Anticipating the effect of post-harvest soil respiration from agricultural fields using high resolution remote sensing and in situ observations

Post-harvest agricultural fields experience a net emission of CO2 to the atmosphere while adjacent fields contribute to the highest rates of carbon removal for North America. The heterogeneity of managed fields requires high resolution observations to capture the incongruous shift in carbon dynamics. Surface temperature estimates from remote sensing carry information about the soil surface where vegetation is sparse or absent. In an agricultural region, areas can transition from highly vegetated to bare soil abruptly. Harvest coincides with a possible cessation of irrigation and subsequent higher surface temperatures. High resolution (70 m x 70 m) temperature calculated from NASA ECOSTRESS observations occur at individual sites every few days, at different times of day. In this study, we use two additional datasets to overcome temporal and spatial data gaps for describing bare fields. NOAA GOES-R satellite images provide temperature and reflectance wavelengths appropriate for vegetation indices in high temporal resolution (multiple images an hour) at coarser resolution (1 km x 1 km). NASA Landsat enables observing the state of vegetated land cover at higher spatial resolution (30 m x 30 m) but more infrequent flyovers (16 day repeat). All of these products have data gaps due to cloud cover. Here we describe a method to estimate bare soil area in agricultural regions and the subsequent contribution to soil respiration. We compare to field data from the Soil Respiration Database and FLUXNET to constrain the effect of agricultural land management on regional carbon balance.