Amplitude-phase characteristics of SAT annual cycle in Asia: Tendencies of change derived from observations and reanalyses and from numerical experiments with IAP RAS CM

摘要

Amplitude-phase characteristics (APCs) of surface air temperature (SAT) annual cycle (SAT) are analyzed. From meteorological observations for the XX century and meteorological reanalyses for its second half it is found that alongside with the well-known negative correlation of SAT AC amplitude T_(s,1) with annual mean SAT T_(s,m) a peculiarity in the North Pacific exists where T_(s,1) and T_(s,m) are positively intercorrelated. In contrast, SAT AC phase characteristics show more regional behaviour. In particular southward of the characteristic annual mean position of the snow-ice boundary (SIB) SAT AC is harmonized under climate warming while northward it is deharmonized. In the Far East (southward about 50°N) SAT AC shifts as a whole with its extrema occuring earlier with increasing annual mean SAT. From the energy-balance climate considerations these tendencies of change of the SAT AC APCs in the middle and high latitudes are associated to the influence of the albedo-SAT feedback due to the SIB movement and in the Far East ―to the interannual cloudiness variability. Tendencies of change for SAT AC related to the SIB movement are simulated reasonably well by the climate model of intermediate complexity in the experiments with greenhouse gases atmospheric loading. In contrast, the tendencies resulting from the cloudiness variability are not reproduced by this model.