Environmental Sensor Networks: A revolution in Earth System Science?

Environmental Sensor Networks (ESNs) facilitate the study of fundamental processes and the development of hazard response systems. They have evolved from passive logging systems that require manual downloading, into 'intelligent' sensor networks that comprise a network of automatic sensor nodes and communications systems which actively communicate their data to a Sensor Network Server (SNS) where these data can be integrated with other environmental datasets. At present ESN's can be classified into three types: Large Scale Single Function Networks (which use large single purpose nodes to cover a wide geographical area), Localised Multifunction Sensor Networks (typically monitor a small area in more detail, often with wireless ad-hoc systems), and Biosensor Networks (which use emerging biotechnologies to monitor environmental processes as well as developing proxies for immediate use). In the future, sensor networks will integrate these three elements (Heterogeneous Sensor Networks). We describe the development of a glacial ESN (Glacsweb) to monitor subglacial processes in order to understand glacier response to climate change. We discuss the advantages of the new system, and research highlights, as well as the problems of real world ESNs. We argue that Environmental Sensor Networks will become a standard research tool for future Earth System and Environmental Science. Not only do they provide a 'virtual' connection with the environment, they allow new field and conceptual approaches to the study of environmental processes to be developed. We suggest that although technological advances have facilitated these changes, it is vital that Earth Systems and Environmental Scientists utilise them.