About

Xiaomeng Jin is an Assistant Professor with a Ph.D. in Earth and Environmental Sciences from Columbia University. Her research focuses on using remote sensing observations combined with earth system models and in-situ measurements to understand the sources, chemical formation, and impacts of air pollution. Her work integrates multiple approaches to study air quality, emphasizing the chemical and physical processes that govern air pollution and its effects on the environment and human health.

Research topics

• Geography
• Development economics
• Environmental planning
• Natural resource economics
• Economics
• Business
• Economic growth
• Environmental resource management
• Biology
• Meteorology
• Physics
• Environmental science
• Atmospheric sciences
• Ecology
• Chemistry

Selected publications

• Geostationary Air Quality Monitoring Substantiates Column NO ₂ as a Better O ₃ Formation Regime Indicator in China

  Journal of Geophysical Research Atmospheres · 2026-04-27

  articleOpen access

  Abstract China has become a global hotspot of ozone (O 3 ) pollution, and understanding O 3 formation regime is crucial for air quality management. Satellite‐observed formaldehyde‐to‐nitrogen‐dioxide ratio (HCHO/NO 2 , FNR) has long been demonstrated as an efficient way to infer O 3 formation regime. However, reported FNR thresholds that divide O 3 formation regimes into VOC‐limited, transitional, and NO x ‐limited regimes uncover considerable differences. Using data from the world's first geostationary air quality monitoring instrument Geostationary Environment Monitoring Spectrometer, we report the spatiotemporal variations, particularly diurnal features, of O 3 ‐FNR relationships and O 3 formation regimes in China. We find that O 3 ‐FNR relationships fluctuate significantly over time and across locations, with coefficients of variation (CVs) of 0.22 and 0.27, respectively. We identified the amount of HCHO as a key factor. Given the strong correlation between NO 2 and LRO x /LNO x (chemical loss of HO 2 +RO 2 (LRO x ) to chemical loss of NO x (LNO x )), we demonstrate that O 3 formation regime thresholds alter minimally when column NO 2 is used as the indicator in China, with the CVs reduced to around 0.1. This finding highlights its potential to provide a more reliable diagnosis for large‐scale, space‐based O 3 formation sensitivity, offering promising insights for advancing O 3 pollution management in China.

  PublisherDOI

• Growing impacts of fire smoke on ozone pollution and associated mortality burden in the United States

  Science Advances · 2026-04-29

  articleOpen access

  Fire smoke pollution is an emerging health risk factor, yet prior studies have focused mostly on fine particulate matter (PM 2.5 ) and neglected the health impacts from other pollutants, most notably ozone (O 3 ). Here, we quantify changes in ground-level O 3 concentrations during smoke episodes across the contiguous US using surface air quality measurements, satellite data, and machine learning models. After correcting for meteorological variability, smoke contribution to daily ground-level O 3 can reach up to 6.9 parts per billion (16% increase relative to nonsmoke days) at certain US monitoring locations, averaged over all smoke days from 2006 to 2023. Smoke O 3 patterns are poorly correlated with smoke PM 2.5 patterns, demonstrating that their health impacts do not necessarily coincide in space and time. We estimate that smoke O 3 can lead to 2045 annual excess deaths (95% confidence interval: 1325 to 2755) averaged across 2006 to 2023 using established exposure-response functions of all-source O 3 exposure. The increasing mortality due to smoke O 3 partially offset the observed declining trend in nonsmoke O 3 mortality. Over the study period, estimated deaths from smoke O 3 were equivalent to 15.8% of smoke PM 2.5 mortality, and this proportion reached 61.5% in 2023.

  PublisherDOI

• Satellite Retrieval of Tropospheric NO2 under Fire Conditions

  2026-03-13

  articleOpen accessSenior authorCorresponding

  Tropospheric nitrogen oxides (NOx = NO + NO2) are key atmospheric pollutants with adverse impacts on human health and environmental quality. In the atmosphere, nitric oxide (NO) is rapidly oxidized to nitrogen dioxide (NO2), making satellite observations of NO2 an effective proxy for monitoring tropospheric NOx distributions. Open fires, such as wildfires, emit large amounts of NOx into the atmosphere, and their impacts are becoming increasingly severe under climate change. Satellite-based NO2 observations provide broad spatial coverage and continuous monitoring capabilities for assessing NO2 under fire conditions. However, due to the lack of explicit consideration of fire-related priori information in current satellite NO2 retrieval algorithms, the resulting data products exhibit large uncertainties under fire conditions. Therefore, we use the Peking University OMI NO2 (POMINO) retrieval algorithm to investigate the impact of including fire-related priori information on the retrieval of tropospheric NO2 vertical column densities (VCDs). We conduct sensitivity experiments by including and excluding fire-related priori information in the retrieval of tropospheric NO2 VCDs from TROPOMI observations. These experiments focus on the western United States during September 2020, a period of intense wildfire activity. To provide priori information for these retrievals, we use GEOS-Chem simulations with and without fire emissions, as well as with different fire emission injection heights. In addition, GEOS-CF is employed for a comprehensive comparative analysis. Our results show that including fire-related priori information in the retrieval significantly increases tropospheric NO2 VCDs. Tropospheric NO2 VCDs increase by up to 100% in regions heavily impacted by fires and by about 80% in surrounding areas. Differences in fire emission injection height lead to approximately 30% variations in the retrieved VCDs, indicating a secondary but non-negligible effect. Validation against EPA surface NO2 measurements shows improved agreement when fire-related priori information is included, particularly in fire-affected regions. These results highlight the importance of incorporating fire-related priori information in satellite NO2 retrievals to obtain more accurate NO2 data and to better support air quality assessments under fire conditions.

