Latest Villafranchian climate and landscape reconstructions at Pirro Nord (southern Italy)

Geology ◽  
2019 ◽  
Vol 47 (9) ◽  
pp. 829-832 ◽  
Author(s):  
Hugues-Alexandre Blain ◽  
Ana Fagoaga ◽  
Francisco Javier Ruiz-Sánchez ◽  
Josep Francesc Bisbal-Chinesta ◽  
Massimo Delfino
Keyword(s):  
Southern Italy ◽  
Numerical Data ◽  
Summer Rainfall ◽  
Distribution Patterns ◽  
Early Pleistocene ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Climate Conditions ◽  
First Occurrence ◽  
The Mean

Abstract Early Pleistocene terrestrial climate conditions in the Mediterranean region, especially between 1.3 and 1.7 Ma, are poorly understood. Here, the amphibian and reptile fossil record from 24 fissures (Cava Pirro) of the Pirro Nord karstic complex (southern Italy) is used to infer quantitative paleoclimatic and paleoenvironmental reconstructions. These numerical data indicate that the mean annual temperature may have been somewhat lower (–1.6 to –3.6 °C compared to modern temperatures) than that of today, and the mean annual precipitation slightly higher (+90 to +240 mm) than modern values. Seasonality was more pronounced, with cooler summers (–0.4 to –2.0 °C) and much colder winters (–1.2 to –6.0 °C). Rainfall distribution patterns during the year show more precipitation during the winter (+14 to +43 mm), with quantities of summer rainfall (–1.7 to +6.6 mm) being similar to modern values. The associated landscape comprised an open dry environment with scattered patches of woodland, locally along water courses or around swamps. This ecological scenario fits with early Pleistocene cold conditions, where the first occurrence of some eastern emigrants suggests a scenario of trans-Adriatic dispersal, as may have also occurred for the earliest European hominins.

scholarly journals Upside-down fluxes Down Under: CO<sub>2</sub> net sink in winter and net source in summer in a temperate evergreen broadleaf forest

2018 ◽  
Vol 15 (12) ◽  
pp. 3703-3716 ◽  
Author(s):  
Alexandre A. Renchon ◽  
Anne Griebel ◽  
Daniel Metzen ◽  
Christopher A. Williams ◽  
Belinda Medlyn ◽  
...  
Keyword(s):  
Large Scale ◽  
Vegetation Index ◽  
Ecosystem Respiration ◽  
Vapour Pressure Deficit ◽  
Summer Rainfall ◽  
Mean Annual Precipitation ◽  
Surface Conductance ◽  
Mean Annual Temperature ◽  
Eddy Covariance Method ◽  
Area Index

Abstract. Predicting the seasonal dynamics of ecosystem carbon fluxes is challenging in broadleaved evergreen forests because of their moderate climates and subtle changes in canopy phenology. We assessed the climatic and biotic drivers of the seasonality of net ecosystem–atmosphere CO2 exchange (NEE) of a eucalyptus-dominated forest near Sydney, Australia, using the eddy covariance method. The climate is characterised by a mean annual precipitation of 800 mm and a mean annual temperature of 18 ∘C, hot summers and mild winters, with highly variable precipitation. In the 4-year study, the ecosystem was a sink each year (−225 g C m−2 yr−1 on average, with a standard deviation of 108 g C m−2 yr−1); inter-annual variations were not related to meteorological conditions. Daily net C uptake was always detected during the cooler, drier winter months (June through August), while net C loss occurred during the warmer, wetter summer months (December through February). Gross primary productivity (GPP) seasonality was low, despite longer days with higher light intensity in summer, because vapour pressure deficit (D) and air temperature (Ta) restricted surface conductance during summer while winter temperatures were still high enough to support photosynthesis. Maximum GPP during ideal environmental conditions was significantly correlated with remotely sensed enhanced vegetation index (EVI; r2 = 0.46) and with canopy leaf area index (LAI; r2 = 0.29), which increased rapidly after mid-summer rainfall events. Ecosystem respiration (ER) was highest during summer in wet soils and lowest during winter months. ER had larger seasonal amplitude compared to GPP, and therefore drove the seasonal variation of NEE. Because summer carbon uptake may become increasingly limited by atmospheric demand and high temperature, and because ecosystem respiration could be enhanced by rising temperatures, our results suggest the potential for large-scale seasonal shifts in NEE in sclerophyll vegetation under climate change.

