Coarse-mode mineral dust size distributions, composition and optical properties from AER-D aircraft measurements over the tropical eastern Atlantic
Coarse-mode mineral dust size distributions, composition and optical properties from AER-D aircraft measurements over the tropical eastern Atlantic
复制标题
AER-D 飞机在热带东大西洋上空测量的粗模矿物尘埃尺寸分布、成分和光学特性
DOI：
--
复制
发表时间：
2018
影响因子：
6.3
通讯作者：
B. Murray
中科院分区：
文献类型：
--
作者：
C. Ryder;F. Marenco;J. Brooke;V. Estellés;R. Cotton;P. Formenti;J. McQuaid;H. Price;Dantong Liu;P. Ausset;P. Rosenberg;Jonathan W. Taylor;T. Choularton;K. Bower;H. Coe;M. Gallagher;J. Crosier;G. Lloyd;E. Highwood;B. Murray
抽象的。矿物尘是气候系统的一个重要组成部分，
辐射平衡，云特性，地球化学循环，区域
循环和降水，以及对
航空、太阳能发电和人类健康。粉尘大小和成分
对所有这些过程都有影响。然而，尘埃大小的变化
在运输过程中的分布和组成，特别是对于粗
粒子，人们对它们的了解很少，在气候模型中也没有得到很好的体现。
在这里，我们提出了新的现场空中观测灰尘在撒哈拉空气
层（SAL）和海洋边界层（MBL）在其开始时
跨大西洋的运输途径，从气溶胶
属性-2015年8月的粉尘（AER-D）现场工作，
正值北非粉尘出口旺季。本研究着重于
粗模式粉尘特性，包括粒度分布，质量负载，
形状、组成、折射率和光学性质。大小
从0.1到100 µm直径（d）的分布，
结合了粗糙和巨大的尘埃模式。在MBL内，平均值
有效直径（deff）和体积中值直径（VMD）分别为4.6和6.0 µm，巨颗粒的众数为
20-30 µm，成分以石英为主，
d > 1 µm的铝硅酸盐。在SAL内，颗粒
直径大于20微米的卫星在5公里的高度上总是存在，
浓度超过10 - 5 cm-3，占40%以上，
尘埃总量平均deff和VMD分别为4.0和5.5 µm
分别SAL中检测到的颗粒大于可解释的颗粒
仅凭沉积理论粗模成分占主导地位，
石英和铝硅酸盐;聚集模式表现出强烈的
富含硫酸盐和海盐颗粒的贡献。在SAL中，测量
在550 nm处表示d < 2.5 µm的单次散射衍射（SSA），
0.93至0.98（平均值0.97）。光学性质计算的完整
粒径分布（0.1 < d < 100 µm）导致较低的
SSA为0.91-0.98（平均0.95），质量消光系数为0.27-0.35 m2 g−1（平均0.32 m2 g−1）。SSA的变异性主要是
受粉尘成分（主要是铁）的变化控制，而不是
与以前的观察结果相比，
在撒哈拉沙漠上，大小是主要的影响因素。重要的是
模型能够捕捉这两种尘埃的变异性和演变
成分和尺寸分布与运输，以准确地
代表了沙尘对气候的影响。这些结果提供了新的SAL
灰尘数据集，充分代表粗和巨大的颗粒，以帮助模型
验证和开发。
Abstract. Mineral dust is an important component of the climate system, affecting the
radiation balance, cloud properties, biogeochemical cycles, regional
circulation and precipitation, as well as having negative effects on
aviation, solar energy generation and human health. Dust size and composition
has an impact on all these processes. However, changes in dust size
distribution and composition during transport, particularly for coarse
particles, are poorly understood and poorly represented in climate models.
Here we present new in situ airborne observations of dust in the Saharan Air
Layer (SAL) and the marine boundary layer (MBL) at the beginning of its
transatlantic transport pathway, from the AERosol
Properties – Dust (AER-D) fieldwork in August 2015,
within the peak season of North African dust export. This study focuses on
coarse-mode dust properties, including size distribution, mass loading,
shape, composition, refractive indices and optical properties. Size
distributions from 0.1 to 100 µm diameter (d) are presented, fully
incorporating the coarse and giant modes of dust. Within the MBL, mean
effective diameter (deff) and volume median diameter (VMD) were 4.6 and 6.0 µm respectively, giant particles with a mode at
20–30 µm were observed, and composition was dominated by quartz and
alumino-silicates at d > 1 µm. Within the SAL, particles
larger than 20 µm diameter were always present up to 5 km altitude, in
concentrations over 10−5 cm−3, constituting up to 40 % of
total dust mass. Mean deff and VMD were 4.0 and 5.5 µm
respectively. Larger particles were detected in the SAL than can be explained
by sedimentation theory alone. Coarse-mode composition was dominated by
quartz and alumino-silicates; the accumulation mode showed a strong
contribution from sulfate-rich and sea salt particles. In the SAL, measured
single scattering albedos (SSAs) at 550 nm representing d < 2.5 µm were
0.93 to 0.98 (mean 0.97). Optical properties calculated for the full
size distribution (0.1 < d < 100 µm) resulted in lower
SSAs of 0.91–0.98 (mean 0.95) and mass extinction coefficients of 0.27–0.35 m2 g−1 (mean 0.32 m2 g−1). Variability in SSA was mainly
controlled by variability in dust composition (principally iron) rather than
by variations in the size distribution, in contrast with previous observations
over the Sahara where size is the dominant influence. It is important that
models are able to capture the variability and evolution of both dust
composition and size distribution with transport in order to accurately
represent the impacts of dust on climate. These results provide a new SAL
dust dataset, fully representing coarse and giant particles, to aid model
validation and development.
登录
查看更多内容
影响因子：
3.8
作者：
R. Weigel;P. Spichtinger;C. Mahnke;M. Klingebiel;A. Afchine;A. Petzold;M. Krämer;A. Costa;
通讯作者：
R. Weigel;P. Spichtinger;C. Mahnke;M. Klingebiel;A. Afchine;A. Petzold;M. Krämer;A. Costa;
DOI：
10.1002/2015jd023283
发表时间：
2015-06
期刊：
Journal of Geophysical Research: Atmospheres
影响因子：
--
作者：
H. Sodemann;T. Lai;F. Marenco;C. Ryder;C. Flamant;P. Knippertz;P. Rosenberg;M. Bart;J. McQuaid
通讯作者：
H. Sodemann;T. Lai;F. Marenco;C. Ryder;C. Flamant;P. Knippertz;P. Rosenberg;M. Bart;J. McQuaid
影响因子：
6.3
作者：
A. Rocha-Lima;J. Martins;L. Remer;M. Todd;J. H. Marsham;S. Engelstaedter;C. Ryder;C. Cavazos-Guerra;P. Artaxo;P. Colarco;R. Washington
通讯作者：
A. Rocha-Lima;J. Martins;L. Remer;M. Todd;J. H. Marsham;S. Engelstaedter;C. Ryder;C. Cavazos-Guerra;P. Artaxo;P. Colarco;R. Washington
通过耳廓狐飞机观测了解撒哈拉沙漠上的矿物尘埃和边界层过程的进展
影响因子：
6.3
作者：
Ryder C
通讯作者：
Ryder C