Preprints
Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology
A climatology of rain-on-snow events for Norway
Published: 2018-09-10
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Rain-on-snow (ROS) events are complex multivariate hydrometeorological phenomena requiring a combination of rain and snowpack. Impacts include floods and landslides, and rain may freeze within the snowpack or on bare ground, potentially affecting vegetation, wildlife, and permafrost. ROS events occur mainly in high-latitude and mountainous areas, where sparse observational networks hinder [...]
Meridional atmospheric heat transport constrained by energetics and mediated by large-scale diffusion
Published: 2018-08-31
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Meridional atmospheric heat transport (AHT) has been investigated through three broad perspectives: dynamic perspective, linking AHT to the poleward flux of moist static energy (MSE) by atmospheric motions; an energetic perspective, linking AHT to energy input to the atmosphere by top-of-atmosphere radiation and surface heat fluxes; and a diffusive perspective, representing AHT in terms [...]
Why does Amazon precipitation decrease when tropical forests respond to increasing CO2?
Published: 2018-08-30
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Earth system models predict a zonal dipole of precipitation change over tropical South America, with decreases over the Amazon and increases over the Andes. Much of this has been attributed to the physiological response of the rainforest to elevated CO2, which describes a basin-wide reduction in stomatal conductance and transpiration. While robust in Earth system model experiments, details of [...]
Modifications to Internal Tide Conversion Parameterizations and Implementation into Barotropic Ocean Models
Published: 2018-08-15
Subjects: Civil and Environmental Engineering, Engineering, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Parameterization of the tidal energy conversion from barotropic to baroclinic modes through internal tide generation over rough and steep submarine topography is a necessary dissipative force for barotropic ocean models. We present and unify two forms of parameterizations that differ by assuming that wave generation is either only due to the local topographic features, or that it includes the [...]
Hamiltonian distributed chaos and predictability in large-scale climate dynamics
Published: 2018-08-14
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is shown that the large-scale climate dynamics, represented by the daily indices of the North Atlantic (NAO), Pacific/North American (PNA), Arctic (AO) and Antarctic (AAO) oscillations, Asian-Australian Monsoons (ISM, WNPM and AUSM) and El Nino/La Nina phenomenon (Nino indices) as well as global temperature anomalies (land), is dominated by the Hamiltonian distributed chaos with the stretched [...]
Ocean Drilling Perspectives on Meteorite Impacts
Published: 2018-08-08
Subjects: Earth Sciences, Geophysics and Seismology, Oceanography and Atmospheric Sciences and Meteorology, Paleobiology, Paleontology, Physical Sciences and Mathematics, Planetary Geomorphology, Planetary Geophysics and Seismology, Planetary Sciences, Stratigraphy
Extraterrestrial impacts are a ubiquitous process in the solar system, reshaping the surface of rocky bodies of all sizes. On early Earth, impact structures may have been a nursery for the evolution of life. More recently, a large meteorite impact caused the end-Cretaceous mass extinction, causing the extinction of 75% of species known from the fossil, including non-avian dinosaurs, and clearing [...]
Higher potential compound flood risk in Northern Europe under anthropogenic climate change
Published: 2018-07-18
Subjects: Applied Mathematics, Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Hydrology, Multivariate Analysis, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Oceanography and Atmospheric Sciences and Meteorology, Other Physical Sciences and Mathematics, Physical Sciences and Mathematics, Physics, Statistics and Probability
The published version of this article is available at https://advances.sciencemag.org/content/5/9/eaaw5531. Compound flooding (CF) is an extreme event taking place in low-lying coastal areas as a result of co-occurring high sea level and large amounts of runoff, caused by precipitation. The impact from the two hazards occurring individually can be significantly lower than the result of their [...]
What Even Is Climate?
Published: 2018-06-26
Subjects: Climate, Geography, Oceanography and Atmospheric Sciences and Meteorology, Other Geography, Physical Sciences and Mathematics, Social and Behavioral Sciences
Although the concept of climate is easy to understand, there is not any uncontroversial definition of it. Most definitions fall back to the simple formulation that `climate is the statistics of weather. Recent attempts at a definition called versions of this saying vague. Climate is policy-relevant, and discussions on climate and climate change benefit from clarity on the topic. Beyond the policy [...]
A strong role for the AMOC in partitioning global energy transport and shifting ITCZ position in response to latitudinally discrete solar forcing in the CESM1.2
Published: 2018-06-14
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This preprint is a non peer reviewed version submitted to the Journal of Climate. This work has been accepted for publication with an updated title, A strong role for the AMOC in partitioning global energy transport and shifting ITCZ position in response to latitudinally discrete solar forcing in the CESM1.2. The accepted version is substantially different from the preprint version due to the [...]
Methyl, ethyl, and propyl nitrates: global distribution and impacts on reactive nitrogen in remote marine environments
Published: 2018-05-27
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Alkyl nitrates (RONO2) are important components of tropospheric reactive nitrogen that serve as reservoirs for nitrogen oxides (NOx ≡ NO + NO2). Here we implement a new simulation of atmospheric methyl, ethyl, and propyl nitrate chemistry in a global chemical transport model (GEOS‐Chem). We show that the model can reproduce the spatial and seasonal variability seen in a 20‐year ensemble of [...]
Pervasive iron limitation at subsurface chlorophyll maxima of the California Current
Published: 2018-05-24
Subjects: Biogeochemistry, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Subsurface chlorophyll maximum layers (SCMLs) are nearly ubiquitous in stratified water columns and exist at horizontal scales ranging from the submesoscale to the extent of oligotrophic gyres. These layers of heightened chlorophyll and/or phytoplankton concentrations are generally thought to be a consequence of a balance between light energy from above and a limiting nutrient flux from below, [...]
Revisiting the surface-energy-flux perspective on the sensitivity of global precipitation to climate change
Published: 2018-05-23
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate models simulate an increase in global precipitation at a rate of approximately 1-3% per Kelvin of global surface warming. This change is often interpreted through the lens of the atmospheric energy budget, in which the increase in global precipitation is mostly offset by an increase in net radiative cooling. Other studies have provided different interpretations from the perspective of the [...]
Determination of the diffusion constants of dimethylsulfide and dimethylsulfoniopropionate by diffusion-ordered nuclear magnetic resonance spectroscopy
Published: 2018-05-18
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The diffusion coefficients (D) for both dimethylsulfide (DMSP) and dimethylsulfoniopropionate (DMSP) were determined using diffusion-ordered nuclear magnetic resonance spectroscopy (DOSY). Diffusion coefficients were measured across a temperature range (285 – 315 K, 12 – 42°C) and DDMSP was determined in both artificial seawater (30.5‰) and in MilliQ water (0‰). Diffusion constants were within [...]
Prognostic validation of a neural network unified physics parameterization
Published: 2018-05-17
Subjects: Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Weather and climate models approximate diabatic and sub-grid-scale processes in terms of grid-scale variables using parameterizations. Current parameterizations are de- signed by humans based on physical understanding, observations and process modeling. As a result, they are numerically efficient and interpretable, but potentially over-simplified. However, the advent of global high-resolution [...]
Increasingly Powerful Tornadoes in the United States
Published: 2018-05-11
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Storm reports show an upward trend in the power of tornadoes from longer and wider paths and higher damage ratings. Quantifying the magnitude of the increase is difficult given diurnal and seasonal influences on tornadoes embedded within natural variations and made worse by changes for rating damage. Here the authors solve this problem by fitting a statistical model to a metric of power during [...]