The new year has arrived with a foot of snow. It's a great news for the sequoias.
This is a very short update with temperature reporting over last two weeks. Temperatures stayed significantly above normal through Dec 23, well above freezing during the day, reaching +8C on that day. However, they dropped to negative 15-16 Celsius by Dec 25. The red line shows air temperature from the sensor above ground under the protective cone near one of the sequoias.
Underground temperature shown in blue tells the story of a very gradual temperature slide from 5C to about 1.5C, still clearly positive and never going below water freezing point.
Once the underground sensor shows 0C or below, I intend to conduct an experiment with the heating wire installed at 1 foot depth. It will happen probably in two-three days from now as the air temp will remain below freezing for the most part.
