Lidar observation and model simulation of a volcanic-ash-induced cirrus cloud during the Eyjafjallajökull eruption

Abstract. Heterogeneous ice formation induced by volcanic ash from the Eyjafjallajokull volcano eruption in April 2010 is investigated based on the combination of a cirrus cloud observed with a backscatter lidar over Julich (western Germany) and model simulations along backward trajectories. The microphysical properties of the cirrus cloud could only be represented by the microphysical model under the assumption of an enhanced number of efficient ice nuclei originating from the volcanic eruption. The ice nuclei (IN) concentration determined by lidar measurements directly before and after cirrus cloud occurrence implies a value of around 0.1 cm−3 (in comparison normal IN conditions: 0.01 cm−3). This leads to a cirrus cloud with rather small ice crystals having a mean radius of 12 μm and a modification of the ice particle number (0.08 cm−3 instead of 3 × 10−4 cm−3 under normal IN conditions). The effectiveness of ice nuclei was estimated by the use of the microphysical model and the backward trajectories based on ECMWF data, establishing a freezing threshold of around 105% relative humidity with respect to ice in a temperature range from −45 to −55 °C . Only with these highly efficient ice nuclei was it possible for the cirrus cloud to be formed in a slightly supersaturated environment.

[1]  Philippe Labazuy,et al.  Eyjafjallajökull ash concentrations derived from both lidar and modeling , 2012 .

[2]  Richard Cotton,et al.  In situ observations of volcanic ash clouds from the FAAM aircraft during the eruption of Eyjafjallajökull in 2010 , 2012 .

[3]  V. Freudenthaler,et al.  Dual-wavelength linear depolarization ratio of volcanic aerosols: Lidar measurements of the Eyjafjallajökull plume over Maisach, Germany , 2012 .

[4]  T. Leisner,et al.  Ice nucleation properties of fine ash particles from the Eyjafjallajökull eruption in April 2010 , 2011 .

[5]  Albert Ansmann,et al.  Ash and fine-mode particle mass profiles from EARLINET-AERONET observations over central Europe after the eruptions of the Eyjafjallajökull volcano in 2010 , 2011 .

[6]  Albert Ansmann,et al.  Evaluating the structure and magnitude of the ash plume during the initial phase of the 2010 Eyjafjallajökull eruption using lidar observations and NAME simulations , 2011 .

[7]  Albert Ansmann,et al.  Ice formation in ash‐influenced clouds after the eruption of the Eyjafjallajökull volcano in April 2010 , 2011 .

[8]  B. Luo,et al.  Ice nucleation properties of volcanic ash from Eyjafjallajökull , 2011 .

[9]  H. Bingemer,et al.  Atmospheric ice nuclei in the Eyjafjallajökull volcanic ash plume , 2011 .

[10]  Josef Gasteiger,et al.  Volcanic ash from Iceland over Munich: mass concentration retrieved from ground-based remote sensing measurements , 2010 .

[11]  U. Schumann,et al.  Airborne observations of the Eyjafjalla volcano ash cloud over Europe during air space closure in April and May 2010 , 2010 .

[12]  D. Cziczo,et al.  Impact of heterogeneous ice nuclei on homogeneous freezing events in cirrus clouds , 2010 .

[13]  V. Freudenthaler,et al.  The 16 April 2010 major volcanic ash plume over central Europe: EARLINET lidar and AERONET photometer observations at Leipzig and Munich, Germany , 2010 .

[14]  M. Krämer.  The role of heterogeneous freezing in cirrus formation: new model sensitivity studies , 2010 .

[15]  M. D. Petters,et al.  Predicting global atmospheric ice nuclei distributions and their impacts on climate , 2010, Proceedings of the National Academy of Sciences.

[16]  Vincent Noel,et al.  A global view of horizontally oriented crystals in ice clouds from Cloud‐Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) , 2010 .

[17]  S. Brooks,et al.  Heterogeneous freezing of ice on atmospheric aerosols containing ash, soot, and soil , 2009 .

[18]  David N. Whiteman,et al.  Accuracy assessment and correction of Vaisala RS92 radiosonde water vapor measurements , 2009 .

