Sentences with phrase «sulphate aerosol indirect effects»

Not exact matches

c G: greenhouse gases; Sul: direct sulphate aerosol effect; Suli: (first) indirect sulphate effect; OzT: tropospheric ozone; OzS: stratospheric ozone; Vol: volcanism; Sol: solar; BC+OM: black carbon and organic matter.).

Most studies consider a range of anthropogenic forcing factors, including greenhouse gases and sulphate aerosol forcing, sometimes directly including the indirect forcing effect, such as Knutti et al. (2002, 2003), and sometimes indirectly accounting for the indirect effect by using a wide range of direct forcing (e.g., Andronova and Schlesinger, 2001; Forest et al., 2002, 2006).

The bottom line is that uncertainties in the physics of aerosol effects (warming from black carbon, cooling from sulphates and nitrates, indirect effects on clouds, indirect effects on snow and ice albedo) and in the historical distributions, are really large (as acknowledged above).

Thus the balance is that soot has more positive effect than the combined direct and indirect negative effects of sulphate (and other) aerosols.

This was shown to be the case for near - surface temperatures in the PCM (Meehl et al., 2004), in the Hadley Centre Climate Model version 2 (HadCM2; Gillett et al., 2004c) and in the GFDL CM2.1 (see Table 8.1) model (Knutson et al., 2006), although none of these studies considered the indirect effects of sulphate aerosols.

In addition, some models include the indirect effects of tropospheric sulphate aerosols on clouds (e.g., Tett et al., 2002), whereas others consider only the direct radiative effect (e.g., Meehl et al., 2004).

Note that most models do not use other forcings described in Chapter 6 such as soot, the indirect effect of sulphate aerosols, or land - use changes.

In fact, most of the GCM studies of the indirect aerosol effect used sulphate as a surrogate for the total anthropogenic fraction of the aerosol (e.g., Boucher and Lohmann, 1995; Feichter et al., 1997; Lohmann and Feichter, 1997).

In terms of sulphate aerosols, both the direct radiative effects and the indirect effects on clouds were acknowledged, but the importance of carbonaceous aerosols from fossil fuel and biomass combustion was not recognised (Chapters 2, 7 and 10).

The RF bar chart was now broken into aerosol components (sulphate, fossil - fuel soot and biomass burning aerosols) with a separate range for indirect effects (Chapters 2 and 7; Sections 8.2 and 9.2).