Faculty Publications

Title

A Multiyear Constraint on Ammonia Emissions and Deposition Within the US Corn Belt

Document Type

Article

Keywords

agriculture, ammonia emissions, deposition, forests, mitigation, reactive nitrogen, tall tower, US Corn Belt, WRF-Chem modeling

Journal/Book/Conference Title

Geophysical Research Letters

Volume

48

Issue

6

Abstract

The US Corn Belt is a global hotspot of atmospheric ammonia (NH3), a gas known to adversely impact the environment and human health. We combine hourly tall tower (100 m) measurements and bi-weekly, spatially distributed, ground-based observations from the Ammonia Monitoring Network with the US National Emissions Inventory (NEI) and WRF-Chem simulations to constrain NH3 emissions from April to September 2017–2019. We show that: (1) NH3 emissions peaked from May to July and were 1.6–1.7 times the annual NEI average; (2) average growing season NH3 emissions from agricultural lands were remarkably similar across years (3.27–3.64 nmol m−2 s−1), yet showed substantial episodic variability driven by meteorology and land management; (3) dry deposition was 40% of gross emissions from agricultural lands and exceeded 100% of gross emissions in natural lands. Our findings provide an important benchmark for evaluating future NH3 emissions and mitigation efforts.

Department

Department of Earth and Environmental Sciences

Original Publication Date

3-28-2021

DOI of published version

10.1029/2020GL090865

Repository

UNI ScholarWorks, Rod Library, University of Northern Iowa

Language

en

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