The growth of the concentration of CO2 results in the global warming. The atmospheric temperature can impact the intensity and the shape of line of the molecular absorption spectrum of CO2, so that the atmospheric vertical temperature profile changes affect the measured absorption spectrum of CO2 by the satellite. This study focuses on the influence of the vertical temperature profile changes at different latitudes and the discontinuity of the profile in the upper layers of the atmosphere on the accuracy of retrieving CO2 concentration. The simulation results suggested that the error of retrieving CO2 concentration caused by the vertical temperature profile changes in the upper layers was much less than 1%.
As an important part of the earth, atmosphere plays a vital role in filtering the solar radiation, adjusting the temperature and organizing the water circulation and keeping human survival. The passive atmospheric wind measurement is based on the imaging interferometer technology and Doppler effect of electromagnetic wave. By using the wind imaging interferometer to get four interferograms of airglow emission lines, the atmospheric wind velocity, temperature, pressure and emission rate can be derived. Exploring the multi-functional and integrated innovation of detecting wind temperature, wind velocity and trace gas has become a research focus in the field. In the present paper, the impact factors of the fixed optical path difference(OPD) of near infrared wind imaging interferometer(NIWII) are analyzed and the optimum value of the fixed optical path difference is simulated, yielding the optimal results of the fixed optical path difference is 20 cm in near infrared wave band (the O2(a1Δg) airglow emission at 1.27 microns). This study aims at providing theoretical basis and technical support for the detection of stratosphere near infrared wind field and giving guidance for the design and development of near infrared wind imaging interferometer.
CO2 is the greenhouse gas that influenced by human activities most and has a great impact on the climate change. Monitoring of global CO2 variations on a basis of, high precision has great significance for the study of global climate change and carbon cycle, as well as the understanding of CO2 sources and sinks. This study develops the forward model and inversion software system GF_VRTM-V1.0 for space-borne near-infrared hyperspectral measurements of CO2 into a ground-based observation version. The simulation results are compared with the ground-based data of the column-averaged mole fraction of carbon dioxide measured at Fuling, and showed general agreement.
The spectra of O2 A-band (0.76 μm) and CO2 near-infrared emissions (1.6 μm) for Medium-resolution Satellite (SCIAMACHY) are simulated by the SCIATRAN model (V3.1.29), and compared with the ESFT and LBL method, as the inversion accuracy and time consuming. The time consuming of LBL was more than ESFT with the relative error less than 1%, especially for the CO2 band. But for the CO2 (2.0 um) of High-resolution Satellite, the opposite result was found. That is to say, the LBL method was more suitable for High-resolution Satellite. Different wavelength intervals and integral wavelength steps are applied to the LBL to select the most appropriate combination for High-resolution SatelliteO2 A-band (0.76 μm) and CO2 near-infrared band (1.58 μm).