SENSORS: Sensor Networks for the Study of Heterogeneous Fluxes in Lakes

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

Hemond 0330272 Modern sensor technology has a great potential to help advance both understanding and monitoring of the environment. These benefits can be maximized by linking sensors together in intelligent networks. This project will create a unique network of fixed and mobile sensors that can be adaptively controlled to most effectively and efficiently study the coupling between lake physics and the biologically-mediated cycling of methane, a globally important greenhouse gas. One major challenge that such a sensor network will address is the high degree of physically-driven chemical and biological heterogeneity, at multiple scales, that typically occurs in natural waters. Heterogeneity poses both practical and philosophical problems. Firstly, can one determine a meaningful average state of the system using traditional (a limited number of) observations? Secondly, given chemical and biological processes that are non-linear, can average values alone predict chemical fluxes, or is it necessary to have information on structure, and to employ higher order statistics? The only practical way to obtain the needed information density will be through sensor networks. A novel and significant feature of the proposed network will be utilization of the complementary strengths of fixed chemical sensors and miniaturized mobile analytical instrumentation, integrated via electronic and acoustic networking, and operating under intelligent control algorithms. The network will be tested in a study of the coupled, heterogeneous, time-varying, and multi-scale geochemical and physical processes that control the cycling of methane. [redundant with para 1]. Intellectual goals include advances in the applied science of sensor networks as well as advances in the fundamental understanding of how heterogeneous mixing processes govern methane consumption within the water column. This project will be carried out by a multidisciplinary team of investigators, and coordinated under a system engineering plan. The project also has broader community significance, as lakes and related surface waters provide important goods and services, and are integral components of the biosphere. As humans increasingly rely on these systems for food, potable water, and maintenance of ecosystem integrity, a better understanding of their biogeochemical cycles and increased ability to monitor their health is necessary. The proposed sensor network and the observations it generates will advance the understanding, monitoring, and management of surface waters. Data generated by the sensor network will be made available via internet connections for undergraduate and K- 12 education, public awareness, and use by local water resource managers.