Application of the Raman lidar for remote sensing of CO2 VMRs at several CO2 emission source areas.

Abstract

We, for the first time, developed a Raman lidar system which can remotely detect surface CO2 volume mixing ratio (VMR). Indoor CO2 cell measurements show that the accuracy of the Raman lidar is calculated to be 99.89%. We carried out the field measurement using our Raman lidar at an artificial CO2 leakage site where a CO2 leakage spot is located 0.2 km away from the Raman lidar. The results show good agreement between CO2 VMRs measured by the Raman lidar system (CO2 VMRRaman LIDAR) and those measured by in situ instruments (CO2 VMRIn-situ). The correlation coefficient (R), mean absolute error (MAE), root mean square error (RMSE), and percentage difference between CO2 VMRIn-situ and CO2 VMRRaman LIDAR are 0.81, 0.27%, 0.37%, and 4.92%, respectively. Surface CO2 VMRs were retrieved at several distances from the Raman Lidar. The average values of R, MAE, and RMSE between CO2 VMRIn-situ and CO2 VMRRaman LIDAR are 0.92, 2.78 ppm, and 3.26 ppm, respectively. We detected CO2 emitted from a stack of a resource recovery facility 450 m away from Raman lidar. CO2 VMRRaman LIDAR was in the range of 600 to 1400 ppmv.