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Geophysical Fluid Dynamics
Published in Osamu Morita, Classical Mechanics in Geophysical Fluid Dynamics, 2019
Problem 1. The global average of the mean sea level pressure of the atmosphere is 1013.25 hPa. Calculate the global average of the height6 of the atmosphere, supposing the density of the atmosphere is constant (ρ = 1.00 kg m−3). Let the magnitude of the acceleration due to gravity be 9.80 ms−2.
Atmospheric Circulation: General
Published in Yeqiao Wang, Atmosphere and Climate, 2020
Pressure measures the atmospheric mass and, on average, is the force exerted by the mass of the atmosphere per unit area. The global average pressure at the Earth's surface is 986 hPa. Pressure at sea level is typically around 1000 hPa, while the pressure at higher altitudes is lower. Pressure decreases with
New line positions analysis of the 2ν 1 and ν 1 + ν 3 bands of NO2 at 3637.848 and 2906.070 cm−1
Published in Molecular Physics, 2020
Agnès Perrin, L. Manceron, F. Kwabia Tchana
The NO2 gas bottle used (Sigma-Aldrich, France 99.5%) was found to contain NO, N2O and other impurities at a much higher level than the stated purity. It was first purified following the standard procedure [3] by pumping on the frozen solid at about 200 K until the bluish colour due to the formation of N2O3 disappeared. This eliminated about 80% of the main impurities. We thus added a further step by letting 5 mmoles of the gas mixture react with about 0.5 mmole of ozone, prepared separately from 99.999% pure O2. The remaining ozone and oxygen were removed by pumping above a cold bath at about 210 K. This successfully removed the NO and N2O traces. The total pressure was measured using a Pfeiffer 10 hPa capacitive gauge. A small contamination due to CO2 remained visible, but could be quantified to about 0.2% of the gas sample, using IR integrated intensity measurements and mass spectrometry. The MS measurements were collected from the same gas sample flask, with an instrument connected to the gas handling manifold. These were compared to a background spectrum of the instrument and collected within a few minutes to assess the CO2 content.
Energy accumulation during the growth of forced wave induced by a moving atmospheric pressure disturbance
Published in Coastal Engineering Journal, 2020
where is the central pressure drop; Rm is defined as the disturbance radius to represent the spatial scale of pressure disturbance; U is the disturbance moving speed, which is assumed to be constant; x and y are the horizontal plane coordinates, t is time. y = 0 is the track of pressure disturbance center. As widely known, a decrease of atmospheric pressure with 1 hPa will lead to about 1 cm elevation of water level in static equilibrium. Here, is introduced to present the maximum water level rise under static equilibrium condition, which is chosen as a vertical length scale. Choosing as the horizontal length scale, the velocity of shallow water wave as a velocity scale, a reference time is given as . The Froude number is defined as .
First analysis of the ν2+ν7 and ν2+ν9 and ν2+ν6 combination bands of HNO3: evidence of perturbations due to large amplitude OH torsion in the 2191 excited state
Published in Molecular Physics, 2022
A. Perrin, L. Manceron, R. Armante, F. Kwabia-Tchana, P. Roy, D. Doizi
High-resolution spectra of HNO3 were recorded with the Bruker IFS125HR Fourier transform spectrometer of the AILES Beamline at Synchrotron SOLEIL (Saint-Aubin, France). As HNO3 reacts and quickly decomposes in contact with metal or oxidisable surfaces, its handling requires special precautions and the AILES special long path glass cell made for highly corrosive or reactive species [9] was used. The cell was fitted here with wedged diamond windows (Advanced Diamond Materials, USA) mounted with Teflon™-coated silicone gaskets (Eriks, France). It includes a triple-envelope glass body (Verrerie Soufflée Normalisée, France) with an inner volume of about 14 L (15 cm ID × 80 cm length) surrounded by an annular cylindrical space for circulating cold ethanol and a third envelope for the insulating vacuum (5×10−5 hPa). The gas temperature was measured in four different points of the cell by PTFE-coated Pt-100 sensors, corresponding to both ends and to the middle top and bottom. The pressure was measured using a Pfeiffer 10 hPa capacitive gauge. The metal parts in contact with gas were coated with a thick PTFE layer (STIM, France) and the mirrors were mounted on Teflon™ bellows (Elkinger, Germany), allowing for travel and tilt adjustments. The cell uses a simple White-configuration with gold-coated mirrors with a special Al2O3 solid protective layer (Optimask, France). The optical path length was set to 2.72 m for the ν2 region around 5.8 µm (FTS2 in Table 1) and set to 16.32 m for the 4.6 µm region (FTS 262729 in Table 1). These spectra were recorded at 296 and 250 K, respectively.