Metrics for assessing growing year climate similarity
Several examples of metrics that may be used to compare climate
variables are presented. The examples use cumulative growing degree
days and cumulative precipitation during the growing season to derive
metrics for the similarity of the climate variable profiles between
two or more years. The growiong season was defined to be from
May through September, and a temperature of 50 degrees Fahrenheit was
used as the base for computing growing degree days. The key metrics
use the area between the climate variable profiles for two years
to compute a normalized similarity value that is represented as a
circle in a grid allowing two climate variable to be compared
simultaneously. The diagonal of the grid is used to indicate the
relative average annual temperature of each growing year that is being
compared, ranging from blue to red for cold to hot years.
|Growing season similarity metrics for years 2007 to 2014.
The metrics are for May through September cumulative growing
degree days (upper triangle) and cumulative precipitation
(lower tringle). Colors along the diagonal indicate average
annual temperature relative to the years being compared. Blue
indicates cold, red indicates hot and shades of purple
indicate intermediate temperatures.
|Comparison of growing seasons by year using the average
differences in cumulative growing degree days and
precipitation relative to the reference year (reference year
minus all other years).
Figures for other locations and date ranges are also
|Plot of initial and final cumulative precipitation and
cumulative growing degree days for the May through September
growing season. Steeper slopes indicate higher amounts of
precipitation during the growing season.
|Cumulative growing degree days from May through
|Cumulative precipitation from May through September.
|Year-by-year differences in cumulative growing degree