Burning biomass and emitting aerosols in smoke - what are the links to climate parameters?

Biomass burning, whether to fuel settlements (as discussed in post 17/11/15) or as the cause of slash-and-burn land clearing within the Amazon, elevates atmospheric aerosol levels (besides of course emitting CO2...). The map below shows the "smoke aerosol distribution (D < 2.5 μm; in μg m–2) and wind field in the BL over South America during the transect flights from Rondonia to the western Amazon" (Andeae et al, 2004).

These increased local aerosols (aerosol optical depth) within the Amazon basin in biomass-burning season, have shown to be correlated to increased cloud cover, cloud height and increased rainfall by Lin et al (2006). 

Another study, by Koren et al (2004), concluded from satellite imagery that heavy smoke over the Amazon basin reduces cumulus cloud formation by up to 37% compared to zero-smoke. 

Andeae et al (2004) has a different take at examining the "Smoking of rain clouds" - they show that cloud droplet size is reduced, delaying precipitation rain-out at lower levels. This means, that the aerosols and particulates from the biomass burning can travel longer distances in the upper cloud formations and thus spread the effect over larger areas. What I found interesting here, is that they suggest that with this delayed precipitation, cloud cover increased in height (consistent with Lin et al 2006) and tops may overshoot into the stratosphere. With the "smoke" and water vapour now becoming part of stratosphere, these very locally sourced pollutants can have an impact on large scale circulation patterns, and especially partially affect the radiative properties of the Earth. Due to the complexity of these mechanisms and factors involved, the extent of this effect cannot yet be accurately modelled, but the probability to influence the global climate circulations has been suggested to be high.

As important as this mechanism may be, Roberts et al (2003) analysed this too but concluded that the dominant factor influencing a change to the hydrological system in the Amazon remains the dominant land-use change from forest to pasture.

Thoughts: 

We can see that there are different conclusions drawn from the examination of how the smoke of burning biomass in the Amazon affects the local and even global climate parameters. One thing is for certain - the affect on cloud cover (whether it is the increased height, reduced droplet size or even reduced/increased cloud-cover all together) makes up a forcing factor that alters the natural climate. With the alterations to the natural climate induced by the patterns of land-cover change, this added forcing is another complication for the ecosystems and populations to react to.