Preprints
Filtering by Subject: Atmospheric Sciences
Moist convective scaling: Insights from an idealised model
Published: 2024-04-17
Subjects: Atmospheric Sciences
The response of clouds and moist-convective processes to heat-loss to space by long-wave radiative cooling is an important feedback in the earth's atmosphere. It is known that moist convection increases roughly in equilibrium with radiative cooling, an assumption often made in simplified models of the tropical atmosphere. In this study, we use an idealised 2D model of the atmosphere introduced by [...]
Improving Urban Climate Adaptation Modelling in the Community Earth System Model (CESM) Through Transient Urban Surface Albedo Representation
Published: 2024-04-03
Subjects: Atmospheric Sciences, Civil Engineering, Climate, Computational Engineering, Environmental Engineering, Environmental Sciences
Increasing the albedo of urban surfaces, through strategies like white roof installations, has emerged as a promising approach for urban climate adaptation. Yet, modelling these strategies on a large scale is limited by the use of static urban surface albedo representations in the Earth system models. In this study, we developed a new transient urban surface albedo scheme in the Community Earth [...]
An optimized methane retrieval approach based on Kalman filter for mapping methane point emissions from spaceborne imaging spectrometer
Published: 2024-02-29
Subjects: Atmospheric Sciences
Methane (CH4) emissions from point sources in the energy sector plays a crucial role in global CH4 budget. Spaceborne imaging spectrometer has shown superior ability for monitoring these emission events over large spatial coverages and extended timeframes. Presently, the Matched Filter (MF), which is a data-driven method, is widely employed for satellite-based retrieval of CH4 emission flux [...]
Satellite-based surveys reveal substantial methane point-source emissions in major oil & gas basins of North America during 2022-2023
Published: 2024-02-28
Subjects: Atmospheric Sciences, Environmental Monitoring, Oil, Gas, and Energy, Remote Sensing
Utilizing imaging spectroscopy technology to identify methane super-emitters plays a vital role in mitigating methane emissions in the Oil & Gas (O&G) sector. While earlier research has uncovered significant point-source methane emissions from O&G production in the US and Canada, which are key regions with large methane emissions, a comprehensive post-COVID-19 survey has been notably [...]
Graph Characterization of Higher Order Structure in Atmospheric Chemical Reaction Mechanisms
Published: 2024-02-13
Subjects: Atmospheric Sciences, Biogeochemistry, Environmental Chemistry, Other Applied Mathematics, Other Environmental Sciences
Atmospheric chemical reactions play an important role in air quality and climate change. While the structure and dynamics of individual chemical reactions are fairly well understood, the emergent properties of the entire atmospheric chemical system, which can involve many different species that participate in many different reactions, are not well described. In this work, we leverage [...]
Climate and Air Quality Impact of Using Ammonia as an Alternative Shipping Fuel
Published: 2024-02-07
Subjects: Atmospheric Sciences, Oil, Gas, and Energy
As carbon-free fuel, ammonia has been proposed as an alternative fuel to facilitate maritime decarbonization. Deployment of ammonia-powered ships is proposed as soon as 2024. However, emissions of NOx, NH3 and N2O resulting from ammonia combustion could cause impacts on air quality and climate. In this study, we assess whether and under what conditions switching to ammonia fuel might affect [...]
Daily global methane super-emitter detection and source identification with sub-daily tracking
Published: 2024-02-01
Subjects: Atmospheric Sciences, Oil, Gas, and Energy
We use the Shortwave Infrared bands of the Visible Infrared Imaging Radiometer Suite (VIIRS) satellite instruments to retrieve atmospheric methane enhancements with 750m resolution. We show that the three VIIRS instruments in orbit uniquely enhance the currently-employed capabilities of tracking methane super-emission events. The VIIRS instrument on Suomi-NPP and the TROPOMI instrument on [...]
