About

Daniel Jacob is the Vasco McCoy Family Professor of Atmospheric Chemistry and Environmental Engineering at Harvard University. He serves as the Area Chair for Environmental Science & Engineering and is a Faculty Associate at the Harvard University Center for the Environment. His primary teaching area is Environmental Science & Engineering. Dr. Jacob is involved in atmospheric chemistry modeling and environmental research, with a focus on understanding and quantifying emissions related to climate change, such as methane emissions from landfills and urban areas. His work provides valuable insights for policymakers and contributes to the broader field of atmospheric chemistry and environmental engineering.

Research topics

• Chemistry
• Meteorology
• Environmental chemistry
• Inorganic chemistry
• Photochemistry
• Organic chemistry
• Chromatography
• Stereochemistry

Selected publications

• A Reproducible Workflow for Modelling of ¹ H to ¹³ C Polarization Transfer Kinetics Using Solid‐State NMR

  Magnetic Resonance in Chemistry · 2026-03-09

  articleOpen access1st authorCorresponding

  ABSTRACT Quantitative analysis of solid‐state NMR data, based on magic‐angle spinning with cross‐polarization experiments (CP‐MAS), often requires extensive signal processing, from the transformation of raw time‐domain data (FIDs) to the extraction of quantitative data and the modelling of signal intensity kinetics. Many current workflows rely on semi‐manual peak fitting and heterogeneous tools across laboratories for intensity curve modelling, limiting reproducibility and throughput. In this work, we propose a fully reproducible and open workflow combining two key methodological approaches: (1) an adaptive bucketing approach, extraction of relevant variables for analysis (ERVA), implemented in NMRProcFlow application, to automatically segment 13 C spectra into chemically relevant spectral regions; and (2) an online modelling platform that allows users to fit intensity curves over contact time with multiple models, guided by objective indicators including fit quality scores and parameter sensitivity metrics. This integrated approach provides a fast, user‐friendly and transparent path from FIDs to kinetic model parameters, opening new perspectives for reproducible quantitative solid‐state NMR.

  PublisherDOI

• Seasonality and declining intensity of methane emissions from the Permian and nearby US oil and gas basins

  2025-07-02 · 2 citations

  preprintOpen access

  We quantify weekly methane emissions and trends from oil and gas production in the US Permian Basin for 2019–2023, and in nearby basins for 2022–2023, by analytical inversion of Tropospheric Monitoring Instrument (TROPOMI) satellite observations with the Integrated Methane Inversion (IMI) at 25-km resolution. Permian oil and gas emissions averaged 4.0 ± 1.1 Tg a-1 over 2019–2023, with large seasonal variation but little interannual variability. Methane intensity fell from 5.2% to 3.2% as production surged. Intensity in the New Mexico Permian fell from 4.5% to 2.1%, approaching the state’s 2026 target of <2%. Emissions were on average 60% higher in the winter than summer, which we corroborate with Permian Basin Tower Network measurements, Insight M aircraft data, and GHGSat satellite observations. This seasonality may be driven in part by higher winter emissions from liquid storage tanks due to decreased separator efficiency in cold conditions. Similar but weaker seasonality along with decreasing emissions and intensities is found in weekly inversions for the Anadarko, Barnett, Eagle Ford, and Haynesville basins in 2022–2023. Our work suggests that better weatherization of oil and gas facilities could significantly reduce methane emissions.

  PublisherOA PDFDOI

• Quantifying urban and landfill methane emissions in the United States using TROPOMI satellite data

