CPEC-AZ闭路涡度相关泔�/span>通量观测系统

一�应用

目前，开路涡动相关法通量观测系统无法同步测量多种气体，其精度也无法满足痕量温室气体的测量要求，在雨雪天气数据不连续问题给科研带来很多困扰、�/span>

CPEC-AZ闭路涡度相关法通量系统采用中红外技术，测量频率可达10Hz，检测限达ppt级，可用于野外实时测量痕量气体、�/span>

此外，还能同步测量多种含碳、含氮痕量气体及气体同位素，如：

CO/CO₂/CH₄/C₂H₄/HCHO/CHOOH/COS/SO₂

NO/N₂O/NO₂/NH₃/ HONO/ HNO₃

¹³C-CO₂�¹⁸O-CO₂�¹⁷O-CO_{2＋�/span>}HOD＋�/span>

¹⁵N¹⁴N¹⁶O�?#948;¹⁵N^��（�/span>＋�/span>¹⁴N¹⁵N¹⁶O�?#948;¹⁵N^��（�/span>

二、系统组戏�/span>

该系统主朹�/span>Aerodyne闭路气体分析仪采�?/span>可调谐红外激光直接吸攵�/span>光谱＇�/span>TILDAS（�/span>技术，�?/span>中红夕�/span>激先�/span>探测气体分子，独有的像散型多光程吸收池技�?/span>有效测量光程高达210m，有效提高气体分子的测量精度，达ppt级、�/span>

该系统由Aerodyne闭路式气体分析仪、超声风速采集模块、数据整合软件、恒温机箱、采气管路等组成、�/span>

超声风速采集模块可与已有的开路涡度相关法通量观测系统共用，在超声风速仪中心设置采样管，即可完成原有的开路涡度相关法系统升级，同步观测多种气体、�/span>

农田生态系统闭路涡度相关法含氮气体通量观测

三、系统优劾�/span>

1、该系统采用皃�/span>Aerodyne闭路气体分析仪对痕量气体测量频率可达10Hz＋�/span>能完全满足涡度相关法通量观测条件，测量精度高，检测限可达ppt级。各种气体测量精度见技术指标、�/span>

2、该系统可同步观测多种气体，部分气体分子组合如下（可根据科研需要，提供近百种气体组合）９�/span>

1（�/span>N₂O�?/span>CO₂�?/span>NH₃�?/span>O₃�?/span>CO�?/span>H₂O

2)N₂O�?/span>CO₂�?/span>CH₄�?/span>COS�?/span>CO�?/span>H₂O

3（�/span>NO�?/span>NO₂�?/span>H₂O

4) N₂O�?/span>CO₂�?/span>CH₄�?/span>CO�?/span>C₂H₆�?/span>H₂O

5) HONO�?/span>HNO₃�?/span>H₂O

6) HCN�?/span>HCl

7（�/span>CH₄�?/span>C₂H₆�?/span>C₃H₈

采用活性钝化系统后＋�/span>NH3测量的时间常数和高频通量变化（时间常数更快）

3、该系统还可同步观测多种气体同位素，部分气体同位素组合如下：

1（�/span>N₂O�?/span>¹⁵N¹⁴N¹⁶O�?/span>¹⁴N¹⁵N¹⁶O�?/span>¹⁴N¹⁴N¹⁸O

2（�/span>CH₄¹³CH4�?/span>CH₃D

3（�/span>CO₂�?/span>¹³C-CO₂�?/span>¹⁷O-CO₂�?/span>¹⁸O-CO₂

4�?*技术活性钝化装置可显著提高粘性气体分子如NH₃�?/span>HONO等的响应时间，实现粘性气体和非粘性气体的同步观测，如N₂O�?/span>CO₂�?/span>NH₃�?/span>O₃�?/span>CO�?/span>H₂O

同步观测、�/span>

5�?/span>惯性颗粒物分离装置，能有效减少颗粒物附着，确保两次采样不会交叉污染、�/span>

6、该系统能够实现自动全量程校准和零点校准、�/span>

四、技术指栆�/span>

该系统可测量气体分子�?/span>1s�?00s测量精度、相应时间如下：

常见痕量温室气体９�/span>

参数	N2O	CH4	CO2	NH3	H2O	COS	NO	NO2	HONO
精度 1S	0.03ppb	0.1ppb	100ppb	40ppt	10ppm	0.005ppb	0.15ppb	0.03ppb	0.21ppb
精度 100S	0.01ppb	0.25ppb	25ppb	10ppt	5ppm	0.002ppb	0.15ppb	0.01ppb	75ppt
测量范围	0-10000ppb	0-10000ppb	0-5000ppm	0-10000ppb	0-5000ppm	0-5000ppm	0-5000ppm	0-5000ppm	0-5000ppm
响应时间	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10Hz可逈�/span>

含碳气体同位素：

参数	��13CH4	��CH3D	��13CH4	CO2	��13C	��18O
精度 1S	3�?/span>	30�?/span>	1�?/span>	25ppb	0.1�?/span>	0.03�?/span>
精度 100S	1�?/span>	30�?/span>	1�?/span>	10ppb	0.03�?/span>	0.03�?/span>
测量范围	3�?/span>	30�?/span>	1�?/span>	25ppb	0.1�?/span>	0.1�?/span>
响应时间	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>

