Evaluation of aerosol microphysical, optical and radiative properties measured with a multiwavelength photometer
<p>An evaluation of aerosol microphysical, optical and radiative properties measured with a multiwavelength photometer named CW193 was performed in this study. The instrument has a highly integrated design, smart control performance and is composed of three parts (the optical head, robotic dri...
| Main Authors: | , , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2022-04-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/15/2139/2022/amt-15-2139-2022.pdf |
| Summary: | <p>An evaluation of aerosol microphysical, optical and
radiative properties measured with a multiwavelength photometer named
CW193 was performed in this study. The instrument has a highly integrated
design, smart control performance and is composed of three parts (the optical
head, robotic drive platform and stents system). Based on synchronous
measurements, the CW193 products were validated using reference data from the
AERONET CE318 photometer. The results show that the raw digital counts from
CW193 agree well with the counts from AERONET (<span class="inline-formula"><i>R</i>>0.989</span>), with daily
average triplets of around 1.2 % to 3.0 % for the ultraviolet
band and less than 2.0 % for the visible and infrared bands. Good
aerosol optical depth agreement (<span class="inline-formula"><i>R</i>>0.997</span>, 100 % within
expected error) and root mean square error (RMSE) values ranging from 0.006
(for the 870 nm band) to 0.016 (for the 440 nm band) were obtained, with the
relative mean bias (RMB) ranging from 0.922 to 1.112 and the aerosol optical
depth bias within <span class="inline-formula">±0.04</span>. The maximum deviation of the peak value for
fine-mode particles varied from about 8.9 % to 77.6 %, whereas the
variation for coarse-mode particles was about 13.1 % to 29.1 %. The deviation variations of the single scattering albedo were
approximately 0.1 %–1.8 %, 0.6 %–1.9 %, 0.1 %–2.6 % and 0.8 %–3.5 %
for the 440, 675, 870 and 1020 nm bands, respectively. For the
aerosol direct radiative forcing, deviations of approximately 4.8 %–12.3 %
were obtained at the earth's surface and 5.4 %–15.9 % for the top of the
atmosphere. In addition, the water vapor retrievals showed satisfactory
accuracy, characterized by a high <span class="inline-formula"><i>R</i></span> value (<span class="inline-formula">∼0.997</span>), a small
RMSE (<span class="inline-formula">∼0.020</span>) and a good expected error distribution (100 % within expected error). The water
vapor RMB was about 0.979, and the biases mostly varied within <span class="inline-formula">±0.04</span>,
whereas the mean values were concentrated within <span class="inline-formula">±0.02</span>.</p> |
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| ISSN: | 1867-1381 1867-8548 |