scholarly journals Dust Storms in Northern China: Long-Term Spatiotemporal Characteristics and Climate Controls

2017 ◽  
Vol 30 (17) ◽  
pp. 6683-6700 ◽  
Author(s):  
Qingyu Guan ◽  
Xiazhong Sun ◽  
Jing Yang ◽  
Baotian Pan ◽  
Shilei Zhao ◽  
...  
Keyword(s):  
Wind Speed ◽  
Dust Storm ◽  
Northern China ◽  
Dust Storms ◽  
Effect Of Temperature ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Spatiotemporal Characteristics ◽  
Dust Generation ◽  
The Mean

Airborne dust derived from desertification in northern China can be transported to East Asia and other regions, impairing human health and affecting the global climate. This study of northern China dust provides an understanding of the mechanism of dust generation and transportation. The authors used dust storm and climatological data from 129 sites and normalized difference vegetation index (NDVI) datasets in northern China to analyze spatiotemporal characteristics and determine the main factors controlling dust storms occurring during 1960–2007. Dust storm–prone areas are consistent with the spatial distribution of northern China deserts where the average wind speed (AWS) is more than 2 m s−1, the mean annual temperature (MAT) ranges from 5° to 10°C, and the mean annual precipitation (MAP) is less than 450 mm. Dust storms commonly occur on spring afternoons in a 3- to 6-h pattern. The three predominant factors that can affect DSF are the maximum wind speed, AWS, and MAT. During 1960–2007, dust storm frequency (DSF) in most regions of northern China fluctuated but had a decreasing trend; this was mainly caused by a gradual reduction in wind speed. The effect of temperature on DSF is complex, as positive and negative correlations exist simultaneously. Temperatures can affect source material (dust, sand, etc.), cyclone activity, and vegetation growth status, which influence the generation of dust storms. NDVI and precipitation are negatively correlated with DSF, but the effect is weak. Vegetation can protect the topsoil environment and prevent dust storm creation but is affected by the primary decisive influence of precipitation.

Efficacy of climate transfer functions: introduction of Eurasian populations of Larix into Alberta

1999 ◽  
Vol 29 (11) ◽  
pp. 1660-1668 ◽  
Author(s):  
Gerald E Rehfeldt ◽  
Nadja M Tchebakova ◽  
Leonard K Barnhardt
Keyword(s):  
Regression Models ◽  
Transfer Functions ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Quadratic Regression ◽  
Degree Days ◽  
Plant Populations ◽  
Growth And Survival ◽  
The Mean ◽  
Practical Implications

Growth and survival of eight populations of Larix sukaczewii Dylis and one of both Larix sibirica Ledeb. and Larix gmelinii (Rupr.) Rupr. were used to assess the effectiveness of climate transfer functions for predicting the 13-year performance of Eurasian provenances introduced to Alberta. Quadratic regression models showed that transfer distances for five climate variables (mean annual temperature, degree-days <0°C, mean temperature in the coldest month, ratio of the mean annual temperature to mean annual precipitation, and the summer-winter temperature range) were particularly effective in predicting height and survival. Optimal transfer distances did not differ significantly from zero, and as a result, the best growth and survival in Alberta should be obtained by matching the provenance climate to that of the planting site for the five variables. Verification of the climate transfer functions with independent data from Russian provenance tests were strongly supportive. The results demonstrate the effectiveness of climate transfer functions for describing the response of plant populations to the environment and thereby have practical implications in reforestation.

scholarly journals Climate change effects and UV-B radiation in the Vojvodina region, Serbia under the SRES-A2

2015 ◽  
Vol 19 (suppl. 2) ◽  
pp. 289-298 ◽  
Author(s):  
Slavica Malinovic-Milicevic ◽  
Dragutin Mihailovic ◽  
Nusret Dreskovic ◽  
Vladimir Djurdjevic ◽  
Gordan Mimic ◽  
...  
Keyword(s):  
21St Century ◽  
Climate Model ◽  
Precipitation Amount ◽  
Mean Annual Precipitation ◽  
Strong Increase ◽  
Extreme Temperatures ◽  
Climate Conditions ◽  
Climate Change Effects ◽  
The Mean ◽  
Maximum Temperatures

