The winter Arctic Oscillation, the timing of spring, and carbon fluxes in the Northern Hemisphere

摘要: [1] Various observations show trends toward warmer and earlier springs in the Northern Hemisphere. We hypothesize that positive trend winter Arctic Oscillation (AO) has led to higher temperatures, advanced spring, increased seasonal amplitudes atmospheric CO2. To test this hypothesis, we modeled leaf-out terrestrial carbon fluxes using Simple Biosphere model, Version 2 (SiB2) National Centers for Environmental Prediction (NCEP) reanalysis 1958–2002. found our were consistent with observed phenology AO can statistically explain 20–70% of eastern United States northern Europe. also temperatures associated respiration. At same time, these date leaf-out, increasing total spring uptake CO2 by plants. These seasonally asymmetric respiration photosynthesis help concentration.