scholarly journals The Accent-Vocbas Field Campaign on Biosphere-Atmosphere Interactions in a Mediterranean Ecosystem of Castelporziano (Rome): Site Characteristics, Climatic and Meteorological Conditions,and Eco-Physiology of Vegetation

2016 ◽  
pp. 189-221
2016 ◽  
Vol 23 ◽  
pp. 30-41 ◽  
Author(s):  
Zelalem Mengiste Taye ◽  
Fernando Martínez-Peña ◽  
José Antonio Bonet ◽  
Juan Martínez de Aragón ◽  
Sergio de-Miguel

2007 ◽  
Vol 7 (9) ◽  
pp. 2233-2257 ◽  
Author(s):  
J. D. Fast ◽  
B. de Foy ◽  
F. Acevedo Rosas ◽  
E. Caetano ◽  
G. Carmichael ◽  
...  

Abstract. We describe the large-scale meteorological conditions that affected atmospheric chemistry over Mexico during March 2006 when several field campaigns were conducted in the region. In-situ and remote-sensing instrumentation was deployed to obtain measurements of wind, temperature, and humidity profiles in the boundary layer and free atmosphere at four primary sampling sites in central Mexico. Several models were run operationally during the field campaign to provide forecasts of the local, regional, and synoptic meteorology as well as the predicted location of the Mexico City pollutant plume for aircraft flight planning purposes. Field campaign measurements and large-scale analyses are used to define three regimes that characterize the overall meteorological conditions: the first regime prior to 14 March, the second regime between 14 and 23 March, and the third regime after 23 March. Mostly sunny and dry conditions with periods of cirrus and marine stratus along the coast occurred during the first regime. The beginning of the second regime was characterized by a sharp increase in humidity over the central plateau and the development of late afternoon convection associated with the passage of a weak cold surge on 14 March. Over the next several days, the atmosphere over the central plateau became drier so that deep convection gradually diminished. The third regime began with the passage of a strong cold surge that lead to humidity, afternoon convection, and precipitation over the central plateau that was higher than during the second regime. The frequency and intensity of fires, as determined by satellite measurements, also diminished significantly after the third cold surge. The synoptic-scale flow patterns that govern the transport of pollutants in the region are described and compared to previous March periods to put the transport into a climatological context. The complex terrain surrounding Mexico City produces local and regional circulations that govern short-range transport; however, the mean synoptic conditions modulate the thermally-driven circulations and on several days the near-surface flow is coupled to the ambient winds aloft.


2009 ◽  
Vol 6 (6) ◽  
pp. 1043-1058 ◽  
Author(s):  
S. Fares ◽  
S. Mereu ◽  
G. Scarascia Mugnozza ◽  
M. Vitale ◽  
F. Manes ◽  
...  

Abstract. Biosphere-atmosphere interactions were investigated on a sandy dune Mediterranean ecosystem in a field campaign held in 2007 within the frame of the European Projects ACCENT and VOCBAS. The campaign was carried out in the Presidential estate of Castelporziano, a peri-urban park close to Rome. Former campaigns (e.g. BEMA) performed in Castelporziano investigated the emission of biogenic volatile organic compounds (BVOC). These campaigns focused on pseudosteppe and evergreen oak groves whereas the contribution of the largely biodiverse dune vegetation, a prominent component of the Mediterranean ecosystem, was overlooked. While specific aspects of the campaign will be discussed in companion papers, the general climatic and physiological aspects are presented here, together with information regarding BVOC emission from the most common plant species of the dune ecosystem. During the campaign regular air movements were observed, dominated by moderate nocturnal land breeze and diurnal sea breeze. A regular daily increase of ozone concentration in the air was also observed, but daily peaks of ozone were lower than those measured in summer on the same site. The site was ideal as a natural photochemical reactor to observe reaction, transport and deposition processes occurring in the Mediterranean basin, since the sea-land breeze circulation allowed a strong mixing between biogenic and anthropogenic emissions and secondary pollutants. Measurements were run in May, when plant physiological conditions were optimal, in absence of severe drought and heat stress. Foliar rates of photosynthesis and transpiration were as high as generally recorded in unstressed Mediterranean sclerophyllous plants. Most of the plant species emitted high level of monoterpenes, despite measurements being made in a period in which emissions of volatile isoprenoids could be restrained by developmental and environmental factors, such as leaf age and relatively low air temperature. Emission of isoprene was generally low. Accounting for the high monoterpene spring emission of the dune ecosystem may be important to correct algorithms at regional and ecosystem levels, and to interpret measurements of fluxes of volatile isoprenoids and secondary pollutants.


2007 ◽  
Vol 7 (1) ◽  
pp. 2037-2089 ◽  
Author(s):  
J. D. Fast ◽  
B. de Foy ◽  
F. Acevedo Rosas ◽  
E. Caetano ◽  
G. Carmichael ◽  
...  