In this article we considered the extreme temperatures, precipitation and UV-B radiation in Vojvodina region, Serbia. We describe the actual climate conditions for the period 1981?2007 and applied a dynamic downscaling technique using the EBU-POM regional coupled climate model under the SRES-A2 scenario to assess the changes for the period 2021-2100. The results indicate that a warmer and drier climate in the Vojvodina region can be expected at the end of the century. Projection of climate indicates to a strong increase in the mean annual minimum temperatures, and much smaller increase in the mean annual maximum temperatures. The increase of both extreme temperatures is predicted to be the highest in the winter and the lowest in the summer. Mean annual precipitation is projected to increase toward the end of the first half of the 21st century and to decrease for the last 30 years of the 21st century. Precipitation amount will be the highest during the winter and spring. The model simulations show that, by the end of this century, annual mean UV-B dose will recover by 5.2%. Recovery will be faster in the first half of the 21st century and more slowly later on. The UV-B doses recovery is expected to be the highest during the autumn and spring.

scholarly journals INFLUENCES OF BIOLOGICAL PREPARATIONS ON SOIL PROPERTIES IN THE SPRING WHEAT CROP

2018 ◽  
Author(s):  
Rita ČEPULIENĖ ◽  
Darija JODAUGIENĖ
Keyword(s):  
Spring Wheat ◽  
Soil Surface ◽  
Chemical Compounds ◽  
Mean Annual Precipitation ◽  
Wheat Crop ◽  
Mean Annual Temperature ◽  
Biological Processes ◽  
Micro Structure ◽  
The Mean ◽  
Fertilizer Rates

The natural biochemical, biophysical and biological processes in the soil is changing due to the intensive use of pesticides. At present, it is actual fertilization technologies, which are based on non-fertilizer rates increase bat on their rational use because in the fertilizer is unnecessary chemical compounds that promote mineral nutritional elements leaching. Have been studied the effect of biological preparations BactoMix, AgroMik and Rizobakterin on soil physical properties. Experiments were carried out in 2015–2016 at the Experimental Station of Aleksandras Stulginskis University on Calcari-Endohypogleyic Luvisol. The mean annual temperature of the study site is 6.0–6.5 °C, mean annual precipitation is 600–650 mm and mean annual length of sun shine is 1750–1800 hour (Lithuanian Hydrometeorological Service). Biological preparations sprayed on the soil surface and incorporated in the soil by sowing spring wheat. The use of biological preparations had a tendency to reduce soil density (from 2.3 to 5.3 %), to increase soil porosity (from 0.6 to 2.1 %). Biological preparations had no significant influence on quantity couples filled with moisture and air. The hardness of the soil after spring wheat harvest was the smallest in the fields sprayed by Rizobakterin preparation. The use of biological preparations BaktoMix and Rizobakterin significantly increased soil moisture. The following preparations significantly decreased soil pulverized fractions (micro structure) and significantly increased amount of particles larger than 10 mm.

scholarly journals Calcareous nannofossil, ostracode and foraminifera biostratigraphy of Plio-Pleistocene deposits, Rhodes (Greece), with a correlation to the Vrica section (Italy)

2001 ◽  
Vol 20 (2) ◽  
pp. 143-154 ◽  
Author(s):  
Erik Thomsen ◽  
Tine L. Rasmussen ◽  
Annette Hastrup
Keyword(s):  
Deep Water ◽  
Brackish Water ◽  
Southern Italy ◽  
Early Pleistocene ◽  
Calcareous Nannofossil ◽  
Marine Deposits ◽  
First Occurrence ◽  
Degree Of Certainty ◽  
Relative Delay ◽  
Calcareous Nannofossil Biostratigraphy

Abstract. The Kalithea Bay section is situated on the southeastern coast of the island of Rhodes. The section comprises a sedimentary sequence ranging from brackish water gravel and nearshore sand to deep-water clay. The brackish water and nearshore deposits are assigned to the Kritika Formation, while the deep-water deposits are assigned to the Lindos Bay clay. Calcareous nannofossil biostratigraphy shows that the age of the marine sequence is Early Pleistocene. The brackish water sediments cannot be dated with any degree of certainty. The marine deposits are rich in ostracodes and foraminifera and several species have been recognized, which previously have been used as biostratigraphic markers in the Plio-Pleistocene deposits of Rhodes. Biostratigraphic correlation between the Kalithea Bay section and the Plio-Pleistocene boundary stratotype at Vrica, southern Italy, shows that the ostracodes and foraminifera events generally are diachronous relative to the calcareous nannofossil events. The only exception is the first occurrence of the benthic foraminifera Hyalinea balthica. As calcareous nannofossil events are thought to be virtually synchronous within the Mediterranean region, it is concluded that the diachroneity is due to a relative delay in the appearance of ostracodes and foraminifera at Kalithea, caused by differences in the palaeobathymetric settings between the two sites.

