A quantitative comparison study for Raman lidar and ceilometer observations, and for model simulations of mass concentration estimates of smoke particles is presented. Layers of biomass burning aerosol particles were observed in the lower troposphere, at 2 to 5 km height on 4 to 6 June 2019, over Kuopio, Finland. These long-range-transported smoke particles originated from a Canadian wildfire event. The most pronounced smoke plume detected on 5 June was intensively investigated. Optical properties were retrieved from the multi-wavelength Raman polarization lidar Polly^XT. Particle linear depolarization ratios (PDRs) of this plume were measured to be 0.08±0.02 at 355 nm and 0.05±0.01 at 532 nm, suggesting the presence of partly coated soot particles or particles that have mixed with a small amount of dust or other non-spherical aerosol type. The layer-mean PDR at 355 nm (532 nm) decreased during the day from ∼0.11 (0.06) in the morning to ∼0.05 (0.04) in the evening; this decrease with time could be linked to the particle aging and related changes in the smoke particle shape properties. Lidar ratios were derived as 47±5 sr at 355 nm and 71±5 sr at 532 nm. A complete ceilometer data processing for a Vaisala CL51 ceilometer is presented from a sensor-provided attenuated backscatter coefficient to particle mass concentration (including the water vapor correction for high latitude for the first time). Aerosol backscatter coefficients (BSCs) were measured at four wavelengths (355, 532, 1064 nm from Polly^XT and 910 nm from CL51). Two methods, based on a combined lidar and sun-photometer approach, are applied for mass concentration estimations from both Polly^XT and the ceilometer CL51 observations. In the first method, no. 1, we used converted BSCs at 532 nm (from measured BSCs) by corresponding measured backscatter-related Ångström exponents, whereas in the second method, no. 2, we used measured BSCs at each wavelength independently. A difference of ∼12 % or ∼36 % was found between Polly^XT and CL51 estimated mass concentrations using method no. 1 or no. 2, showing the potential of mass concentration estimates from a ceilometer. Ceilometer estimations have an uncertainty of ∼50 % in the mass retrieval, but the potential of the data lies in the great spatial coverage of these instruments. The mass retrievals were compared with the Modern-Era Retrospective analysis for Research and Applications, version 2 (MERRA-2) meteorological and aerosol reanalysis. The inclusion of dust (as indicated by MERRA-2 data) in the retrieved mass concentration is negligible considering the uncertainties, which also shows that ceilometer observations for mass retrievals can be used even without exact knowledge of the composition of the smoke-dominated aerosol plume in the troposphere.

中文翻译：

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来自多波长拉曼偏振激光雷达和芬兰云高仪的远程传输加拿大生物质燃烧气溶胶的质量浓度估计

介绍了拉曼激光雷达和云高仪观测的定量比较研究，以及烟雾粒子质量浓度估计的模型模拟。2019 年 6 月 4 日至 6 日，在芬兰库奥皮奥上空，在 2 至 5 公里高的对流层低层观察到了生物质燃烧气溶胶颗粒层。这些远程传输的烟雾颗粒源于加拿大的一次野火事件。对 6 月 5 日检测到的最明显的烟羽进行了深入调查。从多波长拉曼偏振激光雷达 Polly ^XT检索光学特性。该羽流的粒子线性去极化率 (PDR)在 355 nm 处测量为0.08±0.02和0.05±0.01在 532 nm 处，表明存在部分涂覆的烟灰颗粒或与少量灰尘或其他非球形气溶胶类型混合的颗粒。在355nm（532纳米）的层均值PDR白天从降低 ~0.11（0.06）在早晨~0.05晚上（0.04）; 这种随时间的减少可能与颗粒老化和烟雾颗粒形状特性的相关变化有关。激光雷达比率 在 355 nm 和71±5处推导出为47±5 sr sr 在 532 nm。维萨拉 CL51 云高仪的完整云高仪数据处理是从传感器提供的衰减后向散射系数到粒子质量浓度（包括首次对高纬度进行水汽校正）。气溶胶反向散射系数 (BSC) 在四个波长（来自 Polly ^{XT 的}355、532、1064 nm 和来自 CL51 的 910 nm）进行测量。基于组合激光雷达和太阳光度计方法的两种方法被应用于两种 Polly ^{XT 的}质量浓度估计和云高仪 CL51 观测。在第一种方法中，没有。1，我们使用了 532 nm 的转换 BSC（来自测量的 BSC）通过相应的测量反向散射相关 Ångström 指数，而在第二种方法中，没有。2，我们在每个波长独立使用测量的 BSC。的差异〜12  ％或〜36  ％的波利之间发现^XT和CL51估计使用方法没有质量浓度。1 或没有。图 2 显示了云高仪估计质量浓度的潜力。云高仪估计的不确定性约为 50 % 在质量检索中，但数据的潜力在于这些仪器的巨大空间覆盖范围。将质量反演与研究和应用的现代时代回顾性分析第 2 版 (MERRA-2) 气象和气溶胶再分析进行了比较。考虑到不确定性，在检索到的质量浓度中包含的灰尘（如 MERRA-2 数据所示）可以忽略不计，这也表明，即使不准确了解以烟雾为主的气溶胶羽流的成分，也可以使用云高仪观测进行质量检索在对流层。