  ArXiv.org · 2025-05-16

  preprintOpen access

  Urban areas are major sources of methane due to population needs for landfills, natural gas distribution, wastewater treatment, and residential combustion. Here we apply an inversion of TROPOMI satellite observations of atmospheric methane to quantify and attribute annual methane emissions at 12x12 km2 resolution for 12 major US urban areas in 2022. The US Environmental Protection Agency Greenhouse Gas Inventory (EPA GHGI) is used as prior estimate. Our results indicate that the GHGI underestimates methane emissions by 80% on average for the 12 urban areas, with 22%-290% underestimations in most urban areas, except Los Angeles and Cincinnati where emissions are overestimated by 32%-37%. This is corroborated by independent surface-based observations in the Northeast Corridor and Los Angeles. Landfills are the principal cause of urban emission underestimates, with downstream gas activities contributing to a lesser extent than previously found. Examination of individual landfills other than in Los Angeles shows that emissions reported by facilities with gas collection and control systems to the Greenhouse Gas Reporting Program (GHGRP) and used in the GHGI are too low by a factor of 4 when using the prevailing recovery-first reporting method. This is because GHGRP-estimated gas collection efficiencies (average 70%, range 40-87%) are much higher than inferred from our work (average 38%, range 5-90%). Los Angeles landfills have much higher collection efficiencies (average 78% in GHGRP; 85% in our work) than elsewhere in the US, suggesting that operational practices there could help inform methane mitigation in other urban areas.

  PublisherOA PDFDOI

• Large and increasing stratospheric contribution to tropospheric ozone over East Asia

  2025-05-07

  preprintOpen access

  Abstract. Severe surface ozone pollution in South Korea and China in May–June is due in part to an elevated background subsiding from the free troposphere (750–350 hPa). Using IAGOS commercial aircraft observations and the GEOS-Chem model, we show that free tropospheric ozone over East Asia in May–June is the highest in the world and has increased from 68±3 ppb (mean and interannual standard deviation) in 2000–2004 to 78±4 ppb in 2015–2019. Free tropospheric ozone over East Asia is highest when carbon monoxide (CO) is low, both in the observations and GEOS-Chem, implying a large stratospheric influence on ozone. We find from GEOS-Chem that East Asia is a global hotspot for stratospheric downwelling of ozone and that this makes a major contribution to the free tropospheric ozone over the region in May–June. Stratospheric downwelling of ozone over East Asia in GEOS-Chem increased by 40 % from 2000–2004 to 2015–2019, which can explain the observed free tropospheric ozone increase over this period. Increased stratospheric downwelling over East Asia appears to be driven by a strengthening of the jet stream. The large and increasing stratospheric contribution to the surface ozone background over East Asia is a major impediment to meeting ozone air quality standards.

  PublisherOA PDFDOI

• A decadal, hourly high-resolution satellite dataset of aerosol optical properties over East Asia

  Earth system science data · 2025-11-03 · 1 citations

  articleOpen access

  Abstract. Formerly known as one of the most polluted regions of the globe, East Asia underwent a dramatic improvement of air quality, especially for aerosols, starting in the 2010s. Numerous satellites have observed East Asia for a long time duration, but often with a low spatial or temporal resolution, limiting their ability to capture small-scale variabilities or provide continuous observations of long-range transport of aerosols. In this study, we provide an hourly aerosol optical property (AOP) dataset retrieved from the Korean Geostationary Ocean Color Imager (GOCI), with a high spatial resolution of 2 km at nadir, covering the entire operational period from March 2011–March 2021. The dataset is retrieved using the Yonsei Aerosol Retrieval Algorithm, providing aerosol optical depth (AOD) at 550 nm as the primary product, along with fine mode fraction, single scattering albedo, Ångström exponent, and aerosol type as ancillary products. Seasonal validation of AOD against the Aerosol Robotic Network (AERONET) showed that the fraction of data points within the expected error range of 0.05+15 % varied from 56.4 % in June–July–August to 64.5 % in September–October–November, with the mean bias generally within ±0.05. Compared to the operational version, the high-resolution product demonstrated improved retrieval capability in the presence of broken clouds, along complex coastlines, and in capturing AOD variability at the sub-district level. The decadal AOD exhibited a decreasing trend over four major cities within the observation domain. We expect this data to be widely used in climate modelling, reanalysis, atmospheric chemistry, marine optics, environmental health studies, variability and trend analysis, contributing to a more comprehensive understanding of the interactions between climate change, trace gases, human health, and AOPs. The dataset presented in this work is publicly available for download at https://doi.org/10.5281/zenodo.16656274 (Lee et al., 2025).

