Preprints
Filtering by Subject: Oceanography and Atmospheric Sciences and Meteorology
Holocene relative sea-level changes and glacial isostatic adjustment of the U.S. Atlantic coast
Published: 2019-10-01
Subjects: Climate, Earth Sciences, Environmental Sciences, Geomorphology, Glaciology, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics, Sedimentology, Stratigraphy, Tectonics and Structure
The first quality-controlled Holocene sea-level database for the U.S. Atlantic coast has been constructed from 686 sea-level indicators. The database documents a decreasing rate of relative sea-level (RSL) rise through time with no evidence of sea level being above present in the middle to late Holocene. The highest rates of RSL rise are found in the mid-Atlantic region. We employ the database to [...]
Skillful seasonal prediction of key carbon cycle components: NPP and fire risk
Published: 2019-09-20
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Seasonal forecasts of global CO₂ concentrations rely on the well-documented relationship with the El Niño–Southern Oscillation (ENSO), combined with estimated anthropogenic emissions. Here, we investigate the skill of the GloSea5 seasonal forecasting system for two carbon cycle processes that underlie the global CO₂–ENSO relationship: the impact of meteorological conditions on CO₂ uptake by [...]
Wide-swath altimetric satellite data assimilation with structured-error detrending
Published: 2019-09-18
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
For decades now, satellite altimetric observations have been successfully integrated in numerical oceanographic models using data assimilation (DA). So far, sea surface height (SSH) data were provided by one-dimensional nadir altimeters. The next generation Surface Water and Ocean Topography (SWOT) satellite altimeter will provide two-dimensional wide-swath altimetric information with an [...]
Coupled climate and subarctic Pacific nutrient upwelling over the last 850,000 years
Published: 2019-09-06
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
High latitude deep water upwelling has the potential to control global climate over glacial timescales through the biological pump and ocean-atmosphere CO2 exchange. However, there is currently a lack of continuous long nutrient upwelling records with which to assess this mechanism. Here we present geochemical proxy records for nutrient upwelling and glacial North Pacific Intermediate Water [...]
Considering the role of adaptive evolution in models of the ocean and climate system
Published: 2019-08-30
Subjects: Earth Sciences, Ecology and Evolutionary Biology, Life Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Numerical models have been highly successful in simulating global carbon and nutrient cycles in today’s ocean, together with observed spatial and temporal patterns of chlorophyll and plankton biomass at the surface. With this success has come some confidence in projecting the century-scale response to continuing anthropogenic warming. There is also increasing interest in using such models to [...]
Solar signals in observation indeed implied enhanced predictability since 1977
Published: 2019-08-28
Subjects: Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
This is a Correspondence submitted to Nature GeoScience following the undermentioned paper: Gabriel Chiodo, Jessica Oehrlein, Lorenzo M. Polvani, John C. Fyfe & Anne K. Smith, Insignificant influence of 11-year solar cycle on the North Atlantic Oscillation, Nature Geoscience, volume 12, pages 94–99 (2019). It is a non-peer reviewed preprint.
Collapse of Eurasian ice sheets 14,600 years ago was a major source of global Meltwater Pulse 1a
Published: 2019-08-21
Subjects: Climate, Earth Sciences, Environmental Sciences, Geology, Glaciology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Rapid sea-level rise caused by the collapse of large ice sheets is a global threat to human societies. In the last deglacial period, the rate of global sea-level rise peaked at more than 4 cm/yr during Meltwater Pulse 1a, which coincided with the abrupt Bølling warming event 14,650 yr ago. However, the sources of the meltwater have proven elusive, and the contribution from Eurasian ice sheets has [...]
Quantifying Eulerian Eddy Leakiness in An Idealized Model
Published: 2019-08-21
Subjects: Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
An idealized eddy-resolving ocean basin, closely resembling the North Pacific ocean, is simulated using MITgcm. We identify rotationally coherent Lagrangian vortices (RCLVs) and sea surface height (SSH) eddies based on the Lagrangian and Eulerian framework, respectively. General statistical results show that RCLVs have a much smaller coherent core than SSH eddies with the ratio of radius is about [...]
Shifting velocity of temperature extremes under climate change
Published: 2019-08-20
Subjects: Climate, Environmental Indicators and Impact Assessment, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Rapid changes in climatic conditions threaten both socioeconomic and ecological systems, as these might not be able to adapt or to migrate at the same pace as that of global warming. In particular, an increase of weather and climate extremes can lead to increased stress on human and natural systems, and a tendency for serious adverse effects. Relying on the EURO-CORDEX simulations, we compare the [...]
High-resolution terrestrial climate, bioclimate and vegetation for the last 120,000 years
Published: 2019-08-15
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Paleobiology, Physical Sciences and Mathematics
The variability of climate has profoundly impacted a wide range of macroecological processes in the Late Quaternary. Our understanding of these has greatly benefited from palaeoclimate simulations, however, high-quality reconstructions of ecologically relevant climatic variables have been limited to a few selected time periods, thus impeding continuous time analyses. Here, we present a 0.5° [...]
A century of reduced ENSO variability during the Medieval Climate Anomaly
Published: 2019-08-13
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Climate model simulations of El Niño–Southern Oscillation (ENSO) behavior for the last millennium demonstrate interdecadal to centennial changes in ENSO variability that can arise purely from stochastic processes internal to the climate system. That said, the instrumental record of ENSO does not have the temporal coverage needed to capture the full range of natural ENSO variability observed in [...]
Bayesian calibration of the Mg/Ca paleothermometer in planktic foraminifera
Published: 2019-08-07
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Mg/Ca ratio of planktic foraminifera is a widely-used proxy for sea-surface temperature, but is also sensitive to other environmental factors. Previous work has relied on correcting Mg/Ca for non-thermal influences. Here, we develop a set of Bayesian models for Mg/Ca in four major planktic groups -- Globigerinoides ruber (including both pink and white chromotypes), Trilobatus sacculifer, [...]
Vertical Eddy Iron Fluxes Support Primary Production in the Open Southern Ocean
Published: 2019-08-05
Subjects: Biogeochemistry, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The primary productivity of the Southern Ocean ecosystem, and associated biological carbon pump, is limited by the availability of the micronutrient iron. Riverine sediments and atmospheric dust supply iron at the ocean margins, but in the vast open ocean, iron reaches phytoplankton primarily when iron-rich sub-surface waters enter the euphotic zone, linking vertical transport processes to [...]
Interannual, probabilistic prediction of water resources over Europe following the heatwave and drought 2018
Published: 2019-08-01
Subjects: Earth Sciences, Hydrology, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The year 2018 was one of the hottest and driest years in Europe having a large impact on agriculture, ecosystems and society. The associated drought in central and northern Europe underpins the need for water resources predictions at the seasonal to interannual time scale. In this study, we propose a probabilistic, terrestrial prediction system including water resources utilizing the Terrestrial [...]
Analog forecasting of extreme-causing weather patterns using deep learning
Published: 2019-07-31
Subjects: Artificial Intelligence and Robotics, Atmospheric Sciences, Computational Engineering, Computer Sciences, Engineering, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Numerical weather prediction (NWP) models require ever-growing computing time/resources, but still, have difficulties with predicting weather extremes. Here we introduce a data-driven framework that is based on analog forecasting (prediction using past similar patterns) and employs a novel deep learning pattern-recognition technique (capsule neural networks, CapsNets) and impact-based [...]