fields which cannot be readily determined by conventional (site-specific) atmospheric sensors. Also, neutrally-buoyant superpressure balloons (tetroons) have been tracked more than 400 km per night indicating atmospheric pathways of migrating insects between agricultural regions in South central Texas. Such atmospheric trajectories often reveal substantial day-to-day variation of aerobiological pathways, and consequently, affect the risk of pest infestations and host infections. Further, the NEXRAD network of WSR-88D Doppler weather radars can measure the aerial abundance, speed, and displacement direction of concentrated biota over areas of more than 1,000 square kilometers. Emphasis is placed on identifying biologically-relevant, temporal and spatial scales of atmospheric motion and other atmospheric variables which help control the abundance and dispersal of airborne biota, specifically insects, spores, pollen, fungi, and plant pathogens. Major technologies including the NEXRAD network of WSR-88D Doppler weather radars are described, and examples are presented for aerobiological applications.

Last Modified: 4/16/2014
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