This graphic shows the Earth's postition on its orbit around the sun on October 1st. We have entered the yellow sector of our orbit which means that in the northern hemisphere the nights are longer than the days and the nights' length is increasing - at maximal speed around the equinox. Surprisingliy the Arctic sea ice area was at its minimum around the equinox and started to grow afterwards with almost no delay (see Seasonality > Ice > Sea Ice > Satellite Images > Arctic). This would mean that the sea ice system depends directly on daylength and responds almost immediately on a change. Surprising as water systems normally react delayed in time on thermal changes, even more than terrestrial systems.
