This repository contains a high spatial resolution database of spring onset indicators derived from the Extended Spring Indices (SI-x) phenological models as well as the code used to generate these phenological products. The SI-x models transform daily minimum and maximum temperatures into a set of consistent indices that track the timing of first leaf and first bloom for key indicator species, and that also allow the calculation of the so-called damage index by subtracting the date of first leaf from the date of the last freeze.
This dataset is available at 1 km spatial resolution and covers American (1980 to 2022) and European regions (1950 to 2020).
The first leaf and first bloom indices are validated with ground phenological observations collected over both regions.
The American product is based on DAYMET version 4 (https://daymet.ornl.gov/) and the European region on a downscaled E-Obs database version 3 (ftp://palantir.boku.ac.at/Public/ClimateData).
This product can support both scientists and decision makers in their quest to hind- and forecast climate change impacts in these areas
In the USA this product is recognized as an official climate change indicator (https://www.globalchange.gov/indicators/start-of-spring)
An interactive visualization of this database is available here: https://emma.users.earthengine.app/view/spring-onset
For more information see our publications: