Kite Flying Straight Up
What is causing my single line, run of the mill, pound shop kite to fly straight up? Not out at any angle, vertical, straight up above my head even at one mile?
Ha ha - my friend, you have found your first BIG thermal! A region of rising air that is slightly warmer than the surrounding air. It starts off as a huge bubble attached to the ground, but then rises right up to cloud base as a column or elongated bubble. All around it, air is slowly drifting downwards, balancing out the volume of rising air. Your kite was stretching the line tight, with the breeze coming from directly below it.
Lots of my Flight Reports document the effect of thermals on my kites. These effects are actually at work nearly every time you go out to fly, but they are not always so obvious as the experience you had. Here's a good one, written after an outing with the Dowel Dopero kite.
Thermals are amazing. As a sailplane pilot in the 1970s, I remember climbing to 10,900 feet above the airfield in a small single-seater. It was a strong thermal, pegging the variometer at 5 m/s (1000 feet per minute straight up) at times. It was a hot day, even by Australian outback standards, but the air was uncomfortably cold up there above 10,000 feet. Technically I should have been on oxygen at that altitude, but I didn't stay long since other people were waiting on the aircraft.
These days I just let my kites do the thermalling :-) Have fun, and also realize that sinking air has the opposite effect - the kite stays low for no apparent reason, before suddenly deciding to return to its normal line angles once again.