University of Wyoming stratospheric aerosol size distributions available on the anonymous ftp site: cat.uwyo.edu. Within the directory ftp://cat.uwyo.edu/pub/permanent/balloon/Aerosol_InSitu_Meas/  you will find the following subdirectories and files:

 

ftp://cat.uwyo.edu/pub/permanent/balloon/Aerosol_InSitu_Meas/Laramie_Wy_41N_105W/SizeDist_0.5km_Stratosphere/

·         Log normal size distributions (either unimodal or bimodal) for 0.5 km averages of in situ concentration measurements, 1971 - present.

 

ftp://cat.uwyo.edu/pub/permanent/balloon/Aerosol_InSitu_Meas/Laramie_Wy_41N_105W/Nr_0.5km_Stratosphere/

·         0.5 km averages of in situ aerosol concentration measurements, 1971 - present. These data files are used to derive the 0.5 km lognormal size distributions.

 

ftp://cat.uwyo.edu/pub/permanent/balloon/Aerosol_InSitu_Meas/Laramie_Wy_41N_105W/Nr_0.5km_Incl_Trop_o3/

·         0.5 km averages of in situ aerosol concentration measurements and ozone for stratosphere and troposphere, for selected files. Additional files available on request.

 

ftp://cat.uwyo.edu/pub/permanent/balloon/Aerosol_InSitu_Meas/Laramie_Wy_41N_105W/Nr_Full_Profiles/

·         0.5 km averages of in situ aerosol concentration measurements and ozone for stratosphere and troposphere, for selected files. Additional files available on request.

 

There are similar directory structures and files for a small number of measurements from

Niamey, Niger            - /aftp/pub/permanent/balloon/Aerosol_InSitu_Meas/Niamey_NI_13N_2E

Darwin, Australia       - /aftp/pub/permanent/balloon/Aerosol_InSitu_Meas/Darwin_AU_13S_132E

·         Not available yet

Lauder, New Zealand - /aftp/pub/permanent/balloon/Aerosol_InSitu_Meas/Lauder_NZ_45S_170E/

·         Not available yet

 

 

These files result from in-situ balloonborne size resolved aerosol concentration measurements collected above Laramie, Wyoming (41°N, 105°W) and the other locations using University of Wyoming aerosol counters. Almost all flights from Laramie take place between 06:00 and 09:00 local time. The sizes measured always include condensation nuclei (CN, r > 0.01 mm) and particles with radius ³ 0.15, 0.25 mm. Measurements with radius ³ 0.15 - 2.0 mm in 12 size classes have been completed since 1991. See Deshler et al. (2003) for a table with the complete measurement history.

 

Principal Investigator: Terry Deshler, Professor, Department of Atmospheric Science, University of Wyoming, Laramie, WY 82071, USA, 307-766-2006, deshler@uwyo.edu

 

Acknowledgments: The measurements over the years have been primarily supported by the National Science Foundation and the National Aeronautics and Space Administration, with some support from the Naval Research Laboratory

 

Structure of Size Distribution Files:

The file name corresponds to the date of the flight in YYMMDD and a two letter place identifier. The extension indicates the averaging interval, SD2 = 0.5 km average. The lower altitude corresponds to the tropopause for that day, while the upper altitude is the top of the sounding.

The first line of the data file contains the date, instruments used, flight number, and sizes measured. The next two lines contain column labels and units for the data columns.

 

Data file columns:

1 - Type of fit: 1-> monomodal (=> 11 columns), 2-> bimodal (=> 14 columns)

2 - Potential temperature (K), calculated

3 - Altitude (km), calculated from hydrostatic equation

4 - Pressure (hPa), measured with Vaisala sensor, precision ~0.5 hPa

5 - Temperature (K), measured with Vaisala sensor, precision ~0.1 K

6 - Surface area (mm2 cm-3), calculated, precision ± 40%

7 - Volume (mm3 cm-3), calculated, precision ± 40%

8 - Error of the fit (see below)

9 - N1 = (CN - N2) (cm-3), measured

10 - r1 (mm), calculated from size distributions fit to aerosol measurements

11 - s1, calculated from size distributions fit to aerosol measurements

12 - N2 (cm-3), calculated from size distributions fit to aerosol measurements

13 - r2 (mm),, calculated from size distributions fit to aerosol measurements

14 - s2, calculated from size distributions fit to aerosol measurements

 

Error of the fit = S{ln (Nm(r) / Nc(r)}2. Nm(r) is the measured number concentration and Nc(r) the number concentration calculated from the size distributions fit to the measurements. Altitudes for which reasonable size distributions could not be obtained are not included.

