Abstract. We profile trace gas and particulate emissions from near-field airborne measurements of discrete smoke plumes in Brazil during the 2012 biomass burning season.

A strong blocking anticyclone developed over Scandinavia through the last week of February and persisted into early March 2018, driving a bitter easterly wind from Siberia and bringing a severe cold outbreak and significant snowfall to the UK. A second spell of severe weather and low temperatures then returned to the UK over 17–19 March. The severe weather was preceded by a split in the stratospheric polar vortex and the onset of a sudden stratospheric warming event. In turn, there was an equatorward shift in the tropospheric Atlantic jet, which set up an amplified Greenland ridge that stretched from central Russia, over Scandinavia to Iceland, and across the North Atlantic to Hudson Bay. Here, we revisit the severe cold outbreak that impacted the UK, discussing the sequence of events and synoptic setup, followed by a more in‐depth examination of the contributing factors, including a sudden stratospheric warming event.

Abstract. Biomass burning represents one of the largest sources of particulate matter to the atmosphere, which results in a significant perturbation to the Earth's radiative balance coupled with serious negative impacts on public health. Globally, biomass burning aerosols are thought to exert a small warming effect of 0.03 Wm -2 , however the uncertainty is 4 times greater than the central estimate. On regional scales, the impact is substantially greater, particularly in areas such as the Amazon Basin where large, intense and frequent burning occurs on an annual basis for several months (usually from August-October). Furthermore, a growing number of people live within the Amazon region, which means that they are subject to the deleterious effects on their health from exposure to substantial volumes of polluted air. Initial results from the South American Biomass Burning Analysis (SAMBBA) field experiment, which took place during September and October 2012 over Brazil, are presented here. A suite of instrumentation was flown on-board the UK Facility for Airborne Atmospheric Measurement (FAAM) BAe-146 research aircraft and was supported by ground based measurements, with extensive measurements made in Porto Velho, Rondonia. The aircraft sampled a range of conditions with sampling of fresh biomass burning plumes, regional haze and elevated biomass burning layers within the free troposphere. The physical, chemical and optical properties of the aerosols across the region will be characterized in order to establish the impact of biomass burning on regional air quality, weather and climate.

Abstract. We profile trace gas and particulate emissions from near-field airborne measurements of discrete smoke plumes in ) and more than six times the amount of organic aerosol was emitted from the rainforest fire per unit of fuel combustion (EF OC of 5.00 ± 1.58 g kg ).Particulate phase species emitted from the fires sampled are generally lower than those reported in previous studies and in emission inventories, which is likely a combination of differences in fire combustion efficiency and fuel content, along 15 with different measurement techniques. Previous modelling studies focussed on the biomass burning season in tropical South America have required significant scaling of emissions to reproduce in-situ and satellite aerosol concentrations over the region.Our results do not indicate that emission factors used in inventories are biased low, which could be one potential cause of the 1 Atmos. Chem. Phys. Discuss.,

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