Fig. 4: Physical interpretation of changes in individual feedback parameters.
From: The radiative feedback continuum from Snowball Earth to an ice-free hothouse
a Inversion strength, plotted as the difference in annual-mean zonal-mean potential temperature Θ between the 700-hPa level (Θ700) and the surface (Θs). b Spatial structure of the annual-mean zonal-mean lapse-rate feedback parameter value (see SI Section S3). The spatial mean of this field gives the differential lapse-rate feedback parameter as estimated using annual-mean global-mean fields (SI Fig. S6). c Lapse-rate feedback parameter \({\lambda }_{L}^{{{{{{\rm{diff}}}}}}}\). The red line is an approximation using only the global-mean atmospheric temperature profile, given by Eq. (S19) in SI Section S3, and the blue line is \({\lambda }_{L}^{{{{{{\rm{diff}}}}}}}\) repeated from Fig. 3. d Global ice area (as in Fig. 1c). e Albedo feedback parameter. The red line is an approximation using only the sensitivity of the total ice area to global temperature (i.e., the slope of the curve in d), given by Eq. (S21) in SI Section S3, and the blue line is \({\lambda }_{\alpha }^{{{{{{\rm{diff}}}}}}}\) repeated from Fig. 3. f Pattern of amplified surface warming, shown as the change in the local departure of the zonal-mean temperature from the global-mean temperature, normalized by the change in the global-mean temperature (see SI Section S3). The black vertical dashed line in each panel indicates the pre-industrial (PI) climate. In a, b, and f, the black solid line indicates the 50% contour of the ice cover. All quantities are plotted versus the global surface temperature T.
