Evaluation of natural aerosols in CRESCENDO Earth system models (ESMs): mineral dust
Evaluation of natural aerosols in CRESCENDO Earth system models (ESMs): mineral dust
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DOI：
10.5194/acp-21-10295-2021
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发表时间：
2021-07
影响因子：
6.3
通讯作者：
R. Checa‐Garcia;Y. Balkanski;S. Albani;T. Bergman;K. Carslaw;A. Cozic;C. Dearden;B. Marticorena;M. Michou;T. van Noije;P. Nabat;F. O’Connor;D. Oliviè;J. Prospero;Philipp Le Sager;Michael Schulz;C. Scott
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作者：
R. Checa‐Garcia;Y. Balkanski;S. Albani;T. Bergman;K. Carslaw;A. Cozic;C. Dearden;B. Marticorena;M. Michou;T. van Noije;P. Nabat;F. O’Connor;D. Oliviè;J. Prospero;Philipp Le Sager;Michael Schulz;C. Scott
抽象的。本文介绍了一个分析的矿物粉尘气溶胶模拟的五个地球系统模式（ESM）的项目中，题为协调研究地球系统和气候：实验，知识，传播和推广（CRESCENDO）。我们量化了每个模型描述的全球粉尘循环的全球排放量，以及干和湿沉降，报告了干湿沉降的比例在模型之间的巨大差异，与排放的颗粒大小的范围不直接相关。5个ESM的多模式平均粉尘排放量为2836 Tg yr-1，但主要由于排放的最大粉尘颗粒大小的差异，因此存在很大的不确定性。四种粒径不大于10 µ m的ESM子集的多模型平均值为1664（σ=651）Tg yr−1。在模拟中，再分析得到的相同的推动风的总沙尘排放量使我们在模型之间具有更好的一致性;即在三个ESM下，多模型的平均全球排放量为1613（σ=278）Tg yr−1，而在没有推动风和相同模型的情况下，则为1834（σ=666）Tg yr−1。全球平均尘埃质量消光效率的显着差异解释了为什么即使是具有相对相似的全球尘埃负荷预算的模型也可以显示出尘埃光学厚度的强烈差异。对观测的比较已经完成的尘埃光学厚度的基础上中分辨率成像光谱仪（中分辨率成像光谱仪）卫星产品，显示全球的一致性，在优惠的尘埃源和跨大西洋运输。源区域的全球定位与MODIS是一致的，但我们发现，区域和季节性差异模型和观测时，我们量化的互相关性的时间序列的灰尘排放区域。为了忠实地比较模型之间的本地排放量，我们引入了一个重新网格化的归一化方法，也可以与来自尘埃事件频率的卫星产品进行比较。沙尘总沉降与仪器网络进行比较，以评估全球和区域差异。我们发现，模型与观测数据站远离灰尘源的因素在10内，但近似的灰尘颗粒大小分布的排放造成的实际范围内的沉积值时，仪器接近灰尘排放区域的误报。观测到的粉尘表面浓度也被复制到10倍以内。总气溶胶光学厚度与AERONET（AErosol ROBOtic NETwork）站，灰尘占主导地位的比较显示模型之间的差异很大，虽然增加模型间的一致性时，模拟进行轻推风。模型集合一致性的增加也意味着更好的协议与观测，我们已经确定的灰尘总沉积，表面浓度和光学深度（对AERONET和MODIS检索）。我们介绍了一种方法来确定每个模式的贡献一致的多模态的直接辐射效应，我们适用于研究的直接辐射效应的多模态表示的尘埃颗粒尺寸分布，包括最大的颗粒。
Abstract. This paper presents an analysis of the mineral dust aerosol modelled by five Earth system models (ESMs) within the project entitled Coordinated Research in Earth Systems and Climate: Experiments, kNowledge, Dissemination and Outreach (CRESCENDO). We quantify the global dust cycle described by each model in terms of global emissions, together with dry and wet deposition, reporting large differences in the ratio of dry over wet deposition across the models not directly correlated with the range of particle sizes emitted. The multi-model mean dust emissions with five ESMs is 2836 Tg yr−1 but with a large uncertainty due mainly to the difference in the maximum dust particle size emitted. The multi-model mean of the subset of four ESMs without particle diameters larger than 10 µ m is 1664 (σ=651) Tg yr−1. Total dust emissions in the simulations with identical nudged winds from reanalysis give us better consistency between models; i.e. the multi-model mean global emissions with three ESMs are 1613 (σ=278) Tg yr−1, but 1834 (σ=666) Tg yr−1 without nudged winds and the same models. Significant discrepancies in the globally averaged dust mass extinction efficiency explain why even models with relatively similar global dust load budgets can display strong differences in dust optical depth. The comparison against observations has been done in terms of dust optical depths based on MODIS (Moderate Resolution Imaging Spectroradiometer) satellite products, showing global consistency in terms of preferential dust sources and transport across the Atlantic. The global localisation of source regions is consistent with MODIS, but we found regional and seasonal differences between models and observations when we quantified the cross-correlation of time series over dust-emitting regions. To faithfully compare local emissions between models we introduce a re-gridded normalisation method that can also be compared with satellite products derived from dust event frequencies. Dust total deposition is compared with an instrumental network to assess global and regional differences. We find that models agree with observations within a factor of 10 for data stations distant from dust sources, but the approximations of dust particle size distribution at emission contributed to a misrepresentation of the actual range of deposition values when instruments are close to dust-emitting regions. The observed dust surface concentrations also are reproduced to within a factor of 10. The comparison of total aerosol optical depth with AERONET (AErosol RObotic NETwork) stations where dust is dominant shows large differences between models, although with an increase in the inter-model consistency when the simulations are conducted with nudged winds. The increase in the model ensemble consistency also means better agreement with observations, which we have ascertained for dust total deposition, surface concentrations and optical depths (against both AERONET and MODIS retrievals). We introduce a method to ascertain the contributions per mode consistent with the multi-modal direct radiative effects, which we apply to study the direct radiative effects of a multi-modal representation of the dust particle size distribution that includes the largest particles.