摘要
Summer precipitation anomalies over eastern China axe characterized spatially by meridionally banded structnres fluctu- ating on interannual and interdecadal timescales, leading to regional droughts and floods. In addition to long-term trends, how these patterns may change under global warming has important implications for agricultural planning and water resources over this densely populated area. Using the latest Hadley Centre climate model, HadGEM3-GC2, this paper investigates the potential response of summer precipitation patterns over this region, by comparing the leading modes between a 4×CQ simulation and the model＇s pre-industrial control simulation. Empirical Orthogonal Function （EOF） analyses show that the first two leading modes account for about 20% of summer rainfall variability. EOF1 is a monopole mode associated with the developing phase of ENSO events and EOF2 is a dipole mode associated with the decaying phase of ENSO. Under 4×CO2 forcing, the dipole mode with a south-north orientation becomes dominant because of a strengthened influence from exces- sive warming of the Indian Ocean. On interdecadal time scales, the first EOF looks very different from the control simulation, showing a dipole mode of east-west contrast with enhanced influence from high latitudes.
Summer precipitation anomalies over eastern China axe characterized spatially by meridionally banded structnres fluctu- ating on interannual and interdecadal timescales, leading to regional droughts and floods. In addition to long-term trends, how these patterns may change under global warming has important implications for agricultural planning and water resources over this densely populated area. Using the latest Hadley Centre climate model, HadGEM3-GC2, this paper investigates the potential response of summer precipitation patterns over this region, by comparing the leading modes between a 4×CQ simulation and the model＇s pre-industrial control simulation. Empirical Orthogonal Function （EOF） analyses show that the first two leading modes account for about 20% of summer rainfall variability. EOF1 is a monopole mode associated with the developing phase of ENSO events and EOF2 is a dipole mode associated with the decaying phase of ENSO. Under 4×CO2 forcing, the dipole mode with a south-north orientation becomes dominant because of a strengthened influence from exces- sive warming of the Indian Ocean. On interdecadal time scales, the first EOF looks very different from the control simulation, showing a dipole mode of east-west contrast with enhanced influence from high latitudes.
基金
jointly sponsored by the National Key R&D Program of China(Grant No.2016YFA0600404)
the National Natural Science Foundation of China(Grant Nos.41530532 and 41605057)
the China Special Fund for Meteorological Research in the Public Interest(Grant No.GYHY201506001-1)
the Jiangsu Collaborative Innovation Center for Climate Change,and the UK-China Research & Innovation Partnership Fund through the Met Office Climate Science for Service Partnership(CSSP) China as part of the Newton Fund
