South American Biomass Burning Analysis (SAMBBA)

生物质燃烧气溶胶(BBA)显著扰动地面通量和大气加热率，其CCN特性扰动云微物理，从而影响云的辐射特性、降水和云寿命，从而对区域辐射收支产生重大影响。除了气候变化外，对加热率和CCN的如此大的影响很可能还会影响地区天气预报。人们越来越认识到，生物质燃烧会影响生物圈，但其影响的大小需要量化。然而，由于黑碳与有机和无机物种的混合，BBA是一种复杂且鲜为人知的气溶胶物种。此外，排放量很难量化，很难用模型来表示。现在是应对这些挑战的时候了，因为测量方法和模式能力在过去几年中都得到了迅速发展，现在已经足够先进，可以通过测量来充分限制BBA的过程和性质；这些可以用来挑战用于数值天气预报和气候模式的新的气溶胶方案。亚马逊是世界上最重要的生物质燃烧地区之一，在旱季受到生物质强烈燃烧的显著影响，导致高度浑浊的条件，因此是量化这些过程并确定这些相互作用对该区域天气和气候的影响的关键环境。虽然之前已经对亚马逊地区的BBA及其辐射影响进行了大规模研究，但现在这些研究已经有十多年的历史了，鉴于近年来模型和测量的快速发展，在解决所有上述问题方面可以取得相当大的科学进展。因此，我们正在提议一个主要的联盟方案，SAMBBA，一个由7个大学伙伴和英国气象局组成的联盟，它将提供一套亚马逊BBA的地面、飞机和卫星测量数据，并利用这些数据1)改进我们对BB排放的了解；2)挑战和改进最新的气溶胶过程模式；3)挑战和改进卫星反演；4)使用具有广泛预测气溶胶计划的下一代气候和数值预报模式对亚马逊和周围地区的区域气候和天气进行测试预测；5)评估生物质燃烧对亚马逊生物圈的影响。主要的现场试验将在2012年9月进行，基地设在巴西的波尔图维洛。每年的这个时候，整个地区都会发生大范围的燃烧，导致高度浑浊的条件。英国大型研究飞机(FAAM)将用于采样气溶胶的化学、物理和光学性质以及气相前体浓度。辐射测量也将使用飞机上的先进辐射计，卫星数据也将被利用。生物质燃烧气溶胶在当地、天气、季节和气候时间尺度上的影响非常显著，需要使用一系列模型来建立和测试关键过程并量化影响。我们将用在SAMBBA期间进行的新的、全面的观测来挑战载有生物质燃烧气溶胶详细过程描述的模型，以评估模型的性能并改进参数化。将使用具有一系列复杂性和空间分辨率的数值天气预报和气候模式模拟来调查吸收气溶胶可能影响区域和更广泛尺度上的动力学和气候的方式。该办法的核心是使用一系列新的模式，这些模式可以通过对气溶胶和云的耦合描述来调查这种相互作用，以充分调查空间尺度上的反馈，这些反馈的分辨率足够好，可以评估这种过程。

Biomass burning aerosol (BBA) exerts a considerable impact on regional radiation budgets as it significantly perturbs the surface fluxes and atmospheric heating rates and its CCN properties perturb cloud microphysics and hence affect cloud radiative properties, precipitation and cloud lifetime. It is likely that such large influences on heating rates and CCN will affect regional weather predictions in addition to climatic changes. It is increasingly recognised that biomass burning affects the biosphere but the magnitude of the effects need to quantified. However, BBA is a complex and poorly understood aerosol species because of the mixing of the black carbon with organic and inorganic species. Furthermore, emission rates are poorly quantified and difficult to represent in models. It is now timely to address these challenges as both measurement methods and model capabilities have developed rapidly over the last few years and are now sufficiently advanced that the processes and properties of BBA can be sufficiently constrained by measurements; these can be used to challenge the new aerosol schemes used in numerical weather prediction (NWP) and climate models. Amazonia is one of the most important biomass burning regions in the world, being significantly impacted by intense biomass burning during the dry season leading to highly turbid conditions, and is therefore a key environment for quantifying these processes and determining the influence of these interactions on the weather and climate of the region. Though previous large scale studies of BBA over Amazonia and its radiative impacts have been performed, these are now over a decade old and considerable scientific progress can be made towards addressing all of the above questions given the rapid advance of models and measurements in recent years. We are therefore proposing a major consortium programme, SAMBBA, a consortium of 7 university partners and the UK Met Office, which will deliver a suite of ground, aircraft and satellite measurements of Amazonian BBA and use this data to 1) improve our knowledge of BB emissions; 2) challenge and improve the latest aerosol process models; 3) challenge and improve satellite retrievals; 4) test predictions of aerosol influences on regional climate and weather over Amazonia and the surrounding regions made using the next generation of climate and NWP models with extensive prognostic aerosol schemes; and 5) assess the impact of .biomass burning on the Amazonian biosphere. The main field experiment will take place during September 2012 and is based in Porto Vehlo, Brazil. At this time of year, widespread burning takes place across the region leading to highly turbid conditions. The UK large research aircraft (FAAM) will be used to sample aerosol chemical, physical and optical properties and gas phase precursor concentrations. Measurements of radiation will also be made using advanced radiometers on board the aircraft and satellite data will also be utilised. The influences of biomass burning aerosols are highly significant at local, weather, seasonal, and climate temporal scales necessitating the use of a hierarchy of models to establish and test key processes and quantify impacts. We will challenge models carrying detailed process descriptions of biomass burning aerosols with the new, comprehensive observations being made during SAMBBA to evaluate model performance and to improve parameterisations. Numerical Weather Prediction and Climate model simulations with a range of complexity and spatial resolution will be used to investigate the ways in which absorbing aerosol may influence dynamics and climate on regional and wider scales. At the heart of the approach is the use of a new range of models that can investigate such interactions using coupled descriptions of aerosols and clouds to fully investigate feedbacks at spatial scales that are sufficiently well resolved to assess such processes.