The effects of the Syrian civil war on atmospheric ammonia as seen from IASI
Résumé
The Syrian civil war started a decade ago, in March 2011, causing dramatic social, political, economic
and environmental consequences over the whole area of Syria and nearby countries. Agriculture in
particular suffered massively, which affected the economy directly since the agricultural sector makes up
to 26% of the gross domestic product (GDP) of the country. Several studies used satellite-retrieved data
and imagery to examine the spatio-temporal changes in the region, for the period of the conflict.
In this study we investigate the impacts of the Syrian civil war on atmospheric ammonia (NH?) emitted
from industrial and agricultural activities during the 2008-2019 period. Our analyses are based on the
NH? measurements from the IASI instruments on board the Metop satellites. Firstly, land-use changes
and decrease of agriculture-emitted ammonia are explored over the country, and especially in the north-
eastern part of Syria that has suffered from the conflict that included ISIS and Kurdish fighters. We also
investigate the changes in atmospheric NH? at an ammonia production plant, which activities have been
suspended due to several conflict-related events. We show that the NH? columns retrieved from IASI are
directly affected by the war, and that periods of intense conflict and siege are reflected in lower NH?
concentrations, which are not driven by meteorology. The interpretation of the identified changes in
atmospheric NH? are supported by different datasets: NO? columns from GOME-2, satellite imagery,
and MODIS land cover type, reanalysis data from ECMWF (ERA5) to look at meteorological factors that
may affect atmospheric ammonia concentrations, as well as the burned area from the Aqua/Terra
combined MODIS product to check for fires.