The four-wavelength Photoacoustic Aerosol Absorption Spectrometer (PAAS-4<i>λ</i>)
<p>In this paper, the Photoacoustic Aerosol Absorption Spectrometer (PAAS-4<span class="inline-formula"><i>λ</i></span>) is introduced. PAAS-4<span class="inline-formula"><i>λ</i></span> was specifically developed for long-ter...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2023-06-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://amt.copernicus.org/articles/16/2753/2023/amt-16-2753-2023.pdf |
| Summary: | <p>In this paper, the Photoacoustic Aerosol Absorption Spectrometer (PAAS-4<span class="inline-formula"><i>λ</i></span>) is introduced. PAAS-4<span class="inline-formula"><i>λ</i></span> was specifically developed for long-term monitoring tasks in (unattended) air quality stations. It uses four wavelengths coupled to a single acoustic resonator in a compact and robust set-up. The instrument has been thoroughly characterized and carefully calibrated in the laboratory using NO<span class="inline-formula"><sub>2</sub></span>/air mixtures and Nigrosin aerosol. It has an ultimate <span class="inline-formula">1<i>σ</i></span> detection limit below 0.1 Mm<span class="inline-formula"><sup>−1</sup></span>, at a measurement precision and accuracy of 3 % and 10 %, respectively. In order to demonstrate the PAAS-4<span class="inline-formula"><i>λ</i></span> suitability for long-term monitoring tasks, the instrument is currently validated at the air quality monitoring station Pallas in Finland, about 140 km north of the Arctic circle. A total of 11 months of PAAS-4<span class="inline-formula"><i>λ</i></span> data from this deployment are presented and discussed in terms of instrument performance. Intercomparisons with the filter-based photometers of a continuous soot monitoring system (COSMOS), the Multi-Angle Absorption Photometer (MAAP), and Aethalometer (AE33) demonstrate the capabilities and value of PAAS-4<span class="inline-formula"><i>λ</i></span>, as well as for the validation of the widely used filter-based instruments.</p> |
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| ISSN: | 1867-1381 1867-8548 |