Preprints
Filtering by Subject: Climate
Developing a coral proxy system model to compare coral and climate model estimates of changes in paleo-ENSO variability
Published: 2020-02-04
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Coral records of surface-ocean conditions extend our knowledge of interannual El Niño-Southern Oscillation (ENSO) variability into the pre-instrumental period. That said, the wide range of natural variability within the climate system as well as multiple sources of uncertainties inherent to the coral archive produce challenges for the paleoclimate community to detect forced changes in ENSO using [...]
Enhanced iceberg discharge in the western North Atlantic during all Heinrich events of the last glaciation
Published: 2020-01-13
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
A series of catastrophic iceberg discharges to the North Atlantic, termed Heinrich events, punctuated the last ice age. During Heinrich events, coarse terrigenous debris released from the drifting icebergs was preserved in deep-sea sediments, serving as an indicator of iceberg passage. Quantifying the vertical flux of ice-rafted debris (IRD) in open-ocean settings can resolve questions regarding [...]
Feedback between drought and deforestation in the Amazon
Published: 2020-01-09
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Hydrology, Natural Resources and Conservation, Natural Resources Management and Policy, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Sustainability
Deforestation and drought are among the greatest environmental pressures on the Amazon rainforest, possibly destabilizing the forest-climate system. Deforestation in the Amazon reduces rainfall regionally, while this deforestation itself has been reported to be facilitated by droughts. Here we quantify the interactions between drought and deforestation spatially across the Amazon during the early [...]
Using a consistency factor for detection and attribution of anthropogenic impacts on phenological phases in Germany
Published: 2020-01-01
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
An important consequence of climate change is the impact on the seasonal cycle of vegetation flora and fauna. Although it is generally understood that anthropogenic mechanisms play a major role in the warming trend of the climate and that the timing of such phases, especially spring timing events, depends largely on the temperature, the link has yet to be quantitatively shown for different kind [...]
Glacial cooling and climate sensitivity revisited
Published: 2019-12-26
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Last Glacial Maximum (LGM), one of the best-studied paleoclimatic intervals, offers a prime opportunity to investigate how the climate system responds to changes in greenhouse gases (GHGs) and the cryosphere. Previous work has sought to constrain the magnitude and pattern of glacial cooling from paleothermometers, but the uneven distribution of the proxies, as well as their uncertainties, has [...]
Stronger Atlantic hurricanes: Validating Elsner et al. (2008)
Published: 2019-12-04
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Using satellite derived wind speed estimates from tropical cyclones over the 25-year period 1981--2006, Elsner et al. (2008) showed the strongest tropical cyclones getting stronger. They related the increasing intensity to rising ocean temperatures consistent with theory. Oceans continued to warm since that paper was published so the intensity of the strongest cyclones should have continued [...]
An interpreted language implementation of the Vaganov-Shashkin tree-ring proxy system model
Published: 2019-12-04
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
We describe the implementation of the Vaganov-Shashkin tree-ring growth model (VSM) in MATLAB. VSM, originally written in Fortran, mimics subdaily and daily resolution processes of cambial growth as a function of soil moisture, air temperature, and insolation, with environmental forcing modeled as the principle of limiting factors. The re-implementation in a high level interpreted language, [...]
The economic implications of using a truly preindustrial climate baseline
Published: 2019-12-04
Subjects: Climate, Geography, Human Geography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Social and Behavioral Sciences
The pervasive impacts of climate change can result in scientific decisions having unforeseen societal implications. To demonstrate this, we explore the global and regional economic implications of adopting an earlier preindustrial baseline of 1400-1800 for climate policy targets instead of the commonly used early industrial period of 1850-1900 for which we have observational data. Because of [...]
Fossil fuel combustion is driving indoor CO2 toward levels harmful to human cognition
Published: 2019-12-03
Subjects: Climate, Cognitive Neuroscience, Life Sciences, Neuroscience and Neurobiology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Human activities are elevating atmospheric carbon dioxide concentrations to levels unprecedented in human history. The majority of anticipated impacts of anthropogenic CO2 emissions are mediated by climate warming. Recent experimental studies in the fields of indoor air quality and cognitive psychology and neuroscience, however, have revealed significant direct effects of indoor CO2 levels on [...]
A 2,000-year Bayesian NAO reconstruction from the Iberian Peninsula
Published: 2019-11-27
Subjects: Applied Statistics, Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Other Earth Sciences, Physical Sciences and Mathematics, Statistics and Probability
The North Atlantic Oscillation (NAO) is the major atmospheric mode that controls winter European climate variability because its strength and phase determine regional temperature, precipitation and storm tracks. The NAO spatial structure and associated climatic impacts over Europe are not stationary making it crucial to understanding its past evolution in order to improve the predictability of [...]
Wind-driven evolution of the North Pacific subpolar gyre over the last deglaciation
Published: 2019-11-27
Subjects: Climate, Earth Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
North Pacific atmospheric and oceanic circulations are key missing pieces in our understanding of the reorganisation of the global climate system since the Last Glacial Maximum (LGM). Here, using a basin-wide compilation of planktic foraminiferal oxygen isotopes, we show that the North Pacific subpolar gyre extended ~3° further south during the LGM, consistent with sea surface temperature and [...]
Methane, Monsoons, and Modulation of Millennial-scale Climate
Published: 2019-11-20
Subjects: Climate, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Other Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Speleology
Earths orbital geometry exerts a profound influence on climate by regulating changes in incoming solar radiation. Superimposed on orbitally-paced climate change, Pleistocene records reveal substantial millennial-scale variability characterized by trends, tipping points, and rapid swings. However, the extent to which orbital forcing modulates the amplitude and timing of these millennial variations [...]
Coherent streamflow variability in Monsoon Asia over the past eight centuries---links to oceanic drivers
Published: 2019-11-13
Subjects: Climate, Earth Sciences, Hydrology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Monsoon Asia region is home to ten of the world’s biggest rivers, supporting the lives of 1.7 billion people who rely on streamflow for water, energy, and food. Yet, a synoptic understanding of multi-centennial streamflow variability for this region is lacking. Here we produce the first large scale streamflow reconstruction over Monsoon Asia (63 stations in 16 countries), using a novel [...]
Gulf Stream and Kuroshio Current are synchronized
Published: 2019-11-05
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Observational records show that sea surface temperatures along the Gulf Stream and Kuroshio tend to synchronize at decadal time scales. This synchronization, which we refer to as the Boundary Current Synchronization (BCS), is reproduced in global climate models with high spatial resolution. Both in observations and model simulations, BCS is associated with meridional migrations of the atmospheric [...]
Skillful multiyear predictions of ocean acidification in the California Current System
Published: 2019-10-10
Subjects: Biogeochemistry, Climate, Earth Sciences, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The California Current System (CCS) sustains economically valuable fisheries and is particularly vulnerable to ocean acidification, due to the natural upwelling of corrosive waters that affect ecosystem function. Marine resource managers in the CCS could benefit from advanced knowledge of ocean acidity on multiyear timescales. We use a novel suite of retrospective forecasts with an initialized [...]