Search results for "altitud"

Landscape-scale Spatial Distribution of the Lanner Falcon (Falco biarmicus feldeggii) Breeding Population in Italy

2008

Falco biarmicus feldeggii is one of the most threatened taxa in Europe. Its global population is estimated at a few hundred pairs unequally scattered in a vast and fragmented area stretching from Sicily to the Caspian Sea. Most recent counts showed that Italy hosts a large part (>25%) of the whole population. Consequently, Italian authorities promoted a national action plan. In this framework, we carried out the first national survey for the Lanner Falcon in Italy (2003-2004). Our study area covered the whole breeding range, i.e., Sicily and the Italian peninsula (n = 2909 cells 10 × 10 km). When possible, we considered also additional information from previous regional investigations (1993…

Simúlidos (Diptera: Simuliidae) de los ríos de la Comunidad Valenciana: Implicaciones en la salud pública y su control

2018

Los simúlidos (Diptera: Simuliidae) se encuentran distribuidos por casi todo el mundo. Su presencia está ampliamente influenciada por la disponibilidad de cursos de agua con flujo, necesarios para el desarrollo de los estados inmaduros (ADLER & McCREADIE, 2002), ocupando ambientes que van desde cursos temporales hasta grandes ríos. Los simúlidos crían en aguas corrientes, se les puede encontrar tanto en arroyos y torrentes de montaña como en los lentos flujos de agua de los ríos en sus tramos bajos. Además, existen unas pocas especies las cuales se han adaptado a flujos de agua tan escasos donde incluso la corriente es casi imperceptible (BURGER, 1987). En cualquier caso, se sabe que cierto…

2014

Abstract. The case study presented here focuses on the life cycle of clouds in the anvil region of a tropical deep convective system. During the SCOUT-O3 campaign from Darwin, Northern Australia, the Hector storm system has been probed by the Geophysica high-altitude aircraft. Clouds were observed by in situ particle probes, a backscatter sonde, and a miniature lidar. Additionally, aerosol number concentrations have been measured. On 30 November 2005 a double flight took place and Hector was probed throughout its life cycle in its developing, mature, and dissipating stage. The two flights were four hours apart and focused on the anvil region of Hector in altitudes between 10.5 and 18.8 km (…

Unprecedented evidence for deep convection hydrating the tropical stratosphere

2008

[1] We report on in situ and remote sensing measurements of ice particles in the tropical stratosphere found during the Geophysica campaigns TROCCINOX and SCOUT-O3. We show that the deep convective systems penetrated the stratosphere and deposited ice particles at altitudes reaching 420 K potential temperature. These convective events had a hydrating effect on the lower tropical stratosphere due to evaporation of the ice particles. In contrast, there were no signs of convectively induced dehydration in the stratosphere.

Observational and modelling evidence of tropical deep convective clouds as a source of mid-tropospheric accumulation mode aerosols

2008

High concentrations (up to 550 cm−3 STP) of aerosols in the accumulation mode (>0.12 μm) were observed by aircraft above 7.5 km altitude in the dynamically active regions of several deep convect ...

Anti-Hypotensive Treatment and Endothelin Blockade Synergistically Antagonize Exercise Fatigue in Rats under Simulated High Altitude

2013

Rapid ascent to high altitude causes illness and fatigue, and there is a demand for effective acute treatments to alleviate such effects. We hypothesized that increased oxygen delivery to the tissue using a combination of a hypertensive agent and an endothelin receptor A antagonist drugs would limit exercise-induced fatigue at simulated high altitude. Our data showed that the combination of 0.1 mg/kg ambrisentan with either 20 mg/kg ephedrine or 10 mg/kg methylphenidate significantly improved exercise duration in rats at simulated altitude of 4,267 m, whereas the individual compounds did not. In normoxic, anesthetized rats, ephedrine alone and in combination with ambrisentan increased heart…

<title>Methodology for quantitative analysis of scaling effects in multiresolution datasets acquired with airborne sensors flying at different …

2001

Scaling issues are always playing a critical role in most studies based on remote sensing data. The process of getting quantitative scaling information from raw multi-resolution images is not trivial, and many aspects must be taken very carefully into consideration. To get a better picture about the role of spatial resolution, we conducted a series of flights in summer 1997, in several test sites over Spain and Portugal. In order to minimize the time of acquisition (to get minimal changes in atmospheric status and solar illumination) we used three flight altitude levels, that produced images with 1.25 m, 3 m and 12 m resolutions. The main steps in our methodology are: a) Geometrical registr…

A simple model for computing diffuse solar radiation

1989

In this paper a very simple model for predicting the daily diffuse solar radiation at any Italian location using as input few extensively measured meteorological parameters is proposed. In fact the daily diffuse radiation D, MJ.m−2.day−1, here is correlated with only the relative sunshine duration sS and the noon altitude of the sun on the 15th of the month hn, degrees, by the following equation: D=7(sS−(sinhn)1.55 . The validity of this formula is verified using monthly mean daily data from four Italian stations displaced at various latitudes or altitudes or geographical situations (inland or coastal site). The test results show that the deviations between the measured and the computed val…

Niche filling slows the diversification of Himalayan songbirds.

2013

In Himalayan songbirds, the speciation rate is ultimately set by ecological competition, rather than by the rate of acquisition of reproductive isolation. The beginnings of adaptive radiation and speciation have been widely studied — in Darwin's finches, sticklebacks and cichlid fish, for example — but relatively little is known about what happens next. Specifically, what is the rate-limiting step for the establishment of new species? This seven-year study of the 358 songbird species found on the Himalayan slopes suggests that it is the rates at which new niches are created and occupied that limits diversification, not the rate at which new species form through reproductive isolation. Speci…

Aerosol concentrations determine the height of warm rain and ice initiation in convective clouds over the Amazon basin

2017

Abstract. We have investigated how pollution aerosols affect the height above cloud base of rain and ice hydrometeor initiation and the subsequent vertical evolution of cloud droplet size and number concentrations in growing convective cumulus. For this purpose we used in-situ data of hydrometeor size distributions measured with instruments mounted on HALO (High Altitude and Long Range Research Aircraft) during the ACRIDICON-CHUVA campaign over the Amazon during September 2014. The results show that the height of rain initiation by collision and coalescence processes (Dr, in units of meters above cloud base) is linearly correlated with the number concentration of droplets (Nd in cm−3) nucle…