Characterization of ocean biogeochemical processes: a generalized total least-squares estimator of the Redfield ratios
Summary: The chemical composition of the global ocean is governed by biogeochemical processes. These processes interact with each other so that the concentrations of carbon dioxide, oxygen, nitrate and phosphate vary in constant proportions, referred to as the Redfield ratios. We build here the Generalized Total Least-Squares estimator of these ratios. The tests performed on the Atlantic Ocean highlight a variability of the Redfield ratios.
Earth Syst. Dynam. Discuss., 6, 2383-2416, doi:10.5194/esdd-6-2383-2015, 2015
Imprints of climate forcings in global gridded temperature data
Summary: Using regression analysis, near-surface temperatures from several gridded datasets were investigated for the presence of components attributable to external climate forcings and to major internal climate variability modes, over the 1901-2010 period. The spatial patterns of local temperature response and their combination in globally averaged temperature were shown and discussed, with special focus on highlighting the inter-dataset contrasts.
Earth Syst. Dynam. Discuss., 6, 2339-2381, doi:10.5194/esdd-6-2339-2015, 2015
Late quaternary temperature variability described as abrupt transitions on a 1/f noise background
Summary: We analyse scaling in temperature signals for the late quaternary climate, and focus on the effects of regime shifting events such as the Dansgaard-Oeschger cycles and the shifts between glacial and interglacial conditions. When these events are omitted from a scaling description the climate noise is consistent with a 1/f law on time scales from months to 10^5 years. If the events are included in the description, we obtain a model that is inherently non-stationary.
Earth Syst. Dynam. Discuss., 6, 2323-2337, doi:10.5194/esdd-6-2323-2015, 2015
Severe summer heat waves over Georgia: trends, patterns and driving forces
Summary: Georgia experienced a rising number of severe summer heat waves between 1961 and 2010. Heat wave patterns and their relationships to surface and atmospheric predictors reveal a blocking anticyclone over the southern Ural, which attracts warm air from the South, enhances heating processes over Georgia and shifts large-scale wind streams over Eurasia northwards. Moreover, pronounced precipitation and soil moisture deficiency amplifies heat wave severity and persistence.
Earth Syst. Dynam. Discuss., 6, 2273-2322, doi:10.5194/esdd-6-2273-2015, 2015
Early warning signals of tipping points in periodically forced systems
Summary: We find early warnings of abrupt changes in complex dynamical systems such as the climate where the usual early warning indicators do not work. In particular, these are systems that are periodically forced, for example by the annual cycle of solar insolation. We show these indicators are good theoretically in a general setting then apply them to a specific system, that of the Arctic sea ice, which has been conjectured to be close to such a tipping point. We do not find evidence of it.
Earth Syst. Dynam. Discuss., 6, 2243-2272, doi:10.5194/esdd-6-2243-2015, 2015
Two-dimensional prognostic experiments for fast-flowing ice streams from the Academy of Sciences Ice Cap: future modeled histories obtained for the reference surface mass balance
Earth Syst. Dynam. Discuss., 6, 2211-2242, doi:10.5194/esdd-6-2211-2015, 2015
Impacts of climate change on growth period and planting boundaries of winter wheat in China under RCP4.5 scenario
Earth Syst. Dynam. Discuss., 6, 2181-2210, doi:10.5194/esdd-6-2181-2015, 2015
Importance of open-water ice growth and ice concentration evolution: a study based on FESOM-ECHAM6
Summary: Our work is to investigate to what degree the open water ice formation affects the ice and ocean properties. Our results show a positive feedback among the Arctic sea ice, the AMOC, and the surface air temperature in the Arctic. The sea ice transport affects the freshwater budget in regions of deep water formation. A link between the climate of Northern Hemisphere continents and the lead closing rate during ice formation period is also shown by the model.
Earth Syst. Dynam. Discuss., 6, 2137-2179, doi:10.5194/esdd-6-2137-2015, 2015
Deforestation in Amazonia impacts riverine carbon dynamics
Summary: Amazonia is heavily impacted by climate change and deforestation. During annual flooding terrigenous material is imported to the river, converted and finally exported to the ocean or the atmosphere. Changes in the vegetation alter therefore riverine carbon dynamics. Our results show that due to deforestation organic carbon amount will strongly decrease both in the river and exported to the ocean, while inorganic carbon amounts will increase, in the river as well as exported to the atmosphere.
