We present the first observation by the Telescope Array Surface Detector (TASD) of the effect of thunderstorms on the development of cosmic ray single count rate intensity over a 700 km2 area. Observations of variations in the secondary low-energy cosmic ray counting rate, using the TASD, allow us to study the electric field inside thunderstorms, on a large scale, as it progresses on top of the 700 km2 detector, without dealing with the limitation of narrow exposure in time and space using balloons and aircraft detectors. In this work, variations in the cosmic ray intensity (single count rate) using the TASD, were studied and found to be on average at the ~(0.5-1)% and up to 2% level. These observations were found to be both in excess and in deficit. They were also found to be correlated with lightning in addition to thunderstorms. These variations lasted for tens of minutes; their footprint on the ground ranged from 6 km to 24 km in diameter and moved in the same direction as the thunderstorm. With the use of simple electric field models inside the cloud and between cloud to ground, the observed variations in the cosmic ray single count rate were recreated using CORSIKA simulations. Depending on the electric field model used and the direction of the electric field in that model, the electric field magnitude that reproduces the observed low-energy cosmic ray single count rate variations was found to be approximately between 0.2 GV-0.4 GV. This in turn allows us to get a reasonable insight on the electric field and its effect on cosmic ray air showers inside thunderstorms.
|Journal||Physical Review D|
|Publication status||Published - 2022 Mar 15|
Bibliographical noteFunding Information:
Operation and analyses of this study have been supported by NSF Grants No. AGS-1844306 and No. AGS-2112709. The Telescope Array experiment is supported by the Japan Society for the Promotion of Science (JSPS) through Grants-in-Aid for Priority Area 431, for Specially Promoted Research No. JP21000002, for Scientific Research No. (S) JP19104006, for Specially Promoted Research No. JP15H05693, for Scientific Research (S) No. JP15H05741, for Science Research (A) No. JP18H03705, for Young Scientists (A) No. JPH26707011, and for Fostering Joint International Research (B) No. JP19KK0074, by the joint research program of the Institute for Cosmic Ray Research (ICRR), The University of Tokyo; by the U.S. National Science Foundation Awards No. PHY-0601915, No. PHY-1404495, No. PHY-1404502, and No. PHY-1607727; by the National Research Foundation of Korea (2016R1A2B4014967, 2016R1A5A1013277, 2017K1A4A3015188, 2017R1A2A1A05071429); by the Russian Academy of Sciences, RFBR Grant No. 20-02-00625a (INR), IISN Project No. 4.4502.13, and Belgian Science Policy under IUAP VII/37 (ULB). The foundations of Dr. Ezekiel R. and Edna Wattis Dumke, Willard L. Eccles, and George S. and Dolores Doré Eccles all helped with generous donations. The State of Utah supported the project through its Economic Development Board, and the University of Utah through the Office of the Vice President for Research. The experimental site became available through the cooperation of the Utah School and Institutional Trust Lands Administration (SITLA), U.S. Bureau of Land Management (BLM), and the U.S. Air Force. We appreciate the assistance of the State of Utah and Fillmore offices of the BLM in crafting the Plan of Development for the site. Patrick Shea assisted the collaboration with valuable advice on a variety of topics. The people and the officials of Millard County, Utah have been a source of steadfast and warm support for our work which we greatly appreciate. We are indebted to the Millard County Road Department for their efforts to maintain and clear the roads which get us to our sites. We gratefully acknowledge the contribution from the technical staffs of our home institutions. An allocation of computer time from the Center for High Performance Computing at the University of Utah is gratefully acknowledged. We thank Ryan Said and W. A. Brooks of Vaisala Inc. for providing quality NLDN data lightning discharges over and around the TASD under their academic research use policy.
© 2022 American Physical Society.
All Science Journal Classification (ASJC) codes
- Nuclear and High Energy Physics