scholarly journals Study of ambient gamma dose levels at national atmospheric research laboratory, Gadanki, India

2021 ◽  
Vol 44 (1) ◽  
pp. 28
Author(s):  
Nagaraja Kamsali ◽  
KCharan Kumar ◽  
TRajendra Prasad
Keyword(s):  
Research Laboratory ◽  
Gamma Dose ◽  
Atmospheric Research ◽  
Dose Levels

scholarly journals Synchronous polar winter starphotometry and lidar measurements at a High Arctic station

2015 ◽  
Vol 8 (9) ◽  
pp. 3789-3809 ◽  
Author(s):  
K. Baibakov ◽  
N. T. O'Neill ◽  
L. Ivanescu ◽  
T. J. Duck ◽  
C. Perro ◽  
...  
Keyword(s):  
Optical Properties ◽  
Aerosol Optical Depth ◽  
Research Laboratory ◽  
Recent Progress ◽  
High Arctic ◽  
Raman Lidar ◽  
Backscatter Coefficient ◽  
Atmospheric Research ◽  
Lidar Measurements ◽  
Fine Mode

Abstract. We present recent progress on nighttime retrievals of aerosol and cloud optical properties over the PEARL (Polar Environmental Atmospheric Research Laboratory) station at Eureka (Nunavut, Canada) in the High Arctic (80° N, 86° W). In the spring of 2011 and 2012, a star photometer was employed to acquire aerosol optical depth (AOD) data, while vertical aerosol and cloud backscatter profiles were measured using the CANDAC Raman Lidar (CRL). We used a simple backscatter coefficient threshold (βthr) to distinguish aerosols from clouds and, assuming that aerosols were largely fine mode (FM)/sub-micron, to distinguish FM aerosols from coarse mode (CM)/super-micron cloud or crystal particles. Using prescribed lidar ratios, we computed FM and CM AODs that were compared with analogous AODs estimated from spectral star photometry. We found (βthr dependent) coherences between the lidar and star photometer for both FM events and CM cloud and crystal events with averaged, FM absolute differences being

scholarly journals Simultaneous atmospheric measurements using two Fourier transform infrared spectrometers at the Polar Environment Atmospheric Research Laboratory during spring 2006, and comparisons with the Atmospheric Chemistry Experiment-Fourier Transform Spectrometer

2008 ◽  
Vol 8 (2) ◽  
pp. 5305-5358 ◽  
Author(s):  
D. Fu ◽  
K. A. Walker ◽  
R. L. Mittermeier ◽  
K. Strong ◽  
K. Sung ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Atmospheric Chemistry ◽  
Research Laboratory ◽  
Chemical Constituents ◽  
Estimation Method ◽  
Optimal Estimation ◽  
Atmospheric Measurements ◽  
Atmospheric Research ◽  
Polar Environment ◽  
Chemistry Experiment

Abstract. The 2006 Canadian Arctic ACE (Atmospheric Chemistry Experiment) Validation Campaign collected measurements at the Polar Environment Atmospheric Research Laboratory (PEARL, 80.05° N, 86.42° W, 610 m above sea level) at Eureka, Canada from 17 February to 31 March 2006. Two of the ten instruments involved in the campaign, both Fourier transform spectrometers (FTSs), were operated simultaneously, recording atmospheric solar absorption spectra. The first instrument was an ABB Bomem DA8 high-resolution infrared FTS. The second instrument was the Portable Atmospheric Research Interferometric Spectrometer for the Infrared (PARIS-IR), the ground-based version of the satellite-borne FTS on the ACE satellite (ACE-FTS). From the measurements collected by these two ground-based instruments, total column densities of seven stratospheric trace gases (O3, HNO3, NO2, HCl, HF, NO, and ClONO2 were retrieved using the optimal estimation method and these results were compared. Since the two instruments sampled the same portions of atmosphere by synchronizing observations during the campaign, the biases in retrieved columns from the two spectrometers represent the instrumental differences. These differences were consistent with those seen in previous FTS intercomparison studies. Partial column results from the ground-based spectrometers were also compared with partial columns derived from ACE-FTS version 2.2 (including updates for O3, HDO and N2O5 profiles and the differences found were consistent with the other validation comparison studies for the ACE-FTS version 2.2 data products. Column densities of O3, HCl, ClONO2, and HNO3 from the three FTSs were normalized with respect to HF and used to probe the time evolution of the chemical constituents in the atmosphere over Eureka during spring 2006.

Study of Atmospheric Instabilities through Radioactivity

2017 ◽  
Vol 14 (1) ◽  
pp. 15-23
Author(s):  
Charan Kumar K
Keyword(s):  
Research Laboratory ◽  
Activity Concentration ◽  
Inversion Layer ◽  
Lower Troposphere ◽  
Atmospheric Research ◽  
The Stability ◽  
Conditions Of Stability ◽  
Atmospheric Radon ◽  
Radon Concentrations

Radon and its progeny concentration are measured at 1m height from surface of Earth in the premises of National Atmospheric Research Laboratory, Gadanki to observe the changes in activity concentration of radon particularly during instabilities that are occurring in the atmosphere. The measurements were carried out using AlphaGUARD and Alpha Progeny Meter for the measurement of radon and its progenies, respectively. It has been observed that, the changes in daily and weekly atmospheric radon levels are related to the stability or turbulence of the lower troposphere. The analysis reveals that from sunny windless days indicates growth and dissolution of the inversion layer. The study of radon concentrations during several atmospheric instabilities including period during Nilam cyclone, has shown interesting features, which are correlated with the conditions of stability or turbulence in the atmosphere.

