Radar-based measurements of the initiation of the growing
season for the 10 study sites spanned a period of
approximately 8 weeks from March to mid-May. Initiation
of the growing season began at the relatively warm KNI
and NWT sites and proceeded in a general northerly
direction to higher latitude sites. In contrast, radar-based
estimates of the cessation of the growing season spanned a
similar time frame but began from early September to
November. Resulting radar estimates of growing season
length for the 10 study sites ranged from 4 to 7 months and
were generally shorter at higher latitudes. Interannual
variability in radar-based estimates of annual growing
season length at each site ranged from 3 days to 2 months.
Interannual variability in the estimated timing of growing
season initiation averaged only 6 days, while variability in
the estimated timing of growing season cessation was
generally longer, averaging approximately 30 days for the
10 study sites