Infrared solar spectroscopic measurements of free tropospheric CO
Infrared solar spectroscopic measurements of free tropospheric CO
复制标题
自由对流层二氧化碳的红外太阳光谱测量
DOI：
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发表时间：
1999
期刊：
影响因子：
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通讯作者：
B. Connor
中科院分区：
文献类型：
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作者：
C. Rinsland;A. Goldman;F. Murcray;T. Stephen;N. Pougatchev;J. Fishman;S. David;R. D. Baltherwick;P. Novelli;N. Jones;B. Connor
位于夏威夷莫纳罗亚（Mauna Loa）平流层变化探测网络站（北纬19.5度，西经155.6度，海拔3.4公里）记录了CO、C2H6和HCN的高光谱分辨率（0.003/ cm）红外太阳吸收测量数据。这些观测是在1995年8月至1998年2月间的250多天内进行的。报道了海拔3.4 - 16公里区域的柱面测量，大致相当于台站上方的自由对流层。计算的这一层的平均CO混合比已与同一时期在该站原位获得的烧瓶取样CO测量值进行了比较。两者都表现出不对称的季节周期叠加在显著的变率上。前两年的观测显示1月至4月有广泛的最大值，夏末有更明显的CO最小值。在整个观测期内，C2H6和CO 3.4 ~ 16 km柱分别与北纬32°和南纬45°相似红外光谱测量得到的C2H6/CO斜率介于较高和较低值之间高度相关。大约从1997年9月开始，CO、C2H6，特别是HCN的变化增强被观察到。1997年11月观测到的最大HCN自由对流层月平均柱对应于3.4 - 16 km的平均混合比为0.7 ppbv （1 ppbv = 10(exp -9) /单位体积），比背景水平高3倍以上。HCN的增强一直持续到观测系列结束。反轨迹计算表明，排放物起源于东南亚的北纬低纬度地区。同期测量的地表CO混合比和对流层C2H6柱也显示出1997年秋季的异常最大值。在1997-1998年强厄尔尼诺暖期燃烧的强烈而广泛的热带野火可能是排放产物增加的来源。
High spectral resolution (0.003/ cm) infrared solar absorption measurements of CO, C2H6, and HCN have been recorded at the Network for the Detection of Stratospheric Change station on Mauna Loa, Hawaii, (19.5 deg N, 155.6 deg W, altitude 3.4 km). The observations were obtained on over 250 days between August 1995 and February 1998. Column measurements are reported for the 3.4 - 16 km altitude region, which corresponds approximately to the free troposphere above the station. Average CO mixing ratios computed for this layer have been compared with flask sampling CO measurements obtained in situ at the station during the same time period. Both show asymmetrical seasonal cycles superimposed on significant variability. The first two years of observations exhibit a broad January-April maximum and a sharper CO minimum during late summer. The C2H6 and CO 3.4 - 16 km columns were highly correlated throughout the observing period with the C2H6/CO slope intermediate between higher and lower values derived from similar infrared spectroscopic measurements at 32 deg N and 45 deg S latitude, respectively. Variable enhancements in CO, C2H6, and particularly HCN were observed beginning in about September 1997. The maximum HCN free tropospheric monthly mean column observed in November 1997 corresponds to an average 3.4 - 16 km mixing ratio of 0.7 ppbv (1 ppbv = 10(exp -9) per unit volume), more than a factor of 3 above the background level. The HCN enhancements continued through the end of the observational series. Back-trajectory calculations suggest that the emissions originated at low northern latitudes in southeast Asia. Surface CO mixing ratios and the C2H6 tropospheric columns measured during the same time also showed anomalous autumn 1997 maxima. The intense and widespread tropical wild fires that burned during 3 the strong El Nino warm phase of 1997-1998 are the likely source of the elevated emission products.