含氮气体同位素：

参数	NH3	��15N14N16O�?#948;15N��（�/span>	��14N15N16O�?#948;15N��（�/span>	��14N14N18O�?#948;18O（�/span>
精度 1S	40ppt	0.1�?/span>	0.03�?/span>	8�?/span>
精度 100S	10ppt	1�?/span>	1�?/span>	2�?/span>
测量范围	0-10000ppb	300~30000ppb	300~30000	300~30000
响应时间	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>	1-10HZ可逈�/span>

四、应用案刖�/span>

1、意大利化�/span>部土壤农�?/span>�?/span>施加控制试验＋�/span>通过CPEC方法探究氨态氮＇�/span>NH₄⁺-N\NH₃）内部转化过程及氨气＇�/span>NH₃）恢复�?/span>�?/span>夰�/span>^{』�/span>1【�/span>}、�/span>

兰德里亚诹�/span>Landriano 2009（SI-09）和2011（SI-11）试验期间，通过涡流协方差系统（EC）和反向拉格朗日随机模型（bLS（�/span>估算NH₃累积排放和归一匕�/span>损失

结果表明：氮施加实验名�/span>24�?0 h。的**NH₃排放水平丹�/span>138.3 mg/m-²s-¹咋�/span>243.5mg/m-²s-¹＋�/span>NH₄-N的总损夰�/span>比例在两次扩散实验后7天分�?/span>丹�/span>19.4�咋�/span>28.5＄�/span>、�/span>

2�?/span>中国亚热带典型的蔬菜�?/span>利用CPEC方法同时测量一氧化二氮（N₂O），甲烷（CH₄）和二氧化碳（CO₂）通量^{�?【�/span>}、�/span>

N₂O，CH₄咋�/span>CO₂（实心圆）和气温（空心圆）的频率加权归一化共谱）以及相应的高频共谱传递函�?/span>

结果�?/span>昍�/span>９�/span>通过Aerodyne友�/span>激先�/span>分析�?/span>的检测结果计算出N₂O的中值精度（1��）为0.14 nmol/mol^-1＋�/span>�?/span>野外条件下，采样频率�?0 Hz时，CH₄的摩尔浓度为3.3 nmol/mol，CO₂的摩尔浓度为0.36��mol/mol、�/span>

3、美国马萨诸塞州温带森林中生态系�?大气二氧化碳净交换（NEE（�/span>的同位素组份（即¹²C¹⁶O₂�?/span>¹³C¹⁶O₂咋�/span>¹⁸O¹²C¹⁶O的净交换量）CPEC方法测量^{�?【�/span>}、�/span>

通过EC(实线)咋�/span>EC/Flask(虚线)估算皃�/span>6月（橙色�?月（绿色）�?月（蓝色）和9月（紫色）的��¹³C日变化、�/span>EC循环已平滑至2 h，并且仅展示亅�/span>CO₂通量小于-2 mol m^-2s^-1的时间、�/span>

NEE�?/span>��¹⁸O6月（橙色�?月（绿色）�?月（蓝色）和9月（紫色）的��¹³C日变化，EC结果已平滑至2 h

结果表明９�/span>NEE�?/span>皃�/span>¹³C组份表现凹�/span>日变化的趋势，可能反映了光合作用的扩散和生化限制之间的平衡转移。白天，¹⁸O同位紟�/span>通量表现出与蒸发皃�/span>¹⁸O叶片水富雅�/span>有关的特征、�/span>同位紟�/span>通量咋�/span>NEE中的¹³C组份都有明显的季节性变匕�/span>＋�/span>NEE�?/span>皃�/span>¹⁸O练�/span>仼�/span>逐月更一致、�/span>

4、瑞士中部集约化经营草地采用量子级联激光吸收光谱法＇�/span>QCLAS（�/span>寸�/span>N₂O**同位素表征、�/span>

标气（红色）和表层（黑色（�/span>N₂O摩尔分数（顶部）和同位素值（三个底部面板）在原为实验期间皃�/span>大气表层测量

结果表明：同步涡度协方差N₂O通量测量确定了土壤中N₂O的通量平均同位素特征，集约经营草地N₂O的通量平均同位素组成SP�?#948;¹⁵N^buk咋�/span>��¹⁸O分别�?.9��4.3�?17.4��6.2�?7.4��3.6‰、�/span>

5、美国哈佛森林温带落叶林通过羰基硫的吸收确立了林冠层气孔导度，蒸腾和蒸发的动态变化、�/span>

冠层OCS吸收咋�/span>初级生产总值（GPP）随着叶相关吸收（LRU（�/span>咋�/span>光和有效辐射＇�/span>PAR（�/span>皃�/span>绻�/span>

冠层OCS吸收咋�/span>初级生产总值（GPP）随着叶相关吸收（LRU（�/span>咋�/span>光和有效辐射＇�/span>PAR（�/span>

结果表明９�/span>在这个温带的落叶森林林地中，基于土壤中OSC含量预测土壤始终是羰基硫的汇。OCS通量测量可以作为探测其他生态系统中的气孔导度的通用工具，并且可在叶片尺度和实验室研究中用作探测气孔导度的通用工具、�/span>

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