基于太阳吸收光谱观测大气一氧化碳柱总量

基于地基高分辨率傅里叶变换红外光谱技术观测合肥地区一氧化碳(CO)垂直柱总量的变化，连续采集近红外太阳吸收光谱，获得2015年9月至2016年7月整层大气CO的垂直柱总量的时间序列。观测结果显示合肥地区大气中柱平均干空气混合比(XCO)有着明显的季节变化，在2015年10月有着较小值，然后逐渐增加，到2016年3月达到最大值，之后逐渐下降，在2016年7月底达到最小值，并分析了季节变化的原因。为了对地基近红外波段观测进行验证，采用MOPITT卫星数据和站点同一光谱仪采集的中红外光谱反演的CO柱总量与同期测量的数据进行比对。结果表明，MOPITT卫星数据与地基观测值的季节变化一致，而MOPITT观测值整体高于地基FTS观测值；近红外和中红外波段反演的CO柱总量季节变化范围一致。将地基观测和卫星观测数据进行日平均计算, 并进行相关性分析，得到的地基近红外和卫星观测、地基中红外的CO日平均柱总量的线型回归相关系数分别为0.85和0.91，显示出高的相关性，证明了地基近红外波段反演CO垂直柱总量数据的准确性。首次采用地基高分辨率傅里叶变换红外光谱技术观测合肥地区CO的垂直柱总量，并将得到的观测结果与卫星数据比对，得到准确的CO的垂直柱总量，为解大气CO的时空分布状况及其演变规律、追踪合肥地区CO的源汇分布提供理论依据。

Observations of Total Columns of CO Based on Solar Absorption Spectra

Observations of the total columns of carbon monoxide(CO) in Hefei area are performed based on ground-based high resolution Fourier transform infrared spectroscopy, and we continuously collect the near-infrared solar absorption spectra and obtain time series of total column of CO through the atmosphere from September 2015 to July 2016. The observation results show that the column-averaged dry air mole fraction XCO in this area has obvious seasonal variation during the measurement period. Observation result shows that in the measured period XCO in Hefei area has obvious seasonal change. In October 2015 it has a smaller value, and then it gradually increases, in March 2016 it reaches the maximum at the end of July. Then it declines gradually, and gets to the minimum. We also analyze the reason of the XCO seasonal variation. In order to verify the observations based on the near-infrared region, we use MOPITT satellite data and CO total columns retrieved from the mid-infrared spectra collected by the same spectrometer at Hefei site to compare with the simultaneous measurements. The comparison results show that the seasonal variation of MOPITT data is similar to that of ground-based near-infrared observations, and overall MOPITT observations are higher than ground-based FTS observations. The seasonal variation and variation range of column values of CO retrieved from the mid-infrared spectra agree with those from the near-infrared spectra. The correlation coefficients between the daily averaged CO total columns of the ground-based near-infrared observations with those of satellite and mid-infrared observations are 0.85 and 0.91, respectively, which shows the high correlation and proves the accuracy of the CO total columns of the ground-based near-infrared observations. It is the first time to observe the total columns of carbon monoxide(CO) in Hefei area by using ground-based high resolution Fourier transform infrared spectroscopy, and compare them with MOPITT satellite data to get precise result. It provides the theoretical basis to understand the time and space distribution and changes of CO in atmospheric and trace source-sink distribution of CO in Hefei area.