[19]  E. O'connor,et al.  Doppler lidar measurements of oriented planar ice crystals falling from supercooled and glaciated layer clouds , 2009, 0906.0701.

[20]  G. McFarquhar,et al.  Ice nuclei characteristics from M‐PACE and their relation to ice formation in clouds , 2009 .

[21]  Robin J. Hogan,et al.  Fast Lidar and Radar Multiple-Scattering Models. Part I: Small-Angle Scattering Using the Photon Variance–Covariance Method , 2008 .

[22]  H. Bunz,et al.  MAID: a model to simulate UT/LS aerosols and ice clouds , 2008 .

[23]  J. B. Smith,et al.  Supersaturations, microphysics and nitric acid partitioning in a cold cirrus cloud observed during CR-AVE 2006: an observation–modelling intercomparison study , 2008 .

[24]  G. Ernst,et al.  Ice nucleation and overseeding of ice in volcanic clouds , 2008 .

[25]  Richard H. Johnson,et al.  Ten Years of Measurements of Tropical Upper-Tropospheric Water Vapor by MOZAIC. Part II: Assessing the ECMWF Humidity Analysis , 2008 .

[26]  Albert Ansmann,et al.  Influence of Saharan dust on cloud glaciation in southern Morocco during the Saharan Mineral Dust Experiment , 2008 .

[27]  K. Gierens,et al.  Modelling of cirrus clouds – Part 1a: Model description and validation , 2008 .

[28]  Fabrizio Ravegnani,et al.  Contribution of mixing to upward transport across the Tropical Tropopause Layer (TTL) , 2007 .

[29]  B. Gary.  Mesoscale temperature fluctuations in the stratosphere , 2006 .

[30]  Johannes Hendricks,et al.  Physically based parameterization of cirrus cloud formation for use in global atmospheric models , 2006 .

[31]  B. Luo,et al.  The Origin of High Ice Crystal Number Densities in Cirrus Clouds , 2005 .

[32]  Andrew J. Heymsfield,et al.  Extinction‐ice water content‐effective radius algorithms for CALIPSO , 2005 .

[33]  Ulrike Lohmann,et al.  A parameterization of cirrus cloud formation: Heterogeneous freezing , 2003 .

[34]  D. McKenna,et al.  A new Chemical Lagrangian Model of the Stratosphere (CLaMS) 1. Formulation of advection and mixing , 2002 .

[35]  Kenneth Sassen,et al.  A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part II: Microphysical Properties Derived from Lidar Depolarization , 2001 .

[36]  J. Comstock,et al.  A Midlatitude Cirrus Cloud Climatology from the Facility for Atmospheric Remote Sensing. Part III: Radiative Properties , 2001 .

[37]  B. Luo,et al.  Water activity as the determinant for homogeneous ice nucleation in aqueous solutions , 2000, Nature.

[38]  U. Wandinger,et al.  Multiple-Scattering Influence on Extinction-and Backscatter-Coefficient Measurements with Raman and High-Spectral-Resolution Lidars. , 1998, Applied optics.

[39]  K. Sassen.  Evidence for Liquid-Phase Cirrus Cloud Formation from Volcanic Aerosols: Climatic Implications , 1992, Science.

[40]  F. G. Fernald.  Analysis of atmospheric lidar observations: some comments. , 1984, Applied optics.

[41]  J. Klett.  Stable analytical inversion solution for processing lidar returns. , 1981, Applied optics.

[42]  A. Delany,et al.  Airborne ice nuclei near an active volcano , 1976, Nature.

[43]  G. Langer,et al.  Hawaiian volcanos—A source of ice nuclei? , 1974 .

[44]  Kenneth Sassen,et al.  Observations by Lidar of Linear Depolarization Ratios for Hydrometeors. , 1971 .

[45]  K. Gierens.  Atmospheric Chemistry and Physics on the Transition between Heterogeneous and Homogeneous Freezing , 2003 .

[46]  A. Ono,et al.  Volcanoes as a Source of Atmospheric Ice Nuclei , 1959, Nature.