Cloud-to-Ground Lightning Strikes to the Forest of Barro Colorado Island in Panama

Lightning is a significant cause of large tree mortality in the forest of Barro Colorado Island (BCI) in Panama. However, damage to trees from lightning on BCI is often not immediately obvious but becomes more apparent with time as trees either die or are significantly damaged from stresses caused by lightning. Accurately locating and describing cloud-to-ground lightning strikes within this study area is, thus, a critical component of any investigation of the effects of lightning on the forest. To that end, electric field change meters (FCMs) are used in conjunction with a network of CCTV cameras to locate and describe CG lighting on BCI. There are currently two types of FCM used: (1) a single channel FCM with a sampling rate of one million samples per second, and (2) a two channel FCM with sampling rates of ten million and one million samples per second on the fast and slow channels, respectively. Both types of sensors use GPS for high-accuracy timing. The CCTV cameras are primarily used for locating lighting strikes via triangulation, The FCMs are also used to locate strikes; Additionally, they are critical in quantifying characteristics of CG flashes such as stroke multiplicity, presence and duration of continuing current, and peak field change. Initial results from the network of sensors around BCI will be discussed.