NH&amp;lt;sub&amp;gt;3&amp;lt;/sub&amp;gt; emissions from large point sources derived from CrIS and IASI satellite observations

Enrico Dammers,Vitali Fioletov,Simon Whitburn,Debora Griffin,Jan Willem Erisman,Karen Cady-Pereira,Chris A Mclinden,Lieven Clarisse,Yonatan Gainairu-Matz,Shelley Van Der Graaf,Erik Lutsch,Mark W Shephard,Martin Van Damme,Pierre Francois Coheur,Cathy Clerbaux,Martijn Schaap

doi:10.5194/acp-19-12261-2019

Abstract

Abstract. Ammonia (NH3) is an essential reactive nitrogen species in the biosphere and through its use in agriculture in the form of fertilizer (important for sustaining humankind). The current emission levels, however, are up to 4 times higher than in the previous century and continue to grow with uncertain consequences to human health and the environment. While NH3 at its current levels is a hazard to environmental and human health, the atmospheric budget is still highly uncertain, which is a product of an overall lack of measurements. The capability to measure NH3 with satellites has opened up new ways to study the atmospheric NH3 budget. In this study, we present the first estimates of NH3 emissions, lifetimes and plume widths from large (>∼5 kt yr−1) agricultural and industrial point sources from Cross-track Infrared Sounder (CrIS) satellite observations across the globe with a consistent methodology. The same methodology is also applied to the Infrared Atmospheric Sounding Interferometer (IASI) (A and B) satellite observations, and we show that the satellites typically provide comparable results that are within the uncertainty of the estimates. The computed NH3 lifetime for large point sources is on average 2.35±1.16 h. For the 249 sources with emission levels detectable by the CrIS satellite, there are currently 55 locations missing (or underestimated by more than an order of magnitude) from the current Hemispheric Transport Atmospheric Pollution version 2 (HTAPv2) emission inventory and only 72 locations with emissions within a factor of 2 compared to the inventories. The CrIS emission estimates give a total of 5622 kt yr−1, for the sources analyzed in this study, which is around a factor of ∼2.5 higher than the emissions reported in HTAPv2. Furthermore, the study shows that it is possible to accurately detect short- and long-term changes in emissions, demonstrating the possibility of using satellite-observed NH3 to constrain emission inventories.

Highlights

Ammonia (NH3) is one of the most important reactive nitrogen species in the biosphere and essential for sustaining humankind through its use in agriculture in the form of fertilizer
For quality assurance of the estimated emissions, we filter out low-quality fits with r < 0.5 and an upwind–downwind signal-to-noise ratio (SNR) < 2. (McLinden et al, 2016), defined as where Cd and Cu are the mean down- and upwind total columns, σd and σu are the standard deviations, and Nd and Nu are the number of down- and upwind values
We presented the first NH3 emission estimates based on the Cross-track Infrared Sounder (CrIS)-NH3 satellite observations, where both the emissions and lifetimes of NH3 are derived simultaneously for a variety of agricultural and industrial point sources

Summary

Introduction

Ammonia (NH3) is one of the most important reactive nitrogen species in the biosphere and essential for sustaining humankind through its use in agriculture in the form of fertilizer. Through fertilization of ecosystems, deposited NH3 and other reactive nitrogen species play an important role in the sequestration of carbon dioxide (Oren et al, 2001; de Vries et al, 2014). Particulate matter is shown to have impact on human health, shortening human life expectancy and affecting pregnancy outcomes (Pope III et al, 2002, 2009; Stieb et al, 2012; Lelieveld et al, 2015; Giannakis et al, 2019). Particulate matter impacts global climate change directly through the change in radiative forcing and indirectly through its effects on cloud formation (Adams et al, 2001; Myhre et al, 2013)

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