Earth Syst. Dynam. Discuss., 6, 2101-2136, doi:10.5194/esdd-6-2101-2015, 2015
Alluvial plain dynamics in the southern Amazonian foreland basin
Summary: This paper analyses the behaviour of 12 tributaries of the río Mamoré and their influence on alluvial plain dynamics. These rivers are extremely active: between 1984 and 2014, 7 of these 12 rivers underwent a total of 41 crevasses and 29 avulsions. Most of the sedimentary load of these rivers is deposited on the alluvial plains before they reach the Mamoré. Crevasses and avulsions are not controlled by ENSO cycles, but rather are the result of intrabasinal processes.
Earth Syst. Dynam. Discuss., 6, 2063-2100, doi:10.5194/esdd-6-2063-2015, 2015
A simple model of the anthropogenically forced CO2 cycle
Earth Syst. Dynam. Discuss., 6, 2043-2062, doi:10.5194/esdd-6-2043-2015, 2015
A novel bias correction methodology for climate impact simulations
Summary: - We introduce a novel technique to bias correct climate model output for impact simulations that preserves its physical consistency and multivariate structure - The methodology considerably improves the representation of extremes in climatic variables relative to conventional bias correction strategies - Illustrative simulations of biosphere-atmosphere carbon and water fluxes with a biosphere model (LPJmL) show that the novel technique can be usefully applied to drive climate impact models
Earth Syst. Dynam. Discuss., 6, 1999-2042, doi:10.5194/esdd-6-1999-2015, 2015
Delaying future sea-level rise by storing water on Antarctica
Summary: Sea level will continue to rise for centuries. We investigate the option to delay sea-level rise by pumping ocean water onto Antarctica. Due to wave propagation ice is discharged much faster back into the ocean than expected from pure advection. A millennium-scale storage of >80% of the additional ice requires a distance of >700km from the coast line. The pumping energy required to elevate ocean water to mitigate a sea level rise of 3mm/yr exceeds 7% of current global primary energy supply.
Earth Syst. Dynam. Discuss., 6, 1979-1997, doi:10.5194/esdd-6-1979-2015, 2015
Observationally based analysis of land–atmosphere coupling
Summary: A generalized linear method specifically designed to assess the reciprocal forcing between connected fields is applied to the latest available observational datasets of global precipitation, evapotranspiration, vegetation and soil moisture. The analysis evidenced a robust coupling between soil moisture and precipitation and a strong link with volcanic eruptions and ENSO cycles, mediated by the effects of evapotranspiration and vegetation.
Earth Syst. Dynam. Discuss., 6, 1939-1977, doi:10.5194/esdd-6-1939-2015, 2015
The role of spatial scale and background climate in the latitudinal temperature response to deforestation
Earth Syst. Dynam. Discuss., 6, 1897-1937, doi:10.5194/esdd-6-1897-2015, 2015
Comparing peasants' perceptions of precipitation change with precipitation records in the tropical Callejón de Huaylas, Peru
Summary: Working on the interface of water availability and water demand in a small Andean catchment, peasants’ reports on detrimental precipitation changes during the last decades have attracted our scientific interest. We could not confirm any precipitation trends in this period with nearby precipitation records, but we found precipitation patterns that very likely pose challenges for rain-fed farming - in addition to potential other stresses by environmental and sociopolitical changes.
Earth Syst. Dynam. Discuss., 6, 1863-1896, doi:10.5194/esdd-6-1863-2015, 2015
Global warming projections derived from an observation-based minimal model
Summary: A conceptual model for the global temperature response to CO2 emissions is presented. Based on observation data, projections of future warming are computed for instructive emission scenarios. Delays in initiation of global emission reduction is found to be the most important factor driving global warming over the next two centuries. The model is intended as a tool for communicating the issue to non-climate scientists, students, policy-makers, and the general public.
Earth Syst. Dynam. Discuss., 6, 1789-1813, doi:10.5194/esdd-6-1789-2015, 2015
Coupled Climate–Economy–Biosphere (CoCEB) model – Part 2: Deforestation control and investment in carbon capture and storage technologies
Summary: We extend the global climate-economy-biosphere (CoCEB) model by adding a biomass equation and the related exchanges of CO2 and investigate the relationship between the effects of using carbon capture and storage (CCS) and deforestation control, and the economy growth rate. This endeavor reduces the impacts of climate change and positively affects economy growth. Also, the results for CCS remained sensitive to the formulation of CCS costs while those for deforestation control were less sensitive.
Earth Syst. Dynam. Discuss., 6, 865-906, doi:10.5194/esdd-6-865-2015, 2015