 

Structure of Aerosol Concentration Files:

The file name corresponds to the date of the flight in YYMMDD and a two letter place identifier. The extension 5km or asc indicates the averaging: 5km=0.5 km average, asc=full data resolution. The lower altitude corresponds to the tropopause for that day for the files in the directory .../Nr_0.5km_Stratosphere/, while the upper altitude is the top of the sounding. The structure of all Nr_ files are the same, with the exception that ozone may or may not be included. If included it appears as the 5th column.

 

The first line of the data file contains the date, instruments used, flight number, and number of sizes measured (NoCh). The next two lines contain column labels and units for the data columns.

 

Data file columns:

1 - Potential temperature (K), calculated

2 - Altitude (km), calculated from hydrostatic equation

3 - Pressure (hPa), measured with Vaisala sensor, precision ~0.5 hPa

4 - Temperature (K), measured with Vaisala sensor, precision ~0.1 K

5 – Concentration (cm-3) of condensation nuclei (CN), if measured, otherwise values of 1.01E=39.

6 – NoCh+4 - N(r>x.xx) concentration (cm-3), where x.xx = particle radius. For precision and detection limit see discussion below. A more complete discussion is provided by Deshler et al. [2003].

 

The minimum concentration measurable with these instruments is given by S / F. for sample frequency, S=0.1 Hz, and flow rate, F. For example, the minimum concentration detectable is 5.7 x 10-4 cm-3 for F = 167 cm3 s-1, and 5.7 x 10-3 cm-3 for F = 16.7 cm3 s-1. When the aerosol concentration is below the detection threshold of the instrument the concentration is arbitrarily assigned a value of 1.01E-39. The first channel at which this occurs is arbitrarily assigned a value of 1.01 E-06 and is used to fix the large particle tail of the size distribution.

Poisson statistics define the fractional uncertainty of a counting measurement as its inverse square root, C-0.5 for C counts in one sample, becoming important at low concentrations. The aerosol concentration, N = C S / F. Thus the Poisson error fraction, in terms of concentration, is (N F / S)-0.5. For these instruments: S = 0.1 Hz, F = 16.7 cm3 s-1 for a two channel counter and CN counter, and F = 167 cm3 s-1 for a counter with more than two channels. In the stratosphere these flow rates are reduced to about 80% of these values by temperature differences between outside air and pump. This leads to uncertainties of 85, 25, and 8% for concentrations of 0.01, 0.1, and 1.0 cm-3 at the low flow rate and concentrations of 0.001, 0.01, 0.1 cm-3 at the high flow rate. This error dominates at concentrations below 0.1 (0.01) cm-3 for the low (high) flow rate instrument. At concentrations higher than these a concentration error of ±10% reflects comparisons of concentration measurements from two instruments using identical aerosol in the laboratory.

 

For references and a description of the instruments see:

Hofmann, D. J. and T. Deshler, Stratospheric cloud observations during formation of the Antarctic ozone hole in 1989, J. Geophys. Res., 96, ­2897-2912, 1991.

Deshler, T., B. J. Johnson, and W. R. Rozier, Balloonborne measurements of Pinatubo aerosol during 1991 and 1992 at 41°N, vertical profiles, size distribution, and volatility, Geophys. Res. Lett., 20, 1435-1438, 1993.

Deshler, T., and S. J. Oltmans, Vertical profiles of volcanic aerosol and polar stratospheric clouds above Kiruna, Sweden: Winters 1993 and 1995, J. Atmos. Chem, 30, 11-23, 1998.

Deshler, T., M. E. Hervig, D. J. Hofmann, J. M. Rosen, and J. B. Liley, Thirty years of in situ stratospheric aerosol size distribution measurements from Laramie, Wyoming (41°N), using balloon-borne instruments, J. Geophys. Res., 108(D5), 4167, doi:10.1029/2002JD002514, 2003. (see Deshler_et_al_JGR_2003.pdf)

Deshler, T., R. Anderson-Sprecher, H. Jäger, J. Barnes, D. J. Hofmann, B. Clemesha, D. Simonich, M. Osborn, R. G. Grainger, and S. Godin-Beekmann (2006), Trends in the nonvolcanic component of stratospheric aerosol over the period 1971–2004, J. Geophys. Res, 111, D01201, doi:10.1029/2005JD006089.

