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Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - UK Ammonia Emissions Estimated With Satellite Observations and GEOS‐Chem
AU - Marais, Eloise
AU - Pandey, Alok Kumar
AU - Van Damme, Martin
AU - Clarisse, Lieven
AU - Coheur, Pierre-Francois
AU - Shephard, Mark W.
AU - Cady-Pereira, Karen E.
AU - Misselbrook, Tom
AU - Zhu, Lei
AU - Luo, Gan
AU - Yu, Fangqun
PY - 2021/9/27
Y1 - 2021/9/27
N2 - Agricultural emissions of ammonia (NH 3) impact air quality, human health, and the vitality of aquatic and terrestrial ecosystems. In the UK, there are few direct policies regulating anthropogenic NH 3 emissions and development of sustainable mitigation measures necessitates reliable emissions estimates. Here, we use observations of column densities of NH 3 from two space-based sensors (IASI and CrIS) with the GEOS-Chem model to derive top-down NH 3 emissions for the UK at fine spatial (∼10 km) and time (monthly) scales. We focus on March-September when there is adequate spectral signal to reliably retrieve NH 3. We estimate total emissions of 272 Gg from IASI and 389 Gg from CrIS. Bottom-up emissions are 27% less than IASI and 49% less than CrIS. There are also differences in seasonality. Top-down and bottom-up emissions agree on a spring April peak due to fertilizer and manure application, but there is also a comparable summer July peak in the top-down emissions that is not in the bottom-up emissions and appears to be associated with dairy cattle farming. We estimate relative errors in the top-down emissions of 11%–36% for IASI and 9%–27% for CrIS, dominated by column density retrieval errors. The bottom-up versus top-down emissions discrepancies estimated in this work impact model predictions of the environmental damage caused by NH 3 emissions and warrant further investigation.
AB - Agricultural emissions of ammonia (NH 3) impact air quality, human health, and the vitality of aquatic and terrestrial ecosystems. In the UK, there are few direct policies regulating anthropogenic NH 3 emissions and development of sustainable mitigation measures necessitates reliable emissions estimates. Here, we use observations of column densities of NH 3 from two space-based sensors (IASI and CrIS) with the GEOS-Chem model to derive top-down NH 3 emissions for the UK at fine spatial (∼10 km) and time (monthly) scales. We focus on March-September when there is adequate spectral signal to reliably retrieve NH 3. We estimate total emissions of 272 Gg from IASI and 389 Gg from CrIS. Bottom-up emissions are 27% less than IASI and 49% less than CrIS. There are also differences in seasonality. Top-down and bottom-up emissions agree on a spring April peak due to fertilizer and manure application, but there is also a comparable summer July peak in the top-down emissions that is not in the bottom-up emissions and appears to be associated with dairy cattle farming. We estimate relative errors in the top-down emissions of 11%–36% for IASI and 9%–27% for CrIS, dominated by column density retrieval errors. The bottom-up versus top-down emissions discrepancies estimated in this work impact model predictions of the environmental damage caused by NH 3 emissions and warrant further investigation.
KW - ammonia
KW - emissions
KW - Earth observations
KW - GEOS-Chem
KW - agriculture
KW - UK
U2 - 10.1029/2021JD035237
DO - 10.1029/2021JD035237
M3 - Journal article
VL - 126
JO - Journal of Geophysical Research: Atmospheres
JF - Journal of Geophysical Research: Atmospheres
SN - 0747-7309
IS - 18
M1 - e2021JD035237
ER -