Ash and ice clouds during the Mt Kelud February 2014 eruption as interpreted from IASI and AVHRR/3 observations

Abstract

Abstract. During the Mt Kelud February 2014 eruption the ash cloud was detectable on 13-14 February in the infrared with the reverse absorption technique by, for example, the Advanced Very High Resolution Radiometer (AVHRR/3). The Infrared Atmospheric Sounding Interferometer (IASI) observed the ash cloud also on 15 February when AVHRR did not detect any ash signal. The differences between ash detection with AVHRR/3 and IASI are discussed along with the reasons for the differences, supported by radiative transfer modelling. The effect of concurrent ice clouds on the ash detection and the ash signal in the IASI measurements is demonstrated. Specifically, a radiative transfer model is used to simulate IASI spectra with ash-only, with ice cloud only and with both ash and ice clouds. It is shown that modelled IASI spectra with ash and ice clouds reproduce the measured IASI spectra better than ash-only-or ice-only-modelled spectra. The ash and ice modelled spectra that best reproduce the IASI spectra contain about a factor of 12 less ash than the ash-only spectra that come closest to reproducing the measured spectra.

Quantitative Verification and Calibration of Volcanic Ash Ensemble Forecasts Using Satellite Data

“…Kelut, located in Java, Indonesia (7.93°S, 112.31°E, 1.73‐km summit elevation), erupted at approximately 1600 universal time coordinated (UTC) on 13 February 2014 (Kylling, ). The Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP) instrument aboard Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observations (Winker et al, ; Winker et al, ), which made an overpass over the region at around 13/1800 UTC, revealed the ash to consist of a broad region associated with the umbrella cloud reaching to a maximum altitude of about 19 km and a core region reaching to a maximum altitude of about 25 km.…”

Estimation of optimal dispersion model source parameters using satellite detections of volcanic ash

“…Kelut, located in Java, Indonesia (7.93°S, 112.31°E, 1.73 km summit elevation), erupted at approximately 1600 UTC on 13 February 2014 [ Kylling , ]. The Darwin VAAC initially estimated the maximum height of the ash cloud to be at Flight Level 450 (13.7 km) based on the MTSAT image at 1632 UTC on 13 February (Figure a) and later revised this to Flight Level 550 (16.7 km) based on the 2232 UTC on 13 February image (Figure c) several hours later.…”

Toward quantitative forecasts of volcanic ash dispersal: Using satellite retrievals for optimal estimation of source terms

“…Kelut, located in Java, Indonesia (7.93°S, 112.31°E, 1.73 km summit elevation), erupted at approximately 1600 UTC on 13 February 2014 [ Kylling , ]. The event was well covered by numerous satellite instruments including the airborne lidar (Cloud‐Aerosol Lidar with Orthogonal Polarization (CALIOP)) on board CALIPSO [ Winker et al , ].…”