Mapping gaseous dimethylamine, trimethylamine, ammonia, and their particulate counterparts in marine atmospheres of China's marginal seas – Part 1: Differentiating marine emission from continental transport
<p>To study sea-derived gaseous amines, ammonia, and primary particulate aminium ions in the marine atmosphere of China's marginal seas, an onboard URG-9000D Ambient Ion Monitor-Ion Chromatograph (AIM-IC, Thermo Fisher) was set up on the front deck of the R/V <i>Dongfanghong-3</i...
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| Autores principales: | , , , , , |
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| Formato: | article |
| Lenguaje: | EN |
| Publicado: |
Copernicus Publications
2021
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| Materias: | |
| Acceso en línea: | https://doaj.org/article/0b09cab42333485eb154f832a0545f55 |
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| Sumario: | <p>To study sea-derived gaseous amines, ammonia, and primary particulate aminium ions in the marine atmosphere of China's marginal seas, an onboard URG-9000D Ambient Ion Monitor-Ion Chromatograph (AIM-IC, Thermo Fisher) was set up on the front deck of the R/V <i>Dongfanghong-3</i> to
semi-continuously measure the spatiotemporal variations in the concentrations of atmospheric trimethylamine (TMA<span class="inline-formula"><sub>gas</sub></span>), dimethylamine (DMA<span class="inline-formula"><sub>gas</sub></span>), and ammonia (<span class="inline-formula">NH<sub>3gas</sub></span>) along with their particulate matter (PM<span class="inline-formula"><sub>2.5</sub></span>) counterparts. In this study, we differentiated marine emissions of the gas species from continental transport using data obtained from 9 to 22 December 2019 during the cruise over the Yellow and Bohai seas, facilitated by additional short-term measurements collected at a coastal site near the Yellow Sea during the summer, fall, and winter of 2019. The data obtained from the cruise and coastal sites demonstrated that the observed TMA<span class="inline-formula"><sub>gas</sub></span> and protonated trimethylamine (TMAH<span class="inline-formula"><sup>+</sup></span>) in PM<span class="inline-formula"><sub>2.5</sub></span> over the Yellow and Bohai seas overwhelmingly originated from marine sources. During the cruise, no significant correlation (<span class="inline-formula"><i>P</i>>0.05</span>) was observed between the simultaneously measured TMAH<span class="inline-formula"><sup>+</sup></span> and TMA<span class="inline-formula"><sub>gas</sub></span> concentrations. Additionally, the concentrations of TMAH<span class="inline-formula"><sup>+</sup></span> in the marine atmosphere varied around <span class="inline-formula">0.28±0.18</span> <span class="inline-formula">µg m<sup>−3</sup></span> (average <span class="inline-formula">±</span> standard deviation), with several episodic hourly average values exceeding 1 <span class="inline-formula">µg m<sup>−3</sup></span>, which were approximately 1 order of magnitude larger than those of TMA<span class="inline-formula"><sub>gas</sub></span> (approximately <span class="inline-formula">0.031±0.009</span> <span class="inline-formula">µg m<sup>−3</sup></span>). Moreover, there was a significant negative correlation (<span class="inline-formula"><i>P</i><0.01</span>) between the concentrations of TMAH<span class="inline-formula"><sup>+</sup></span> and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M21" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn></msub><mo>+</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="29pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="df1f0fc1093d7c213f3735ccc009a4e7"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-16413-2021-ie00001.svg" width="29pt" height="14pt" src="acp-21-16413-2021-ie00001.png"/></svg:svg></span></span> in PM<span class="inline-formula"><sub>2.5</sub></span>. Therefore, the observed TMAH<span class="inline-formula"><sup>+</sup></span> in PM<span class="inline-formula"><sub>2.5</sub></span> was overwhelmingly derived from primary sea-spray aerosols. Using TMA<span class="inline-formula"><sub>gas</sub></span> and TMAH<span class="inline-formula"><sup>+</sup></span> in PM<span class="inline-formula"><sub>2.5</sub></span> as tracers for sea-derived basic gases and sea-spray particulate aminium ions, the values of non-sea-derived DMA<span class="inline-formula"><sub>gas</sub></span>, <span class="inline-formula">NH<sub>3gas</sub></span>, and non-sea-spray particulate DMAH<span class="inline-formula"><sup>+</sup></span> in PM<span class="inline-formula"><sub>2.5</sub></span> were estimated. The estimated average values of each species contributed 16 %, 34 %, and 65 % of the observed average
concentrations for non-sea-derived DMA<span class="inline-formula"><sub>gas</sub></span>, <span class="inline-formula">NH<sub>3gas</sub></span>, and non-sea-spray particulate DMAH<span class="inline-formula"><sup>+</sup></span> in PM<span class="inline-formula"><sub>2.5</sub></span>, respectively. Uncertainties remained in the estimations, as TMAH<span class="inline-formula"><sup>+</sup></span> may decompose into
smaller molecules in seawater to varying extents. The non-sea-derived gases
and non-sea-spray particulate DMAH<span class="inline-formula"><sup>+</sup></span> likely originated from long-range
transport from the upwind continents based on the recorded offshore winds
and increased concentrations of non-sea-salt <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M38" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">SO</mi><mn mathvariant="normal">4</mn></msub><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="34pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="61181720b4e129b8ce7d7bf8e7fb56af"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-16413-2021-ie00002.svg" width="34pt" height="16pt" src="acp-21-16413-2021-ie00002.png"/></svg:svg></span></span> (nss-<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M39" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">SO</mi><mn mathvariant="normal">4</mn></msub><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="34pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="931004d6f3751a00b1fe721f8caa5d5e"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-16413-2021-ie00003.svg" width="34pt" height="16pt" src="acp-21-16413-2021-ie00003.png"/></svg:svg></span></span>) and <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M40" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn></msub><mo>+</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="29pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="9dc882e152edb8830cdea3e4b4fa1729"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-16413-2021-ie00004.svg" width="29pt" height="14pt" src="acp-21-16413-2021-ie00004.png"/></svg:svg></span></span> in PM<span class="inline-formula"><sub>2.5</sub></span>. The lack of a detectable increase in particulate DMAH<span class="inline-formula"><sup>+</sup></span>, <span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M43" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">NH</mi><mn mathvariant="normal">4</mn></msub><mo>+</mo></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="29pt" height="14pt" class="svg-formula" dspmath="mathimg" md5hash="1e12af20907fc5fee0a99900be272a3f"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-16413-2021-ie00005.svg" width="29pt" height="14pt" src="acp-21-16413-2021-ie00005.png"/></svg:svg></span></span>, and nss-<span class="inline-formula"><math xmlns="http://www.w3.org/1998/Math/MathML" id="M44" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msup><msub><mi mathvariant="normal">SO</mi><mn mathvariant="normal">4</mn></msub><mrow><mn mathvariant="normal">2</mn><mo>-</mo></mrow></msup></mrow></math><span><svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="34pt" height="16pt" class="svg-formula" dspmath="mathimg" md5hash="49b217b63d1c482925a977dc3467ca54"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="acp-21-16413-2021-ie00006.svg" width="34pt" height="16pt" src="acp-21-16413-2021-ie00006.png"/></svg:svg></span></span> concentrations in several <span class="inline-formula">SO<sub>2</sub></span> plumes did not support the secondary formation of particulate DMAH<span class="inline-formula"><sup>+</sup></span> in the marine atmosphere.</p> |
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