> ![](media/image1.wmf){width="6.5in" height="4.222222222222222in"}

Figure 1 Representative aerosol optical depth spectra measured by AATS-6
aboard the R/V Vodyanitskiy during ACE-2.

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height="7.091666666666667in"}

Figure 2 Aerosol optical depth (λ = 630 nm) retrieved from AVHRR
radiances (Durkee et al., this issue) during 1515 UTC NOAA-14 overpass
of the ACE-2 sampling region on 10 July 97; locations of R/V
Vodyanitskiy during the period 1451-1524 UTC and Pelican during the
period 1454-1500 UTC.

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height="5.634722222222222in"}

Figure 3 For 10 July 97: (a) Temporal variation of total column aerosol
optical depth measured by AATS-6 aboard the R/V Vodyanitskiy, (b)
comparison of AATS-6 aerosol optical depths and AVHRR aerosol optical
depths calculated for the ship location, (c) comparison of AATS-14
aerosol optical depths acquired from the Pelican at an altitude of 60 m
ASL and AVHRR aerosol optical depths calculated for the plane location.

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height="5.622222222222222in"}

Figure 4 Aerosol optical depth and extinction profiles retrieved from
AATS-14 measurements made between 1500 and 1515 UTC during Pelican
flight near R/V Vodyanitskiy on 10 July 97.

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height="5.622222222222222in"}

Figure 5 For 10 July 97: water vapor density and columnar water vapor
profiles calculated from AATS-14 measurements and from UWPH measurements
(Gassó et al., this issue) during Pelican ascent 1500-1605 UTC, and from
ship radiosonde 1656-1715 UTC; mean columnar water vapor retrieved from
AATS-6 measurements 1500-1730 UTC.

> ![](media/image6.wmf){width="7.495833333333334in"
> height="5.634722222222222in"}

Figure 6 Scatter diagram of columnar water vapor calculated from
radiosonde measurements and from AATS-6 measurements during ACE-2. Each
AATS-6 data point represents the mean calculated over the time period
spanned by the radiosonde measurements; horizontal bars show the
corresponding standard deviation (wide ticks) and the range (narrow
ticks) for that time period.

> ![](media/image7.wmf){width="7.495833333333334in"
> height="5.634722222222222in"}

Figure 7 NOAA/PMEL aerosol size distribution measured aboard R/V
Vodyanitskiy at 1500 UTC on 10 July 97 (a,b); corresponding calculated
extinction spectra (c,d). Dried (RH=10%: x symbols) size distribution
has been humidified to 80% (circles) and 90% (diamonds) RH using
hygroscopic growth models of (a) Swietlicki et al. (this issue) and (b)
Hoppel et al. (1990). Corresponding particulate extinction spectra
calculated at AATS-6 wavelengths for three refractive indices: m=1.33-0i
(smallest values for each set of three), m=1.40-.0035i (intermediate
values for each set of three), and m=1.48-.01i (largest values for each
set of three).

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Figure 8 For 10 July 97: (a) ship radiosonde temperature and RH
profiles, Pelican RH profile; (b) shipboard lidar (University of Munich)
relative backscatter profiles at 532 nm between 1414 and 1726 UTC; and
(c) time variation of the height of aerosol lidar backscatter signal
peak and AATS-6 marine boundary layer aerosol optical depth at 525 nm.

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height="5.634722222222222in"}

Figure 9 For 10 July 97: (a) profiles of aerosol extinction calculated
at 525 nm for a refractive index of 1.40-.0035i by combining shipboard
mean aerosol size distribution measurements during the period 1445-1515
UTC with the radiosonde RH profile measured 1656-1715 UTC above ship
location and with the RH profile measured by Pelican UWPH (Gassó et al.,
this issue) during aircraft ascent 1500-1605 UTC; RH values are listed
beside the data points. (b) Aerosol extinction profiles calculated at
five AATS-6 wavelengths by combining shipboard 30-min average particle
size distribution measurements centered at 1700 UTC and 1700 UTC
radiosonde RH profile. (c) Comparison of aerosol extinction profiles
calculated from ship (1445-1515 UTC) and from aircraft (1500-1515 UTC;
Collins et al., this issue) in-situ particle size distribution
measurements, from AATS-14 measurements (1500-1515 UTC), and from
shipboard lidar backscatter measurements for times near 1500 UTC. (d)
Comparison of aerosol extinction profiles calculated from shipboard
in-situ aerosol size distribution measurements and from shipboard lidar
backscatter measurements for times near 1700 UTC.

> ![](media/image11.wmf){width="7.495833333333334in"
> height="5.634722222222222in"}

Figure 10 For 10 July: marine boundary layer aerosol optical depth
spectra derived from AATS-6 measurements (circles with error bars) and
calculated from shipboard in-situ aerosol size distribution measurements
for three values of refractive index for (a) 1500 UTC and (b) 1700 UTC.
For in-situ results connected by solid red, green, and blue lines,
growth factors based only on the Swietlicki et al. (this issue)
shipboard measurements for non-sea salt Aitken and accumulation aerosol
modes were used. For the results connected by dashed red, green, and
blue lines, the non-sea salt growth factors were used for particles with
dry diameter \< 1.2 μm, and growth factors based on the Swietlicki et
al. (this issue) sea salt measurements were applied to particles with
dry diameter ≥ 1.2 μm.

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height="5.634722222222222in"}

Figure 11 (a) Marine boundary layer aerosol optical depth and columnar
water vapor measured by AATS-6, columnar water vapor measured by
radiosonde (triangle); (b) boundary layer aerosol optical depth
calculated from shipboard in-situ aerosol size distribution measurements
for a refractive index of 1.40-.0035i for 10 July 97.

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height="5.634722222222222in"}

Figure 12 For 10 July 97: (a) comparison of Ångström wavelength
exponent, α, calculated from AATS-6 MBL AODs (cyan) and from AATS-6
total column AODS (red), from extinction derived from shipboard aerosol
size distribution measurements (PSD)at AATS-6 wavelengths for RH 55%
(black triangles) and RH 80% (blue circles) and at nephelometer
wavelengths for RH 55% (magenta diamonds), and from shipboard
nephelometer measurements of particle scattering coefficient (green x
symbols), and (b) comparison of aerosol extinction coefficients
calculated at 550 nm from ship particle size data at RH 55% for a
refractive index 1.40-.0035i and from aerosol scattering coefficients
measured by shipboard nephelometer at a sampling RH 55%.

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height="5.634722222222222in"}

Figure 13 For 22 July 97: (a) Columnar aerosol optical depth and water
vapor measured by AATS-6, columnar water vapor measured by radiosonde
(triangle); (b) comparison of Ångström wavelength exponent, α,
calculated from AATS-6 column AODs and from shipboard nephelometer
measurements of particle scattering coefficient at RH 55%.

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height="5.622222222222222in"}

Figure 14 For 22 July 97: (a) shipboard lidar relative backscatter
profiles at 532 nm, (b) corresponding aerosol extinction profiles
derived from the relative backscatter profiles, (c) AATS-6 AOD at 525 nm
and lidar-inferred AOD at 532 nm.

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height="5.634722222222222in"}

Figure 15 Scatter diagrams of Ångström wavelength exponents calculated
from (a) aerosol extinction spectra derived from shipboard particle size
measurements and (b) shipboard nephelometer scattering measurements
versus Ångström exponents calculated from AATS-6 total column AOD
measurements acquired during portions of nine days during ACE-2. Data
have been segregated by air mass source region according to the
classification scheme of Quinn et al. (this issue). The solid lines
represent the regression fits, and the dotted lines one-to-one
correspondence.