For better knowledge of the carbon cycle, there is a need for spaceborne measurements of atmospheric CO₂ concentration. Because the gradients are relatively small, the accuracy requirements are better than 1%. We analyze the feasibility of a CO₂-weighted-column estimate, using the differential absorption technique, from high-resolution spectroscopic measurements in the 1.6- and 2-μm CO₂ absorption bands. Several sources of uncertainty that can be neglected for other gases with less stringent accuracy requirements need to be assessed. We attempt a quantification of errors due to the radiometric noise, uncertainties in the temperature, humidity and surface pressure uncertainty, spectroscopic coefficients, and atmospheric scattering. Atmospheric scattering is the major source of error [5 parts per 10⁶ (ppm) for a subvisual cirrus cloud with an assumed optical thickness of 0.03], and additional research is needed to properly assess the accuracy of correction methods. Spectroscopic data are currently a major source of uncertainty but can be improved with specific ground-based sunphotometry measurements. The other sources of error amount to several ppm, which is less than, but close to, the accuracy requirements. Fortunately, these errors are mostly random and will therefore be reduced by proper averaging.

© 2003 Optical Society of America

You do not have subscription access to this journal. Citation lists with outbound citation links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Cited by links are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

You do not have subscription access to this journal. Article level metrics are available to subscribers only. You may subscribe either as an OSA member, or as an authorized user of your institution.

Contact your librarian or system administrator
or
Log in to access OSA Member Subscription

Related Journal Articles

• Turn-Key Raman Lidar for Profiling Atmospheric Water Vapor, Clouds, and Aerosols (AO)
• Simple Monte Carlo Methods to Estimate the Spectra Evaluation Error in Differential-Optical-Absorption Spectroscopy (AO)
• Tropospheric emission spectrometer for the Earth Observing System’s Aura satellite (AO)
• Trade-off studies of a hyperspectral infrared sounder on a geostationary satellite (AO)
• In-flight performance and calibration of SPICAV SOIR onboard Venus Express (AO)

Related Conference Papers

• Advanced IR Laser Spectrometers for Identifying the Origin of Earth's Cirrus Clouds and Life on Mars
• Cavity ringdown spectroscopy with optical-heterodyne detection and miniature external-cavity tunable lasers
• Multi-wavelength sensing of CO and CO2 in air by rapidly-swept, continuous-wave cavity ringdown spectroscopy
• Sensitive detection of methane via absorption spectroscopy using a mid-infrared DFB interband cascade laser
• Simultaneous Measurements of NO₂ and its Dimer N₂O₄ at Room Temperature with a Multiplexed Intra-pulse Quantum Cascade Laser Spectrometer