Search results for "Green"
showing 10 items of 1660 documents
Inadvertent climate modification due to anthropogenic lead
2009
Atmospheric particles are thought to initiate the majority of terrestrial precipitation. Field-based measurements of ice-crystal residues, together with controlled environment experiments on artificial clouds, suggest that anthropogenic lead-containing particles are among the most efficient ice-forming substances in the atmosphere.
Interannual variability of Greenland winter precipitation sources: 2. Effects of North Atlantic Oscillation variability on stable isotopes in precipi…
2008
[1] A new Lagrangian moisture source diagnostic is applied to identify the atmospheric conditions relevant for the fractionation of stable water isotopes during evaporation over the ocean and subsequent transport to Greenland. Northern Hemisphere winter months with positive and negative North Atlantic Oscillation (NAO) index are studied on the basis of ERA-40 reanalysis data. Diagnosed moisture transport conditions are supplied to a Rayleigh-type isotope fractionation model to derive estimates for the isotopic composition of stable isotopes in winter precipitation on the Greenland plateau for the two NAO phases. Because of changes in atmospheric circulation, moisture source locations for pr…
Interannual variability of Greenland winter precipitation sources: Lagrangian moisture diagnostic and North Atlantic Oscillation influence
2008
[1] We present a new Lagrangian diagnostic for identifying the sources of water vapor for precipitation. Unlike previous studies, the method allows for a quantitative demarcation of evaporative moisture sources. This is achieved by taking into account the temporal sequence of evaporation into and precipitation from an air parcel during transport, as well as information on its proximity to the boundary layer. The moisture source region diagnostic was applied to trace the origin of water vapor for winter precipitation over the Greenland ice sheet for 30 selected months with pronounced positive, negative, and neutral North Atlantic Oscillation (NAO) index, using the European Centre for Medium-…
Spatial distribution of temperature trends in Sicily
2013
Climate change resulting from the enhanced greenhouse effect is expected to have great impacts on hydrological cycle and consequently on ecosystems. The effects of climate variability have direct implications on water management, as water availability is related to changes in temperature and precipitation regimes. At the same time, this kind of alterations drives ecological impacts on flora and fauna. For these reasons, many studies have been carried out to investigate the existence of some tendency in temperature and/or precipitation series in different geographic domains. In order to verify the hypothesis of temperature increase in Sicily (Italy), temperature data from about 80 spatially …
A multi-model assessment of the impact of sea spray geoengineering on cloud droplet number
2012
Artificially increasing the albedo of marine boundary layer clouds by the mechanical emission of sea spray aerosol has been proposed as a geoengineering technique to slow the warming caused by anthropogenic greenhouse gases. A previous global model study (Korhonen et al., 2010) found that only modest increases (< 20%) and sometimes even decreases in cloud drop number (CDN) concentrations would result from emission scenarios calculated using a windspeed dependent geoengineering flux parameterisation. Here we extend that work to examine the conditions under which decreases in CDN can occur, and use three independent global models to quantify maximum achievable CDN changes. We find that dec…
Multilayer modelling of ozone fluxes on winter wheat reveals large deposition on wet senescing leaves
2015
Understanding how ozone is deposited on vegetation canopies is needed to perform tropospheric greenhouse gas budgets and evaluate the associated damage on vegetation. In this study, we propose a new multilayer scheme of ozone deposition on vegetation canopies that predicts stomatal, cuticular and soil deposition pathways separately. This mechanistic ozone deposition scheme is based on the multi-layer, multi-leaf mass and energy transfer model MuSICA. This model was chosen because it explicitly simulates the processes of rain interception, through fall and evaporation at different depths within the vegetation canopy, so that ozone deposition on wet leaf cuticles can be explicitly modelled wi…
Hyperspectral response of agronomic variables to background optical variability: Results of a numerical experiment
2022
Understanding how biophysical and biochemical variables contribute to the spectral characteristics of vegetation canopies is critical for their monitoring. Quantifying these contributions, however, remains difficult due to extraneous factors such as the spectral variability of canopy background materials, including soil/crop-residue moisture, soil-type, and non-photosynthetic vegetation (NPV). This study focused on exploring the spectral response of two important agronomic variables (1) leaf chlorophyll content (Cab ) and (2) leaf area index (LAI) under various canopy backgrounds through a global sensitivity analysis of wheat-like canopy spectra simulated using the physically-based PROSAIL …
How effective are the vegetated surfaces for the CO2 sequestration? Analyzing parameters and methods
2021
Human activities are severe sources of greenhouse gases and, particularly, of CO 2 . This trend, according with the highly demanding criteria released by the international institutions, must be suitably cut, in order of turning the pollutant emissions within limits that will guarantee a sustainable and environmentally safe development of the human species. Apart the measures that are since long time usually implemented in the technological systems, other interventions should be properly adopted in supporting the sustainability of the anthropic activities. These actions mainly apply to the so-called bioclimatic and passive measures and, particularly, could usefully refer to the plantation of…
Teaching Green Analytical Chemistry on the Example of Bioindication and Biomonitoring (B & B) Technologies
2019
Teaching of Green Analytical Chemistry (GAC) requires a not inconsiderable willingness on the part of the lecturer to familiarize himself with a relatively new field in analytical chemistry. Although there is much that can be derived from Green and Sustainable Chemistry, the GAC’s forward-looking perspectives in particular are independent approaches that must not be neglected. In the first chapter of this article, approaches are pursued “how (teachers) learn to learn,” ultimately based on a consensus on ethics, which allows dealing with people, society and the environment to become an interdisciplinary unit. The end of all this is a smart method of conflict management which provides solutio…
Teaching Green Analytical Chemistry on the Example of Bioindication and Biomonitoring (B & B) Technologies
2019
Teaching of Green Analytical Chemistry (GAC) requires a not inconsiderable willingness on the part of the lecturer to familiarize himself with a relatively new field in analytical chemistry. Although there is much that can be derived from Green and Sustainable Chemistry, the GAC’s forward-looking perspectives in particular are independent approaches that must not be neglected. In the first chapter of this article, approaches are pursued “how (teachers) learn to learn,” ultimately based on a consensus on ethics, which allows dealing with people, society and the environment to become an interdisciplinary unit. The end of all this is a smart method of conflict management which provides solutio…