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

2012 ◽  
Vol 8 (2) ◽  
pp. 625-636 ◽  
Author(s):  
N. Sun ◽  
X. Q. Li
Keyword(s):  
Climatic Factors ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Cold Event ◽  
Quantitative Reconstruction ◽  
Subtropical Zone ◽  
Nw China ◽  
Coexistence Approach ◽  
Tianshui Basin ◽  
The Mean

Abstract. The quantitative reconstruction of the palaeoclimate is a prerequisite for understanding climate processes at time scales of centuries and millennia. 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 CA analysis showed that the climate of the Tianshui Basin belonged to the northern subtropical zone between 5200 and 4300 cal yr BP. 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 was approximately 2.2 °C higher than today, and the MAP was approximately 280 mm higher than today from 5200 to 4900 cal yr BP. The MAT was also approximately 2.2 °C higher than today from 4800 to 4300 cal yr BP, while the MAP was approximately 196 mm higher than today. No abrupt cold event occurred between 5200 and 4300 cal yr BP; however, a drought tendency appeared after around 4800 cal yr BP.

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 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 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.

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 1206. Effects of Climatic Variability on Lyme Disease Outbreaks in California

2021 ◽  
Vol 8 (Supplement_1) ◽  
pp. S693-S694
Author(s):  
Raghesh Varot Kangath ◽  
Rajasree Pai Ramachandra ◽  
Buddhika Madurapperuma ◽  
Luke Scaroni
Keyword(s):  
Climate Change ◽  
Lyme Disease ◽  
Temperature Anomaly ◽  
Climatic Factors ◽  
Climatic Variables ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Northern Coast ◽  
Santa Cruz ◽  
Cca Ordination

Abstract Background Climate change has increased the risk of tick borne infections. The life cycle and prevalence of deer ticks are strongly influenced by temperature. Warmer temperatures associated with climate change are projected to increase the range of suitable tick habitats driving the spread of Lyme disease (LD). Short winters could also increase tick activity increasing the risk of exposure. This study examines the relationship between LD incidence and temperature-precipitation and their anomalies in CA counties. Methods Trends and relationships of Lyme Disease (LD) cases and climatic factors were analyzed among the California counties from 2000 to 2019. Lyme disease tabulate data and climatic data were obtained from Centers for Disease Control, and NOAA, and Climate Data Guide respectively. Canonical correspondence analysis (CCA) was performed using variables: (i) LD cases, (ii) precipitation & anomaly, and temperature & anomaly. The CCA ordination explained the variability between LD cases and climatic variables. Biplots were used to visualize the associations between LD cases and climatic anomalies. Results We compared the countywide LD cases in relation to climatic factors in California from 2000 to 2019. A total of 96 cases in 2000, 117 cases in 2009, and 144 cases in 2019 were reported in the 55 counties of California. Santa Clara reported the highest LD cases in 2003 (23 cases; 16%), followed by Los Angeles in 2013 (20 cases; 18%) and Santa Cruz in 2017 (19 cases; 13%). CCA ordination showed distinguishable clustering patterns between southern California counties (Santa Clara, Santa Cruz, Alameda, and San Diego) and northern coast and Klamath mountains range (Humboldt, Trinity, Shasta, and Siskiyou) regions (Fig. 1). Moderate mean annual temperature (56.5 °F - 62.5 °F) and temperature anomaly (3.8 °F - 5.5 °F) were the most important variable predictor for high LD outbreak. The CCA ordination shows the relationships between Lyme Disease and climatic variables for the 55 Counties of California. The bottom right circle represents Lyme cases positively correlated with temperature anomaly (3.8 °F - 5.5 °F) and moderate annual mean temperature (56.5 °F - 62.5 °F). The upper left circle represents Lyme cases negatively correlated with mean annual precipitation. Conclusion Moderate temperature with low moist spell anomalies in the south neighboring CA counties showed a positive influence on LD outbreak. The climatic conditions in those areas suitable for Oak trees and masting acorn resulting in the establishment of tick and host (deer) populations. We recommend robust surveillance and lab testing for patients with a history of tick bites in these regions. Disclosures All Authors: No reported disclosures

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.

The tadpole of Ptychadena schillukorum (Werner, 1908 “1907”) (Amphibia: Anura: Ptychadenidae)

Zootaxa ◽  
2009 ◽  
Vol 2115 (1) ◽  
pp. 65-68 ◽  
Author(s):  
S. GILLES ARMEL NAGO ◽  
BRICE A. SINSIN ◽  
MARK-OLIVER RÖDEL
Keyword(s):  
Democratic Republic Of Congo ◽  
Biosphere Reserve ◽  
West African ◽  
Sub Saharan Africa ◽  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
African Species ◽  
Short Rainy Season ◽  
The Mean ◽  
June July

