Indirect measurements of the composition of ultrafine particles in the Arctic late-winter
Indirect measurements of the composition of ultrafine particles in the Arctic late-winter
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北极冬末超细颗粒成分的间接测量
DOI：
10.1002/essoar.10507333.1
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发表时间：
2021
影响因子：
6.3
通讯作者：
J. Smith
中科院分区：
文献类型：
--
作者：
Deanna Myers;M. Lawler;R. Mauldin;S. Sjostedt;M. Dubey;J. Abbatt;J. Smith
我们提出了间接测量的尺寸分辨超细颗粒组成进行海洋-大气-海冰-积雪（OASIS）运动在Utqiagvik，阿拉斯加州，在2009年3月期间。本研究的重点是在两个生产周期内测量的尺寸分辨颗粒吸湿性和挥发性。在代表该位置背景条件的一段时间内，90%相对湿度下的颗粒吸湿生长因子（HGF）范围为1.45至1.51，结合挥发性测量结果，表明混合物中含有约30%的氨化硫酸盐和约70%的氧化有机物。在这次活动中还观察到两个独立的区域超细颗粒生长事件。事件1与H2SO 4和太阳辐射水平升高相吻合。这些颗粒是高度吸湿的（对于35 nm颗粒，HGF= 2.1），但在160 °C下几乎完全挥发。与这两次事件有关的气团都起源于北冰洋。事件1受海洋上层边界层（200-350米AGL）的影响，而事件2花了更多的时间接近表面（50-150米AGL）和开放的海洋铅，这表明海洋的影响，在生长过程中。事件2颗粒的吸湿性略低（对于35 nm颗粒，HGF= 1.94，对于15 nm颗粒，HGF = 1.67），并且挥发性类似。我们假设在两个事件期间形成的颗粒含有60- 70体积%的吸湿性盐，事件1的平衡是硫酸盐和事件2的氧化有机物。这些观测结果表明，初级海水喷雾可能是北极冬末超细颗粒形成事件的重要引发剂，但各种过程可能是凝结增长的原因。
We present indirect measurements of size‐resolved ultrafine particle composition conducted during the Ocean‐Atmosphere‐Sea Ice‐Snowpack (OASIS) Campaign in Utqiagvik, Alaska, during March 2009. This study focuses on measurements of size‐resolved particle hygroscopicity and volatility measured over two periods of the campaign. During a period that represents background conditions in this location, particle hygroscopic growth factors (HGF) at 90% relative humidity ranged from 1.45 to 1.51, which combined with volatility measurements suggest a mixture of ∼30% ammoniated sulfates and ∼70% oxidized organics. Two separate regional ultrafine particle growth events were also observed during this campaign. Event 1 coincided with elevated levels of H2SO4and solar radiation. These particles were highly hygroscopic (HGF= 2.1 for 35 nm particles), but were almost fully volatilized at 160 °C. The air masses associated with both events originated over the Arctic Ocean. Event 1 was influenced by the upper marine boundary layer (200–350 m AGL), while Event 2 spent more time closer to the surface (50–150 m AGL) and over open ocean leads, suggesting marine influence in growth processes. Event 2 particles were slightly less hygroscopic (HGF= 1.94 for 35 nm and 1.67 for 15 nm particles), and similarly volatile. We hypothesize that particles formed during both events contained 60–70% hygroscopic salts by volume, with the balance for Event 1 being sulfates and oxidized organics for Event 2. These observations suggest that primary sea spray may be an important initiator of ultrafine particle formation events in the Arctic late‐winter, but a variety of processes may be responsible for condensational growth.