Abstract. An increase in stratospheric aerosols caused by the volcanic eruption of Mt. Nabro (13.37 • N, 41.70 •

Abstract. On 4 June 2011, the Puyehue-Cordón Caulle volcanic complex (40.6 • S, 72

No abstract

Abstract. An increase in stratospheric aerosols caused by the volcanic eruption of Mt. Nabro (13.37° N, 41.70° E) on 12 June 2011 was first detected by lidar at Tsukuba (36.05° N, 140.13° E) and Saga (33.24° N, 130.29° E) in Japan. The maximum backscattering ratios at a wavelength of 532 nm were 2.0 at 17.0 km on 10 July 2011 at Tsukuba and 3.6 at 18.2 km on 23 June 2011 at Saga. The maximum integrated backscattering coefficients (IBCs) above the first tropopause height were 4.18 × 10−4 sr−1 on 11 February 2012 at Tsukuba and 4.19 × 10−4 sr−1 on 23 June 2011 at Saga, respectively. A time series of lidar observational results at Tsukuba have also been reported from January 2008 through May 2012. Increases in stratospheric aerosols were observed after the volcanic eruptions of Mt. Kasatochi (52.18° N, 175.51° E) in August 2008 and Mt. Sarychev Peak (48.09° N, 153.20° E) in June 2009. The yearly averaged IBCs at Tsukuba were 2.60 × 10−4 sr−1, 2.52 × 10−4 sr−1, 2.45 × 10−4 sr−1, and 2.20 × 10−4 sr−1 for 2008, 2009, 2010, and 2011, respectively. These values were about twice the IBC background level (1.21 × 10−4 sr−1) from 1997 to 2001 at Tsukuba. We briefly discuss the influence of the increased aerosols on climate and the implications for analysis of satellite data.

Abstract. On 4 June 2011, the Puyehue-Cordón Caulle volcanic complex (40.6° S, 72.1° W) in Chile erupted violently and injected volcanic aerosols into the atmosphere. For the safety of civil aviation, continuous lidar observations were made at Lauder, New Zealand (45.0° S, 169.7° E), from 11 June through 6 July 2011. To study the influence of the volcanic aerosols on Greenhouse gases Observing SATellite (GOSAT) products, we analyzed lidar data at a wavelength of 532 nm and derived the backscattering ratio and depolarization ratio profiles. During June and July, within the altitude range of 10–15 km, the volcanic aerosols had high depolarization ratios (20–35%), an indication of non-spherical volcanic ash particles. The time series of the backscattering ratio during continuous observations had three peaks occurring at about 12 day intervals: 26.7 at 11.2 km on 11 June, 18.1 at 12.0 km on 23 June, and 5.3 at 11.1 km on 6 July. The optical depth of the volcanic aerosols was 0.45 on 11 June, when the continuous lidar observation started, 0.31 on 23 June, and 0.12 on 6 July. The depolarization ratio values remained high up to a month after the eruption and the small wavelength exponent calculated from the backscattering coefficients at 532 nm and 1064 nm suggest that a major constituent of the volcanic aerosols was large, non-spherical particles. The presence of volcanic ash in the stratosphere might affect the error in GOSAT XCO2 retrieval using the 1.6 μm band.