Hannah Nesser

Atmospheric scientist/NASA Postdoctoral Program fellow at JPL using satellite observations to study greenhouse gas emissions (she/her)

[Hannah Nesser @hannahnesser]

Our paper using satellite observations to quantify methane emissions at 25 km x 25 km across the contiguous US is out! We quantify emissions for individual landfills, urban areas, and states and find that EPA estimates reported to the UNFCCC are too low. https://t.co/24QvrNiUHU

[Hannah Nesser @hannahnesser]

3. Correct: We compared two methods to correct BC biases. We found that directly quantifying BC concentrations is more effective and computationally tractable than correcting emissions outside the region of interest.

[Hannah Nesser @hannahnesser]

I'm pleased to announce the publication of our paper on the influence of boundary conditions on regional emission estimates!

https://t.co/bi8v327T0v

[Hannah Nesser @hannahnesser]

2. Quantify: We derived two metrics to estimate errors induced by BCs: the preview estimates errors before completing the analysis to support domain specification, while the diagnostic estimates errors after the analysis to improve error quantification.

[Hannah Nesser @hannahnesser]

A (very belated) thanks to Harvard SEAS for this write-up!

[Harvard SEAS @hseas]

From her Ph.D. at Harvard to her work at @NASAJPL, Hannah Nesser is using data to analyze greenhouse gas fluxes. Her research offers insights into the mechanics of CO₂ uptake and release, advancing both atmospheric science and climate policy decisions. https://t.co/jLeQkGYFoa

[Hannah Nesser @hannahnesser]

Grateful to @NASAEarth Observatory for their write-up of our most recent publication! It's fun to have the emissions map I spent years staring at be their Image of the Day.
https://t.co/FFGHAZgvUo

[Atmospheric Chemistry and Physics @EGU_ACP]

New research article: High-resolution US methane emissions inferred from an inversion of 2019 TROPOMI satellite data: contributions from individual states, urban areas, and landfills https://t.co/kyw4Hvjn9L

[Hannah Nesser @hannahnesser]

(If you’re interested in any of this in more detail, please read the paper or contact me.)

[Hannah Nesser @hannahnesser]

Texas alone produces 21% of contiguous US emissions in our estimate! The Permian Basin explains almost 40% of Texas’ emissions. California, the second largest methane-producing state, generates 7% of contiguous US methane emissions.

[Hannah Nesser @hannahnesser]

There are a lot of numbers here, but at the end of the day I hope that this work gives a bit of hope and direction to efforts to decrease methane emissions. We can do a lot by focusing on the largest emitters!

[Hannah Nesser @hannahnesser]

3. We compare our emissions to state estimates from the EPA Inventory. We find that the top 10 methane-producing states are responsible for 55% of human-caused emissions in the contiguous US. Our emissions are on average 27% larger than the EPA state inventories in these states.

[Hannah Nesser @hannahnesser]

We attribute the change in landfill emissions to overestimated recovery efficiencies at landfill gas facilities and to under-accounting of site-specific operational changes and leaks.

[Hannah Nesser @hannahnesser]

2. Our landfill emissions are 51% larger than EPA's Inventory. At 70 landfills that report to EPA’s Greenhouse Gas Reporting Program—a key input to the Inventory—we find a 77% median increase from reported emissions (and a 204% median increase at gas recovery facilities)!

[Hannah Nesser @hannahnesser]

1. Our emission estimate is 13% higher than the EPA’s 2023 Greenhouse Gas Inventory for 2019. We find that oil and gas, livestock, and landfills explain 89% of human-caused emissions in CONUS.

[Hannah Nesser @hannahnesser]

Our paper using satellite observations to quantify methane emissions at 25 km x 25 km across the contiguous US is out! We quantify emissions for individual landfills, urban areas, and states and find that EPA estimates reported to the UNFCCC are too low. https://t.co/24QvrNiUHU

[Zichong Chen @ZichongChen]

Just out in @NatureClimate! We quantify the contribution of African rice expansion to the recent rise in atmospheric methane, and find it plays a significant but previously unrecognized role. Kudos to my teammates @jimmielin #NickBalasus @hannahnesser! https://t.co/Od5ZsEwGB2

[Hannah Nesser @hannahnesser]

I get (arguably too) excited about applying these ideas to methane because there's so much uncertainty in the distribution of methane sources, but they can be applied to other, non-methane problems too!

[Hannah Nesser @hannahnesser]

Our paper on reducing the computational cost of high-resolution, analytical inversions is out! Thanks to all the co-authors and everyone who listened to me ramble about linear algebra over the last few years.
https://t.co/vGrXCECY3v

[Hannah Nesser @hannahnesser]

We use some math-y ideas to define two methods that use satellite observations to improve our understanding of high-resolution methane emissions at minimal computational cost.