Improved volcanic ash detection based on a hybrid reverse absorption technique

Kwon Ho Lee, Man Sing Wong, Sung Rae Chung, Eunha Sohn

Research output: Journal article publicationJournal articleAcademic researchpeer-review

14 Citations (Scopus)

Abstract

A noble volcanic ash (VA) detection method based on a hybrid reverse absorption technique was successfully applied in the analysis of major volcanic eruptions that occurred in Russia, Iceland, Chile, Italy, and Japan by using the MODerate-resolution Imaging Spectroradiometer (MODIS) observation data. Sensitivity studies using radiative-transfer simulations by using various environmental parameters such as ash loadings, sizes, layer heights, and surface emissions, revealed that VA effects on brightness temperatures (BT) can reach up to 40. K. The advantage of the hybrid algorithm is its ability to detect distinct VA pixels during the day and night from satellite observations. The results showed that the hybrid algorithm can minimize the false detection of VA pixels, while well-known reverse absorption methods show abundant false VA pixels over bright surfaces and cloud formations. Further, the time-and-space distribution of the VA pixels is in good agreement with the data pertaining to operational aerosol products obtained from the scanning imaging absorption spectrometer for atmospheric cartography (SCIAMACHY) instrument on board ESA's Envisat and the cloud-aerosol Lidar and infrared pathfinder satellite observations (CALIPSO). This novel algorithm is expected to provide a fine spatial and temporal resolution of VA monitoring from high spectral or geostationary satellite observation data.
Original languageEnglish
Pages (from-to)31-42
Number of pages12
JournalAtmospheric Research
Volume143
DOIs
Publication statusPublished - 15 Jun 2014

Keywords

  • Brightness temperature
  • Hybrid algorithm
  • MODIS
  • Reverse absorption
  • Volcanic ash

ASJC Scopus subject areas

  • Atmospheric Science

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