Climatology of Large, Episodic Ammonia Blooms in the U.S. Midwest in Spring and Links to Fertilization Application - INSU - Institut national des sciences de l'Univers Access content directly
Conference Papers Year : 2022

Climatology of Large, Episodic Ammonia Blooms in the U.S. Midwest in Spring and Links to Fertilization Application

Abstract

Agricultural activities are the major sources of NH3 emissions to the atmosphere yet have high uncertainties due to varying agricultural practices and limited data availability. For instance, nitrogen fertilizer application contributes ~ 20% of US NH3 emissions, but the timing and amount of application is poorly constrained in space and time. To understand the spatiotemporal distribution and magnitude of NH3 in the Midwest during the growing seasons, we used daily satellite NH3 observations from the Infrared Atmospheric Sounding Interferometer (IASI) and Crop Progress data from the US Department of Agriculture (USDA). NH3 peaks were quantitively identified using time series analyses of 3-day moving averages of satellite NH3 retrievals. Frequent, large scale (>1000 km2), episodic (~ days), and temporally dynamic NH3 plumes are common features for each spring across the Midwest. The magnitudes of these plumes were large with the daily column abundances greater than 5×1016 molec/cm2, which is 7 times higher than the 95th percentile of the annual averaged NH3 column abundance in the contiguous US (0.66×1016 molec/cm2). The dates of the first “excessive” NH3 peaks in spring during 2013 – 2018 showed large interannual variability, varying from early March to April, and were correlated with the crop planting progress for the planting season. For example, in Illinois, in which the dominant crop that requires fertilizer is corn, the date of corn planting (defined as first week of >5% of total corn planted) was consistently about 36 days later than the first NH3 peak (r=0.94), indicating the pre-planting fertilizer application timing. Satellite NH3 observations are capable of showing the interannual variability of crop planting dates and providing top-down constraints for NH3 emitted from nitrogen fertilizers. Compared to other anthropogenic emissions, such as SO2 and NOx, NH3 emissions are less well constrained, particularly daily scale episodic events such as around times of fertilizer application. Our results highlight the potential of using satellite NH3 observations to provide critical insights into the role of agricultural reactive nitrogen (Nr) emissions. The large fertilizer blooms that occur on daily scale in the Midwest may also degrade air quality in downstream areas as these blooms transport to other areas.
No file

Dates and versions

insu-03929381 , version 1 (08-01-2023)

Identifiers

  • HAL Id : insu-03929381 , version 1

Cite

Rui Wang, Daniel Moore, Xuehui Guo, Da Pan, Kang Sun, et al.. Climatology of Large, Episodic Ammonia Blooms in the U.S. Midwest in Spring and Links to Fertilization Application. AGU Fall Meeting 2022, Dec 2022, Chicago, United States. pp.B16G-04. ⟨insu-03929381⟩
40 View
0 Download

Share

Gmail Facebook X LinkedIn More