Radar aeroecology: A call for collaborative radar investigations of organisms in the aerosphere

Civil radar systems are primarily used to monitor weather conditions and track the location and motion of aircraft. However, radar echoes regularly contain signals from other sources. Among these are birds, bats, and insects. Indeed, the capacity of radars to detect such biological scatterers in the planetary boundary layer and lower free atmosphere (i.e. the aerosphere) has been known for over 50 years. This is one example of the emerging scientific discipline of aeroecology, which integrates diverse fields, such as atmospheric science, earth science, geography, ecology, computer science, computational biology, and engineering to broaden understanding about the ecological function and biological importance of the aerosphere. Monitoring and tracking of airborne biological scatterers with radar merits attention from all scientific disciplines, but especially from meteorology, aviation, biology, and ecology. The collaboration of these fields in the area of “radar aeroecology” has great potential for furthering scientific investigations on a diversity of research topics: daily and nightly dispersal, migratory patterns, foraging behavior, distribution and quantification of aerial biomass, aerial biodiversity, phenological patterns related to climate change, impacts of land use policy, and so forth.

Our presentation will focus on the benefits and challenges of developing a cohesive radar aeroecology program within the United States targeted at observations of volant organisms over a variety of spatio-temporal scales. Because of their ability to move over large spatial scales, birds, bats, and insects, contribute to the ecological integrity of multiple ecosystems that span geopolitical boundaries linked by migration or dispersal through the aerosphere. We will consider the potential of improving algorithms for distinguishing biological scatter within radar network data, developing continental scale “bio-scatter” maps, 3-D rendering of biological targets, and quantifying biomass of airborne targets. Additionally, we will discuss radar aeroecology at small spatial scales through the use of radars capable of probing the air space close to the Earth's surface both as a means of validating results from network-wide studies and conducting detailed investigations of localized behavioral patterns of organisms. We will also discuss the impact of dual-polarization measurements on discriminating and classifying types of biological scatter. We realize that much has already been accomplished in the area of radar aeroecology and also acknowledge that Europe has made considerable progress in this nascent field. We hope that this presentation will stimulate interactions and collaborations among ourselves an others working in this important domain.