 

 

A bibligography, since 1990, of the literature in which Wyoming Aerosol counters played a role in the analysis of mid latitude and polar stratospheric cloud measurements follows here:

 

Mid Latitude Measurements

 

Deshler, T., R. Anderson-Sprecher, J. Barnes, B. Clemesha, S. Godin-Beekmann, R. G. Grainger, D. J. Hofmann, H. Jäger, S. Marsh,  M. Osborn, and D. Simonich, Non-volcanic stratospheric aerosol trends: 1971 - 2004, Chapter 5 of the SPARC Assessment of  Stratospheric Aerosol Properties  (L. W. Thomason and Th. Peter editors), WCRP-124, WMO/TD-No. 1295, SPARC Report No. 4.

Deshler, T., R. Anderson-Sprecher, H. Jäger, J. Barnes, D. J. Hofmann, B. Clemesha, D. Simonich, M. Osborn, R. G. Grainger, and S. Godin-Beekmann (2006), Trends in the nonvolcanic component of stratospheric aerosol over the period 1971–2004, J. Geophys. Res, 111, D01201, doi:10.1029/2005JD006089.

Deshler, T., M. E. Hervig, D. J. Hofmann, J. M. Rosen, and J. B. Liley, Thirty years of in situ stratospheric aerosol size distribution measurements from Laramie, Wyoming (41°N), using balloon-borne instruments, J. Geophys. Res., 108(D5), 4167, doi:10.1029/2002JD002514, 2003.

Jäger, H., and T. Deshler, Correction to Lidar backscatter to extinction, mass and area conversions for stratospheric aerosols based on midlatitude balloonborne size distribution measurements, Geophys. Res. Lett., 30(7), 1382, doi:10.1029/2003GL017189, 2003.

Hofmann, D., J. Barnes, E. Dutton, T. Deshler, H. Jäger, R. Keen, and M. Osborn, Surface-based observations of volcanic emissions to the stratosphere, in Volcanism and the Earth’s Atmosphere, Geophys. Monogr 139, edited by A. Robock and C. Oppenheimer, pp. 57-73, AGU, Washington, D.C., 2003.

Deshler, T., Observations for Chemistry (In Situ): Particles, article for Encyclopedia of Atmospheric Science, Academic Press, 2002.

Jäger, H., and T. Deshler, Lidar backscatter to extinction, mass and area conversions for stratospheric aerosols based on midlatitude balloonborne size distribution measurements, Geophys. Res. Lett., 29(19), 1929, doi:10.1029/2002GL015609, 2002.

Hervig, M. E., and T. Deshler, Evaluation of aerosol measurements from SAGE II, HALOE, and balloonborne optical particle counters, J. Geophys. Res., 107(D3), 10.1029/2001JD000703,  2002.

Hervig, M. E., and T. Deshler, Stratospheric aerosol surface area and volume inferred from HALOE,  CLAES,  and ILAS measurements, J. Geophys. Res., 103, 25345-25352, 1998.

Hofmann, D. J., R. Stone, M. Wood, T. Deshler and J. Harris, An analysis of 25 years of balloonborne aerosol data in search of a signature of the subsonic commercial aircraft fleet. Geophys. Res. Lett., 13, 2433-2436, 1998.

Arnold, F., J. Curtius, S. Spreng, and T. Deshler, Stratospheric aerosol sulfuric acid: First direct in situ measurements using a novel balloon-based mass spectrometer apparatus, J. Atmos. Chem., 30, 3-10, 1998.

Hervig, M. E., T. Deshler, and J. M. Russell III, Aerosol size distributions obtained from HALOE spectral extinction measurements, J. Geophys. Res., 103, 1573-1583, 1998.

Deshler, T., J. B. Liley, G. Bodeker, W. A. Matthews, and D. J. Hofmann, Stratospheric aerosol following Pinatubo, comparison of the north and south mid latitudes using in ­situ measurements, Adv. Space Res., 20, 2057-2061, 1997.