  PublisherDOI

• Wildfire smoke offsets decades of progress in reducing ozone exposure across the United States

  2026-05-23

  articleOpen access

  Ground-level ozone (O3) pollution has declined in the U.S., yet the progress has stalled in recent years, coinciding with increasing wildfire smoke. Using ensemble machine learning models trained on surface observations, we develop a gridded daily smoke O3 dataset across the contiguous U.S. from 2006-2023. We estimate that wildfire smoke placed an additional 29 million people each year in areas exceeding the federal O3 standard, a 74% increase over a no-smoke baseline. Smoke has offset 36% of the reduction in the O3 nonattainment population and 62% of the improvement in population-weighted O3 concentrations over 2006-2023. Smoke ozone follows spatial-temporal patterns distinct from smoke PM2.5. Wildfire smoke is increasingly eroding the O3 health benefits achieved through decades of emission controls, posing a growing challenge for air quality management in a changing climate.

  PublisherDOI

• Global Patterns and Trends in Ground-Level Ozone Chemical Formation Regimes from 1996 to 2022

  2025-02-04

  preprintOpen accessSenior author

  Abstract. Ground-level ozone (O3) formation in urban areas is nonlinearly dependent on the relatively availability of its precursors: oxides of nitrogen (NOx) and volatile organic compounds (VOCs). To mitigate O3 pollution, a crucial question is to identify the O3 formation regime (NOx-limited or VOC-limited). Here we leverage ground-based O3 observations alongside space-based observations of O3 precursors, namely NO2 and formaldehyde (HCHO), to study the long-term shifts in O3 chemical regimes across global source regions. We first derive the regime threshold values for satellite-derived HCHO/NO2 ratio by examining its relationship with the O3 weekend effect. We find that a regime transition from VOC-limited to NOx-limited occurs around 3.5 for HCHO/NO2 with regional variations. By integrating data from four satellite instruments, including GOME, SCIAMACHY, OMI, and TROPOMI, we build a 27-year (1996–2022) satellite HCHO/NO2 record, from which we assess the long-term trends in O3 production regimes. A discernible global trend towards NOx-limited regimes is evident, particularly in developed regions such as North America, Europe, and Japan, with emerging trends in developing countries like China and India over the past two decades. This shift is supported by both increasing HCHO/NO2 ratios and a diminishing O3 weekend effect. Yet, urban areas still hover in the VOC-limited and transitional regime on the basis of annual averages. Our findings stress the importance of adaptive emission control strategies to mitigate O3 pollution.

  PublisherDOI

• Intersections between Trends in NO_<i>x</i> and VOCs and the Impacts on Chemistry of Cities

  WORLD SCIENTIFIC eBooks · 2025-09-29

  book-chapter1st authorCorresponding
  PublisherDOI

• Reply on RC1

  2025-05-12

  peer-reviewOpen access1st authorCorresponding

  <strong class="journal-contentHeaderColor">Abstract.</strong> Ground-level ozone (O₃) formation in urban areas is nonlinearly dependent on the relatively availability of its precursors: oxides of nitrogen (NO_x) and volatile organic compounds (VOCs). To mitigate O₃ pollution, a crucial question is to identify the O₃ formation regime (NO_x-limited or VOC-limited). Here we leverage ground-based O₃ observations alongside space-based observations of O₃ precursors, namely NO₂ and formaldehyde (HCHO), to study the long-term shifts in O₃ chemical regimes across global source regions. We first derive the regime threshold values for satellite-derived HCHO/NO₂ ratio by examining its relationship with the O₃ weekend effect. We find that a regime transition from VOC-limited to NO_x-limited occurs around 3.5 for HCHO/NO₂ with regional variations. By integrating data from four satellite instruments, including GOME, SCIAMACHY, OMI, and TROPOMI, we build a 27-year (1996&ndash;2022) satellite HCHO/NO₂ record, from which we assess the long-term trends in O₃ production regimes. A discernible global trend towards NO_x-limited regimes is evident, particularly in developed regions such as North America, Europe, and Japan, with emerging trends in developing countries like China and India over the past two decades. This shift is supported by both increasing HCHO/NO₂ ratios and a diminishing O₃ weekend effect. Yet, urban areas still hover in the VOC-limited and transitional regime on the basis of annual averages. Our findings stress the importance of adaptive emission control strategies to mitigate O₃ pollution.