Unexpected anthropogenic emission decreases explain recent atmospheric mercury concentration declines
Published: 2024-01-30
Subjects: Atmospheric Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Anthropogenic activities emit ~2000 Mg yr-1 of the toxic pollutant mercury (Hg) into the atmosphere, leading to long-range transport and deposition to remote ecosystems. Global anthropogenic emissions inventories report increases in Northern Hemispheric (NH) Hg emissions during the last three decades, in contradiction with the observed decline in atmospheric Hg concentrations at NH measurement [...]
Inverse modeling of satellite observations shows that the wet tropics drive the 2010-2022 methane increase
Published: 2024-01-04
Subjects: Atmospheric Sciences, Climate
Atmospheric methane concentrations rose rapidly over the past decade and surged in 2020-2022 but the causes are unclear. We find from inverse analysis of GOSAT satellite observations that global methane emissions increased from 500 to 550 Tg a-1 from 2010 to 2019 and surged to 570-590 Tg a-1 in 2020-2022. Concentrations of tropospheric OH (the main methane sink) show no long-term trend over [...]
FootNet v1.0: Development of a machine learning emulator of atmospheric transport
Published: 2023-12-09
Subjects: Atmospheric Sciences, Environmental Monitoring
There has been a proliferation of dense observing systems to monitor greenhouse gas (GHG) concentrations over the past decade. Estimating emissions with these observations is often done using an atmospheric transport model to characterize the source-receptor relationship, which is commonly termed measurement "footprint". Computing and storing footprints using full-physics models is becoming [...]
Particulate nitrate photolysis as a possible driver of rising tropospheric ozone
Published: 2023-10-20
Subjects: Atmospheric Sciences
Tropospheric ozone is an air pollutant and a greenhouse gas whose anthropogenic production is limited principally by the supply of nitrogen oxides (NOx) from combustion. Tropospheric ozone in the northern hemisphere has been rising despite the flattening of NOx emissions in recent decades. Here we propose that this sustained increase could result from the photolysis of nitrate particles (pNO3-) [...]
Rano Kao & Ava Ranga Uka: Rapa Nui Report 2014
Published: 2023-10-10
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Fresh Water Studies
29 March 2014 Objective: Sampling and testing Rano Kao water depth, evaporation and volume. Compare with previous results from 2005, 2008 and 2014 coring expeditions and detect the rate of change in lake water evaporation as compared to Global Meteoric Water Line.
Approaching coherent turbulence and the roll-cell transition with Lagrangian coherent structures and objective fluxes
Published: 2023-10-09
Subjects: Atmospheric Sciences
We present the first analysis of objective and material vortices in Large Eddy Simulations of atmospheric boundary layer turbulence. We extract rotating fluid features that maintain structural coherence over time for near-neutral, transitional, and convective boundary layers. In contrast to traditional analysis of coherent structures in turbulent boundary layers, we provide the first objective [...]
Site selection of desert solar farms based on heterogeneous sand flux
Published: 2023-10-09
Subjects: Atmospheric Sciences, Environmental Indicators and Impact Assessment, Geomorphology, Risk Analysis
Site selection for building solar farms in deserts is crucial and must consider the dune threats associated with sand flux, such as sand burial and dust contamination. Understanding the changes in sand flux can optimize the site selection of desert solar farms. Here we use the ERA5-Land hourly wind data with 0.1°×0.1° resolution to calculate the yearly sand flux from 1950 to 2022. The mean of [...]
Spaceborne assessment of the Soviet Union's role in the 1990s methane slowdown
Published: 2023-10-04
Subjects: Atmospheric Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Oil, Gas, and Energy, Physical Sciences and Mathematics
Methane is the second most important anthropogenic greenhouse gas, amounting to 60% of the radiative forcing from CO2 since pre-industrial times based on emitted compound. Global atmospheric methane concentrations rose by 10-15 ppb/yr in the 1980s before abruptly slowing to 2-8 ppb/yr in the early 1990s. This period in the 1990s is known as the ``methane slowdown'' and has been attributed to the [...]