Preprints
Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology
Irreducible Southern Ocean State Uncertainty due to Global Ocean Initial Conditions
Published: 2021-08-17
Subjects: Oceanography and Atmospheric Sciences and Meteorology
How do ocean initial conditions impact historical and future climate projections in Earth system models? To answer this question, we use the 50-member Canadian Earth System Model (CanESM2) large ensemble, in which individual ensemble members are initialized using a strategic combination of different oceanic initial states and different atmospheric perturbations. We show that global ocean heat [...]
Imprint of the Pacific Walker Circulation in global precipitation δ18O
Published: 2021-07-30
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
*This article is now published, and freely available from Journal of Climate at https://doi.org/10.1175/JCLI-D-21-0190.1* Characterising variability in the global water cycle is fundamental to predicting impacts of future climate change; understanding the role of the Pacific Walker circulation (PWC) in the regional expression of global water cycle changes is critical to understanding this [...]
Creating a climate changed future with the sea level rise interactive- fiction game ‘Lagos2199’
Published: 2021-07-26
Subjects: Climate, Education, Environmental Education, Environmental Sciences, Environmental Studies, Geographic Information Sciences, Geography, Instructional Media Design, International and Area Studies, Nature and Society Relations, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Other Environmental Sciences, Physical and Environmental Geography, Physical Sciences and Mathematics, Science and Mathematics Education, Sustainability
Story-based futures serve an important role in climate change scenario development. Stories are particularly useful in exploring sea level rise possibilities, since we know many coastal areas are specifically vulnerable to accelerating rises in sea level. This discrete change in coastline is different from most other climate change impacts, and offers a clear basis for scientifically-informed, [...]
Energetics and mixing of stratified, rotating flow over abyssal hills
Published: 2021-07-12
Subjects: Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
One of the proposed mechanisms for energy loss in the ocean is through dissipation of internal waves, in particular above rough topography where internal lee waves are generated. Rates of dissipation and diapycnal mixing are often estimated using linear theory and a constant value for mixing efficiency. However, previous oceanographic measurements found that non-linear dynamics may be important [...]
A CMIP6 ensemble for downscaled monthly climate normals over North America
Published: 2021-07-01
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Use of downscaled global climate model projections is expanding rapidly as climate change vulnerability assessments and adaptation planning become mainstream in many sectors. Many climate change impact analyses use climate model projections downscaled at very high spatial resolution (~1km) but very low temporal resolution (20- to 30-year normals). These applications have model selection [...]
Stereophotogrammetry of clouds observed during T-REX
Published: 2021-06-29
Subjects: Oceanography and Atmospheric Sciences and Meteorology
Stereophotogrammetric images collected during the Terrain-induced Rotor Experiment (T-REX), which took place in Owens Valley, California, in the spring of 2006, were used to track clouds and cloud fragments in space and time. We explore how photogrammetric data complements other instruments deployed during T-REX, and how it supports T-REX objectives to study the structure and dynamics of [...]
An Outsized Role for the Labrador Sea in the Multidecadal Variability of the Atlantic Overturning Circulation
Published: 2021-06-15
Subjects: Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate models are essential tools for investigating intrinsic North Atlantic variability related to variations in the Atlantic meridional overturning circulation (AMOC), but recent observations have called into question the fidelity of models that emphasize the importance of Labrador Sea processes. A multi-century pre-industrial climate simulation that resolves ocean mesoscale eddies has a [...]
A new tropical cyclone surge index incorporating the effects of coastal geometry, bathymetry and storm information
Published: 2021-06-14
Subjects: Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Risk Analysis
This study presents a new storm surge hazard potential index (SSHPI) for estimating tropical cyclone (TC) induced maximum surge levels at a coast. The SSHPI incorporates parameters that are often readily available at real-time: intensity in 10-minute maximum wind speed, radius of 50-kt wind, translation speed, coastal geometry, and bathymetry information. The inclusion of translation speed and [...]
Ubiquity of human-induced changes in climate variability
Published: 2021-06-12
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how climate variability responds to increasing anthropogenic perturbations. Here we present a new 100-member large ensemble of climate change projections conducted with the Community Earth System Model version 2 to examine [...]
On the statistical learning analysis of rain gauge data over the Natuna Islands
Published: 2021-06-08
Subjects: Applied Statistics, Atmospheric Sciences, Longitudinal Data Analysis and Time Series, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Statistics and Probability
This article presents state-of-the-art statistical learning methods for analyzing rain gauge data over the Natuna Islands. By using shape preserving piecewise cubic interpolation, we managed to interpolate 671 null values from the daily precipitation data. Dominant periodicity analysis of daily precipitation signals using Lomb-Scargle Power Spectral Density shows annual, intraseasonal, and [...]
Detection of Interannual Ensemble Forecast Signals over the North Atlantic and Europe using Atmospheric Circulation Regimes
Published: 2021-05-27
Subjects: Applied Mathematics, Atmospheric Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
To study the forced variability of atmospheric circulation regimes, the use of model ensembles is often necessary for identifying statistically significant signals as the observed data constitute a small sample and are thus strongly affected by the noise associated with sampling uncertainty. However, the regime representation is itself affected by noise within the atmosphere, which can make it [...]
CO2 capture by pumping surface acidity to the deep ocean
Published: 2021-04-30
Subjects: Chemical Engineering, Climate, Engineering, Environmental Engineering, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The majority of IPCC scenarios call for active CO2 removal (CDR) to remain below 2oC of warm- ing. On geological timescales, ocean uptake regulates atmospheric CO2 concentration, with two homeostats driving CO2 uptake: dissolution of deep ocean calcite deposits and terrestrial weathering of silicate rocks, acting on 1ka to 100ka timescales, respectively. Many current ocean-based CDR proposals [...]
Optimal experiment design for bottom friction parameter estimation
Published: 2021-04-23
Subjects: Design of Experiments and Sample Surveys, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
It is common practice within numerical coastal ocean modelling to perform model calibration with respect to a bottom friction parameter. While many modelling studies employ a spatially uniform coefficient, within the parameter estimation literature the coefficient is typically taken to be spatially (or even temporally) varying. A parameter estimation experiment requires an appropriate set of [...]
A deep-learning estimate of the decadal trends in the Southern Ocean carbon storage
Published: 2021-04-20
Subjects: Atmospheric Sciences, Biogeochemistry, Climate, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Uptake of atmospheric carbon by the ocean, especially at high latitudes, plays an important role in offsetting anthropogenic emissions. At the surface of the Southern Ocean south of 30◦S, the ocean carbon uptake, which had been weakening in 1990s, strengthened in the 2000s. However, sparseness of in-situ measurements in the interior make it difficult to compute changes in carbon storage below [...]
Why is the Hurricane Season So Sharp?
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 [...]