Preprints
Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology
Vertical fluxes conditioned on vorticity and strain reveal submesoscale ventilation
Published: 2021-01-24
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology
It has been hypothesized that submesoscale flows play an important role in the vertical transport of climatically important tracers, due to their strong associated vertical velocities. However, the multi-scale, non-linear and Lagrangian nature of transport makes it challenging to attribute proportions of the tracer fluxes to certain processes, scales, regions or features. Here we show that [...]
An idealized 1.5-layer isentropic model with convection and precipitation for satellite data assimilation research. Part II: model derivation
Published: 2021-01-22
Subjects: Applied Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
In this part II paper we present the analytical derivation of the isentropic 1.5-layer shallow water model described and used in part I of this study. The mathematical derivation presented here is based on a combined asymptotic and slaved Hamiltonian analysis. The scaling assumptions throughout the paper are supported by real observations based on radiosonde data. Eventually, a fully consistent [...]
An idealized 1.5-layer isentropic model with convection and precipitationfor satellite data assimilation research. Part I: model dynamics
Published: 2021-01-22
Subjects: Applied Mathematics, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
An isentropic 1.5-layer model based on modified shallow water equations is presented, including terms mimicking convection and precipitation. This model is an updated version of the isopycnal single-layer modified shallow water model presented in Kent et al. (2017). The clearer link between fluid temperature and model variables together with a double-layer structure make this revised, isentropic [...]
Decrease in air-sea CO2 fluxes caused by persistent marine heatwaves
Published: 2021-01-21
Subjects: Oceanography and Atmospheric Sciences and Meteorology
Regional processes play a key role in the global carbon budget. Major ocean carbon uptake at mid-latitudes counteracts carbon release in the tropics, which is modulated by episodes of marine heatwaves (MHWs). Yet, we lack essential knowledge on persistent MHWs (PMHWs), and their effect on the carbon sensitive areas. Here, based on a 1985-2017 joint analysis of reconstructions, ocean reanalysis, [...]
Near-inertial dissipation due to stratified flow over abyssal topography
Published: 2021-01-12
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Linear theory for steady stratified flow over topography sets the range for topographic wavenumbers over which freely propagating internal waves are generated, and the radiation and breaking of these waves contribute to energy dissipation away from the ocean bottom. However, previous numerical work demonstrated that dissipation rates can be enhanced by flow over large scale topographies with [...]
Yield estimation of the 2020 Beirut explosion using open access waveform and remote sensing data
Published: 2020-12-22
Subjects: Applied Statistics, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics, Statistics and Probability
We report on a multi-technique analysis using publicly available data for investigating the huge, accidental explosion that struck the city of Beirut, Lebanon, on August 4, 2020. Its devastating shock wave led to thousands of injured with more than two hundred fatalities and caused immense damage to buildings and infrastructure. Our combined analysis of seismological, hydroacoustic, infrasonic [...]
Idealized forecast-assimilation experiments for convective-scale Numerical Weather Prediction
Published: 2020-12-18
Subjects: Meteorology, Oceanography and Atmospheric Sciences and Meteorology
To aid understanding of and facilitate research into forecast-assimilation systems of Numerical Weather Prediction (NWP), idealized models that embody essential characteristics of these systems can be used. This article concerns the use of such an idealized fluid model of convective-scale NWP in inexpensive data assimilation (DA) experiments. The forecast model, introduced in Kent et al (2017), [...]
The influence of orbital parameters on the North American Monsoon system during the Last Interglacial Period
Published: 2020-12-17
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology
The response of summer precipitation in the western U.S. to climate variability remains a subject of uncertainty. For example, paleoclimate records indicate the North American monsoon (NAM) was stronger and spatially more extensive during the Holocene, whereas recent modeling suggests a weakened NAM response to increasing temperatures. These illustrate diverging pictures of the NAM response to [...]
Climate change research and action must look beyond 2100
Published: 2020-12-16
Subjects: Environmental Sciences, Environmental Studies, Geography, Human Geography, Nature and Society Relations, Oceanography and Atmospheric Sciences and Meteorology, Physical and Environmental Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences
Anthropogenic activity is changing Earth’s climate and ecosystems in ways that are potentially dangerous and disruptive to humans. Greenhouse gas concentrations in the atmosphere continue to rise, ensuring these changes will be felt for centuries beyond 2100, the current benchmark for prediction. Estimating the effects of past, current, and potential future emissions to only 2100 is therefore [...]
Differences in carbon isotope discrimination between angiosperm and gymnosperm woody plants, and their geological significance
Published: 2020-12-13
Subjects: Biogeochemistry, Climate, Geochemistry, Oceanography and Atmospheric Sciences and Meteorology, Paleobiology
For most of the Phanerozoic Eon, Earth’s woody vegetation has been dominated by C3 plants – predominantly gymnosperms - with angiosperms only emerging as the dominant plant group as CO2 declined during the Cenozoic (66 Ma onward). At present, differences in carbon isotope discrimination (Δ13C) between angiosperm and gymnosperm plants are relatively small (2–3 ‰), but an increasing body of [...]
Atmospheric CO2 estimates for the last 17 million years based on foraminiferal δ11B at Ocean Drilling Program Sites 806 and 807 in the Western Equatorial Pacific
Published: 2020-12-13
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Constraints on the evolution of atmospheric CO2 levels throughout Earth’s history are foundational to our understanding of past variations in climate. Despite considerable effort, estimates of past CO2 levels do not always converge. Here we reconstruct atmospheric CO2 values across major climate transitions over the past 17 million years using the boron isotopic composition (δ11B) of planktic [...]
Enhanced hydrological cycle increases ocean heat uptake and moderates transient climate sensitivity
Published: 2020-11-25
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology
The large-scale moistening of the atmosphere in response to increasing greenhouse gases amplifies the existing patterns of precipitation minus evaporation (P-E) which, in turn, amplifies the spatial contrast in sea surface salinity (SSS). Through a series of CO2 doubling experiments, we demonstrate that surface salinification driven by the amplified dry conditions (P-E < 0), primarily in the [...]
Investigation on the Impacts of COVID-19 Lockdown and Influence Factors on Air Quality in Greater Bangkok, Thailand
Published: 2020-11-06
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
With the outbreak of the COVID-19 pandemic around the world, many countries announced lockdown measures, including Thailand. Several scientific studies have reported on improvements in air quality due to the impact of these COVID-19 lockdowns. This study aims to investigate the effects of the COVID-19 lockdown and its driving influence factors on air pollution in Greater Bangkok, Thailand using [...]
IBM PAIRS: Scalable big geospatial-temporal data and analytics as-a-service
Published: 2020-11-02
Subjects: Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
The rapid growth of geospatial-temporal data from sources like satellites, drones, weather modeling, IoT sensors etc., accumulating at a pace of PetaBytes to ExaBytes annually, opens unprecedented opportunities for both science and industrial applications. However, the sheer size and complexity of such data presents significant challenges for conventional geospatial information systems (GIS) [...]
Global decline of deep water formation with increasing atmospheric CO2
Published: 2020-10-24
Subjects: Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology
Deep water formation is not only the driver of the global ocean circulation; by sending heat and carbon to the deep ocean, it is also crucial for climate change mitigation. Yet its future is uncertain: will it slow down as stratification increases, emerge in polar regions as the wind starts blowing over previously ice-covered waters, or intensify with increased evaporation? Here we present the [...]