Invetigation of Travelling Ionospheric Disturbances during the Memorial Day Weekend Geomagnetic Storm of 27 - 28 OF may, 2017 Over North America.

Using the large GNSS network over North America (70 - 125oW and 25 - 50oN) with a spatial resolution of 0.1 x 0.1o in latitude and longitude and temporal resolution of 1min, we investigate the ionospheric perturbations associated with Traveling Ionospheric Disturbances (TIDs) on 2017 Memorial Day weekend's geomagnetic storm that occurred on the 27 and 28 of May, 2017. Our results were compared with images from the Mid-latitude All-Sky-imager Network for GeoSpace Observation (MANGO) and radio occultation satellite data. The storm was intense, featuring a southward interplanetary field (Bz) below 20 nT for about 4 hr, with a strong increase in the AE from 200 to 1300 nT and the Dst and kp indies were below 120 nT, and above 7 units, respectively. Both medium and large scale TIDs were observed, and their velocity, wavelength, wavefront and period throughout the storm are analyzed. Results show the presence of both poleward and equator-ward propagation of the TIDs. The features of TIDs obtained from keograms and 2-D TEC maps from GNSS-TEC are compared with those obtained from the all-sky imaging system during storm period. Finally, we compared the behavior of TIDs during Memorial Day weekend geomagnetic storm with the TIDs during the May quiet periods.