Code for: Phenological Fluctuations Induce Seasonal Asymmetric Warming in Boreal Forests

Code accompanying the manuscript "Phenological Fluctuations Induce Seasonal Asymmetric Warming in Boreal Forests" (Nature Communications, 2026). The repository contains the Google Earth Engine JavaScript scripts for seasonal compositing of the MODIS products, quality masking, the persistent-forest mask and computation of the leaf area change and change-rate layers, and the Python and R scripts for the paired-grid matching, the inverse distance weighting climate-background removal, the moving-window Huber regression, the asymmetry index, the structural equation modelling and the robustness analyses (block bootstrap, baseline stratification and truncation sensitivity). All input data are public MODIS products and the FLUXNET2015 dataset, as listed in the Data Availability statement of the paper.