Using the tracer flux ratio method with flight measurements to estimate dairy farm CH4 emissions in central California

[摘要] Tracer flux ratio methodology was applied to airborne measurements to quantify methane ( CH₄ ) emissions from two dairy farms in central California during the summer. An aircraft flew around the perimeter of each farm measuring downwind enhancements of CH₄ and a tracer species released from the ground at a known rate. Estimates of CH₄ emission rates from this analysis were determined for whole sites and major sources within a site (animal housing and liquid manure lagoons). Whole-site CH₄ flux rates for each farm, Dairy 1 ( 6108±821 kg CH₄ d ⁻¹ , 95 % confidence interval) and Dairy 2 ( 4018±456 kg CH₄ d ⁻¹ , 95 % confidence interval), closely resembled findings by established methods: ground-based tracer flux ratio and mass balance. Individual source emission rates indicate a greater fraction of the whole-site emissions come from liquid manure management than animal housing activity, similar to bottom-up estimates. Despite differences in altitude, we observed that the tracer release method gave consistent results when using ground or air platforms.

[学科分类] 几何与拓扑