Preprints

Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology

Why is the Hurricane Season So Sharp?

Wenchang Yang, Tsung-Lin Hsieh, Gabriel Vecchi

Published: 2021-04-09
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

Understanding tropical cyclone (TC) climatology is a problem of profound societal significance and deep scientific interest. The annual cycle is the biggest radiatively-forced signal in TC variability, presenting a key test of our understanding and modeling of TC activity. TCs over the North Atlantic (NA) basin, which are usually called hurricanes, have a sharp peak in the annual cycle, with more [...]

Orbital, the Box - An interactive educational tool for in-depth understanding of astronomical climate forcing.

Bryan C. Lougheed

Published: 2021-04-07
Subjects: Adult and Continuing Education, Astrophysics and Astronomy, Climate, Earth Sciences, Education, Educational Methods, Geology, Geophysics and Seismology, Higher Education, Instructional Media Design, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, The Sun and the Solar System

“Orbital, the Box” provides an interactive tool with graphical user interface (GUI) for stimulating active, visual learning for understanding of astronomical climate forcing. This cross-platform tool can be run locally on a personal computer using a standard web browser environment with no need for plugins, thus maximising accessibility for students and teachers alike. The tool facilitates in the [...]

Seasonal changes of iceberg distribution and surface area in the Amundsen Sea Embayment

Aleksandra K. Mazur, Anna K. Wåhlin, Sebastiaan Swart

Published: 2021-04-06
Subjects: Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology

Icebergs have a significant influence on local and potentially global climate by altering ocean and sea ice environments. An object-based method for automatic iceberg detection has been applied to 2442 SAR images acquired during all seasons between 2006-2012 in the Amundsen Sea Embayment (ASE), Antarctica. During this period a total count of icebergs and their surface area were calculated in [...]

Globally resolved surface temperatures since the Last Glacial Maximum

Matthew B Osman, Jessica Tierney, Jiang Zhu, et al.

Published: 2021-03-31
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

Climate changes across the last 24,000 years provide key insights into Earth system responses to external forcing. Climate model simulations and proxy data have independently allowed for study of this crucial interval; however, they have at times yielded disparate conclusions. Here, we leverage both types of information using paleoclimate data assimilation to produce the first observationally [...]

The NCAR airborne 94-GHz cloud radar: calibration and data processing

Ulrike Romatschke, Michael Dixon, Peisang Tsai, et al.

Published: 2021-03-30
Subjects: Oceanography and Atmospheric Sciences and Meteorology

The 94-GHz airborne HIAPER Cloud Radar (HCR) has now been deployed in three major field campaigns. NCAR has developed an extensive set of quality assurance and quality control procedures which are applied to all collected data. Engineering measurements performed both in the laboratory and in an antenna measurement chamber yielded calibration characteristics for the antenna, reflector, and radome. [...]

Spatial spectrum of temperature fluctuations in buoyancy driven chaotic and turbulent atmosphere

Alexander Bershadskii

Published: 2021-03-25
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Planetary Sciences

It is shown, using results of direct numerical simulations, laboratory experiments, measurements in the atmospheric boundary layer, in troposphere, in stratosphere, and the satellite infrared radiances data that in many cases the temperature fluctuations in buoyancy driven chaotic and turbulent atmosphere can be well described by the distributed chaos approach based on the Bolgiano-Obukhov [...]

Crisis at the Salton Sea: The Vital Role of Science

Marilyn Fogel, Hoori Ajami, Emma Aronson, et al.

Published: 2021-03-04
Subjects: Atmospheric Sciences, Biogeochemistry, Chemistry, Climate, Earth Sciences, Environmental Chemistry, Environmental Public Health, Environmental Sciences, Environmental Studies, Geochemistry, Geology, Geomorphology, Hydrology, Medicine and Health Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Public Health, Social and Behavioral Sciences

The Salton Sea—a hypersaline, terminal lake in southern California—is in crisis. A combination of mismanagement and competition among federal, state and local agencies has hindered efforts to address declining lake levels and unstable water chemistry. This delay has heightened the public health threat to regional communities as retreating shorelines expose dry lakebed— a source of potentially [...]

