Radiatively driven NH3 release from agricultural field during wintertime slack season
Radiatively driven NH3 release from agricultural field during wintertime slack season
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冬季农闲季节农田辐射驱动的NH3释放
DOI：
10.1016/j.atmosenv.2021.118228
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发表时间：
2021-01
影响因子：
5
通讯作者：
Jiade Yan
中科院分区：
文献类型：
--
作者：
Jun Zheng;Yuchan Zhang;Yan Ma;Nan Ye;Alexei F. Khalizov;Jiade Yan
采用化学电离质谱仪(CIMS)测量环境氨(NH3)，其时间分辨率为~5×10~(-3)min。在农作淡季的冬季，南京中国的一块农田附近观察到出人意料的高NH3水平，峰值为15.5ppbv，平均为2.1ppbv±91.9ppbv。由于气温较低，气溶胶再分配只能解释NH3的一小部分，而主要来源是土壤排放，NH3浓度与地面温度、太阳辐射强度，特别是地表-空气温差呈显著正相关。土壤中溶解/吸附的NH_3和NH_4NO_3可能来源于微生物通过氨化和硝化作用对含氮有机物的转化。由太阳辐射驱动的对流混合促进了土壤释放的NH3的向上转移，从而产生了所需的高土壤-空气温度梯度。通常使用的基于被动采样器的长期方法不能捕获土壤中的NH3的冬季释放，这导致了一种错误的假设，即在冬季是耕作的淡季，土壤不排放NH3，因此典型的排放清单模型仍然没有解决这个来源。我们的结果表明，与通常的假设相反，即使在冬季，农业本底排放也是NH3的一个不可忽视的来源，这可能对区域大气污染的形成产生重大影响。因此，对于中国北部冬季的灰霾事件，迫切需要一个精细化的NH3排放清单来解释。
A chemical ionization mass spectrometer (CIMS) was deployed to measure ambient ammonia (NH3) with a time-resolution of ~5 min. Unexpectedly high levels of NH3, peaking at 15.5 ppbv and averaging at 2.1 ± 1.9 ppbv, were observed near an agricultural field in Nanjing, China, during wintertime, a slack season for farming. Re-partitioning from aerosols can only explain a small portion of this NH3due to the considerably low air temperature, whereas the major source was emission from soil, as indicated by significant positive correlations of the NH3concentration with the ground surface temperature, solar radiation intensity, and particularly the surface-air temperature difference. The dissolved/adsorbed NH3and NH4NO3in soil likely originated from conversion of nitrogen-containing organic matter by microorganisms through ammonification and nitrification. The upward transfer of NH3released from the soil was facilitated by convective mixing driven by solar radiation, which produced the required high soil-air temperature gradient. This winter release of NH3from the soil is not captured by commonly used long-term, passive-sampler based methods, giving rise to an incorrect assumption that during winter, a slack season for farming, soil emits no NH3and so this source has remained unresolved by typical emission inventory models. Our results indicate that contrary to the common assumption, agricultural background emissions are a non-negligible source of NH3even in wintertime, which may exert a significant impact on regional air pollution formations. Hence, a refined NH3emission inventory is critically needed to account for the haze events in wintertime northern China.
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影响因子：
6.3
作者：
Zhang Yangyang;Tang Aohan;Wang D;an;Wang Qingqing;Benedict Katie;Zhang Lin;Liu Duanyang;Li Yi;Collett Jeffrey L. Jr.;Sun Yele;Liu Xuejun
通讯作者：
Liu Xuejun
影响因子：
6.3
作者：
Peng Xu;Y. Liao;Yun Lin;C. X. Zhao;Chao Yan;M. Cao;G. S. Wang;S. Luan
通讯作者：
Peng Xu;Y. Liao;Yun Lin;C. X. Zhao;Chao Yan;M. Cao;G. S. Wang;S. Luan
影响因子：
6.3
作者：
Jun Zheng;Renyi Zhang;Edward Charles Fortner;R. Volkamer;L. Molina;A. Aiken;J. Jimenez;K. Gaeggeler;J. Dommen;S. Dusanter;P. Stevens;X. Tie
通讯作者：
Jun Zheng;Renyi Zhang;Edward Charles Fortner;R. Volkamer;L. Molina;A. Aiken;J. Jimenez;K. Gaeggeler;J. Dommen;S. Dusanter;P. Stevens;X. Tie
影响因子：
2.9
作者：
A. Nair;F. Yu
通讯作者：
A. Nair;F. Yu
DOI：
10.1073/pnas.1900125116
发表时间：
2019-04-30
影响因子：
11.1
作者：
An, Zhisheng;Huang, Ru-Jin;Ji, Yuemeng
通讯作者：
Ji, Yuemeng