Ansmann, A., I. Mattis, U. Wandinger, F. Wagner, J. Reichardt, and T. Deshler, Evolution of the Pinatubo Aerosol: Raman lidar observations of particle optical depth, effective radius, mass, and surface area over central Europe at 53.4°N, J. Atmos. Sci., 54, 2630-2641, 1997.

Post, M. J.,  C. J. Grund, D. Wang, and T. Deshler, Evolution of Mt. Pinatubo’s aerosol size distributions over the continental United States: Two wavelength lidar retrievals and in situ measurements, J. Geophys. Res., 102, 13,535 -13,542, 1997.

Thomason, L. W., L. R. Poole, and T. Deshler, A global climatology of stratospheric aerosol surface area density deduced from stratospheric aerosol and gas experiment II measurements: 1984-1994, J. Geophys. Res.,102, 8967-8976, 1997.

Poole, L., S. Godin, S. Bekki, T. Deshler, N. Larsen, and T. Peter, Global distributions and changes in stratospheric particles, Chapter 3 in WMO, Scientific Assessment of Ozone Depletion: 1998, World Meteorological Organization, Global Ozone Research and Monitoring Project Report 44, Geneva, Switzerland, 1999.

Jäger, H., T. Deshler, F. Homburg, and V. Freudenthaler, ­Five years of lidar observations of the Pinatubo eruption cloud, in Advances in Atmospheric Remote Sensing with Lidar, Ansmann, Neuber, Rairous, Wandinger (Eds.), Springer, 485-488, 1996

Massie, S. T., T. Deshler, G. E. Thomas, J. L. Mergenthaler, J. M. Russell,­ Evolution of the infrared properties of the Mt. Pinatubo aerosol cloud over Laramie, Wyoming, J. Geophys. Res., 101, 23007-23020, 1996.

Russell, P. B., J. M. Livingston, R. F. Pueschel, J. B. Pollack, S. Brooks, P. Hamill, J. Hughes, L. Thomason, L. Stowe, T. Deshler, E. Dutton, Global to microscale evolution of the Pinatubo volcanic aerosol, derived from diverse measurements and analyses, J. Geophys. Res., 101, 18745-18763, 1996.

Hervig, M.E., J.M. Russell III, L. L. Gordley, J. H. Park, S. R. Drayson, and­ T. Deshler Validation of aerosol measurements made by the Halogen­ Occultation Experiment, J. Geophys. Res., 101, 10267-10276, 1996.

Lambert, A., R. G. Grainger, J. J. Remedios, W. J. Reburn, C. D. Rodgers, F. W. Taylor, A. E. Roche, J. B. Kumer, S. J. Massie, and T. Deshler, Validation of aerosol measurements from the improved stratospheric and mesospheric sounder, J. Geophys. Res., 101, 9811-9830, 1996.

Massie, S. T., et (21 authors) al, Validation studies using multiwavelength Cryogenic Limb Array Etalon Spectrometer (CLAES) observations of ­stratospheric aerosol, J. Geophys. Res., 101, 9757-9774, 1996.

Wandinger, U., A. Ansmann, J. Reichardt, and T. Deshler, Determination of stratospheric-aerosol microphysical properties from independent extinction ­and backscattering measurements with a Raman lidar, Applied Optics 34, ­8315-8329, 1995.

Grainger, R. G., A. Lambert, C. D. Rodgers, F. W. Taylor, and T. Deshler, ­Stratospheric aerosol effective radius, surface area, and volume estimated from infrared measurements, J. Geophys. Res., 100, 16507-16518, 1995.

Jäger, H., T. Deshler, and D. J. Hofmann, Midlatitude lidar backscatter conversions based on balloonborne aerosol measurements,­ Geophys. Res. Lett., 22, 1729-1732, 1995.

Hofmann, D. J., S. J. Oltmans, J. M. Harris, J. A. Lathrop, G. L. Koenig, W. D. Komhyr, R. D. Evans, D. M. Quincy, T. Deshler and B. J. Johnson, Recovery of ­stratospheric ozone over the United States in the winter of 1993-1994,­ Geophys. Res. Lett., 21, 1779-1782, 1994.

Deshler, T., In situ measurements of the size distribution of the Pinatubo ­aerosol over Kiruna on four days between 18 January and 13 February 1992, ­Geophys. Res. Lett., 21, 1323-1326, 1994.

