The ScaLIng Macroweather Model (SLIMM): using scaling to forecast global-scale macroweather from months to decades
Summary: Numerical climate models forecast the weather well beyond the deterministic limit. In this “macroweather” regime, they are random number generators. Stochastic models can have more realistic noises and can be forced to converge to the real-world climate. Existing stochastic models do not exploit the very long atmospheric and oceanic memories. With skill up to decades, our new ScaLIng Macroweather Model (SLIMM) exploits this to make forecasts more accurate than GCMs.
Earth Syst. Dynam., 6, 637-658, doi:10.5194/esd-6-637-2015, 2015
Inter-annual and seasonal trends of vegetation condition in the Upper Blue Nile (Abay) Basin: dual-scale time series analysis
Summary: This study concludes that integrated analysis of course and fine-scale, inter-annual and intra-annual trends enables a more robust identification of changes in vegetation condition. Seasonal trend analysis was found to be very useful in identifying changes in vegetation condition that could be masked if only inter-annual vegetation trend analysis were performed. The finer-scale intra-annual trend analysis revealed trends that were more linked to human activities.
Earth Syst. Dynam., 6, 617-636, doi:10.5194/esd-6-617-2015, 2015
The impact of oceanic heat transport on the atmospheric circulation
Summary: A general circulation model with an aquaplanet setup is used to study the impact of changes in the oceanic heat transport (OHT) on the atmospheric circulation. The atmosphere counterbalances the imposed changes in OHT. A stronger OHT leads to a decline in the intensity and a poleward shift of the maxima of both the Hadley and Ferrel cells. The efficiency of the climate machine, the intensity of the Lorenz energy cycle and the material entropy production of the system decline with increased OHT.
Earth Syst. Dynam., 6, 591-615, doi:10.5194/esd-6-591-2015, 2015
Atmospheric moisture transport: the bridge between ocean evaporation and Arctic ice melting
Summary: There appears to be a connection between two climate change indicators: an increase in evaporation over source regions and Arctic ice melting.
Earth Syst. Dynam., 6, 583-589, doi:10.5194/esd-6-583-2015, 2015
Understanding land surface response to changing South Asian monsoon in a warming climate
Summary: This study using a variable resolution global climate model having high-resolution zooming over the South Asian region indicates that the anthropogenic effects have influenced the recent weakening of the monsoon circulation and decline of precipitation. The simulated increase of surface temperature over the Indian region during the post-1950s is accompanied by a significant decrease of monsoon precipitation and soil moisture. This summer time soil drying is detectable under RCP4.5 scenario.
Earth Syst. Dynam., 6, 569-582, doi:10.5194/esd-6-569-2015, 2015
Ice supersaturation and the potential for contrail formation in a changing climate
Summary: Aviation impacts on climate via contrails, which are often clearly visible in the sky. Contrail formation requires particular cold/moist atmospheric conditions at aircraft cruise altitudes. Climate change is expected to change these conditions. Using simulations from several climate models we conclude that, by 2100, the probability of contrail formation could decrease from 11 to 7%, mostly due to changing conditions in the tropics. There is no consensus on the likely change in mid-latitudes.
Earth Syst. Dynam., 6, 555-568, doi:10.5194/esd-6-555-2015, 2015
Climatology of Vb cyclones, physical mechanisms and their impact on extreme precipitation over Central Europe
Earth Syst. Dynam., 6, 541-553, doi:10.5194/esd-6-541-2015, 2015
Metrics for linking emissions of gases and aerosols to global precipitation changes
Summary: Emissions due to human activity impact on rainfall. This impact depends on the properties of the gases or particles that are emitted. This paper uses improved understanding of relevant processes to produce a new measure, called the Global Precipitation-change Potential, which allows a direct comparison of the effect of different emissions on global-mean rainfall. Carbon dioxide, in the years following its emission, is shown to be less effective than methane emissions at causing rainfall change.
Earth Syst. Dynam., 6, 525-540, doi:10.5194/esd-6-525-2015, 2015
Gender and climate change in the Indian Himalayas: global threats, local vulnerabilities, and livelihood diversification at the Nanda Devi Biosphere Reserve
Earth Syst. Dynam., 6, 505-523, doi:10.5194/esd-6-505-2015, 2015
Modelling short-term variability in carbon and water exchange in a temperate Scots pine forest
Summary: We compared a process-based ecosystem model (LPJ-GUESS) with EC measurements to test whether observed interannual variability (IAV) in carbon and water fluxes can be reproduced because it is important to understand the driving mechanisms of IAV. We show that the model's mechanistic process representation for photosynthesis at low temperatures and during drought could be improved, but other process representations are still lacking in order to fully reproduce the observed IAV.
