Volcanic Aerosol Layer Observed by Shipboard Lidar over the Tropical Western Pacific

Kamei, Atsushi; Sugimoto, Naoki; Matsui, Ichiro; Shimizu, Atsushi; Shibata, Takashi

doi:10.2151/sola.2006-001

Cited by 13 publications

(18 citation statements)

References 19 publications

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“…The peak of R was below the tropopause, but we infer that this represents the volcanic layer because its average A β at 11-13 km altitude was 0.92, whereas that of the stratospheric background aerosols at 13-15 km was 2.54, and the mean value of cirrus clouds at 8-9.5 km was 1.29 × 10 −2 . Although the stratospheric aerosol A β value at 13-15 km is a little larger than the literature value, the A β values of the volcanic aerosols and cirrus clouds are consistent with value reported by previous studies (Kamei et al, 2006;Mona et al, 2012;Ansmann et al, 2012). This result indicates that it should be possible to distinguish between a volcanic aerosol layer and underlying cirrus clouds by using the vertical profile of A β .…”

Section: Discussionsupporting

confidence: 89%

“…A β > 2 indicates relatively smaller particles (radius ≤ 0.5 µm), and A β around zero indicates larger particles (radius ≥ 0.5 µm) (Kaufman et al, 1994;Schuster et al, 2006). For background stratospheric aerosols, A β is about 2.0 (Shibata et al, 1984;Hofmann et al, 2009); for cloud layers A β is about −0.2 to 0.0 (Kamei et al, 2006;Mona et al, 2012), and for volcanic ash A β is about 1.0 (Ansmann et al, 2012). Figure 6a displays the vertical profiles of R, δ and δ p at 532 nm, and Fig.…”

Section: Discussionmentioning

confidence: 99%

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Lidar observation of the 2011 Puyehue-Cordón Caulle volcanic aerosols at Lauder, New Zealand

et al. 2014

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Section: Discussionsupporting

confidence: 89%

Section: Discussionmentioning

confidence: 99%

Lidar observation of the 2011 Puyehue-Cordón Caulle volcanic aerosols at Lauder, New Zealand

et al. 2014

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“…• E) on January 27 and 28 (Kamei et al, 2006). Manam is one of the most active volcanoes in the region; the above mentioned eruptions followed ongoing volcanic activity that started already in October 2004.…”

Section: Yearly Zonal Statisticsmentioning

confidence: 99%

“…The ash clouds of the second eruption on Jan. 28 ascended to 18 km altitude (Smithsonian Institution, 2005). Several days later, stratospheric aerosol layers were detected twice between about 18 to 20 km altitude (layer thickness ranging from 0.2 to 1.4 km) by a shipboard lidar using a Nd:YAG laser operated at 1064 nm and 532 nm (Kamei et al, 2006). The layers were detected in the Western Pacific around 0 -2 Feb.…”

Section: Yearly Zonal Statisticsmentioning

confidence: 99%

“…The elevated values in 2005 are most likely caused by stratospheric sulfate aerosols, formed out of the SO 2 cloud injected in the stratosphere by the eruptions of the Manam volcano (Papua New Guinea, 4.080 • S, 145.037 • E) on January 27 and 28 (Kamei et al, 2006). Manam is one of the most active volcanoes in the region; the above mentioned eruptions followed ongoing volcanic activity that started already in October 2004.…”

Section: Polar Stratospheric Cloudsmentioning

confidence: 99%

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Optical extinction by upper tropospheric/stratospheric aerosols and clouds: GOMOS observations for the period 2002–2008

et al. 2010

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Abstract. Although the retrieval of aerosol extinction coefficients from satellite remote measurements is notoriously difficult (in comparison with gaseous species) due to the lack of typical spectral signatures, important information can be obtained. In this paper we present an overview of the current operational nighttime UV/Vis aerosol extinction profile results for the GOMOS star occultation instrument, spanning the period from August 2002 to May 2008. Some problems still remain, such as the ones associated with incomplete scintillation correction and the aerosol spectral law implementation, but good quality extinction values are obtained at a wavelength of 500 nm. Typical phenomena associated with atmospheric particulate matter in the Upper Troposphere/Lower Stratosphere (UTLS) are easily identified: Polar Stratospheric Clouds, tropical subvisual cirrus clouds, background stratospheric aerosols, and post-eruption volcanic aerosols (with their subsequent dispersion around the globe). For the first time, we show comparisons of GO-MOS 500 nm particle extinction profiles with the ones of other satellite occultation instruments (SAGE II, SAGE III and POAM III), of which the good agreement lends credibility to the GOMOS data set. Yearly zonal statistics are presented for the entire period considered. Time series furthermore convincingly show an important new finding: the sensitivity of GOMOS to the sulfate input by moderate volcanic eruptions such as Manam (2005) itative analysis of the data agrees well with the theoretical PSC formation temperature. Therefore, the importance of the GOMOS aerosol/cloud extinction profile data set is clear: a long-term data record of PSCs, subvisual cirrus, and background and volcanic aerosols in the UTLS region, consisting of hundreds of thousands of altitude profiles with near-global coverage, with the potential to fill the aerosol/cloud extinction data gap left behind after the discontinuation of occultation instruments such as SAGE II, SAGE III and POAM III.

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Features of upper troposphere and lower stratosphere aerosols observed by lidar over Gadanki, a tropical Indian station

et al. 2008

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[1] Upper troposphere (UT) and lower stratosphere (LS) aerosol characteristics are studied over a tropical station Gadanki (13.5°N, 79.2°E), using 532-nm Nd:YAG lidar during [2001][2002][2003][2004][2005]. Scattering ratios (SR) and aerosol extinction are found to exhibit seasonal and interannual variations in UT (10-15 km) and LS (18-30 km). SR is about 1.00-1.2 in the 10-to 30-km altitude region. Aerosol extinction is about 0.5-6 Â 10 À3 km À1 . SR in UT in 2001 and 2004 during winter is lower than that of summer, whereas LS winter profiles are found to have higher SR values. SR values apparently experience a shift in altitude corresponding to the seasonal change in tropopause indicating a relation between the two. UT integrated extinction is about 2.5 times higher than LS extinction. The correlation between UT and LS monthly mean aerosol extinction was weak and negative with a coefficient of 0.4. UT and LS aerosol extinctions over Gadanki are found to exhibit an increasing trend during [2001][2002][2003][2004][2005]. The percentage contribution of integrated aerosol extinction in the 10-to 30-km region to aerosol optical depth (AOD) is about 12%. Correlation coefficient between monthly mean AOD and the 10-to 30-km integrated extinction is about 0.6. The increasing trends in UT and LS aerosols seem to support the finding that emissions from subtropical and tropical Asia may have already started to influence the amount of sulfur containing gases reaching UT and LS. This becomes relevant in the climate change context as it has been shown that increasing aerosol abundances may be impacting the monsoon.

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Volcanic Aerosol Layer Observed by Shipboard Lidar over the Tropical Western Pacific

Cited by 13 publications

References 19 publications

Lidar observation of the 2011 Puyehue-Cordón Caulle volcanic aerosols at Lauder, New Zealand

Lidar observation of the 2011 Puyehue-Cordón Caulle volcanic aerosols at Lauder, New Zealand

Optical extinction by upper tropospheric/stratospheric aerosols and clouds: GOMOS observations for the period 2002–2008

Features of upper troposphere and lower stratosphere aerosols observed by lidar over Gadanki, a tropical Indian station

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