Hofmann, D. J., S. J. Oltmans, W. D. Komhyr, J. M. Harris, J. A. Lathrop, A. O. Langford, T. Deshler, B. J. Johnson, A. Torres, and W. A. Matthews, Ozone ­loss in the lower stratosphere over the United Stated in 1992-1993: Evidence ­for heterogeneous chemistry on the Pinatubo aerosol, Geophys. Res. Lett., 21, 65-68, 1994.

Deshler, T., B. J. Johnson, and W. R. Rozier, Balloonborne measurements of Pinatubo aerosol during 1991 and 1992 at 41oN, vertical profiles, size ­distribution, and volatility, Geophys. Res. Lett., 20, 1435-1438, 1993.

Sheridan, P. J., R. C. Schnell, D. J. Hofmann, and T. Deshler, Electron microscope studies of aerosol layers with likely Kuwaiti origins over ­Laramie, Wyoming, during spring 1991, Geophys. Res. Lett., 19, 389-392,­1992.

Deshler, T., and D. J. Hofmann, Measurements of unusual aerosol layers in the ­upper troposphere over Laramie, Wyoming, in the spring of 1991: Evidence for ­long range transport from the oil fires in Kuwait, Geophys. Res. Lett., 19, ­385-388, 1992.

Sheridan, P. J., R. C. Schnell, D. J. Hofmann, and T. Deshler, Electron microscope studies of  Mt. Pinatubo aerosol layers over Laramie, Wyoming,­ during summer 1991, Geophys. Res. Lett., 19, 203-206, 1992.

Deshler, T., D. J. Hofmann, B. J. Johnson, and W. R. Rozier, Balloonborne ­measurements of the Pinatubo aerosol size distribution and volatility at ­Laramie, Wyoming during the summer of 1991. Geophys. Res. Lett., 19,­ 199-202, 1992.

 

Polar stratospheric clouds measurements

 

Weisser, C., K. Mauersberger, J. Schreiner, N. Larsen, F. Cairo, A. Adriani, J. Ovarlez, and T. Deshler Composition analysis of liquid particles in the Arctic stratosphere under synoptic conditions, Atmos. Chem. Physics, 6, 689-696, 1-3-2006.

Scarchilli, C., A. Adriani, F. Cairo, G. Di Donfrancesco, C. Buontempor, M. Snels, M. L. Moriconei. T. Deshler, N. Larsen, B. Luo, K. Mauersberger, J. Ovarlez, J. Rosen, and J. Schreiner, Determination of PSC particle refractive indices using in situ optical measurements and T-Matrix calculation. Appl. Optics, 16, 3302-, 2005.

Eidhammer, T., and T. Deshler, Evaporation of polar stratospheric particles in situ in a heated inlet, Atmos. Chem. Physics., 5, 97-106, 21-1-2005

Larsen, N., B. M. Knudsen, S. H. Svendsen, T. Deshler, J. M. Rosen, R. Kivi, C. Weisser, J. Schreiner, K. Mauersberger, F. Cairo, J. Ovarlez, H. Oelhaf, and A. Schmidt, Formation of solid particles in synoptic-scale Arctic PSCs in early winter 2002/2003. Atmos. Chem. Physics., 4, 2001-2013, 2004

Vogel, B., R. Müller, T. Deshler, J.-U. Groob, J. Karhu, D. S. McKenna, M. Müller, D. Toohey, G. C. Toon, and F. Stroh, Vertical profiles of activated ClO and ozone loss in the Arctic vortex in January and March 2000: In situ observations and model simulations, J. Geophys. Res., 108(D22), 8334, doi:10.1029/2002JD002564, 2003.

Deshler, T., N. Larsen, C. Weisser, J. Schreiner, K. Mauersberger, F. Cairo, A. Adriani, G. Di Donfrancesco, J. Ovarlez H. Ovarlez, U. Blum, K.H. Fricke, and A. Dörnbrack, Large nitric acid particles at the top of an Arctic stratospheric cloud, J. Geophys. Res., 108(D16), 4517, doi:10.1029/2003JD003479, 2003.

