Search results for "air temperature"
showing 10 items of 47 documents
Global review and synthesis of trends in observed terrestrial near-surface wind speeds: Implications for evaporation
2012
Summary In a globally warming climate, observed rates of atmospheric evaporative demand have declined over recent decades. Several recent studies have shown that declining rates of evaporative demand are primarily governed by trends in the aerodynamic component (primarily being the combination of the effects of wind speed (u) and atmospheric humidity) and secondarily by changes in the radiative component. A number of these studies also show that declining rates of observed near-surface u (termed ‘stilling’) is the primary factor contributing to declining rates of evaporative demand. One objective of this paper was to review and synthesise the literature to assess whether stilling is a globa…
Study on Trichothecene and Zearalenone Presence in Romanian Wheat Relative to Weather Conditions
2019
To evaluate the influence of weather conditions on mycotoxin presence in wheat, deoxynivalenol (DON), 3-acetyldeoxynivalenol (3AcDON), 15-acetyldeoxynivalenol (15AcDON), fusarenon-X (FUS-X), nivalenol (NIV), HT-2 toxin (HT-2), T-2 toxin (T-2), diacetoxyscirpenol (DAS), neosolaniol (NEO) and zearalenone (ZEN) were evaluated in 102 Romanian wheat samples coming from five wheat growing areas during 2015. Only six mycotoxins were detected, while FUS-X, DAS, NEO and NIV were not present in the wheat samples. Mycotoxin concentrations were correlated with precipitation and temperature values during anthesis and the preharvest period. Overall, the highest frequency was registered for DON, while the…
Evaluation of in-farm versus weather station data for use as heat stress indicator in dairy sheep
2005
AbstractHeat stress is a limiting factor in dairy production in hot climates impairing growth, milk production and reproduction. The most widely investigated climatic factors related with heat stress are: air temperature and relative humidity. Previously dairy sheep studies of heat tolerance depended on measurements of physiological functions on individual animals such as rectal temperatures, respiration rates or volumes of air inhaled; unfortunately, such measurements are costly and not feasible on a large scale. This study aims to evaluate in-farm (IF) versus weather station (WS) data to be used as heat stress indicator in dairy sheep. Data were collected in three farms in November 2002 t…
Impact of spatial resolution and satellite overpass time on evaluation of the surface urban heat island effects
2012
Abstract Surface Urban Heat Island (SUHI) effect is defined as the increased surface temperature in urban areas in contrast to surrounding cooler temperatures in rural areas. In this paper, we study the characteristics that a spaceborne sensor must satisfy in terms of spatial resolution and overpass time to properly monitor the SUHI effect. For this, Land Surface Temperature (LST) maps, generated at different spatial resolution using the Airborne Hyperspectral Scanner (AHS) imagery, and in situ data of air temperature and LST obtained from the framework of the Dual-use European Security IR Experiment 2008 have been considered for the city of Madrid (Spain). The results showed that (1) spati…
Foam mat drying of yacon juice: Experimental analysis and computer simulation
2015
Abstract The foam mat drying of yacon juice (YJ) and concentrate yacon juice (CYJ) was conducted under various conditions of thickness of product (0.5, 1.0 and 1.5 cm) and air temperature (50, 60 and 70 °C). After drying the resulted dry powder was removed from the metallic tray and pulverized. Layer thickness and air temperature influenced statistically ( p > 0.5) drying time, moisture content and water activity (Aw) of the product. The shortest drying time to reach the desired Aw (0.1–0.3) corresponds to the condition of 0.5 cm and 70 °C for both juices – 59 and 65 min for the YJ and CYJ, respectively. The process was modeled in terms of heat and mass transfer and then simulated by a fin…
Hydrological response to an abrupt shift in surface air temperature over France in 1987/88.
2015
10 pages; International audience; During the last few decades, Europe has seen a faster increase of observed temperature than that simulated by models. The air temperature over Western Europe showed an abrupt shift at the end of the 1980s, still insufficiently documented. The aim of this study is to assess the characteristics of this shift and its potential impacts on the hydrological cycle over France. Such an assessment is essential for a better understanding of past and future climatic changes and their impact on water resources.A subset of 119 temperature, 122 rainfall, and 30 hydrometric stations was studied, over the entire French metropolitan territory. Several change-point detection…
Weakening of annual temperature cycle over the Tibetan Plateau since the 1870s
2017
The annual cycle of extra-tropical surface air temperature is an important component of the Earth's climate system. Over the past decades, a reduced amplitude of this mode has been observed in some regions. Although attributed to anthropogenic forcing, it remains unclear when dampening of the annual cycle started. Here we use a residual series of tree-ring width and maximum latewood density from the Tibetan Plateau >4,000 m asl to reconstruct changes in temperature seasonality over the past three centuries. The new proxy evidence suggests that the onset of a decrease in summer-to-winter temperature difference over the Tibetan Plateau occurred in the 1870s. Our results imply that the influen…
Association between climate and new daily diagnoses of COVID-19
2020
AbstractBackgroundAlthough evidence is accumulating that climate conditions may positively or negatively influence the scale of coronavirus disease 2019 (COVID-19) outbreaks, uncertainty remains concerning the real impact of climate factors on viral transmission. Methods. The number of new daily cases of COVID-19 diagnosed in Verona (Italy) was retrieved from the official website of Veneto Region, while information on daily weather parameters in the same area was downloaded from IlMeteo website, a renowned Italian technological company specialized in weather forecasts. The search period ranged between March 1 to November 11, 2020. The number of new daily COVID-19 cases and meteorological da…
Position of Blackbird (Turdus Merula) Nests in Orange Trees
2012
Nest placement affects the risk of predation and determines the microclimate for incubation. We have analysed the nest placement of the blackbird nests and the temperatures at which they are exposed in an orange plantation from Eastern Spain. The data come from a 16.9 ha of an orange plantation. In this plot, nest searching techniques were applied. Nest placement and the temperatures at midday were recorded from a sample of 84 nests. Furthermore, a sample of 16 nests was used to determine the daily variation between 8:00 and 20:00 hours. We measured the nest height, tree height, and distance from the tree centre to the nest, and the length of the longest branch. The temperatures inside the…
Maximum and Actual Evapotranspiration for Barley (Hordeum vulgare L.) through NOAA Satellite Images in Castilla-La Mancha, Spain
1996
Abstract An easy-to-follow methodology is developed for the assessment of regional evapotranspiration in Castilla-La Mancha, a semi-arid region of Spain. The methodology is applied to barley crops to monitor the irrigation scheduling over the region, by using remote sensing techniques supplemented by ground measurements. The methodology can be based on either of two models. In the first one, established by Caselles and Delegido, 1 the reference evapotranspiration, ET o , derives from the expression ET o = AR g (T a ) m a x + BR g + C where A, B and C are empirical coefficients, depending on climatic parameters and determined for each region; R g is the daily global radiation; and ( T a ) m …