Lidar ratios of stratospheric volcanic ash and sulfate aerosols retrieved from CALIOP measurements
Lidar ratios of stratospheric volcanic ash and sulfate aerosols retrieved from CALIOP measurements
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从 CALIOP 测量中检索到的平流层火山灰和硫酸盐气溶胶的激光雷达比率
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发表时间：
2017
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影响因子：
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通讯作者：
M. Manton
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文献类型：
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作者：
A. Prata;S. Young;S. Siems;M. Manton
抽象的。我们对火山气溶胶层的夜间 CALIOP（正交偏振云气溶胶激光雷达）观测应用双向透射率约束，以检索 532nm 处颗粒激光雷达比 (Sp) 的估计值。该技术应用于三个火山喷发案例研究，发现这些火山喷发直接将气溶胶注入平流层。大量激光雷达观测可以表征 1-2 周内火山气溶胶层的光学和几何特性。对于 Puyehue-Cordon Caulle 喷发（2011 年 6 月）产生的富含火山灰的层，我们获得的平均颗粒激光雷达比和中值颗粒激光雷达比分别为 69±13sr 和 67sr。对于 Kasatochi（2008 年 8 月）和 Sarychev Peak（2009 年 6 月）产生的富含硫酸盐的气溶胶层，检索到的激光雷达比率的平均值分别为 66±19sr（中位数 60sr）和 63±14sr（中位数 59sr）。 Puyehue 层 (δp = 0.33±0.03) 观察到的 532nm 层积分颗粒消偏振比 (δp) 远大于 Kasatochi (δp = 0.09±0.03) 和 Sarychev (δp = 0.05 ± 0.04) 喷发产生的火山气溶胶层的值。然而，对于 Sarychev 层，我们观察到 δp 随时间从 0.27 到 0.03 呈指数衰减（e 折叠时间为 3.6 天）。对于 Sarychev 案例，观察到层积分衰减颜色比率随时间的类似下降。一般来说，Puyehue 层表现出比 Kasatochi (χ' = 0.35±0.07) 和 Sarychev (χ' = 0.32±0.07) 层更大的颜色比 (χ' = 0.53±0.07)，这表明 Puyehue 层通常由较大的颗粒组成。这些观测结果与新的平流层气溶胶子类型分类方案特别相关，该方案已纳入 2 级 CALIPSO（云气溶胶激光雷达和红外探路者卫星观测）数据产品的第 4 版。
Abstract. We apply a two-way transmittance constraint to nighttime CALIOP (Cloud-Aerosol Lidar with Orthogonal Polarization) observations of volcanic aerosol layers to retrieve estimates of the particulate lidar ratio (Sp) at 532 nm. This technique is applied to three volcanic eruption case studies that were found to have injected aerosols directly into the stratosphere. Numerous lidar observations permitted characterization of the optical and geometric properties of the volcanic aerosol layers over a time period of 1–2 weeks. For the volcanic ash-rich layers produced by the Puyehue-Cordon Caulle eruption (June 2011), we obtain mean and median particulate lidar ratios of 69 ± 13 sr and 67 sr, respectively. For the sulfate-rich aerosol layers produced by Kasatochi (August 2008) and Sarychev Peak (June 2009), the means of the retrieved lidar ratios were 66 ± 19 sr (median 60 sr) and 63 ± 14 sr (median 59 sr), respectively. The 532 nm layer-integrated particulate depolarization ratios (δp) observed for the Puyehue layers (δp = 0.33 ± 0.03) were much larger than those found for the volcanic aerosol layers produced by the Kasatochi (δp = 0.09 ± 0.03) and Sarychev (δp = 0.05 ± 0.04) eruptions. However, for the Sarychev layers we observe an exponential decay (e-folding time of 3.6 days) in δp with time from 0.27 to 0.03. Similar decreases in the layer-integrated attenuated colour ratios with time were observed for the Sarychev case. In general, the Puyehue layers exhibited larger colour ratios (χ′ = 0.53 ± 0.07) than what was observed for the Kasatochi (χ′ = 0.35 ± 0.07) and Sarychev (χ′ = 0.32 ± 0.07) layers, indicating that the Puyehue layers were generally composed of larger particles. These observations are particularly relevant to the new stratospheric aerosol subtyping classification scheme, which has been incorporated into version 4 of the level 2 CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) data products.
影响因子：
3
作者：
Gro, S.;Freudenthaler, V.;Weinzierl, B.
通讯作者：
Weinzierl, B.