Preprints
Filtering by Subject: Climate
COVID-19-related drop in anthropogenic aerosol emissions in China and corresponding cloud and climate effects
Published: 2020-05-11
Subjects: Atmospheric Sciences, Climate, Earth Sciences, Environmental Sciences, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The COVID-19 pandemic has led to massive disruptions of public life on a global scale. To halt the spread of the disease, China temporarily shut down parts of the manufacturing and transportation sectors. Associated anthropogenic aerosol emissions in February 2020 plunged to record lows, causing a temporary improvement of air quality with uncertain effects on cloud formation, atmospheric [...]
Asian monsoon amplifies semi-direct effect of biomass burning aerosols on low cloud formation
Published: 2020-05-11
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Low clouds play a key role in the Earth-atmosphere energy balance and influence agricultural production and solar-power generation. Smoke aloft has been found to enhance marine stratocu-mulus over the Southeast Atlantic in austral spring through aerosol-cloud interactions, but its role in regions with strong human activities and complex monsoon circulation remains unclear. Here we show that [...]
How waves are accelerating global coastal overtopping
Published: 2020-05-08
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The world’s coastal areas are home to about 10% of the human population and support unique and dynamic ecosystems, offering € trillions worth of environmental and societal benefits. Climate change and anthropogenic pressures are however exacerbating devastating hazards such as episodic coastal flooding, the magnitudes of which remain highly uncertain to date. This study, for the first time, [...]
Aerosols bias daily weather prediction
Published: 2020-05-07
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Weather prediction is essential to human daily life. Current numerical weather prediction (NWP) models are still subject to substantial forecast bias and rarely consider the impact of atmospheric aerosols, despite of the consensus of aerosols as the most important sources of uncertainty in predicting climate change. Here we show aerosols as an important driver biasing daily temperature [...]
Constraining global changes in temperature and precipitation from observable changes in surface radiative heating
Published: 2020-04-30
Subjects: Climate, Earth Sciences, Environmental Sciences, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics, Physics
Changes in the atmospheric composition alter the magnitude and partitioning between the downward propagating solar and atmospheric longwave radiative fluxes heating the Earths surface. These changes are computed by radiative transfer codes in Global Climate Models and measured with high precision at surface observation networks. Changes in radiative heating signify changes in the global surface [...]
Inter-model spread in the pattern effect and its contribution to climate sensitivity in CMIP5 and CMIP6 models
Published: 2020-04-24
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Radiative feedbacks depend on the spatial patterns of sea-surface temperature (SST) and thus can change over time as SST patterns evolve – the so-called ‘pattern effect’. This study investigates inter-model differences in the magnitude of the pattern effect and how these differences contribute to the spread in the effective equilibrium climate sensitivity (ECS) within CMIP5 and CMIP6 models. [...]
Equilibrium climate sensitivity controls uncertainty in regional climate change over the 21st century
Published: 2020-04-14
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Improved projections of local temperature change over the 21st century are essential for evaluating impacts and setting policy targets (Lehner and Stocker 2015, Senevirante et al 2016). Uncertainty in these projections is due to two approximately equal factors: uncertainty in greenhouse gas emissions, and uncertainty in the response of climate to those emissions (Hawkins and Sutton 2009). For the [...]
Seasonal Rainfall Forecasts for the Yangtze River Basin in Summer 2019 from an Improved Climate Service
Published: 2020-03-18
Subjects: Atmospheric Sciences, Climate, Meteorology, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Rainfall forecasts for the summer monsoon season in the Yangtze River Basin allow decision-makers to plan for possible flooding, which can affect the lives and livelihoods of millions of people. A trial climate service was developed in 2016, producing a prototype seasonal forecast product for use by stakeholders in the region, based on forecasting rainfall directly using a dynamical model. Here [...]
A spatial reconstruction of Siberian Last Glacial Maximum climate from pollen data
Published: 2020-03-18
Subjects: Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
The Last Glacial Maximum (LGM, around 21.000 years before present) was a period with significantly colder global mean temperature, large Northern Hemisphere ice sheets, and lower CO2 concentrations. Siberia was affected by a lower sea level which led to a closed Bering strait and a northward shift of the Arctic Ocean coastline. However, unlike other high-latitude areas, Siberia was not covered by [...]
Plant Physiology Increases the Magnitude and Spread of the Transient Climate Response in CMIP6 Earth System Models
Published: 2020-02-20
Subjects: Atmospheric Sciences, Climate, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Increasing concentrations of CO2 in the atmosphere not only influence climate through CO2’s effect as a greenhouse gas but also through its impact on plants. Plants respond to atmospheric CO2 concentrations in several ways that can alter surface energy and water fluxes and thus surface climate, including changes in stomatal conductance, water use, and canopy leaf area. These plant physiological [...]
Drivers of Local Ocean Heat Content Variability in ECCOv4
Published: 2020-02-06
Subjects: Climate, Oceanography, Oceanography and Atmospheric Sciences and Meteorology, Physical Sciences and Mathematics
Variation in upper ocean heat content is a critical factor in understanding global climate variability. By using temperature anomaly budgets in a physically consistent ocean state estimate we describe the balance between atmospheric forcing and ocean transport mechanisms for different depth horizons and at varying temporal and spatial resolutions. The processes controlling local variations in [...]
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 [...]