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From: Earle Williams (copied from an e-mail)
Date: 6/17/99
Time: 10:31:14 AM
Remote Name: 192.149.107.107
Hi Gar This is Earle Williams calling, now at a meeting on sprites etc with Walt Lyons and Russ Armstrong at Yucca Ridge. Walt tells me you are in a quandry about how to threshold for your measurements from aloft this summer, and so I have a suggestion. We have found based on our ELF measurements from Rhode Island that a threshold charge moment for sprites and elves is about 300 C-km. This value is greater than the vast majority of ordinary lightnings, as you expect. If you have a roughly calibrated electric field change measurement aloft, then I suggest thresholding at a value of field one computes at your altitude for a 300 C-km moment change at the Earth's surface. If you want any other info, please contact me at earlew@ll.mit.edu Regards Earle