Search results for "armi"
showing 10 items of 874 documents
First Report of Armillaria mellea on a Fern from Italy
2019
Several perennial species of rhizomatous herbaceous ferns are cultivated as ornamental foliage plants. During late summer 1999, in a garden at the foot of Mount Etna, eastern Sicily (Italy), we noted a fern hedge showing patches of withered or stunted plants. The fern was identified as Cyrtomium falcatum (L.f.) C. Presl. (=Polystichum falcatum (L.f.) Diels), a house holly fern or Japanese holly fern, which is an ornamental fern native to East and South Asia. Other woody plants in the immediate vicinity had died over the last few years, including apricot and cedar trees whose stumps had not been removed. A close examination of uprooted ferns revealed the presence of creamy white fan-shaped …
Status of Some Escaped Ornament Perennials in the Flora of Latvia
2019
AbstractThis paper introduces eight ornamental perennial garden escapees that were recorded by the authors of this article on Lucavsala Island, Riga (Latvia) in 2016. Our data on Achillea ptarmica cv. ‘Boule de Neige’, Artemisia ludoviciana, Asclepias syriaca, Campanula lactiflora, Heliopsis helianthoides, Lathyrus latifolius, Phlox paniculata and Rudbeckia hirta contribute to the knowledge about the occurrence of these taxa in wild. All these species are also growing in the collection of ornamental perennials in the Botanical Garden of the University of Latvia. A review of these species in Latvian herbarium collections has been conducted. Five species, Heliopsis helianthoides, Artemisia lu…
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.
Global Warming: Human Intervention in World Climate
2010
In the preceding chapter, we described climate changes that have occurred over very long geological periods. We concluded that Earth is currently in an interglacial interval within a rather long period of glaciations. Indeed, average carbon dioxide concentrations in the atmosphere have been slowly decreasing over the past 600,000 years, with accompanying cooling (Fig. 6.3). There have been, of course, many periodic changes in the CO2 concentrations and average temperature over this period (see Fig. 7.1). However, very recently, something quite unique and startling has occurred. As Fig. 7.1 shows, there has been a remarkable increase in CO2 levels, actually during the past 200 years, from 28…
SOUTHTRAC-GW: An airborne field campaign to explore gravity wave dynamics at the world’s strongest hotspot
2021
The southern part of South America and the Antarctic peninsula are known as the world’s strongest hotspot region of stratospheric gravity wave (GW) activity. Large tropospheric winds are deflected by the Andes and the Antarctic Peninsula and excite GWs that might propagate into the upper mesosphere. Satellite observations show large stratospheric GW activity above the mountains, the Drake Passage, and in a belt centered along 60°S. This scientifically highly interesting region for studying GW dynamics was the focus of the Southern Hemisphere Transport, Dynamics, and Chemistry–Gravity Waves (SOUTHTRAC-GW) mission. The German High Altitude and Long Range Research Aircraft (HALO) was deployed …
Cold cloud microphysical process rates in a global chemistry–climate model
2021
Microphysical processes in cold clouds which act as sources or sinks of hydrometeors below 0 ∘C control the ice crystal number concentrations (ICNCs) and in turn the cloud radiative effects. Estimating the relative importance of the cold cloud microphysical process rates is of fundamental importance to underpin the development of cloud parameterizations for weather, atmospheric chemistry, and climate models and to compare the output with observations at different temporal resolutions. This study quantifies and investigates the ICNC rates of cold cloud microphysical processes by means of the chemistry–climate model EMAC (ECHAM/MESSy Atmospheric Chemistry) and defines the hierarchy of sources…
The future of paleoclimate
2021
Our understanding of natural climate variability rapidly declines over the Common Era (CE) as the pre-instrumental temperature amplitude differs substantially among large-scale reconstructions. Highlighting such differences and emphasizing paleoclimatic findings is crucial for placing anthropogenic climate change in a long-term context. We argue that more proxy records are needed to accurately reconstruct first millennium CE temperature variability and value regional studies producing such data.
Mixing and ageing in the polar lower stratosphere in winter 2015–2016
2018
We present data from winter 2015–2016, which were measured during the POLSTRACC (The Polar Stratosphere in a Changing Climate) aircraft campaign between December 2015 and March 2016 in the Arctic upper troposphere and lower stratosphere (UTLS). The focus of this work is on the role of transport and mixing between aged and potentially chemically processed air masses from the stratosphere which have midlatitude and low-latitude air mass fractions with small transit times originating at the tropical lower stratosphere. By combining measurements of CO, N2O and SF6 we estimate the evolution of the relative contributions of transport and mixing to the UTLS composition over the course of the winte…
Interannual and decadal SST-forced responses of the West African monsoon
2010
International audience; We review the studies carried out during the African Monsoon Multidisciplinary Analysis (AMMA)-EU on the changes of interannual sea surface temperature (SST)-West African monsoon (WAM) covariability at multidecadal timescales, together with the influence of global warming (GW). The results obtained in the AMMA-EU suggest the importance of the background state, modulated by natural and anthropogenic variability, in the appearance of different interannual modes. The lack of reliability of current coupled models in giving a realistic assessment for WAM in the future is also stated.
Isolating the climate change impacts on air-pollution-related-pathologies over central and southern Europe – a modelling approach on cases and costs
2019
Air pollution has important implications for human health and associated external costs to society and is closely related to climate change. This contribution tries to assess the impacts of present (1996-2015) and future (2071-2100 under RCP8.5) air pollution on several cardiovascular and respiratory pathologies and estimate the difference in the costs associated with these health impacts on the European population. For this, air quality data from the regional chemistry-climate modelling system of the Weather Research and Forecasting (WRF) model coupled with Chemistry (WRF-Chem) are used, together with some epidemiological information from the European Commission. The methodology considered…