37 research outputs found
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 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 m. The average AOD value at 0.5 m during winters, particularly in
January and February, is . The mean aerosol extinction law at
Manora Peak during 2002 is best represented by . However
during transparent days, which almost covers 40% of the time, it is represented
by . 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
Serial Studies about Biological Changes of Human Periodontal Ligament Cells
The basic idea of nondestructive testing is that a sample is characterised by its response to a certain kind of excitation. The excitation may be an electric or elastic field with a time pattern described by a step, a pulse, or a sine wave type. The field can be applied locally to characterise the area around a certain sample spot. A raster scan image is then performed by measuring many spots one after the other