@article {275, title = {High Frequency Communications Response to Solar Activity in September 2017 as Observed by Amateur Radio Networks}, journal = {Space Weather}, year = {2019}, month = {2019/01/11}, abstract = {

Abstract Numerous solar flares and coronal mass ejection (CME) induced interplanetary shocks associated with solar active region AR12673 caused disturbances to terrestrial high frequency (HF, 3--30 MHz) radio communications from 4-14 September 2017. Simultaneously, Hurricanes Irma and Jose caused significant damage to the Caribbean Islands and parts of Florida. The coincidental timing of both the space weather activity and hurricanes was unfortunate, as HF radio was needed for emergency communications. This paper presents the response of HF amateur radio propagation as observed by the Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) to the space weather events of that period. Distributed data coverage from these dense sources provided a unique mix of global and regional coverage of ionospheric response and recovery that revealed several features of storm-time HF propagation dynamics. X-class flares on 6, 7, and 10 September caused acute radio blackouts during the day in the Caribbean with recovery times of tens of minutes to hours, based on the decay time of the flare. A severe geomagnetic storm withKpmax\ =\ 8\ +\ and?SYM\ ?\ Hmin\ =\ \ ?\ 146?nT occurring 7-10 September wiped out ionospheric communications first on 14 MHz and then on 7 MHz starting at~1200 UT 8 September. This storm, combined with affects from additional flare and geomagnetic activity, contributed to a significant suppression of effective HF propagation bands both globally and in the Caribbean for a period of 12 to 15 days.

}, keywords = {Amateur Radio, Geomagnetic Storm, Ham Radio, HF Radio Propagation, Radio Blackout, Solar Flare}, issn = {1542-7390}, doi = {10.1029/2018SW002008}, url = {https://doi.org/10.1029/2018SW002008}, author = {Frissell, Nathaniel A. and Vega, Joshua S. and Markowitz, Evan and Gerrard, Andrew J. and Engelke, William D. and Erickson, Philip J. and Miller, Ethan S. and Luetzelschwab, R. Carl and Bortnik, Jacob} } @conference {276, title = {High Frequency Communications Response to Solar Activity in September 2017 as Observed by Amateur Radio Networks}, booktitle = {Fall AGU}, year = {2018}, month = {12/2018}, publisher = {American Geophysical Union}, organization = {American Geophysical Union}, address = {Washington, DC}, abstract = {

Numerous solar flares and coronal mass ejection (CME) induced interplanetary shocks associated with solar active region AR12673 caused disturbances to terrestrial high frequency (HF, 3{\textendash}30 MHz) radio communications from 4-14 September 2017. Simultaneously, Hurricanes Irma and Jose caused significant damage to the Caribbean Islands and parts of Florida. The coincidental timing of both the space weather activity and hurricanes was unfortunate, as HF radio was needed for emergency communications. This paper presents the response of HF amateur radio propagation as observed by the Reverse Beacon Network (RBN) and the Weak Signal Propagation Reporting Network (WSPRNet) to the space weather events of that period. Distributed data coverage from these dense sources provided a unique mix of global and regional coverage of ionospheric response and recovery that revealed several features of storm-time HF propagation dynamics. X-class flares on 6, 7, and 10 September caused acute radio blackouts during the day in the Caribbean with recovery times of tens of minutes to hours, based on the decay time of the flare. A severe geomagnetic storm withKpmax = 8 + and SYM - Hmin = - 146 nT occurring 7-10 September wiped out ionospheric communications first on 14 MHz and then on 7 MHz starting at\ 1200 UT 8 September. This storm, combined with affects from additional flare and geomagnetic activity, contributed to a significant suppression of effective HF propagation bands both globally and in the Caribbean for a period of 12 to 15 days.

}, keywords = {Amateur Radio, Geomagnetic Storm, Ham Radio, HF Radio Propagation, Radio Blackout, Solar Flare}, url = {https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/419847}, author = {Frissell, Nathaniel A. and Vega, Joshua S. and Markowitz, Evan and Gerrard, Andrew J. and Engelke, William D. and Erickson, Philip J. and Miller, Ethan S. and Luetzelschwab, R. Carl and Bortnik, Jacob} } @conference {277, title = {Modeling Amateur Radio Soundings of the Ionospheric Response to the 2017 Great American Eclipse}, booktitle = {Fall AGU}, year = {2018}, month = {12/2018}, publisher = {American Geophysical Union Meeting}, organization = {American Geophysical Union Meeting}, address = {Washington, DC}, abstract = {

On 21 August 2017, a total solar eclipse traversed the continental United States and caused large-scale changes in ionospheric densities. These were detected as changes in medium- and high-frequency radio propagation by the Solar Eclipse QSO Party citizen science experiment organized by the Ham Radio Science Citizen Investigation (hamsci.org). This is the first eclipse-ionospheric study to make use of measurements from a citizen-operated, global-scale HF propagation network and develop tools for comparison to a physics-based model ionosphere. Eclipse effects were observed {\textpm}0.3 hr on 1.8 MHz, {\textpm}0.75 hr on 3.5 and 7 MHz, and {\textpm}1 hr on 14 MHz and are consistent with eclipse-induced ionospheric densities. Observations were simulated using the PHaRLAP raytracing toolkit in conjunction with the eclipsed SAMI3 ionospheric model. Model results suggest 1.8, 3.5, and 7 MHz refracted at h>=125 km altitude with elevation angles θ>=22{\textdegree}, while 14 MHz signals refracted at h \< 125 km with elevation angles θ \< 10{\textdegree}.

}, keywords = {Amateur Radio, Citizen Science, Ham Radio, HF propagation, ionosphere, solar eclipse}, url = {https://agu.confex.com/agu/fm18/meetingapp.cgi/Paper/418915}, author = {Frissell, N. A. and Katz, J. D. and Gunning, S. W. and Vega, J. S. and Gerrard, A. J. and Earle, G. D. and Moses, M. L. and West, M. L. and Huba, J. D. and Erickson, P. J. and Miller, E. S. and Gerzoff, R. B. and Liles, W. and Silver, H. W.} }