Earth Syst. Dynam., 6, 485-503, doi:10.5194/esd-6-485-2015, 2015
Propagation of biases in humidity in the estimation of global irrigation water
Earth Syst. Dynam., 6, 461-484, doi:10.5194/esd-6-461-2015, 2015
A framework for the cross-sectoral integration of multi-model impact projections: land use decisions under climate impacts uncertainties
Earth Syst. Dynam., 6, 447-460, doi:10.5194/esd-6-447-2015, 2015
Decomposing uncertainties in the future terrestrial carbon budget associated with emission scenarios, climate projections, and ecosystem simulations using the ISI-MIP results
Summary: Our study focused on uncertainties in terrestrial C cycling under newly developed scenarios with CMIP5. This study presents first results for examining relative uncertainties of projected terrestrial C cycling in multiple projection components. Only using our new model inter-comparison project data sets enables us to evaluate various uncertainty sources in projection periods. The information on relative uncertainties is useful for climate science and climate change impact evaluation.
Earth Syst. Dynam., 6, 435-445, doi:10.5194/esd-6-435-2015, 2015
Climate and carbon cycle dynamics in a CESM simulation from 850 to 2100 CE
Summary: We present the first last-millennium simulation with the Community Earth System Model (CESM) including an interactive carbon cycle in both ocean and land component. Volcanic eruptions emerge as the strongest forcing factor for the preindustrial climate and carbon cycle. We estimate the climate-carbon-cycle feedback in CESM to be at the lower bounds of empirical estimates (1.3ppm/°C). The time of emergence for interannual global land and ocean carbon uptake rates are 1947 and 1877, respectively.
Earth Syst. Dynam., 6, 411-434, doi:10.5194/esd-6-411-2015, 2015
Policies, economic incentives and the adoption of modern irrigation technology in China
Summary: Econometric analyses results revealed that policy support via subsidies and extension services have played an important role in promoting the adoption of irrigation technology. Strikingly, the present irrigation pricing policy has played significant but contradictory roles in promoting the adoption of different types of irrigation technology. Irrigation pricing showed a positive impact on household-based irrigation technology, and a negative impact on community-based irrigation technology.
Earth Syst. Dynam., 6, 399-410, doi:10.5194/esd-6-399-2015, 2015
On studying relations between time series in climatology
Summary: Connections between time series should be studied with methods developed in time series analysis rather than with cross-correlation coefficients and regression equations. The approach includes time series modeling in both time and frequency domains. Two climatic time series with zero cross correlation are shown to be closely connected at timescales from 2.5 to 10 years and a full time- and frequency-domain description of the system is given for this teleconnection in a climate system.
Earth Syst. Dynam., 6, 389-397, doi:10.5194/esd-6-389-2015, 2015
Migration and global environmental change: methodological lessons from mountain areas of the global South
Earth Syst. Dynam., 6, 375-388, doi:10.5194/esd-6-375-2015, 2015
Establishment and maintenance of regulating ecosystem services in a dryland area of central Asia, illustrated using the Kökyar Protection Forest, Aksu, NW China, as an example
Earth Syst. Dynam., 6, 359-373, doi:10.5194/esd-6-359-2015, 2015
The ocean carbon sink – impacts, vulnerabilities and challenges
Summary: Rapidly rising atmospheric CO2 concentrations caused by human actions over the past 250 years have raised cause for concern that changes in Earth’s climate system may progress at a much faster pace and larger extent than during the past 20,000 years. Questions that yet need to be answered are what the carbon uptake kinetics of the oceans will be in the future and how the increase in oceanic carbon inventory will affect its ecosystems. Major future ocean carbon research challenges are discussed.
Earth Syst. Dynam., 6, 327-358, doi:10.5194/esd-6-327-2015, 2015
Exploring objective climate classification for the Himalayan arc and adjacent regions using gridded data sources
Summary: A three-step climate classification – input variable selection, principal components analysis and k-means clustering – was applied to a spatial domain covering the Himalayan arc and adjacent plains regions using input data from four global meteorological reanalyses. This revealed a reanalysis ensemble consensus for eight macro-climate zones. Zonal statistics revealed consistent, distinct climatologies. This approach has implications for resource assessments and data set bias characterisations.
Earth Syst. Dynam., 6, 311-326, doi:10.5194/esd-6-311-2015, 2015