The spectra of O_2 A-band(0.76 μm) and CO_2 near-infrared emissions(1.6 μm) are simulated by the SCIATRAN radiative transfer model(V3.1.23), and compared with those observed by GOSAT-FTS(Greenhouse gases Observing S...The spectra of O_2 A-band(0.76 μm) and CO_2 near-infrared emissions(1.6 μm) are simulated by the SCIATRAN radiative transfer model(V3.1.23), and compared with those observed by GOSAT-FTS(Greenhouse gases Observing SATellite-Fourier Transform Spectrometer). Systematic deviations between the observed and simulated spectra are found to exist,especially for the O_2 A-band. The discrepancies are characterized by their mean differences averaged over the observed spectral ranges. A correction is applied to the observed GOSAT-FTS L1B(V141.141) spectra by scaling the spectral intensity measured by TANSO-FTS(Thermal and Near infrared Sensor for carbon Observation Fourier Transform Spectrometer) onboard GOSAT.The average columnar CO_2 concentrations(XCO_2) are retrieved from the observed and the corrected GOSAT-FTS spectra by using the SCIATRAN inversion algorithm. Compared with the GOSAT-FTS L2 XCO_2 data products retrieved from the observed spectra of GOSAT-FTS, the SCIATRAN retrievals from the corrected spectra show a much better agreement, with the relative error less than 1%. But the results of GOSAT TANSO-FTS(V161.160) show smaller residuals than GOSAT TANSO-FTS(V141.141) without mean residual correction. The results indicate that the mean residual correction would increase the precision of XCO_2 retrieval for spectra with systematic deviations.展开更多
基金supported by the National Major Project (Grant No. 32-Y30B089001-13/15)the State Key Program of National Natural Science Foundation of China (Grant No. 41530422)+2 种基金the National Natural Science Foundation of China (Grant Nos. 61540018, 61275184, 61405153)the National High Technology Research and Development Program of China (Grant No. 2012AA121101)the Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20130201120047)
文摘The spectra of O_2 A-band(0.76 μm) and CO_2 near-infrared emissions(1.6 μm) are simulated by the SCIATRAN radiative transfer model(V3.1.23), and compared with those observed by GOSAT-FTS(Greenhouse gases Observing SATellite-Fourier Transform Spectrometer). Systematic deviations between the observed and simulated spectra are found to exist,especially for the O_2 A-band. The discrepancies are characterized by their mean differences averaged over the observed spectral ranges. A correction is applied to the observed GOSAT-FTS L1B(V141.141) spectra by scaling the spectral intensity measured by TANSO-FTS(Thermal and Near infrared Sensor for carbon Observation Fourier Transform Spectrometer) onboard GOSAT.The average columnar CO_2 concentrations(XCO_2) are retrieved from the observed and the corrected GOSAT-FTS spectra by using the SCIATRAN inversion algorithm. Compared with the GOSAT-FTS L2 XCO_2 data products retrieved from the observed spectra of GOSAT-FTS, the SCIATRAN retrievals from the corrected spectra show a much better agreement, with the relative error less than 1%. But the results of GOSAT TANSO-FTS(V161.160) show smaller residuals than GOSAT TANSO-FTS(V141.141) without mean residual correction. The results indicate that the mean residual correction would increase the precision of XCO_2 retrieval for spectra with systematic deviations.
基金National Natural Science Foundation of China(11703061),Hefei Institutes of Physical Science Present Foundation(YZJJ201607),Laboratory Innovation Foundation(CXJJ-17S002)。
文摘OH自由基是中高层大气中重要的氧化剂,决定着臭氧以及其他温室气体的浓度变化,甚至气候变化。为了实现中高层大气OH自由基的精细探测与精确反演,需要构造正演模型,模拟得到仪器接收到的大气中的A2Σ+-X2Π(0,0)309nm波段的太阳共振荧光发射信号。本文基于分子光谱能级跃迁理论计算得到OH(0,0)振动能级上的荧光发射率因子g,结合辐射传输模型SCIATRAN模拟出的太阳辐照度和观测视线路径上的OH柱量,模拟出OH荧光发射光谱,叠加上大气背景光谱并卷积仪器函数,最终模拟得到仪器接收的包含OH浓度信息的光谱。模拟结果与国外在轨仪器MAHRSI(Middle Atmosphere High-Resolution Spectrograph Investigation),SHIMMER(Spatial Heterodyne Imager for Mesospheric Radicals)的在轨实测结果一致性较好。还分析了影响模拟结果的因素,在之后的正演过程中加以修正,使正演模型更接近实际辐射传输过程。
