Characteristics of Aerosol Spectral Optical Depths over Manora Peak, Nainital −- A High Altitude Station in the Central Himalayas

We present, for the first time, spectral behaviour of aerosol optical depths (AODs) over Manora Peak, Nainital located at an altitude of $\sim$ 2 km in the Shivalik ranges of central Himalayas. The observations were carried out using a Multi-Wavelength solar Radiometer during January to December 2002. The main results of the study are extremely low AODs during winter, a remarkable increase to high values in summer and a distinct change in the spectral dependencies of AODs from a relatively steeper spectra during winter to a shallower one in summer. During transparent days, the AOD values lie usually below 0.08 while during dusty (turbid) days, it lies between 0.08 to 0.69 at 0.5 $\mu$m. The average AOD value at 0.5 $\mu$m during winters, particularly in January and February, is $\sim 0.03\pm0.01$. The mean aerosol extinction law at Manora Peak during 2002 is best represented by $0.10 \lambda^{-0.61}$. However during transparent days, which almost covers 40% of the time, it is represented by $0.02 \lambda^{-0.97}$. This value of wavelength exponent, representing reduced coarse concentration and presence of fine aerosols, indicates that the station measures aerosol in the free troposphere at least during part of the year.Comment: 10 pages, 5 figures, significantly shortened, main conclusions unchanged, accepted for publication in Jr. of Geophys. Reasearch - Atmosphere

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Seeing and microthermal measurements near Devasthal top

Results of the seeing measurements carried out near Devasthal top on 43 nights during March to April 1999 are presented. Open air seeing measurements were carried out with a differential image motion monitor (DIMM) using a 38 cm telescope with the mirror about 2 m above the ground. This, in combination with our earlier reported measurements carried out during October to November 1998 on 37 nights show a median seeing of 1."1 and 35% of the time seeing is better than 1."0. A trend in the seeing evolution is noticed with better seeing towards the later part of the night. By analysing the temporal evolution of seeing for seeing fluctuations it is found that the mean ratio of two seeing values separated by a time interval of ?t grows with a time constant of about 17 minutes. To quantify the optical image degradation caused by atmospheric turbulence very near to the ground, microthermal measurements were also simultaneously performed with DIMM observations. Microthermal measurements show that most of the contribution to seeing comes from the 6 - 12 m slab of the atmosphere with a mean value of 0."86. A significant decrease in turbulence over the height of the mast is noticed with a mean value of 0."22 for the 12 - 18 m slab. A seeing of ~ 0."6 can be achieved by locating the telescope at a height of ~ 13 m above the ground

Evaluation of Devasthal site for optical astronomical observations

Based on an extensive site survey conducted during 1980-1990 in the Shivalik Hills of the Central Himalayan range, a promising site Devasthal has been identified. The longitude and latitude of Devasthal Peak are 79° 41′ E and 29° 23′ N. It is situated at an altitude of 2540 m and about 50 km by road from Nainital towards East. The surroundings of Devasthal are thinly populated and it is logistically well suited for establishing modern optical observational facilities. The prevailing wind direction at Devasthal is NW. For a large fraction of the night time, variation in the ambient temperature was less than a degree and wind speed was less than 10 m/s. During spectroscopic nights (> 200 in a year) relative humidity is less than 80% for about 70% of the time. During 1997 and 1998 seeing measurements using differential image motion techniques have been carried out close to ground at two locations namely Site 1 and Site 2 in Devasthal. Our observations for Site 1 carried over 88 nights yield a median seeing value of 1.\!\!^{\prime\prime} 4. For Devasthal Site 2 observations carried over 37 nights yield a median seeing value of 1.\!\!^{\prime\prime} 1. Devasthal Site 2 has therefore been selected for locating a modern 3 m optical telescope

Site characterization for the UPSO-TIFR telescope

Uttar Pradesh State Observatory, Naini Tal and Tata Institute of Fundamental Research, Mumbai plan to install jointly a 3 metre size optical telescope at Devasthal located east of Naini Tal about 50 km by road. The site has been selected after a decade of survey in Kumaon and Garhwal hills. The altitude of the peak is 2450 ± 5 meters, while longitude and latitude are 79° 40' 57'' E and 29° 22' 46'' N respectively. The location of the site is such that logistics of access and transportation are not too difficult and at the same time, it is far from urban development, has more than 200 astronomically useful nights, dark sky, low atmospheric extinction and most importantly seeing better than 1 arcsec for about 40% of the time. Extensive efforts are going on to characterize the site more precisely