Voigt, C., N. Larsen, T. Deshler, C. Kröger, J. Schreiner; K. Mauersberger, B. Luo, A. Adriani, F. Cairo, G. Di Donfrancesco, J. Ovarlez, H. Ovarlez, A. Dörnbrack, B. Knudsen, J. Rosen, In situ mountain-wave polar stratospheric cloud measurements: Implications for nitric acid trihydrate formation J. Geophys. Res., 108 (D5) 10.1029/2001JD001185, 2003.

Schreiner, J., C. Voigt, C. Weisser, A. Kohlmann, K. Mauersberger, T. Deshler, C. Kröger, J. Rosen, N. Kjome, N. Larsen, A. Adriani, F. Cairo, G. Di Donfrancesco, J. Ovarlez, H. Ovarlez, A. Dörnbrack, Chemical, microphysical, and optical properties of polar stratospheric clouds, J. Geophys. Res., 108, D5, 8313, doi:10.1029/2001JD000825, 2003.

Renard, J., G. Berthet, C. Robert, M. Chartier, M. Pirre, C. Brogniez, M. Herman, C. Verwaerde, J. Balois, J. Ovarlez, H. Ovarlez, J. Crespin, and T. Deshler, Optical and physical properties of stratospheric aerosols from balloon measurements in the visible and near-infrared domains. II. Comparison of extinction, reflectance, polarization, and counting measurements, Appl. Optics, 41, 7540-7549, 2002.

Larsen, N., S. Hoyer, Svendsen, B. M. Knudsen, I. S. Mikkelsen, C. Voigt, A. Kohlmann, J. Schreiner, K. Mauersberger, T. Deshler, C. Kröger, J. M. Rosen, N. T. Kjome, A. Adriani, F. Cairo, G. Di Donfrancesco, J. Ovarlez, H. Ovarlez, A. Dörnbrack, T. Birner, Microphysical mesoscale simulations of polar stratospheric cloud formation constrained by in situ measurements of chemical and optical cloud properties, J. Geophys. Res., 107(D20), 8301, doi:10.1029/2001JD000999, 2002.

Höpfner, M., H. Oelhaf, G. Wetzel, F. Friedl-Vallon, A. Kleinert, A. Lengel, G. Maucher, H. Nordmeyer, N. Glatthor, G. Stiller, T. v. Clarmann, H. Fischer, C. Kröger, T. Deshler, Evidence of scattering of tropospheric radiation by PSCs in mid-IR limb emission spectra: MIPAS-B observations and KOPRA simulations, Geophys. Res. Lett., 29, 10.1029/2001GL014443, 2002.

Schiller, C., T. Deshler, and T. Peter, Contamination-induced particle production during balloon flights: Origin for unexpected ice particle observations in the Arctic?, Geophys. Res. Lett., 28, 3247-3250,  2001

Voigt, C., J. Schreiner, A. Kohlmann, K. Mauersberger, N. Larsen, T. Deshler, C. Kröger, J. Rosen, A. Adriani, F. Cairo, G. Di Donfrancesco, M. Viterbini, J. Orvalez and H. Orvalez, C. David, and A. Dörnbrack, Nitric acid trihydrate (NAT) in polar stratospheric cloud particles, Science,  290, 1756-1758, 2000.

Borrmann, S., A. Thomas, V. Rudakov, V. Yushkov, B. Lepuchov, T. Deshler, N. Vinnichenko, V. Khattatov, and L. Stefanutti, Stratospheric aerosol measurements in the Arctic winter of 1996/1997 with the M-55 Geophysika high-altitude research aircraft, Tellus, 52B, 1088-1103, 2000.

Riviere, E. D., N. Huret, F. G.-Taupin, J.-B. Renard, M. Pirre, S. D. Eckermann, N. Larsen, T. Deshler, F. Lefevre, S. Payan, C. Camy-Peyret, Role of lee waves in the formation of solid polar stratospheric clouds: Cases studies from February 1997, J. Geophys. Res., 105, 6845-6853, 2000.

Deshler, T. B. Nardi, A. Adriani, F. Cairo, G. Hansen, F. Fierli, A. Hauchercorne, and L. Pulvirenti,  Determining the index of refraction of polar stratospheric clouds above Andoya (69°N) by combining size-resolved concentration and optical scattering measurements, J. Geophys. Res., 105, 3943-3953, 2000.

