Atmospheric brown clouds: Impacts on South Asian climate and hydrological cycle

Ramanathan et al. 10.1073/pnas.0500656102.

Supporting Information

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Supporting Text
Supporting Figure 8
Supporting Figure 9
Supporting Figure 10
Supporting Figure 11
Supporting Figure 12
Supporting Figure 13
Supporting Figure 14
Supporting Figure 15

Supporting Figure 8

Fig. 8. The regional distribution of the annual mean ABC forcing for 1995–1999. (A) Top-of-the-atmosphere forcing. (B) Surface forcing. (C) Atmospheric forcing. The forcing was obtained by differencing solar fluxes from the ABC_1998 case from those from the GHGs+SO4_1998 case.

Fig. 9. Latitudinal gradient in the ABC annual mean forcing.

Supporting Figure 10

Fig. 10. Seasonal variation in the ABC forcing for 1995–1999, averaged over Northern Indian Ocean (NIO) and South Asia. TOA, top of the atmosphere.

Fig. 11. Vertical distribution of the ABC radiative heating, averaged over South Asia and NIO.

Fig. 12. Annual mean latent heat fluxes for the ABC_1998 case for two different periods and the change between the two periods.

Supporting Figure 13

Fig. 13. The 1930–2000 trend in atmospheric temperatures (A) and humidities (B) over India.

Fig. 14. Regional pattern of simulated rainfall trend from 1930 to 2000. (A) Observed trends. (B) Simulated trends.

Supporting Figure 15

Fig. 15. Change in the meridional circulation due to the ABC from 1985 to 2000 during winter. The fields have been averaged from 60°E to 100°E, essentially covering the entire Indian Ocean and the South Asian region. The changes were obtained by differencing the 1985–2000 averaged streamlines: ABC_1998-GHGs+SO4_1998. During the wintertime, however, the ABC had an entirely different effect on the monsoonal circulation. The ABC solar heating led (Fig. 13) to rising motions north of the equator with sinking motions toward the poles (1). The net impact of this readjustment of the winter circulation is a disruption of the winter rainfall pattern (1).

1. Chung, C. E., Ramanathan, V. & Kiehl, J. T. (2002) J. Climate 15, 2462–2476.