  PublisherOA PDFDOI

• Supplementary material to "Using new geospatial data and 2020 fossil fuel methane emissions for the Global Fuel Exploitation Inventory (GFEI) v3"

  2025-02-11 · 3 citations

  preprintOpen access
  PublisherDOI

• Human herpesvirus 1 associated with epizootics in Belo Horizonte, Minas Gerais, Brazil

  bioRxiv (Cold Spring Harbor Laboratory) · 2025-03-24

  preprintOpen access

  Abstract Human activity in sylvatic environments and resulting contact with wildlife, such as non-human primates (NHP), can lead to pathogen spillover or spillback. Both NHPs and humans host a variety of herpesviruses. While these viruses typically cause asymptomatic infections in their natural hosts, they can lead to severe disease or even death when they move into novel hosts. In early 2024, deaths of Callithrix penicillata , the black-tufted marmoset, were reported in an urban park in Belo Horizonte, Minas Gerais, Brazil. The epizootic was investigated in collaboration with CETAS/IBAMA and the Zoonoses Department of Belo Horizonte. Nine marmoset carcasses, and 4 sick marmosets were found in the park; the latter exhibited severe neurological symptoms and systemic illness before succumbing within 48 hours. Carcasses were tested for rabies virus and were all negative, and necropsy findings revealed widespread organ damage. In addition, the samples were tested for yellow fever virus, with negative results. Finally, molecular testing, viral isolation and phylogenetic analysis demonstrated human herpesvirus 1 (HHV-1) as the causative agent. The likely source of infection was human-to-marmoset transmission, facilitated by close interactions such as feeding and handling. This study highlights the risks of pathogen spillover between humans and nonhuman primates, emphasizing the need for enhanced surveillance and public awareness to mitigate future epizootics.

  PublisherOA PDFDOI

• An ecosystem for producing and sharing metadata within the web of FAIR Data

  GigaScience · 2025-01-01 · 4 citations

  articleOpen access1st authorCorresponding

  BACKGROUND: Descriptive metadata are vital for reporting, discovering, leveraging, and mobilizing research datasets. However, resolving metadata issues as part of a data management plan can be complex for data producers. To organize and document data, various descriptive metadata must be created. Furthermore, when sharing data, it is important to ensure metadata interoperability in line with FAIR (Findable, Accessible, Interoperable, Reusable) principles. Given the practical nature of these challenges, there is a need for management tools that can assist data managers effectively. Additionally, these tools should meet the needs of data producers and be user-friendly, requiring minimal training. RESULTS: We developed Maggot (Metadata Aggregation on Data Storage), a web-based tool to locally manage a data catalog using high-level metadata. The main goal was to facilitate easy data dissemination and deposition in data repositories. With Maggot, users can easily generate and attach high-level metadata to datasets, allowing for seamless sharing in a collaborative environment. This approach aligns with many data management plans as it effectively addresses challenges related to data organization, documentation, storage, and the sharing of metadata based on FAIR principles within and beyond the collaborative group. Furthermore, Maggot enables metadata crosswalks (i.e., generated metadata can be converted to the schema used by a specific data repository or be exported using a format suitable for data collection by third-party applications). CONCLUSION: The primary purpose of Maggot is to streamline the collection of high-level metadata using carefully chosen schemas and standards. Additionally, it simplifies data accessibility via metadata, typically a requirement for publicly funded projects. As a result, Maggot can be utilized to promote effective local management with the goal of facilitating data sharing while adhering to the FAIR principles. Furthermore, it can contribute to the preparation of the future EOSC FAIR Web of Data within the European Open Science Cloud framework.

