Observation of polar patches occurrences during low solar activity

A dual-frequency GPS Ionospheric Scintillation and TEC Monitor (GISTM) receiver, GSV4004B, has been installed at Alert, Canada (82.48° N, 297.75° E, corresponding to 86.95° N, 155.77° E geomagnetic coordinate) since May 2008 to study the ionospheric variability at a high-latitude location. This GISTM receiver is able to measure the Total Electron Content (TEC), and both the amplitude and phase scintillations. This study focuses on the polar patches occurrences observed over Alert for 26-month period from June 2008 until July 2010 where it was mostly during the minimum state of solar activity. It is found that the difference in the occurrences of small patches between months of the same year was about 1-2% (for low intensity patches) and 1-10% (moderate-high intensity). This difference increased to 1-4% (low intensity) and 1-12% (moderate-high intensity) for large patches. UT dependence can be seen where ~80 large and ~300 small patches were identified ~1000 to 2000 UT from June to October in both 2008 and 2009, and they doubled in 2010.