Global atmospheric changes versus the Indian rainfall variation

2020 ◽  
Vol 13 (13) ◽  
Author(s):  
Gargi Akhoury ◽  
Kirti Avishek
Keyword(s):  
Rainfall Variation ◽  
Indian Rainfall ◽  
Atmospheric Changes

scholarly journals Variability of L Dwarfs in the Near Infrared

2003 ◽  
Vol 211 ◽  
pp. 455-456 ◽  
Author(s):  
José A. Caballero ◽  
Víctor J. S. Béjar ◽  
Rafael Rebolo
Keyword(s):  
Time Scales ◽  
Near Infrared ◽  
Brown Dwarfs ◽  
L Dwarfs ◽  
Atmospheric Changes ◽  
Changes Over Time ◽  
Over Time

We have obtained series of images in the near infrared J and Ks bands for seven L-type dwarfs with a duration of 3 to 6 hours. We present results on: 1) the amplitude of variability associated with atmospheric changes over time scales from minutes to several hours; 2) the search for cool companions in wide orbits; 3) the search for transits of brown dwarfs and planetary companions in very close orbits.

Does climate change affect the chronobiological trends in occurrence of acute coronary syndromes?

2021 ◽  
Vol 28 (Supplement_1) ◽  
Author(s):  
L Kuzma ◽  
A Kurasz ◽  
M Niwinska ◽  
EJ Dabrowski ◽  
M Swieczkowski ◽  
...  
Keyword(s):  
Climate Change ◽  
Acute Coronary Syndromes ◽  
Hospital Admissions ◽  
Global Climate ◽  
Weather Conditions ◽  
Temperature Changes ◽  
Funding Sources ◽  
Relative Risks ◽  
Coronary Syndromes ◽  
Atmospheric Changes

Abstract Funding Acknowledgements Type of funding sources: None. Background Acute coronary syndromes (ACS) are the leading cause of death all over the world, in the last years chronobiology of their occurrence has been changing. Purpose The aim of this study was to assess the influence of climate change on hospital admissions due to ACS. Methods Medical records of 10,529 patients hospitalized for ACS in 2008–2017 were examined. Weather conditions data were obtained from the Institute of Meteorology. Results Among the patients, 3537 (33.6%) were hospitalized for STEMI, 3947 (37.5%) for NSTEMI, and 3045 (28.9%) for UA. The highest seasonal mean for ACS was recorded in spring (N = 2782, mean = 2.52, SD = 1.7; OR 1.07; 95% CI 1.0-1.2; P = 0.049) and it was a season with the highest temperature changes day to day (Δ temp.=11.7). On the other hand, every 10ºC change in temperature was associated with an increased admission due to ACS by 13% (RR 1.13; 95% CI 1.04-1.3; P = 0.008). Analysis of weekly changes showed that the highest frequency of ACS occurred on Thursday (N = 1703, mean = 2.7, SD = 1.9; OR 1.16; 95% CI 1.0-1.23; P = 0.004), in STEMI subgroup it was Monday (N = 592, mean = 0.9, SD = 1.6, OR 1.2; 95% CI 1.1-1.4; P = 0.002). Sunday was associated with decreased admissions due to all types of ACS (N = 1098, mean = 1.7, SD = 1.4; OR 0.69; 95% CI 0.6-0.8, P < 0.001). In the second half of the study period (2013-2018) the relative risks of hospital admissions due to ACS were 1.043 (95%CI: 1.009-1.079, P = 0.014, lag 0) and 0.957 (95%CI: 0.925-0.990, P = 0.010, lag 1) for each 10ºC decrease in temperature; 1.049 (95% CI: 1.015-1.084, P = 0.004, lag 0) and 1.045 (95%CI: 1.011-1.080, P = 0.008, lag 1) for each 10 hPa decrease in atmospheric pressure and 1.180 (95% CI: 1.078-1.324, P = 0.007, lag 0) for every 10ºC change in temperature. For the first half of the study the risk was significantly lower. Conclusion We observed a shift in the seasonal peak of ACS occurrence from winter to spring which may be related to temperature fluctuation associated with climate change in this season. The lowest frequency of ACS took place on weekends. Atmospheric changes had a much more pronounced effect on admissions due to ACS in the second half of the analyzed period, which is in line with the dynamics of global climate change.

scholarly journals Effects of water and soil conservation works on runoff and sediment variation in the areas with high and coarse sediment yield of the middle Yellow River