scholarly journals The quantitative reconstruction of the paleoclimate between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China

2011 ◽  
Vol 7 (4) ◽  
pp. 2741-2762 ◽  
Author(s):  
N. Sun ◽  
X. Q. Li
Keyword(s):  
Climatic Factors ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Quantitative Reconstruction ◽  
Subtropical Zone ◽  
Nw China ◽  
Limit Value ◽  
Climate Event ◽  
Tianshui Basin ◽  
The Mean

Abstract. The quantitative reconstruction of the paleoclimate is the ultimate goal of studying past global change. Here, the Coexistence Approach (CA) was applied to reconstruct climatic factors quantitatively based on the fossil charcoal records between 5200 and 4300 cal yr BP in the Tianshui Basin, NW China. The climate of the Tianshui Basin belonged to the northern subtropical zone from 5200–4300 cal yr BP. The climatic tolerance ranges were selected, and the lower limit value was regarded as the logical climate factor to reflect the values of climatic factors. The CA analysis showed that the mean annual temperature (MAT) was approximately 13.2°C, and the mean annual precipitation (MAP) was approximately 778 mm between 5200 and 4900 cal yr BP. The MAT was approximately 13.2°C, and the MAP was approximately 688 mm between 4800 and 4300 cal yr BP. The MAT increased approximately 2.2°C, and the MAP increased approximately 280 mm from 5200–4900 cal yr BP. The MAT also increased approximately 2.2°C from 4800–4300 cal yr BP, while the MAP increased around 196 mm. No climate event occurred from 5200–4300 cal yr BP; however, a drought tendency appeared after 4800 cal yr BP.

scholarly journals Factors controlling alterations in the performance of a runoff model in changing climate conditions

2018 ◽  
Vol 66 (4) ◽  
pp. 381-392 ◽  
Author(s):  
Patrik Sleziak ◽  
Ján Szolgay ◽  
Kamila Hlavčová ◽  
Doris Duethmann ◽  
Juraj Parajka ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Air Temperature ◽  
Mean Annual Precipitation ◽  
Moisture Regime ◽  
Validation Period ◽  
Average Volume ◽  
Climate Conditions ◽  
Soil Moisture Regime ◽  
The Mean ◽  
Runoff Model

Abstract In many Austrian catchments in recent decades an increase in the mean annual air temperature and precipitation has been observed, but only a small change in the mean annual runoff. The main objective of this paper is (1) to analyze alterations in the performance of a conceptual hydrological model when applied in changing climate conditions and (2) to assess the factors and model parameters that control these changes. A conceptual rainfall-runoff model (the TUW model) was calibrated and validated in 213 Austrian basins from 1981–2010. The changes in the runoff model’s efficiency have been compared with changes in the mean annual precipitation and air temperature and stratified for basins with dominant snowmelt and soil moisture processes. The results indicate that while the model’s efficiency in the calibration period has not changed over the decades, the values of the model’s parameters and hence the model’s performance (i.e., the volume error and the runoff model’s efficiency) in the validation period have changed. The changes in the model’s performance are greater in basins with a dominant soil moisture regime. For these basins, the average volume error which was not used in calibration has increased from 0% (in the calibration periods 1981–1990 or 2001–2010) to 9% (validation period 2001–2010) or –8% (validation period 1981–1990), respectively. In the snow-dominated basins, the model tends to slightly underestimate runoff volumes during its calibration (average volume error = –4%), but the changes in the validation periods are very small (i.e., the changes in the volume error are typically less than 1–2%). The model calibrated in a colder decade (e.g., 1981–1990) tends to overestimate the runoff in a warmer and wetter decade (e.g., 2001–2010), particularly in flatland basins. The opposite case (i.e., the use of parameters calibrated in a warmer decade for a colder, drier decade) indicates a tendency to underestimate runoff. A multidimensional analysis by regression trees showed that the change in the simulated runoff volume is clearly related to the change in precipitation, but the relationship is not linear in flatland basins. The main controlling factor of changes in simulated runoff volumes is the magnitude of the change in precipitation for both groups of basins. For basins with a dominant snowmelt runoff regime, the controlling factors are also the wetness of the basins and the mean annual precipitation. For basins with a soil moisture regime, landcover (forest) plays an important role.

