chilldate

Vector - daily high temperatures for a given year

tasmax

Vector - daily low temperatures for a given year

tasmin

Vector - day of year values for a given year (1:365 or 1:366 depending on calendar)

Vector - day lengths for each day for a given year (calculated from daylength function).

daylen

Scalar - base temperature for determining chill hours. Typically this is 44.96 degrees Fahrenheit, but can be plant specific.

baset

Plant type 1 (default), 2, or 3. plant = 1 for lilac, plant = 2 for arnold red, or plant =3 for zabelli.

plant

This function calculates the estimated day of the calendar year where the chill requirement is met for each of the three plants used in the extended spring indices (SI-x, Schwarz et al. 2006; 2013).

Computes the extended spring indices (SI-x) and false spring
exposure indices (FSEI). The SI-x indices are standard indices used for
analysis in spring phenology studies. In addition, the FSEI is also from
research on the climatology of false springs and adjusted to include an
early and late false spring exposure index. The indices include the
first leaf index, first bloom index, and false spring exposure indices,
along with all calculations for all functions needed to calculate
each index. The main function returns all indices, but each function can
also be run separately.
Allstadt et al. (2015) <doi: 10.1088/1748-9326/10/10/104008>
Ault et al. (2015) <doi: 10.1016/j.cageo.2015.06.015>
Peterson and Abatzoglou (2014) <doi: 10.1002/2014GL059266>
Schwarz et al. (2006) <doi: 10.1111/j.1365-2486.2005.01097.x>
Schwarz et al. (2013) <doi: 10.1002/joc.3625>.

chilldate: Chill Date Calculator

Description

Usage

Arguments

Value

References