Troposphere / Air Quality 2

The results of ground-based regular spectroscopic measurements of CO total content (TC) over Moscow and Zvenigorod (53 km to the West from the Moscow measurement site) during 2010-2015, over ZOTTO station (Central Siberia, summer periods of 2010-2014 years) and Beijing (regular, 2010-2015) for typical and anomalous (during wild fires and anthropogenic hazes) emission rates are presented and compared with satellite TC data (spectrometers MOPITT, AIRS, IASI).  Origin of main transported polluting air masses were calculated using simplest dispersion and trajectory models . This approach allows us to obtain empiric coefficients of correlation and transition relationships between satellite and ground-based CO TC data as well as for aerosol optical depth AOD. The comparison has demonstrated good agreement (R²=0.4-0.8) of satellite and ground-based data under low pollution conditions and systematic underestimation of satellite CO TC (150-380 %) and relatively low correlation (R²=0.3-0.6) under conditions of intense surface emissions.

Comparison of AERONET (10 Eurasian stations) and MODIS (Terra and Aqua) AOD diurnal data has demonstrated good correlation (R²=0.5-0.8) between them for most of sites.

TEMPO is now well into its implementation phase, having passed both its Key Decision Point C and the Critical Design Reviews (CDRs) for the instrument and ground systems. The CDR for the Mission component will occur at a later date, after the host spacecraft has been selected. TEMPO is on schedule to measure atmospheric pollution for greater North America from space using ultraviolet and visible spectroscopy. TEMPO measures from Mexico City to the Canadian oil sands, and from the Atlantic to the Pacific, hourly and at high spatial resolution. TEMPO provides a tropospheric measurement suite that includes the key elements of tropospheric air pollution chemistry. Measurements are from geostationary (GEO) orbit, to capture the inherent high variability in the diurnal cycle of emissions and chemistry. The small product spatial footprint resolves pollution sources at sub-urban scale. Together, this temporal and spatial resolution improves emission inventories, monitors population exposure, and enables effective emission-control strategies.

TEMPO takes advantage of a GEO host spacecraft to provide a modest cost mission that measures the spectra required to retrieve O3, NO2, SO2, H2CO, C2H2O2, H2O, aerosols, cloud parameters, and UVB radiation. TEMPO thus measures the major elements, directly or by proxy, in the tropospheric O3 chemistry cycle. Multi-spectral observations provide sensitivity to O3 in the lowermost troposphere, substantially reducing uncertainty in air quality predictions. TEMPO quantifies and tracks the evolution of aerosol loading. It provides near-real-time air quality products that will be made widely, publicly available.

TEMPO provides much of the atmospheric measurement capability recommended for GEO-CAPE in the 2007 National Research Council Decadal Survey, Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond. Instruments from Europe (Sentinel 4) and Asia (GEMS) will form parts of a global GEO constellation for pollution monitoring later this decade, with a major focus on intercontinental pollution transport. TEMPO will launch at a prime time to be a component of this constellation.

The TROPOspheric Monitoring Instrument (TROPOMI) will be launched in 2016 onboard the ESA Sentinel-5 Precursor (S-5P) platform and will provide global observations of atmospheric trace gases, with unprecedented spatial resolution. In 2019, this will be complemented by geostationary observations from the Sentinel 4 UVN instrument to be delivered at hourly resolution over Europe. Sulfur dioxide (SO₂) measurements from both S5P and S4 will significantly improve the current capabilities for anthropogenic and volcanic emissions monitoring, and will extend the long-term datasets from past and existing UV sensors (TOMS, GOME, SCIAMACHY, OMI, GOME-2, OMPS). Together with GEMS and TEMPO these will form a new constellation of atmospheric composition sensors.

This presentation gives an overview on the development of SO₂ retrieval schemes performed at BIRA-IASB as part of level-2 algorithm prototyping activities for both S5P and S4. We describe the different algorithms, their main features and discuss the results of their application to spectra from the OMI and OMPS sensors. We also show comparisons with other satellite retrievals and ground-based measurements with a focus on anthropogenic SO₂, for strongly polluted regions  and weak sources (only detectable in long-term averaged data). 

The Middle East is well known for oil, gas and petrochemical industry. Those industrial activities are the main source of the anthropogenic air pollutants SO2 and NOx. However, the information on SO2 and NOx emissions from bottom-up emission inventories is very limited for this region. For the GlobEmission project, we derive SO2 and NOx emissions from OMI satellite observations. To estimate SO2 emissions, we t the SO2 columns of averaged OMI satellite observations with a simple dispersion model and combine this with calculated SO2 lifetime. We analyze the trend from the tting results based on a 3-year moving average from 2005 to 2015. The NOx emissions are derived by the KNMI algorithm DECSO. The ratio of SO2 and NOx is analyzed to identify the type of industry. We compare our derived emissions with the HTAP v2 bottom-up emission inventory.