<p>Global and regional air quality measurements play an important role in the everyday life of people, inasmuch as atmospheric constituents such as ozone (O<sub>3</sub>), carbon monoxide (CO), nitrogen dioxide (NO<sub>2</sub>), sulfur dioxide (SO<sub>2</sub>), methane (CH<sub>4</sub>), and aerosols may cause severe<!-- I guess I&#8217;m conservative in my wording; I&#8217;d say &#8220;significant&#8221; rather than &#8220;severe&#8221;.
--> threats to human health and agriculture productivity. Space-based sensors on satellites<!-- Redundant with &#8220;Space-based&#8221;; you could say &#8220;Satellite sensors&#8221; instead (which I prefer to &#8220;Space-based&#8221;) --> are able to detect these atmospheric constituents directly and indirectly at high spatial and temporal scales. The TROPOspheric Monitoring Instrument (TROPOMI) on the Copernicus Sentinel-5 Precursor (Sentinel-5P) satellite provides measurements of O<sub>3</sub>, NO<sub>2</sub>, SO<sub>2</sub>, CH<sub>4</sub>, CO, formaldehyde (HCHO), aerosols, and cloud in ultraviolet-visible (UV-VIS), near infrared (NIR), and shortwave infrared (SWIR) spectral ranges. The Ozone Monitoring Instrument (OMI) aboard the Aura mission measures ozone, aerosols, clouds, surface UV irradiance, and trace gases including NO<sub>2</sub>, SO<sub>2</sub>, HCHO, BrO, and OClO using UV electromagnetic spectrum bands. The Ozone Mapping Profiler Suite (OMPS) on the Suomi National Polar-Orbiting Partnership (Suomi-NPP or SNPP) provides environmental data products including O<sub>3</sub>, NO<sub>2</sub>, SO<sub>2, </sub>and aerosols. The Microwave Limb Sounder (MLS) on Aura has been monitoring atmospheric chemical species (CO, volcanic SO<sub>2</sub>, O<sub>3</sub>, N<sub>2</sub>O, BrO), temperature, humidity, and cloud ice since 2004.<!-- MLS measures more than the species indicated here. Do you want to add an "etc." rather than list all? --> MLS measurements help understand stratospheric ozone chemistry, and the effects of air pollutants injected into the upper troposphere and low stratosphere. The Thermal And Near infrared Sensor for carbon Observation - Fourier Transform Spectrometer (TANSO-FTS) on the Greenhouse Gases Observing Satellite (GOSAT) covers a wide spectral range from VIS to thermal infrared (TIR), which enables remote observations of the greenhouse gases carbon dioxide (CO<sub>2</sub>) and CH<sub>4</sub>. Furthermore, atmospheric constituent data are also available in the second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) NASA's atmospheric reanalysis data collection. MERRA-2 uses an upgraded version of the Goddard Earth Observing System Model, version 5 (GEOS-5) data assimilation system, enhanced with more aspects of the Earth system. <!-- Check this. I added &#8220;atmospheric constituent data&#8221;, because the sentence didn&#8217;t make sense without it, and I believe that&#8217;s what this sentence was about. --></p><p>The NASA Goddard Earth Sciences Data and Information Services Center (GES DISC) supports over a thousand data collections in the focus areas of Atmospheric Composition, Water & Energy Cycles, and Climate Variability. Some of these data collections include atmospheric composition products from the ongoing TROPOMI, OMI, OMPS, MLS, TANSO-FTS, and MERRA-2 missions and projects. The GES DISC web site (https://disc.gsfc.nasa.gov) provides multiple tools designed to help data users easily search, subset, visualize, and download data from these diverse sources in a unified way. We will demonstrate several methodologies employing these tools to monitor air quality.</p>
Uncertainties in emissions estimates of greenhouse gases and air pollutants in India and their impacts on regional air quality
