CLouds and Aerosol Radiative Impacts and Forcing: Year 2016 (CLARIFY-2016)

云和气溶胶辐射影响和强迫：2016 年 (CLARIFY-2016)

• 批准号: NE/L013797/1
• 负责人: James Haywood
• 金额: $ 87.6万
• 依托单位: UNIVERSITY OF EXETER
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2016
• 资助国家: 英国
• 起止时间: 2016 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FL013797%2F1
• 关键词: CLouds; Aerosol; Radiative; Impacts; Forcing

Biomass burning aerosol (BBA) exerts a considerable impact on climate by impacting regional radiation budgets as it significantly reflects and absorbs sunlight, and its cloud nucleating properties perturb cloud microphysics and hence affect cloud radiative properties, precipitation and cloud lifetime. However, BBA is a complex and poorly understood aerosol species as it consists of a complex cocktail of organic carbon and inorganic compounds mixed with black carbon and hence large uncertainties exist in both the aerosol-radiation-interactions and aerosol-cloud-interactions, uncertainties that limit the ability of our current climate models to accurately reconstruct past climate and predict future climate change. The African continent is the largest global source of BBA (around 50% of global emissions) which is transported offshore over the underlying semi-permanent cloud decks making the SE Atlantic a regional hotspot for BBA concentrations. While global climate models agree that this is a regional hotspot, their results diverge dramatically when attempting to assess aerosol-radiation-interactions and aerosol-cloud-interactions. Hence the area presents a very stringent test for climate models which need to capture not only the aerosol geographic, vertical, absorption and scattering properties, but also the cloud geographic distribution, vertical extent and cloud reflectance properties. Similarly, in order to capture the aerosol-cloud-interactions adequately, the susceptibility of the clouds in background conditions; aerosol activation processes; uncertainty about where and when BBA aerosol is entrained into the marine bundary layer and the impact of such entrainment on the microphysical and radiative properties of the cloud result in a large uncertainty. BBA overlying cloud also causes biases in satellite retrievals of cloud properties which can cause erroneous representation of stratocumulus cloud brightness; this has been shown to cause biases in other areas of the word such as biases in precipitation in Brazil via poorly understood global teleconnection processes. It is timely to address these challenges as both measurement methods and high resolution 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. This measurement/high resolution model combination can be used to challenge the representation of aerosol-radiation-interaction and aerosol-cloud-interaction in coarser resolution numerical weather prediction (NWP) and climate models. Previous measurements in the region are limited to the basic measurements made during SAFARI-2000 when the advanced measurements needed for constraining the complex cloud-aerosol-radiation had not been developed and high resolution modelling was in its infancy.We are therefore proposing a major consortium programme, CLARIFY-2016, a consortium of 5 university partners and the UK Met Office, which will deliver a suite of ground and aircraft measurements to measure, understand, evaluate and improve:a) the physical, chemical, optical and radiative properties of BBAsb) the physical properties of stratocumulus cloudsc) the representation of aerosol-radiation interactions in weather and climate models d) the representation of aerosol-cloud interactions across a range of model scales. The main field experiment will take place during September 2016, based in Walvis Bay, Namibia. The UK large research aircraft (FAAM) will be used to measure in-situ and remotely sensed aerosol and cloud and properties while advanced radiometers on board the aircraft will measure aerosol and cloud radiative impacts. While the proposal has been written on a stand-alone basis, we are closely collaborating and coordinating with both the NASA ORACLES programme (5 NASA centres, 8 USA universities) and NSF-funded ONFIRE programme (22 USA institutes).

