Extended Abstract (2.1M)P1.7
Hurricane lightning: a new campaign to investigate hurricane intensification by using lightning observations
Xuan-Min Shao, LANL, Los Alamos, NM; and J. D. Harlin, T. Hamlin, D. M. Suszcynsky, and C. A. Jeffery
Los Alamos National Laboratory (LANL) recently funded a three-year effort to investigate hurricane intensification processes by using lightning observations and hurricane modeling. The objective is to improve the forecast accuracy on rapid hurricane intensification, large-scale transition and reorganization of a multiscale hurricane system by using a model that assimilates knowledge of critical small-scale processes, specifically the eyewall convection provided by a lightning imaging system. In 2005, LANL's Sferic Array (LASA) showed clearly positive correlation between eyewall lightning activity and the hurricane intensification for Katrina, Rita and Wilma. Since the sensors were not deployed for hurricane study, some of the contributing sensors were as far as 3000 km from hurricane centers, and therefore only limited data were available. In 2008, we plan to deploy LASA sensors in the Gulf region to better cover the hurricane active area. The planned sensors consist of VLF and VHF radio frequency band for each sensor. The VLF band will serve to provide charge moment measurement for individual discharge events, and the VHF band will provide detailed 3-d imaging of the lightning structures. Combination of the two simultaneous observations will be used to infer charge structure and charge amount inside a lightning active eyewall. In addition, the VLF band alone will be used to detect, geolocate, and characterize hurricane lightning activity at distances that are beyond the detectable range for VHF. As for the earlier LASA sensors, the full VLF waveform will be captured and recorded for detailed study, and will be used to determine the lightning type, discharge current, and to provide source height for distant impulsive intracloud events. This presentation will report LANL's ongoing and planned hurricane lightning research activity.
Poster Session 1, Lightning Applications, Studies and Technology in the Atmospheric Sciences
Tuesday, 22 January 2008, 9:45 AM-11:00 AM, Exhibit Hall B
Previous paper Next paper