Pérez Sosa, Eduardo Serrano-Notivoli, Roberto Fraga, Helder Saz, Miguel Ángel Hernández-Navarro, María Luz Prospective analysis of spatiotemporal variations in chill during winter, heat accumulation for flowering and spring frost in fruit trees in northeast Spain Int. j. biometeorol. 10.1007/s00484-026-03214-4 2026 2026