生物质燃烧气溶胶（BBA）通过显著反射和吸收太阳光，影响区域辐射收支，从而对气候产生重大影响，其云成核特性干扰云微物理，从而影响云的辐射特性、降水和云寿命。然而，BBA是一种复杂且知之甚少的气溶胶物种，因为它由有机碳和无机化合物与黑碳混合而成，因此在气溶胶-辐射相互作用和气溶胶-云相互作用中都存在很大的不确定性，这些不确定性限制了我们当前气候模式准确重建过去气候和预测未来气候变化的能力。非洲大陆是全球最大的BBA来源（约占全球排放量的50%），它通过潜在的半永久性云甲板向海上输送，使东南大西洋成为BBA浓度的区域热点。虽然全球气候模型一致认为这是一个区域热点，但在试图评估气溶胶-辐射相互作用和气溶胶-云相互作用时，它们的结果大相径庭。因此，该地区对气候模式提出了非常严格的考验，这些模式不仅需要捕获气溶胶的地理、垂直、吸收和散射特性，还需要捕获云的地理分布、垂直范围和云的反射率特性。同样，为了充分捕捉气溶胶与云的相互作用，云在背景条件下的敏感性；气溶胶活化过程；BBA气溶胶在何时何地被带入海洋边界层的不确定性，以及这种夹带对云的微物理和辐射特性的影响，导致了很大的不确定性。BBA覆盖的云也会导致卫星反演云特性的偏差，从而导致层积云亮度的错误表示；这已被证明会导致世界其他地区的偏差，例如巴西的降水偏差，这是由于人们对全球遥相关过程知之甚少。随着测量方法和高分辨率模型能力在过去几年中迅速发展，现在已经足够先进，可以充分限制BBA的过程和性质，因此解决这些挑战是及时的。这种测量/高分辨率模式组合可用于挑战气溶胶-辐射相互作用和气溶胶-云相互作用在粗分辨率数值天气预报（NWP）和气候模式中的表现。该地区以前的测量仅限于在SAFARI-2000期间进行的基本测量，当时还没有开发出限制复杂云-气溶胶辐射所需的高级测量，高分辨率模拟也处于初级阶段。因此，我们提出了一个主要的联合项目，CLARIFY-2016，这是一个由5所大学合作伙伴和英国气象局组成的联盟，它将提供一套地面和飞机测量，以测量、理解、评估和改进：a)物理、化学、b)层积云的物理性质；c)天气和气候模式中气溶胶-辐射相互作用的表示；d)一系列模式尺度上气溶胶-云相互作用的表示。主要的实地试验将于2016年9月在纳米比亚的沃尔维斯湾进行。英国大型研究飞机（FAAM）将用于测量现场和遥感气溶胶和云及其特性，而飞机上的先进辐射计将测量气溶胶和云的辐射影响。虽然该提案是独立编写的，但我们正在与NASA ORACLES计划（5个NASA中心，8所美国大学）和nsf资助的ONFIRE计划（22个美国研究所）密切合作和协调。

项目成果

Optimizing the performance of aerosol photoacoustic cells using a finite element model. Part 1: Method validation and application to single-resonator multipass cells

• DOI: 10.1080/02786826.2019.1650161
• 发表时间: 2019-08-29
• 期刊: AEROSOL SCIENCE AND TECHNOLOGY
• 影响因子: 5.2
• 作者: Cotterell, Michael, I;Ward, Gareth P.;Langridge, Justin M.
• 通讯作者: Langridge, Justin M.

Intercomparison of airborne and surface-based measurements during the CLARIFY, ORACLES and LASIC field experiments

CLARIFY、ORACLES 和 LASIC 现场实验期间机载和地面测量的相互比较

• DOI: 10.5194/amt-2022-59
• 发表时间: 2022
• 作者: Barrett P

Cloud processing and weeklong ageing affect biomass burning aerosol properties over the south-eastern Atlantic

• DOI: 10.1038/s43247-022-00517-3
• 发表时间: 2022-08
• 期刊: Communications Earth & Environment
• 影响因子: 7.9
• 作者: H. Che;Michal Segal-Rozenhaimer;Luyuan Zhang;Caroline Dang;P. Zuidema;Amie N. Dobracki;A. Sedlacek;H. Coe;Huihui Wu;Jonathan W. Taylor;Xiaoye Zhang;J. Redemann;J. Haywood

Sensitivity and accuracy of refractive index retrievals from measured extinction and absorption cross sections for mobility-selected internally mixed light absorbing aerosols

• DOI: 10.1080/02786826.2020.1757034
• 发表时间: 2020-05-20
• 期刊: AEROSOL SCIENCE AND TECHNOLOGY
• 影响因子: 5.2
• 作者: Cotterell, Michael I.;Szpek, Kate;Langridge, Justin M.
• 通讯作者: Langridge, Justin M.

Supplementary material to "Intercomparison of airborne and surface-based measurements during the CLARIFY, ORACLES and LASIC field experiments"

“CLARIFY、ORACLES 和 LASIC 现场实验期间机载和地面测量的相互比较”的补充材料

• DOI: 10.5194/amt-2022-59-supplement
• 发表时间: 2022
• 作者: Barrett P