2018 ◽  
Vol 38 ◽  
pp. 01033
Author(s):  
Wei Ying Sun ◽  
Pan Zhang ◽  
Li Li ◽  
Jiang Nan Chen
Keyword(s):  
Sediment Yield ◽  
Water Conservation ◽  
Human Activities ◽  
Soil Conservation ◽  
Yellow River ◽  
Soil And Water Conservation ◽  
Contribution Rate ◽  
Rainfall Variation ◽  
Runoff Reduction ◽  
Soil And Water

The areas with high and coarse sediment yield of the middle Yellow River is well known for its severe erosion, high sediment yields. Since 1982 when the 8 key soil and water conservation harnessing regions has been built, the ecological environment has been gradually improved and the amount of sediment and runoff entering the Yellow River has been reduced continuously. Some researchers considered that it was owing to the water and soil conservation works (WSCW), while others believed that it was caused by the rainfall variation, but this has not been quantified for the effect respectively. This paper deals with the effects of WSCW on runoff and sediment variation. The study has been carried out in the Sanchuanhe River watershed, where was listed as one of the 8 key soil and water conservation harnessing regions. The results show that the contribution rate of human activities was 80.2% after 1st harnessing stage (1970-1979), 43.0% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 98.4%, and was 44.8% after 4th harnessing stage (1997-2006). With regard to the influence on runoff reduction in the watershed, the contribution rate of human activities was 62.5% compared with the natural factors after 1st harnessing stage (1970-1979), 28.4% after 2nd harnessing stage (1980-1989), in 3rd harnessing stage (1990-1996) it reached 69.6%, and was 37.0% after 4th harnessing stage (1997-2006). The results revealed that human activities exerted the largest effects on the sediment reduction and explained 66.6% of the variation in the specific sediment yield. This study suggests that a combination of human activities and rainfall variation effectively reduces runoff and sediment delivery of the Loess Plateau. Generally The runoff reduction and contribution of rainfall variation to runoff reduction in this area were as large as human activities. After many years' harnessing the great benefit have been obtained in water and soil loss control in this watershed.

scholarly journals Indian Rainfall

Nature ◽  
1878 ◽  
Vol 18 (451) ◽  
pp. 193-193
Author(s):  
S. A. HILL
Keyword(s):  
Indian Rainfall

Detrended multifractal characterization of Indian rainfall records

2021 ◽  
Vol 151 ◽  
pp. 111297
Author(s):  
Alivia Sarker ◽  
Provash Mali
Keyword(s):  
Indian Rainfall

scholarly journals Natural and Managed Grasslands Productivity during Multiyear in Ex-Arable Lands (in the Context of Climate Change)

Agriculture ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 215
Author(s):  
Liudmila Tripolskaja ◽  
Asta Kazlauskaite-Jadzevice ◽  
Virgilijus Baliuckas ◽  
Almantas Razukas
Keyword(s):  
Climate Change ◽  
Soil Properties ◽  
Dry Matter ◽  
Arable Land ◽  
Rainfall Amount ◽  
Rainfall Variation ◽  
Global Issue ◽  
Term Change ◽  
The Impact

Ex-arable land-use change is a global issue with significant implications for climate change and impact for phytocenosis productivity and soil quality. In temperate humid grassland, we examined the impact of climate variability and changes of soil properties on 23 years of grass productivity after conversion of ex-arable soil to abandoned land (AL), unfertilized, and fertilized managed grassland (MGunfert and MGfert, respectively). This study aimed to investigate the changes between phytocenosis dry matter (DM) yield and rainfall amount in May–June and changes of organic carbon (Corg) stocks in soil. It was found that from 1995 to 2019, rainfall in May–June tended to decrease. The more resistant to rainfall variation were plants recovered in AL. The average DM yield of MGfert was 3.0 times higher compared to that in the AL. The DM yields of AL and MG were also influenced by the long-term change of soil properties. Our results showed that Corg sequestration in AL was faster (0.455 Mg ha−1 year−1) than that in MGfert (0.321 Mg ha−1 year−1). These studies will be important in Arenosol for selecting the method for transforming low-productivity arable land into MG.

Field evidence for coal combustion links the 252 My-old Siberian Traps with global carbon disruption

2021 ◽  
Author(s):  
Linda Elkins-Tanton ◽  
Steven Grasby ◽  
Benjamin Black ◽  
Roman Veselovskiy ◽  
Omid Ardakani ◽  
...  
Keyword(s):  
Organic Matter ◽  
Carbon Isotope ◽  
Flood Basalts ◽  
Siberian Traps ◽  
Field Evidence ◽  
Carbon Isotope Excursion ◽  
Show Evidence ◽  
Volcaniclastic Rocks ◽  
Atmospheric Changes ◽  
Global Carbon

