Half-a-century(1971–2020)of glacier shrinkage and climatic variability in the Bhaga basin,western Himalaya

Glacier shrinkage is a globally occurring phenomena.High-resolution change detection based on frequent mapping and monitoring of high-altitude glaciers is necessary to precisely evaluate future water availability and to understand glacier evolution under different climatic scenarios in the Hindukush-Karakoram-Himalayan(HKH)region.This also holds true for the Bhaga basin of the western Himalaya.This study investigates glacier and glacier lake changes in the Bhaga basin,over the last five decades based on satellite imagery including Corona KH4(1971),Landsat 7 Enhanced Thematic Mapper Plus(ETM+;2000),Linear Imaging Self-Scanning Sensor(LISS Ⅳ;2013),and Sentinel 2(2020).Regional temperature and precipitation trends were evaluated from gridded climatic datasets(1900–2020).In the Bhaga basin 306 glaciers(>0.2 km^(2))were mapped with a total area of 360.3±4.0 km^(2),of which 55.7±0.6 km^(2)was covered with debris in 2013.The total glacier covered area decreased by∼8.2±1.5%(0.16±0.03%yr-1)during the entire observation period 1971–2020,with noticeable heterogeneity between tributary watersheds.In the past two decades(2000–2020),the deglaciation rate has increased significantly(0.25%yr-1)compared to the previous decades(1971–2000;0.12%yr-1).Glacier lake area increased by 0.6±0.1 km^(2)(0.012 km^(2)yr-1)between 1971 and 2020.The NCEP/NCAR climatic data reveals an increase of 0.63℃in temperature and a decrease of 6.39 mm in precipitation for the period 1948–2018.In comparison,APHRODITE data shows an increasing trend in temperature of 1.14℃between 1961 and 2015 and decreasing trend in precipitation of 31 mm between 1951 and 2007.Both NCEP/NCAR and APHRODITE data reveal significant temperature increase and precipitation decrease since the 1990s,which have probably augmented ice loss in the Bhaga basin during the early 21st century.

Paleo-glacial reconstruction of the Thajwas glacier in the Kashmir Himalaya using 10Be cosmogenic radionuclide dating

Quantitative glacial chronologies of past glaciations are sparse in the Himalaya, and mostly absent in the Kashmir Himalaya. We used cosmogenicBe exposure dating, and geomorphological mapping to reconstruct glacial advances of the Thajwas Glacier(TG) in the Great Himalayan Range of the Kashmir Himalaya. FromBe exposure dating of ten moraine boulders, four glacial stages with ages ~20.77 ±2.28 ka, ~11.46 ± 1.69 ka, ~9.12 ± 1.39 ka and ~4.19 ± 0.78 ka, were identified. The reconstructed cosmogenic radionuclide ages confirmed the global Last Glacial Maximum(g LGM), Younger Dryas, Early Holocene, and Neoglaciation episodes. As per area and volume change analyses, the TG has lost 51.1 km~2 of its area and a volume of 2.64 km~3 during the last 20.77 ± 2.28 ka. Overall, the results suggested that the TG has lost 64% of area and 73% of volume from the Last glacial maximum to Neoglaciation and about 85.74% and 87.67% of area and volume, respectively, from Neoglaciation to the present day. The equilibrium line altitude of the TG fluctuated from 4238 m a.s.l present to3365 m a.s.l during the g LGM(20.77 ± 2.28 ka). The significant cooling induced by a drop in mean ambient temperature resulted in a positive mass balance of the TG during the g LGM. Subsequently the melting accelerated due to the continuing rise of the global ambient temperature. Paleo-glacial history reconstruction of the Kashmir Himalaya, with its specific geomorphic and climatic setting, would help close the information gap about the chronology of past regional glacial episodes.

Investigating the fission dynamics of the following neutron shell closed nuclei within a stochastic dynamical approach:^(210)Po,^(212)Rn,and ^(213)Fr

The dissipative dynamics of nuclear fission is a well confirmed phenomenon that can be either described by a Kramers-modified statistical model or by a dynamical model employing the Langevin equation.Although dynamical models as well as statistical models incorporating fission delays have been found to explain the measured fission observables in several studies,they present conflicting results for shell closed nuclei in the mass region of 200.Notably,an analysis of the recent data on neutron shell closed nuclei in the excitation energy range of 40-80 MeV failed to provide a satisfactory description of the data,which was attributed to a mismatch with shell effects and/or entrance channel effects,without reaching a definite conclusion.In the present study,we demonstrate that a well established stochastic dynamical code can simultaneously reproduce the available data for pre-scission neutron multiplicities and fission and evaporation residue excitation functions for the following neutron shell closed nuclei^(210)Po and^(212)Rn and their isotopes^(206)Po and^(214,216)Rn without the need for including any extra shell or entrance channel effects.The relevant calculations are performed by using a phenomenological universal friction form factor with no ad-hoc adjustment of the model parameters.However,we note a significant deviation,beyond experimental errors,for some Frisotopes.

Stabilization of the Anatase Phase of Ti_(1-x)Sn_(x)O_(2) (x < 0.5) Nanofibers

We experimentally investigate the stabilization of the anatase phase of Ti_(1-x)Sn_(x)O_(2)(x<0.5)nanofibers when synthesized by an electrospinning method.The as-spun nanofibers became nano-grained,polycrystalline nanofibers after calcination and the diameters of the nanofibers depend on Sn content.Stabilization of the anatase phase in Ti-rich compositions and incorporation of Sn ions were confirmed by X-ray diffraction,Raman,X-ray absorption near-edge structure,and photoluminescence(PL)spectroscopies.Results from the PL study also demonstrated the tunable nature of the optical properties,with the emission maximum shifting towards higher wavelength with increasing Sn concentration.