  PublisherOA PDFDOI

• Affinity-guided discovery of dimeric sesquiterpenes from Xylopia vielana as potent VEGFR-2 inhibitors with anti-angiogenic activity

  Bioorganic Chemistry · 2025-09-02 · 2 citations

  article1st author
  PublisherDOI

• Observing the Diurnal Variations of Ozone‐NO _x ‐VOC Chemistry Over the U.S. From the Geostationary TEMPO Instrument

  Geophysical Research Letters · 2025-07-15 · 6 citations

  articleOpen access1st authorCorresponding

  Abstract Ground‐level ozone (O 3 ) is an air pollutant formed by the photochemical reactions between oxides of nitrogen (NO x ) and volatile organic compounds (VOCs). A key challenge in mitigating O 3 pollution is to determine whether the O 3 production is NO x ‐limited or NO x ‐saturated. Using the hourly observations of O 3 precursors, formaldehyde (HCHO) and NO 2 , from the newly launched geostationary Tropospheric Emissions: Monitoring of Pollution (TEMPO), we present the first space‐based observations of diurnal variations of O 3 ‐NO x ‐VOC chemistry over the CONUS during 2024 warm season. We integrate a steady‐state model with global simulations to derive the regime thresholds of the HCHO to NO 2 ratio (HCHO/NO 2 ), and identify the O 3 production regimes using the provisional TEMPO products, which have been validated with limited measurements. We find that O 3 production is dominated by NO x ‐saturated regime in the morning but NO x ‐limited regime in the afternoon over major U.S. O 3 nonattainment metropolitan areas.

  PublisherOA PDFDOI

• Effects of mobile emission reduction on ozone under future carbon neutrality scenarios in Korea

  Atmospheric Environment · 2025-11-20

  articleOpen accessSenior author

  Tropospheric ozone (O 3 ), formed through photochemical reactions between volatile organic compounds (VOCs) and nitrogen oxides (NO x ≡ NO + NO 2 ), poses detrimental risks to health and ecosystems. In South Korea, the fourth-highest maximum daily 8-h average (MDA8) O 3 concentrations have increased from 53 to 89 ppbv over the past three decades, and the implementation of the carbon neutrality strategy in South Korea is expected to alter emissions of O 3 precursors (NO x , VOCs). In particular, emission changes in the transportation sector can affect ozone concentrations in densely populated urban areas, thereby impacting public health outcomes. Therefore, we investigate O 3 responses to transportation decarbonization using a global 3-D chemical transport model (GEOS-Chem) under mobile NO x and VOCs emission reduction scenarios. Across all scenarios involving 40 % reductions in mobile NO x emissions in South Korea, with additional VOC reductions and expanded coverage to China in some cases, MDA8 O 3 concentrations increased. Furthermore, O 3 production regimes in South Korea remain NO x -saturated or transitional in major cities despite NO x reductions, while suburban and remote forested regions are becoming more limited by NO x availability. NO x -only mobile emission reductions led to substantial MDA8 O 3 increases (up to 4.7 ppbv) and additional six exceedance days compared to results from the control run, whereas concurrent VOCs reductions mitigated both the magnitude (2.7 ppbv) and the number of ozone exceedance days. Also, emission reductions for both NO x and VOC in South Korea and China resulted in reducing O 3 exceedance days in May–July compared to results implemented only in South Korea, highlighting the importance of transboundary VOC mitigation. • O 3 increased under 40 % NO x /VOC mobile emission reduction scenarios for the carbon neutrality. • NO x -saturated or transitional O 3 production regime in urban areas maintained despite 40 % reduction in mobile NO x emissions. • Mobile NO x and VOC reductions increased O 3 and exceedance days in the SMA. • Both NO x -VOC reductions in South Korea and China reduced O 3 exceedances more than Korea-only reduction.

  PublisherDOI

Frequent coauthors

• Arlene M. Fiore

  Massachusetts Institute of Technology

  42 shared

• Randall V. Martin

  Washington University in St. Louis

  29 shared

• Johannes Urpelainen

  Johns Hopkins University

  25 shared

• Ryan Kennedy

  20 shared

• Nada Maamoun

  Kiel University

  14 shared

• Aaron van Donkelaar

  Washington University in St. Louis

  13 shared

• R. C. Cohen

  University of California, Berkeley

  11 shared

• Mohammad Z. Al‐Hamdan

  10 shared

Labs

• Xiaomeng Jin's LabPI

  Research focuses on air quality, remote sensing, climate, and wildfires.

Education

• Ph.D., Earth and Environmental Sciences

  Columbia University

  2020