The Ptychadenidae Dubois, 1987 are a frog family endemic to Sub-Saharan Africa and Madagascar (Frost 2008). Within the genus Ptychadena Boulenger, 1917 49 species are currently recognized as valid (Frost 2008), most of them breeding in temporary savanna ponds (Rödel 2000; Channing 2001; Channing & Howell 2006). In the Pendjari Biosphere Reserve (PBR) in northern Benin this genus is extraordinary diverse. Here we recorded seven sympatric and partly syntopic Ptychadena species (Nago et al. 2006). The tadpoles of six West African species, P. bibroni (Hallowell, 1845), P. pumilio (Boulenger, 1920), P. oxyrhynchus (Smith, 1849), P. tellinii (Peracca, 1904), P. tournieri (Guibé & Lamotte, 1955) and P. trinodis (Boettger, 1881) have already been described (Lamotte & Zuber-Vogeli 1953; Guibé & Lamotte 1958; Lamotte et al. 1958, 1959; Lamotte & Perret 1961; Perret 1966; Rödel 2000; Rödel & Spieler 2000). Hence, P. schillukorum (Werner, 1908 “1907”) is the only West African savanna Ptychadena with an unknown tadpole. P. schillukorum ranges from Senegal, east to south-western Ethiopia and southern Somalia, south to Malawi, central Mozambique, south-eastern Democratic Republic of Congo and western Angola (Channing 2001; Nago et al. 2006). Recently it was reported from Egypt (Baha el Din 2006). It is hence either a very widespread savanna species or a member of a complex of cryptic species (see Nago et al. 2006 and Frost 2008 for synonyms of P. schillukorum). In West Africa it only occurs in drier savannas. In PBR these frogs breed in shallow savanna ponds, often in syntopy with Phrynobatrachus francisci Boulenger, 1912 and Phrynobatrachus natalensis (Smith, 1849) (Nago et al. 2006). The PBR is located in the Soudanian savanna zone in northern Benin (N 10°30-11°30, E 0°50-2°00). The climate is characterized by a short rainy season from late May or even June/July to early October. The mean annual precipitation is 1000 mm and the mean annual temperature is 27°C. For more details see Nago et al. (2006).

Correlation of Alaskan varve Thickness with Climatic Parameters, and use in Paleoclimatic Reconstruction

1983 ◽  
Vol 20 (3) ◽  
pp. 308-321 ◽  
Author(s):  
James A. Perkins ◽  
John D. Sims
Keyword(s):  
Mean Annual Precipitation ◽  
Mean Annual Temperature ◽  
Climatic Parameters ◽  
Climatological Data ◽  
Dominant Source ◽  
Varve Thickness ◽  
Paleoclimatic Reconstruction ◽  
Regional Correlation ◽  
The Mean ◽  
Northern Alaska

The thickness of varves in the sediments of Skilak Lake, Alaska, are correlated with the mean annual temperature (r = 0.574), inversely correlated with the mean annual cumulative snowfall (r = −0.794), and not correlated with the mean annual precipitation (r = 0.202) of the southern Alaska climatological division for the years 1907–1934 A.D. Varve thickness in Skilak Lake is sensitive to annual temperature and snowfall because Skilak Glacier, the dominant source of sediment for Skilak Lake, is sensitive to these climatic parameters. Trends of varve thickness are well correlated with trends of mean annual cumulative snowfall ( = −0.902) of the southern Alaska climatological division and with trends of mean annual temperature of the southern ( = 0.831) and northern ( = 0.786) Alaska climatological divisions. Trends of varve thickness also correlate with trends of annual temperature in Seattle and North Head, Washington ( = 0.632 and 0.850, respectively). Comparisons of trends of varve thickness with trends of annual temperature in California, Oregon, and Washington suggest no widespread regional correlation. Trends of annual snowfall in the southern Alaska climatological division and trends of annual temperature in the southern and northern Alaska climatological divisions are reconstructed for the years 1700–1906 A.D. Climatic reconstructions on the basis of varve thickness in Skilak Lake utilize equations derived from the regression of series of smoothed climatological data on series of smoothed varve thickness. Reconstruction of trends of mean annual cunulative snowfall in the southern Alaska climatological division suggests that snowfall during the 1700s and 1800s was much greater than that during the early and mid-1900s. The periods 1770–1790 and 1890–1906 show marked decreases in the mean annual snowfall. Reconstructed trends of the annual temperature of the northern and southern Alaska climatological divisions suggest that annual temperatures during the 1700s and 1800s were lower than those of the early and mid-1900s. Two periods of relatively high annual temperatures coincide with the periods of low annual snowfall thus determined.

scholarly journals Determining the paleoclimate and elevation of the late Eocene Florissant flora: support from the coexistence approach

2016 ◽  
Vol 53 (6) ◽  
pp. 565-573 ◽  
Author(s):  
Stephanie J. Zaborac-Reed ◽  
Estella B. Leopold
Keyword(s):  
Late Eocene ◽  
Mean Annual Temperature ◽  
Coexistence Approach ◽  
The Mean ◽  
Close Relatives ◽  
Warm Temperate

Published estimates on the paleoclimate of the Florissant fossil beds site of Colorado (34.1 Ma) have led to extremely different estimates of paleoelevation. The purpose of this paper is to review the paleoclimate methods used and to add the coexistence approach (CA) method to estimate paleotemperature for the Florissant site. The basis of the CA method is the dependence on overlapping climatic requirements for different taxa in the flora and their nearest living relatives. These relationships tie the fossil identities to the actual plant habitats and climatic requirements of close relatives. Based on the CA method, we conclude that the mean annual temperature ranged between 14.3 and 18.2 °C. These results support the conclusions offered by several other studies that the Florissant was a warm temperate to subtropical flora, and they are consistent with recent conclusions by structural geologists as well as other studies, indicating that the Florissant site was deposited at a relatively low elevation, probably between 1 and 1.5 km.

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