Shallow or deep? A reinterpretation of the Rifian Corridor’s unique sandy contourites

Daan Beelen, Lesli Joy Wood, Mohammed Najib Zaghloul, et al.

Published: 2021-02-25
Subjects: Climate, Earth Sciences, Geology, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Paleontology, Sedimentology, Stratigraphy

This study proposes that sandstone layers exposed in the Fez-Meknes region of Northern Morocco (Ben Allou (Sidi Chaded) and El Adergha localities), have been misinterpreted as unique examples of geostrophically-driven, deep marine (150 - 400 m water depth) sandy contourites. Instead, our independent paleontological, sedimentological, and stratigraphic analyses show that these sandstones represent [...]

High-resolution observations of the North Pacific transition layer from a Lagrangian float

Alexis K. Kaminski, Eric A. D'Asaro, Andrey Y. Shcherbina, et al.

Published: 2021-02-11
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

A crucial region of the ocean surface boundary layer (OSBL) is the strongly-sheared and -stratified transition layer (TL) separating the mixed layer from the upper pycnocline, where a diverse range of waves and instabilities are possible. Previous work suggests that these different waves and instabilities will lead to different OSBL behaviours. Therefore, understanding which physical processes [...]

Reduced High-Latitude Land Seasonality in Climates with Very High Carbon Dioxide

Matthew Henry, Geoffrey K Vallis

Published: 2021-02-10
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology

Observations of warm past climates and projections of future climate change show that the Arctic warms more than the global mean, particularly during winter months. Past warm climates such as the early Eocene had above-freezing Arctic continental temperatures year-round. In this paper, we show that a reduced Arctic land seasonality with increased greenhouse gases is a robust consequence of the [...]

Dynamical attribution of North Atlantic interdecadal predictability to oceanic and atmospheric turbulence under realistic and optimal stochastic forcing

Dafydd Stephenson, Florian Sévellec

Published: 2021-02-01
Subjects: Climate, Environmental Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

Unpredictable variations in the ocean originate from both external atmospheric forcing and chaotic processes internal to the ocean itself, and are a crucial sink of predictability on interdecadal timescales. In a global ocean model, we present i.) an optimisation framework to compute the most efficient noise patterns to generate uncertainty and ii.) a uniquely inexpensive, dynamical method for [...]

Observations of nonlinear momentum fluxes over the inner continental shelf

Thomas Pell Connolly, Steven J Lentz

Published: 2021-01-31
Subjects: Oceanography and Atmospheric Sciences and Meteorology

Nonlinear momentum fluxes over the inner continental shelf are examined using moored observations from multiple years at two different locations in the Middle Atlantic Bight. Inner shelf dynamics are often described in terms of a linear alongshore momentum balance, dominated by frictional stresses generated at the surface and bottom. In this study, observations over the North Carolina inner shelf [...]

The active and passive roles of the ocean in generating basin-scale heat content variability

Dafydd Stephenson, Florian Sévellec

Published: 2021-01-28
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics

The role of ocean circulation in transforming surface forcing into interannual-to-multidecadal oceanic variability is an area of ongoing debate. Here, a novel method, establishing exact causal links, is used to quantitatively determine the role of ocean active and passive processes in transforming stochastic surface forcing into heat content variability. To this end, we use a global ocean model [...]

Vertical fluxes conditioned on vorticity and strain reveal submesoscale ventilation

Dhruv Balwada, Qiyu Xiao, Shafer Smith, et al.

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

Onno Bokhove, Luca Cantarello, Steven Tobias

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 [...]

search

You can search by:

  • Title
  • Keywords
  • Author Name
  • Author Affiliation