scholarly journals Inferencias paleoclimáticas para el Mioceno tardío en la cuenca de Angastaco basadas en el análisis fisionómico foliar: Formación Palo Pintado, Salta, Argentina

2020 ◽  
Vol 47 (2) ◽  
pp. 418
Author(s):  
Juan M. Robledo ◽  
Maricel Y. Horn ◽  
Claudia I. Galli ◽  
Luisa M. Anzótegui
Keyword(s):  
Late Miocene ◽  
Environmental Conditions ◽  
Sedimentary Rocks ◽  
Annual Precipitation ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Humid Environment ◽  
The Mean ◽  
La Rioja ◽  
Basin Region

The continental sedimentary rocks that constitute the Palo Pintado Formation of the late Miocene from Salta province, presents a great paleoclimatic interest due to the environmental conditions prevailing during this geochronologic interval. The geological and paleobotanical data suggest that during the sedimentary rocks accumulation of the Palo Pintado Formation (Angastaco Basin), wetter conditions would have existed comparing with other nearby and contemporary Formations, for example the Playa del Zorro Aloformation (late Miocene of Catamarca) and the Chiquimil (late Miocene of Tucumán), Salicas and the Toro Negro Formations (both from the late Miocene of La Rioja). In this study, the margin and the foliar area of the leaves contained on rocks from the Palo Pintado Formation are analyzed, in order to obtain the mean annual temperature (MAT) and the mean annual precipitation (MAP). The resulting values were: 23.98 °C and 330.8 mm. These results are coincident by the interpretation of different authors, who consider that the Palo Pintado Formation would have been deposited under a relatively humid environment, possibly as a consequence of the rains that affected locally the Angastaco basin región.

Glacier Clusters identification across Chilean Andes using Topo-Climatic variables

2021 ◽  
Author(s):  
Alexis Caro ◽  
Fernando Gimeno ◽  
Antoine Rabatel ◽  
Thomas Condom ◽  
Jean Carlos Ruiz
Keyword(s):  
Climatic Variables ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Climate Conditions ◽  
Partitioning Around Medoids ◽  
The Andes ◽  
Southern Patagonia ◽  
Rock Glaciers ◽  
Elevation Difference ◽  
Chilean Andes

&lt;p&gt;This study presents a glacier clustering for the Chilean Andes (17.6-55.4&amp;#176;S) realized with the Partitioning Around Medoids (PAM) algorithm and using topographic and climatic variables over the 1980-2019 period. We classified ~24,000 glaciers inside thirteen different clusters (C1 to C13). These clusters show specific conditions in terms of annual and monthly amounts of precipitation, temperature, and solar radiation. In the Northern part of Chile, the Dry Andes (17-36&amp;#176;S) gather five clusters (C1-C5) that display mean annual precipitation and temperature differences up to 400 mm/yr and 8&amp;#176;C, respectively, and a mean elevation difference reaching 1800 m between glaciers in C1 and C5 clusters. In the Wet Andes (36-56&amp;#176;S) the highest differences were observed at the Southern Patagonia Icefield (50&amp;#176;S), with mean annual values for precipitation above 3700 mm/yr (C12, maritime conditions) and below 1000 mm/yr in the east of Southern Patagonia Icefield (C10), and with a difference in mean annual temperature near 4&amp;#176;C and mean elevation contrast of 500 m.&lt;/p&gt;&lt;p&gt;This classification confirms that Chilean glaciers cannot be grouped only latitudinally as it has been commonly considered, hence contributing to a better understanding of recent glacier volume changes at regional and watershed scales. An example of this was observed in the Maipo watershed (33&amp;#176;S), where the Echaurren Norte glacier is located, which is the reference glacier for Chile and WGMS because it has the oldest time series of mass balance monitoring in the Andes, followed by the Piloto Este glacier, since the 70's. Indeed, we identified that Echaurren Norte glacier only has similarities with 5% of the glacierized surface area of the Maipo watershed. Echaurren Norte glacier is within a glacier cluster that presents warmer and wetter climate conditions (3.1&amp;#176;C, 574 mm/yr) than the average of the watershed, a cluster that contains also 68% of the glacierized surface composed of rock glaciers.&lt;/p&gt;

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