Hyperspectral plant signatures can be used as a sho rt-term, as well as long-term (100-yr timescale) monitoring technique to verify that CO 2 sequestration fields have not been compromised. An influx of CO2 gas into the soil can stress vegetation, which caus es changes in the visible to nearinfrared reflectance spectral signature of the vege tation. For 29 days, beginning on July 9th, 2008, pure carbon dioxide gas was released through a 100meter long horizontal injection well, at a flow rate of 300 kg/day. Spectral signatures were record ed almost daily from an unmown patch of plants over the injection with a “FieldSpec Pro” sp ectrometer by Analytical Spectral Devices, Inc. Measurements were taken both inside and outside of the CO2 leak zone to normalize observations for other environmental factors affecting the plant s. Four to five days after the injection began, stress wa observed in the spectral signatures of plants within 1 meter of the well. After approximately ten days, moderate to high amounts of stress were measured out to 2.5 meters from the well. This spat ial distribution corresponded to areas of high CO2 flux from the injection. Airborne hyperspectral ima gery, acquired by Resonon, Inc. of Bozeman, MT using their hyperspectral camera, also showed the same pattern of plant stress. Spectral signatures of the plants were also compare d to the CO2 concentrations in the soil, which indicated that the lower limit of soil CO 2 needed to stress vegetation is between 4% and 8% by volume.

Hyperspectral plant signatures can be used as a short-term, as well as long-term (100-year timescale) monitoring technique to verify that CO 2 sequestration fields have not been compromised. An influx of CO 2 gas into the soil can stress vegetation, which causes changes in the visible to near-infrared reflectance spectral signature of the vegetation. For 29 days, beginning on July 9, 2008, pure carbon dioxide gas was released through a 100-m long horizontal injection well, at a flow rate of 300 kg day −1 . Spectral signatures were recorded almost daily from an unmown patch of plants over the injection with a “FieldSpec Pro” spectrometer by Analytical Spectral Devices, Inc. Measurements were taken both inside and outside of the CO 2 leak zone to normalize observations for other environmental factors affecting the plants. Four to five days after the injection began, stress was observed in the spectral signatures of plants within 1 m of the well. After approximately 10 days, moderate to high amounts of stress were measured out to 2.5 m from the well. This spatial distribution corresponded to areas of high CO 2 flux from the injection. Airborne hyperspectral imagery, acquired by Resonon, Inc. of Bozeman, MT using their hyperspectral camera, also showed the same pattern of plant stress. Spectral signatures of the plants were also compared to the CO 2 concentrations in the soil, which indicated that the lower limit of soil CO 2 needed to stress vegetation is between 4 and 8% by volume.