Please don't try to reach this remote point at the windswept crest of the Greenland Ice Cap. First of all, the Arctic Circle is shifting by 15 meters per year, making any exact location a fleeting concept. Second, topographic mapping of central Greenland is not very accurate, so the longitude and elevation noted here may not be very authoritative. The flatness of the terrain and its changes as the ice flows and melts add to the trouble in nailing it down.
The best thing to say is that "the highest point on the Arctic Circle is at its highest elevation as it crosses the middle of the Greenland Ice Cap". Trying to be more precise is a fool's errand.