Evidence of seasonally dependent stratosphere-troposphere exchange and purging of lower stratospheric aerosol from a multiyear lidar data set

Tropospheric and lower stratospheric aerosol backscatter data obtained from a calibrated backscatter lidar at Pasadena, California (34 deg N latitude) over the 1984-1993 period clearly indicate tightly coupled aerosol optical properties in the upper troposphere and lower stratosphere in the winter and early spring, due to the active midlatitude stratospheric-tropospheric (ST) exchange processes occurring at this time of year. Lidar data indicate that during pre-Pinaturbo background conditions, the subsequent purging of the aerosol in the upper troposphere caused a significant reduction in the aerosol content throughout the 8 - 18 km altitude region in the early spring period. The post-Pinatubo evidence of intense exchange in the winter and early spring is a significant increase in the upper tropospheric aerosol content, such that the backscatter levels reach values nearly equivalent to the enhanced backscatter levels existing in the lower stratosphere. The calculated stratospheric mass extrusion rate is consistent with a 45-day lifetime of lower stratospheric aerosol during this part of the year, which implies that midlatitude ST exchange is a significant sink for stratospheric aerosol.

[1]  Colette Brogniez,et al.  Analysis of 5‐year aerosol data from the Stratospheric Aerosol and Gas Experiment II , 1991 .

[2]  M. Wei.  A New Formulation of the Exchange of Mass and Trace Constituents between the Stratosphere and Troposphere , 1987 .

[3]  M. Hoerling,et al.  A global analysis of stratospheric-tropospheric exchange during northern winter , 1993 .

[4]  M. Kavaya,et al.  Lidar aerosol backscatter measurements: systematic, modeling, and calibration error considerations. , 1985, Applied optics.

[5]  J. Holton,et al.  Stratosphere‐troposphere exchange , 1995 .

[6]  Colette Brogniez,et al.  Comparative observations of stratospheric aerosols by ground‐based lidar, balloon‐borne polarimeter, and satellite solar occultation , 1992 .

[7]  G. Ancellet,et al.  Altitude and seasonal characteristics of aerosol backscatter at thermal infrared wavelengths using lidar observations from coastal California , 1989 .

[8]  M. Post.  Atmospheric purging of El Chichon debris , 1986 .

[9]  D. Bowdle,et al.  Comparison of calculated aerosol backscatter at 9.1- and 2.1-microm wavelengths. , 1992, Applied Optics.

[10]  K. Rosenlof,et al.  Estimates of the stratospheric residual circulation using the downward control principle , 1993 .

[11]  Larry W. Thomason,et al.  A diagnostic stratospheric aerosol size distribution inferred from SAGE II measurements , 1991 .

[12]  D. Hofmann.  Twenty Years Of Balloon-Borne Tropospheric Aerosol Measurements , 1993 .

[13]  E. Danielsen,et al.  Stratospheric-Tropospheric Exchange Based on Radioactivity, Ozone and Potential Vorticity , 1968 .

[14]  Keith P. Shine,et al.  On the “Downward Control” of Extratropical Diabatic Circulations by Eddy-Induced Mean Zonal Forces , 1991 .

[15]  R. Charlson,et al.  Factors controlling the acidity of natural rainwater , 1982, Nature.

[16]  V. Mohnen,et al.  Project dustorm report: ozone transport, in situ measurements, and meteorological analyses of tropopause folding , 1977 .

[17]  Richard B. Rood,et al.  Implications of three‐dimensional tracer studies for two‐dimensional assessments of the impact of supersonic aircraft on stratospheric ozone , 1993 .

[18]  D. Haner,et al.  Atmospheric aerosol backscatter measurements using a tunable coherent CO2 lidar. , 1984, Applied optics.

[19]  J. Rosen,et al.  Backscattersonde: a new instrument for atmospheric aerosol research. , 1991, Applied optics.

[20]  Bryan J. Johnson,et al.  Balloonborne measurements of Pinatubo aerosol during 1991 and 1992 at 41°N: Vertical profiles, size distribution, and volatility , 1993 .

[21]  One‐year observations of Mount‐Pinatubo aerosol with an advanced Raman lidar over Germany at 53.5° N , 1993 .

[22]  T R Lawrence,et al.  Aerosol backscattering profiles at lambda = 10.6 mum. , 1982, Applied optics.

[23]  J. Hansen,et al.  Climate forcing by stratospheric aerosols , 1992 .

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

[25]  M. Shapiro.  Turbulent Mixing within Tropopause Folds as a Mechanism for the Exchange of Chemical Constituents between the Stratosphere and Troposphere , 1980 .

[26]  A. Clarke,et al.  Aircraft studies of size‐dependent aerosol sampling through inlets , 1992 .

[27]  M. P. McCormick,et al.  Post-volcanic stratospheric aerosol decay as measured by lidar , 1978 .

[28]  W. C. Graustein,et al.  Transport and residence times of tropospheric aerosols inferred from a global three-dimensional simulation of 210Pb , 1993 .

[29]  G. Sachse,et al.  Three-dimensional analysis of potential vorticity associated with tropopause folds and observed variations of ozone and carbon monoxide , 1987 .

[30]  P. Russell,et al.  The NASA spring 1984 Stratosphere‐Troposphere Exchange experiment: Science objectives and operations , 1991 .

[31]  E. Reiter.  Stratospheric--tropospheric exchange processes , 1975 .

[32]  D. Hofmann,et al.  Increase in the Stratospheric Background Sulfuric Acid Aerosol Mass in the Past 10 Years , 1990, Science.

[33]  M. McCormick,et al.  Methodology for error analysis and simulation of lidar aerosol measurements. , 1979, Applied optics.

[34]  J. Holton.  On the Global Exchange of Mass between the Stratosphere and Troposphere , 1990 .

[35]  D. Tratt,et al.  Airborne CO(2) coherent lidar for measurements of atmospheric aerosol and cloud backscatter. , 1994, Applied optics.

[36]  H. Selkirk,et al.  Air mass origins and troposphere‐to‐stratosphere exchange associated with mid‐latitude cyclogenesis and tropopause folding inferred from 7Be measurements , 1991 .

[37]  E. Browell,et al.  Tropopause fold structure determined from airborne lidar and in situ measurements , 1987 .

[38]  Owen B. Toon,et al.  The potential effects of volcanic aerosols on cirrus cloud microphysics , 1992 .

[39]  R. Duce,et al.  Relationships between the dust concentrations over eastern Asia and the remote North Pacific , 1992 .

[40]  A. Clarke.  Atmospheric nuclei in the Pacific midtroposphere: Their nature, concentration, and evolution , 1993 .

[41]  M. Patrick McCormick,et al.  The poleward dispersal of Mount Pinatubo volcanic aerosol , 1993 .

[42]  Z. Li,et al.  Gobi dust storms and The Great Green Wall , 1994 .

[43]  D. O. Staley.  On the Mechanism of Mass and Radioactivity Transport from Stratosphere to Troposphere , 1962 .