scholarly journals A New Bruker IFS 125HR FTIR Spectrometer for the Polar Environment Atmospheric Research Laboratory at Eureka, Nunavut, Canada: Measurements and Comparison with the Existing Bomem DA8 Spectrometer

2009 ◽  
Vol 26 (7) ◽  
pp. 1328-1340 ◽  
Author(s):  
Rebecca L. Batchelor ◽  
Kimberly Strong ◽  
Rodica Lindenmaier ◽  
Richard L. Mittermeier ◽  
Hans Fast ◽  
...  
Keyword(s):  
Fourier Transform ◽  
Research Laboratory ◽  
Polar Vortex ◽  
Atmospheric Composition ◽  
The Arctic ◽  
Fourier Transform Spectrometer ◽  
Atmospheric Research ◽  
Polar Environment ◽  
New Instrument ◽  
Total Column

Abstract A new Bruker IFS 125HR Fourier transform spectrometer has been installed at the Polar Environment Atmospheric Research Laboratory at Eureka, Nunavut, Canada (80.05°N, 86.42°W). This instrument will become the Network for the Detection of Atmospheric Composition Change’s (NDACC’s) primary instrument at Eureka, replacing the existing Bomem DA8 Fourier transform spectrometer, and will operate throughout the sunlit parts of the year. This paper introduces the new instrument and describes the retrieval procedure, including a comprehensive error analysis. Total columns of O3, HCl, HF, HNO3, N2O, CH4, and CO are presented for the first full year of measurements (2007). Perturbations in the total column resulting from the presence of the Arctic polar vortex over Eureka and the chemical processes within it are visible, as are annual cycles driven by photochemistry and dynamics. Enhancements in the CO total column resulting from specific biomass burning smoke events can also be seen. An intercomparison between the existing Bomem DA8 and the new Bruker IFS 125HR was carried out in July 2007 and is presented here. The total columns derived from the two instruments are shown to be in excellent agreement, with mean differences for all gases of less than 2.3%.

Assessment of natural radioactivity concentrations and gamma dose levels around Shorapur, Karnataka

2015 ◽  
Author(s):  
S. Rajesh ◽  
P. Avinash ◽  
B. R. Kerur ◽  
S. Anilkumar
Keyword(s):  
Natural Radioactivity ◽  
Gamma Dose ◽  
Dose Levels

The Polar Environment Atmospheric Research Laboratory UV–visible Ground-Based Spectrometer: First measurements of , , BrO, and OClO columns

2009 ◽  
Vol 110 (12) ◽  
pp. 986-1004 ◽  
Author(s):  
Annemarie Fraser ◽  
Cristen Adams ◽  
James R. Drummond ◽  
Florence Goutail ◽  
Gloria Manney ◽  
...  
Keyword(s):  
Research Laboratory ◽  
Atmospheric Research ◽  
Polar Environment ◽  
Uv Visible

scholarly journals The Polar Environment Atmospheric Research Laboratory (PEARL): Sounding the Atmosphere at 80º North

ARCTIC ◽  
2013 ◽  
Vol 66 (3) ◽  
Author(s):  
Pierre F. Fogal ◽  
Lisa M. LeBlanc ◽  
James R. Drummond
Keyword(s):  
Research Laboratory ◽  
Atmospheric Research ◽  
Polar Environment

scholarly journals Multiangle lidar observations of the Atmosphere

2018 ◽  
Vol 176 ◽  
pp. 05057
Author(s):  
Pawar Lalitkumar Prakash ◽  
Yogesh Kumar Choukiker ◽  
K Raghunath
Keyword(s):  
Data Analysis ◽  
Research Laboratory ◽  
Inversion Method ◽  
Backscatter Coefficient ◽  
Lidar System ◽  
Atmospheric Research ◽  
Aerosol Parameters ◽  
2D And 3D ◽  
Lidar Observations

Atmospheric Lidars are used extensively to get aerosol parameters like backscatter coefficient, backscatter ratio etc. National Atmospheric Research Laboratory, Gadanki (13°N, 79°E), India has a powerful lidar which has alt-azimuth capability. Inversion method is applied to data from observations of lidar system at different azimuth and elevation angles. Data Analysis is described and Observations in 2D and 3D format are discussed. Presence of Cloud and the variation of backscatter parameters are seen in an interesting manner.

Physical Properties of Two O-Ring Compounds after Exposure to Reactor Radiation

1966 ◽  
Vol 39 (4) ◽  
pp. 1258-1267
Author(s):  
J. H. Lewis
Keyword(s):  
Tensile Properties ◽  
Room Temperature ◽  
Nuclear Reactor ◽  
Dose Range ◽  
Gamma Dose ◽  
Reactor Radiation ◽  
Network Chain ◽  
Compression Set ◽  
Ring Compounds ◽  
Dose Levels

Abstract Two commercial O-ring compounds, NBR and SBR, specially formulated for radiation resistance were irradiated by means of a nuclear reactor to six gamma-dose levels in the range from 4.9×108 to 15×1011ergs/gm(C). O-rings and compression-set buttons of both materials were irradiated in air at near room temperature; O-rings of NBR were also irradiated in oil. Tensile properties, hardness, and compression set were measured as a function of radiation dose. Fifteen O-rings and five compression buttons were used for each experimental condition to provide statistically valid results. Analytical procedures were used to compute molecular weight between crosslinks and network-chain ratio as a function of dose. The wide dose range provided an accurate assessment of degradation produced by radiation. The highest dose resulted in complete loss of useful mechanical properties. Properties most adversely affected at lower doses were ultimate elongation, hardness, and compression set. While compression set was 50% at a dose of 3×109ergs/gm(C), tensile properties of both materials remained relatively good at a gamma dose of 1.2×1010 ergs/gm(C).

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