TY - JOUR

T1 - Modeling the stratospheric warming following the Mt. Pinatubo eruption

T2 - uncertainties in aerosol extinctions

AU - Arfeuille, F.

AU - Luo, B. P.

AU - Heckendorn, P.

AU - Weisenstein, D.

AU - Sheng, J. X.

AU - Rozanov, E.

AU - Schraner, M.

AU - Broennimann, S.

AU - Thomason, L. W.

AU - Peter, T.

PY - 2013

Y1 - 2013

N2 - In terms of atmospheric impact, the volcanic eruption of Mt. Pinatubo (1991) is the best characterized large eruption on record. We investigate here the model-derived stratospheric warming following the Pinatubo eruption as derived from SAGE II extinction data including recent improvements in the processing algorithm. This method, termed SAGE_ 4 lambda, makes use of the four wavelengths (385, 452, 525 and 1024 nm) of the SAGE II data when available, and uses a data- filling procedure in the opacity- induced "gap" regions. Using SAGE II we derived aerosol size distributions that properly reproduce extinction coefficients also at much longer wavelengths. This provides a good basis for calculating the absorption of terrestrial infrared radiation and the resulting stratospheric heating. However, we also show that the use of this data set in a global chemistry- climate model (CCM) still leads to stronger aerosol- induced stratospheric heating than observed, with temperatures partly even higher than the already too high values found by many models in recent general circulation model (GCM) and CCM intercomparisons. This suggests that the overestimation of the stratospheric warming after the Pinatubo eruption may not be ascribed to an insufficient observational database but instead to using outdated data sets, to deficiencies in the implementation of the forcing data, or to radiative or dynamical model artifacts. Conversely, the SAGE_4 lambda approach reduces the infrared absorption in the tropical tropopause region, result- ing in a significantly better agreement with the post- volcanic temperature record at these altitudes.

AB - In terms of atmospheric impact, the volcanic eruption of Mt. Pinatubo (1991) is the best characterized large eruption on record. We investigate here the model-derived stratospheric warming following the Pinatubo eruption as derived from SAGE II extinction data including recent improvements in the processing algorithm. This method, termed SAGE_ 4 lambda, makes use of the four wavelengths (385, 452, 525 and 1024 nm) of the SAGE II data when available, and uses a data- filling procedure in the opacity- induced "gap" regions. Using SAGE II we derived aerosol size distributions that properly reproduce extinction coefficients also at much longer wavelengths. This provides a good basis for calculating the absorption of terrestrial infrared radiation and the resulting stratospheric heating. However, we also show that the use of this data set in a global chemistry- climate model (CCM) still leads to stronger aerosol- induced stratospheric heating than observed, with temperatures partly even higher than the already too high values found by many models in recent general circulation model (GCM) and CCM intercomparisons. This suggests that the overestimation of the stratospheric warming after the Pinatubo eruption may not be ascribed to an insufficient observational database but instead to using outdated data sets, to deficiencies in the implementation of the forcing data, or to radiative or dynamical model artifacts. Conversely, the SAGE_4 lambda approach reduces the infrared absorption in the tropical tropopause region, result- ing in a significantly better agreement with the post- volcanic temperature record at these altitudes.

KW - 2-DIMENSIONAL MODEL

KW - SIZE DISTRIBUTION

KW - SURFACE-AREA

KW - VALIDATION

KW - EVOLUTION

KW - TRANSPORT

KW - CLIMATE

KW - PARAMETERIZATION

KW - INSTRUMENTS

KW - RETRIEVAL

U2 - 10.5194/acp-13-11221-2013

DO - 10.5194/acp-13-11221-2013

M3 - статья

VL - 13

SP - 11221

EP - 11234

JO - Atmospheric Chemistry and Physics

JF - Atmospheric Chemistry and Physics

SN - 1680-7316

IS - 22

ER -