There are dozens of campaign-type Global Positioning System (GPS) stations within the radius of 20 kilometers on the Helheim Glacier in Greenland. These sites are used to measure glacier flow speed and glacial earthquakes. We acquired continuous GPS measurements at sampling intervals of 1 or 5 seconds. We found that the TEC (Total Electron Content) changes rapidly in a short time. We computed the single difference (SD) of slant TEC (STEC) between two sites for a few minutes. The SD-STEC changed up to 10 TECU (TEC Unit). The histogram of SD-STEC variations higher than 2 TECU in diurnal variation showed Peculiar Ionospheric Disturbance (PID) mainly occur in the night time period. These PID events do not show at mid-latitude sites such as BARGEN GPS sites of UNAVCO, whose inter-site distances are in the range of tens of kilometers. To relate PIDs observed at the Helheim GPS sites to scintillation, we computed 4 scintillation indices: ROT (Rate of TEC), ROTI (Rate of TEC Index), S4 (amplitude scintillation index), and DPR (Delta Phase Rate). Most of these indices can be used to show the presence of scintillation. Especially the DPR plot shows the sequential difference of scintillation events according to the geomagnetic latitude.

Keywords: Greenland, Helheim, scintillation index, short-term