Sugita, T., Y. Kondo, M. Koike, M. Kanada, N. Toriyama, and H. Nakajima, T. Deshler, and R. Imasu, Balloon-borne optical counter for in situ aerosol measurement, J. Atmos. Chem, 32, 183-204, 1999.

Mehrtens, H., U. von Zahn, F. Fierli, B. Nardi, and T. Deshler, Type I PSC-particle properties: Measurements at ALOMAR 1995 to 1997, Geophys. Res. Lett., 26, 603-606, 1999.

Deshler, T., and S. J. Oltmans, Vertical profiles of volcanic aerosol and polar­ stratospheric clouds above Kiruna, Sweden: Winters 1993 and 1995, J. Atmos. Chem, 30, 11-23, 1998.

Kondo, Y., T. Sugita, R. J. Salawitch, M. Koike, and T. Deshler, Effect of Pinatubo aerosols on stratospheric NO, J. Geophys. Res., 102, 1205-1213, 1997.

Deshler, T., B. J. Johnson, D. J. Hofmann, and B. Nardi, Correlations between ­ozone loss and volcanic aerosol at altitudes below 14 km over McMurdo­ Station, Antarctica, Geophys. Res. Lett., 21, 2931-2934, 1996.

Kondo, Y., S. R. Kawa, D. Lary, T. Sugita, A. R. Douglass, E. Lutman, M. Koike, and T. Deshler, Interpretation of nitric oxide profile observed in January 1992 over Kiruna,  J. Geophys. Res., 101, 12555-12566, 1996.

Adriani, A., T. Deshler, G. Di Donfrancesco, and G. P. Gobbi, Polar ­stratospheric clouds and volcanic aerosol during 1992 spring over McMurdo Station, Antarctica: Lidar and particle counter comparisons, J. Geophys. Res., 100, 25877-25898, 1995.

Deshler, T., Th. Peter, R. Müller, and P. J. Crutzen, The lifetime of leewave-induced ice particles in the Arctic stratosphere: I. Balloonborne ­measurements, Geophys. Res. Lett., 21, 1327-1330, 1994.

Peter, Th, P. J. Crutzen, R. Müller, and T. Deshler, The lifetime of ­leewave-induced ice particles in the Arctic stratosphere: II. Stabilization ­due to NAT-coating. Geophys. Res. Lett., 21, 1331-1334, 1994.

Deshler, T., B. J. Johnson, and W. R. Rozier, Changes in the character of polar­ stratospheric clouds over Antarctica in 1992 due to the Pinatubo volcanic ­aerosol, Geophys. Res. Lett., 21, 273-276, 1994.

Adriani, A., T. Deshler, G.P. Gobbi, B.J. Johnson, and G.Di Donfrancesco, Polar ­stratospheric clouds over McMurdo Station, Antarctica, during the 1991 spring: lidar and particle counter measurements, Geophys. Res. Lett., 19, ­1755-1758, 1992.

Deshler, T., A. Adriani, D. J. Hofmann, and G. P. Gobbi, Evidence for­ denitrification in the 1990 Antarctic spring stratosphere: II Lidar and ­aerosol measurements, Geophys. Res. Lett., 18, 1999-2002, 1991.

Gobbi, G. P., T. Deshler, A. Adriani, and D. J. Hofmann, Evidence for ­denitrification in the 1990 Antarctic spring stratosphere: I Lidar and ­temperature measurements, Geophys. Res. Lett., 18, 1995-1998, 1991.

Hofmann, D. J. and T. Deshler, Stratospheric cloud observations during formation of the Antarctic ozone hole in 1989, J. Geophys. Res., 96, ­2897-2912, 1991.

Hofmann, D. J. and T. Deshler, Balloonborne measurements of polar stratospheric clouds and ozone at -93oC in the Arctic in February 1990, Geophys. Res. Lett., 17, 2185-2188, 1990.

Hofmann, D. J., T. Deshler, F. Arnold, and H. Schlager, Balloon observations of nitric acid aerosol formation in the arctic stratosphere: II. Aerosol., Geophys. Res. Lett., 17, 1279-1282, 1990.

Schlager, H., F. Arnold, D. Hofmann, and T. Deshler, Balloon observations of nitric acid aerosol formation in the arctic stratosphere: I. Gaseous nitric acid, Geophys. Res. Lett., 17, 1275-1278, 1990.