The newest shaded area is the normalized histogram of month-to-month indicate P

The newest shaded area is the normalized histogram of month-to-month indicate P

This type of performance recommend that the latest robust matchmaking ranging from regular differences in tropical SST gradients and you may ITCZ venue present in the fresh observations is also utilized in paired environment models

Histograms of PCent in the CMIP3 PI models and observations. Cent and the seasonal range (defined as twice the amplitude of the annual harmonic) of PPenny is given by the dashed lines attaching the filled dots (representing the climatological northernmost and southernmost extent). The annual average for each model is also shown with the shaded diamond. The models are organized on the y axis and color coded by annual average PCent with the same color bar used in Fig. 6. Observations are given by the thick magenta line and the CMIP3 ensemble average is shown in the thick black lines. The vertical dashed black lines are the ensemble average annual mean, northernmost, and southernmost extent PPenny.

These types of efficiency advise that this new powerful relationships anywhere between regular variations in warm SST gradients and you can ITCZ area noticed in the new findings try including found in combined environment habits

Histograms of PCent in the CMIP3 PI models and observations. Penny and the seasonal range (defined as twice the amplitude of the annual harmonic) of PCent is given by the dashed lines attaching the filled dots (representing the climatological northernmost and southernmost extent). The annual average for each model is also shown with the shaded diamond. The models are organized on the y axis and color coded by annual average PCent with the same color bar used in Fig. 6. Observations are given by the thick magenta line and the CMIP3 ensemble average is shown in the thick black lines. The vertical dashed black lines are the ensemble average annual mean, northernmost, and southernmost extent PCent.

The seasonal amplitude of AHTEQ is 2.5 ± 0.3 PW in the models and is larger but within the error bars of that found in the observations (2.2 PW; Table 2). As a consequence, the seasonal amplitude in PCent of 6.6° ± 0.8° is also larger than that in the observations (6.3°). The amplitude and phasing of ?SWABS?, ?OLR?, and ?STORATMOS? closely match those found in the observations (cf. the shaded regions and the solid lines in Fig. 4). In contrast, ?SHF? in the models lags ?SHF? in the observations by 16 days on average. As a result, the net hemispheric contrast in energy input to the atmospheric column is more in phase with the insolation in the models than in the observations and AHTEQ lags the insolation by 25 days in the models as compared to 46 days in the observations. This offers a partial explanation for why the seasonal migration of PPenny lags that in AHTEQ in the models (by 29 days) but not in the observations. However, the root cause of this discrepancy and its relationship to the seasonal migration of the Hadley circulation is unclear to us.

The seasonal amplitude and the regression coefficient (given by the slope of the line) between PPenny and ?SST for each CMIP3 ensemble member is shown in the lower panel of Fig. 6 along with the observations. The ensemble average of the seasonal amplitude of ?SST is 2.0 ± 0.3 K and compares well with that in the observations (1.8 K). Seasonal variations in ?SST are highly correlated with seasonal variations in PPenny in all models with an ensemble mean correlation coefficient of 0.97. The regression coefficient between PPenny and ?SST is 3.7° K ?1 in the CMIP3 ensemble average and compares well with that in the observations (3.3° K ?1 ) but varies significantly (standard deviation of 0.7° K ?1 ) between models (Table 2).