  PublisherOA PDFDOI

• IMEO’s Baseline Science Studies improves country-level methane quantification

  2025-03-15

  preprintOpen access

  UNEP’s International Methane Emissions Observatory (IMEO) is a data-driven, action-focused initiative. IMEO exists to provide open, reliable, integrated methane emissions data to facilitate actions to reduce methane emissions. The Baseline Science Studies are a subset of IMEO’s science studies, which aim to estimate the current total and sectoral methane emissions (with uncertainties) at country-level through multi-scale measurement studies and integration with existing data. It will assist governments, civil society, industry, and other stakeholders to prioritize actions to reduce methane emissions.IMEO’s Baseline Studies couple multi-scale top-down approaches with more granular analysis of bottom-up data to improve the understanding of key methane emission sources relevant to selected countries. The focused sectors for methane emission are oil and gas, agriculture and waste. Currently, there are two Baseline Studies at the design phase for Colombia and Nigeria. We will conduct an initial assessment per country through literature and reports, feed the existing prior to satellite inversion model and apportion the emission by sector. Using the literature review and satellite information, we identify the major methane sources and those with large uncertainties in each country, and design small studies to provide measurement data where little to no data in-country is available. By combining activity data and geospatial mapping, the ultimate aim is creating a gridded methane inventory at the country level. This information will be used to update the country level methane budget and build local capacity to enable future estimations and refinement of sectoral emissions. The presentation here will demonstrate the concept and generalised progress of the IMEO baseline studies

  PublisherDOI

• Evaluating the Utility of Satellite Observations for Improving Bottom-Up National Emission Inventories: Application to Colombia

  2025-03-14

  preprintOpen accessSenior author

  Methane is a potent greenhouse gas, and detailed understanding of its contributions from different countries and source sectors is necessary for climate action. Livestock is the dominant anthropogenic methane source, but bottom-up estimates of its emissions have high uncertainties. Inversions of satellite observations of atmospheric methane can offer valuable top-down information, but the related uncertainties need to be carefully characterized. Colombia has a large proportion of methane from livestock, and past work over the region has identified discrepancies between bottom-up and top-down emissions estimates, particularly for the livestock sector. Here, we explore this discrepancy in detail by quantifying 2023 methane emissions in Colombia and the contributions from different sectors at up to ~12 km × 12 km resolution including error characterization using an analytical inversion ensemble of TROPOMI and GOSAT satellite observations of atmospheric methane. We also assess the potential of future Carbon-I satellite observations to further reduce uncertainties in emissions. We show that choices in the inversion setup, including the number of state vector elements and the prior emission inventories, have a significant impact on emission estimates. The high resolution of our inversion results allows us to relate our emission estimates to bottom-up processes. Results demonstrate the ability of satellite observations of methane to improve our process-based understanding of methane emissions in Colombia.

  PublisherDOI

Recent grants

• Collaborative Research: Type 1: LOI: L02170303: Arctic Climate Response to Decadal Changes in Radiative Forcing from Aerosols and Ozone

  NSF · $478k · 2011–2015

• Collaborative Research: Development and Applications of GEOS-Chem Atmospheric Chemistry in CESM and MUSICA

  NSF · $718k · 2022–2026

• A Comprehensive Coupled Model for Tropospheric Halogen Chemistry: Evaluation of Impacts on Tropospheric Ozone, Hydroxyl Radical (OH), and Mercury

  NSF · $585k · 2016–2020

• Collaborative Research: Impacts of Recent Climate and Emissions Changes on Mercury Bioaccumulation in Arctic Marine Food-Webs

  NSF · $397k · 2010–2014

• ETBC: Global 3-D Modeling of Atmospheric Mercury and its Coupling to the Ocean and Land: Impacts of Past and Future Anthropogenic Emissions

  NSF · $550k · 2010–2014

Frequent coauthors

• Catherine Deborde

  Biopolymères Interactions Assemblages

  405 shared

• Annick Moing

  MetaboHUB

  386 shared

• Mickaël Maucourt

  Biologie du Fruit et Pathologie

  178 shared

• Yves Gibon

  MetaboHUB

  157 shared

• Stéphane Bernillon

  Biologie du Fruit et Pathologie

  150 shared

• James N. Galloway

  McCormick (United States)

  66 shared

• Sylvain Prigent

  66 shared

• W. C. Keene

  University of Virginia

  66 shared

Labs

• Atmospheric Chemistry Modeling GroupPI

Education

• National Higher School (ENSEA)

  ENSEA