<p>The Permo-Triassic Extinction was the most severe in Earth history. The Siberian Traps eruptions are strongly implicated in the global atmospheric changes that likely drove the extinction. A sharp negative carbon isotope excursion coincides within geochronological uncertainty with the oldest dated rocks from the Norilsk section of the Siberian flood basalts. The source of this light carbon has been debated for decades.</p><p>We focused on the voluminous volcaniclastic rocks of the Siberian Traps, relatively unstudied as potential carriers of carbon-bearing gases. Over six field seasons we collected rocks from across the Siberian platform and show the first direct evidence that the earliest eruptions particularly in the southern part of the province burned large volumes of a combination of vegetation and coal. Samples from the Maymecha-Kotuy region, from the Nizhnyaya Tunguska, Podkamennaya Tunguska, and Angara Rivers all show evidence of high-temperature organic matter carbonization and combustion.</p><p>Field evidence indicates a process in which ascending magmas entrain xenoliths of coal and carbonaceous sediments that are carbonized in the subsurface and also combusted either through reduction of magmas or when exposed to the atmosphere. We demonstrate that the volume and composition of organic matter interactions with magmas may explain the global carbon isotope signal, and have significantly driven the extinction.</p>

scholarly journals Relative timing of precipitation and ocean circulation changes in the western equatorial Atlantic over the last 45 kyr

2018 ◽  
Vol 14 (9) ◽  
pp. 1315-1330 ◽  
Author(s):  
Claire Waelbroeck ◽  
Sylvain Pichat ◽  
Evelyn Böhm ◽  
Bryan C. Lougheed ◽  
Davide Faranda ◽  
...  
Keyword(s):  
Mass Transport ◽  
Ocean Circulation ◽  
North Atlantic ◽  
Wavelet Transforms ◽  
Water Mass ◽  
Sediment Cores ◽  
Equatorial Atlantic ◽  
The North ◽  
Atmospheric Changes ◽  
Circulation Changes

Abstract. Thanks to its optimal location on the northern Brazilian margin, core MD09-3257 records both ocean circulation and atmospheric changes. The latter occur locally in the form of increased rainfall on the adjacent continent during the cold intervals recorded in Greenland ice and northern North Atlantic sediment cores (i.e., Greenland stadials). These rainfall events are recorded in MD09-3257 as peaks in ln(Ti ∕ Ca). New sedimentary Pa ∕ Th data indicate that mid-depth western equatorial water mass transport decreased during all of the Greenland stadials of the last 40 kyr. Using cross-wavelet transforms and spectrogram analysis, we assess the relative phase between the MD09-3257 sedimentary Pa ∕ Th and ln(Ti ∕ Ca) signals. We show that decreased water mass transport between a depth of ∼1300 and 2300 m in the western equatorial Atlantic preceded increased rainfall over the adjacent continent by 120 to 400 yr at Dansgaard–Oeschger (D–O) frequencies, and by 280 to 980 yr at Heinrich-like frequencies. We suggest that the large lead of ocean circulation changes with respect to changes in tropical South American precipitation at Heinrich-like frequencies is related to the effect of a positive feedback involving iceberg discharges in the North Atlantic. In contrast, the absence of widespread ice rafted detrital layers in North Atlantic cores during D–O stadials supports the hypothesis that a feedback such as this was not triggered in the case of D–O stadials, with circulation slowdowns and subsequent changes remaining more limited during D–O stadials than Heinrich stadials.

scholarly journals Feedback of trees on nitrogen mineralization to restrict the advance of trees in C4 savannahs

2015 ◽  
Vol 11 (8) ◽  
pp. 20150572 ◽  
Author(s):  
Steven I. Higgins ◽  
Moagi Keretetse ◽  
Edmund C. February
Keyword(s):  
Remote Sensing ◽  
Nitrogen Mineralization ◽  
Negative Feedback ◽  
Nitrogen Limitation ◽  
Seasonal Pattern ◽  
Seasonal Temperature ◽  
Rainfall Variation ◽  
Progressive Nitrogen Limitation

Remote sensing studies suggest that savannahs are transforming into more tree-dominated states; however, progressive nitrogen limitation could potentially retard this putatively CO 2 -driven invasion. We analysed controls on nitrogen mineralization rates in savannah by manipulating rainfall and the cover of grass and tree elements against the backdrop of the seasonal temperature and rainfall variation. We found that the seasonal pattern of nitrogen mineralization was strongly influenced by rainfall, and that manipulative increases in rainfall could boost mineralization rates. Additionally, mineralization rates were considerably higher on plots with grasses and lower on plots with trees. Our findings suggest that shifting a savannah from a grass to a tree-dominated state can substantially reduce nitrogen mineralization rates, thereby potentially creating a negative feedback on the CO 2 -induced invasion of savannahs by trees.

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