Abstract. We describe the large-scale meteorological conditions that affected atmospheric chemistry over Mexico during March 2006 when several field campaigns were conducted in the region. In-situ and remote-sensing instrumentation was deployed to obtain measurements of wind, temperature, and humidity profiles in the boundary layer and free atmosphere at four primary sampling sites in central Mexico. Several models were run operationally during the field campaign to provide forecasts of the local, regional, and synoptic meteorology as well as the predicted location of the Mexico City pollutant plume for aircraft flight planning purposes. Field campaign measurements and large-scale analyses are used to define three regimes that characterize the overall meteorological conditions: the first regime prior to 14 March, the second regime between 14 and 23 March, and the third regime after 23 March. Mostly sunny and dry conditions with periods of cirrus and marine stratus along the coast occurred during the first regime. The beginning of the second regime was characterized by a sharp increase in humidity over the central plateau and the development of late afternoon convection associated with the passage of a weak cold surge on 14 March. Over the next several days, the atmosphere over the central plateau became drier so that deep convection gradually diminished. The third regime began with the passage of a strong cold surge that lead to humidity, afternoon convection, and precipitation over the central plateau that was higher than during the second regime. The frequency and intensity of fires, as determined by satellite measurements, also diminished significantly after the third cold surge. The synoptic-scale flow patterns that govern the transport of pollutants in the region are described and compared to previous March periods to put the transport into a climatological context. The complex terrain surrounding Mexico City produces local and regional circulations that govern short-range transport; however, the mean synoptic conditions modulate the thermally-driven circulations and on several days the near-surface flow is coupled to the ambient winds aloft.


2009 ◽  
Vol 6 (1) ◽  
pp. 1185-1227 ◽  
Author(s):  
S. Fares ◽  
S. Mereu ◽  
G. Scarascia Mugnozza ◽  
M. Vitale ◽  
F. Manes ◽  
...  

Abstract. Biosphere-atmosphere interactions were investigated on a sandy dune Mediterranean ecosystem in a field campaign held in 2007 within the frame of the European Projects ACCENT and VOCBAS. The campaign was carried out in the Presidential estate of Castelporziano, a peri-urban park close to Rome where several investigations on the emission of biogenic volatile organic compounds (BVOC) in Mediterranean area were performed in the past 15 y. While specific aspects of the campaign will be discussed in companion papers, the general climatic and physiological aspects will be presented here together with information regarding BVOC emission from the most common plants present in this ecosystem. During the campaign regular air movements were observed, dominated by moderate nocturnal land breeze and diurnal sea breeze. A regular daily increase of ozone concentration in the air was also observed, but daily peaks of ozone were much lower than those measured downwind of the Rome conurbation. The site was ideal as a natural photochemical reactor to observe reaction, transport and deposition processes occurring in the Mediterranean basin, where a sea-land breeze circulation system allows a strong mixing between biogenic and anthropogenic emissions and secondary pollutants. The campaign investigated emissions from a poorly studied and largely biodiverse ecosystem, often subjected to a combination of environmental stresses and to anthropogenic pollution. Measurements were run in May, when plant physiological conditions were still optimal, in absence of severe drought and heat stress. Foliar rates of photosynthesis and transpiration were as high as generally recorded in unstressed Mediterranean sclerophyllous plants. Most of the plant species emitted high level of monoterpenes, despite measurements being made in a period in which emissions of volatile isoprenoids could be restrained by developmental and environmental factors, such as leaf age and relatively low air temperature. No high isoprene emitting plants were found in the ecosystem. It is speculated that environmental stresses limit the emission during summer, differently than in other Mediterranean ecosystems. Accounting for the high spring emission of the dune ecosystem may be important to correct current algorithms at regional, ecosystem levels, and to interpret measurements of fluxes of volatile isoprenoids and pollutants.


Author(s):  
Justin Farrell

This chapter examines the bitter, long-lasting, and sometimes violent dispute over the Yellowstone bison herd—America's only remaining genetically pure and free-roaming herd, which once numbered more than 30 million but was exterminated down to a mere 23 single animals. This intractable issue hinges on current scientific disagreements about the biology and ecology of the disease brucellosis (Brucella abortus). But in recent years, a more radical, grassroots, and direct action activist group called the Buffalo Field Campaign (BFC) has found success by shifting the focus of the debate away from science, toward the deeper religious dimensions of the issue. The chapter shows how the infusion of the conflict with moral and spiritual feeling has brought to the fore deeper questions that ultimately needed to be answered, thus making this a public religious conflict as much as a scientific one, sidestepping rabbit holes of intractability. It observes the ways in which BFC activists engaged in a phenomenon called moral and religious “muting.” This has theoretical implications for understanding how certain elements of culture (e.g., individualism and moral relativism) can organize and pattern others—especially in post hoc explanations of religiously motivated activism.


Author(s):  
A.I. Belenkov ◽  
◽  
S.V. Zhelezova ◽  
D.V. Bereza

The article considers the issues of the influence of the main tillage on the yield of crops of grain-tilled crop rotation: vetch-oat mixture - winter wheat - potatoes - barley. It was found that in addition to the reception of soil cultivation, the productivity of agrocenoses was also influenced by meteorological conditions.


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