Comparing imaging spectroscopy and in situ observations of Chino dairy complex emissions

Methane, CH4, and ammonia, NH3, directly and indirectly influence the atmospheric radiative balance. Long wave infrared (LWIR) airborne hyperspectral imagery and in situ data of CH4, CO2, and NH3 plumes were collected from the Chino Dairy Complex in the Los Angeles Basin. LWIR data showed significant emissions heterogeneity between dairies with good spatial agreement with in situ measurements. Remote sensing data also showed topographic effects on plumes mapped for at least 19 km. Repeated in situ measurements showed that emissions were persistent on half-year timescales. Inversion of one dairy plume found annual emissions of 4.1×10⁵ kg CH4, 2.2×10⁵kg NH3, and 2.3×10⁷ kg CO2, suggesting 3500, 4000, and 2100 head of cattle, respectively. Far field data showed chemical conversion of Chino NH3 occurs within the confines of the Los Angeles Basin on % day timescale, faster than previously published values.