ON THE EDDY TRANSFER OF WATER VAPOR ABOVE AN OUTDOOR SURFACE

1962 ◽  
Vol 40 (9) ◽  
pp. 1182-1190
Author(s):  
D. R. Hay ◽  
E. V. Pemberton
Keyword(s):  
Refractive Index ◽  
Water Vapor ◽  
Moist Air ◽  
Radio Path ◽  
Local Fluctuations ◽  
Standard Deviations ◽  
Extended Path ◽  
Upward Transfer

Fluctuations in the refractive index of the air above an outdoor surface have been examined by a 180-ft microwave interferometer. The observed standard deviations of refractivity are less than 10−6. These deviations are associated with instability of the air at the interferometer path but not with instability of the air immediately above it. Smallest refractivity deviations occur for weak eddy transfer of water vapor downwards through moist air in the radio path; intermediate deviations are associated with strong eddy transfer of vapor upwards through drier air in the path. Largest refractivity deviations are observed for less vigorous upward transfer of water vapor from the surface. It is suggested that the more vigorous eddies disperse the entrained water vapor more rapidly into smaller eddies than do the less vigorous eddies; and hence, lesser local fluctuations in air refractivity appear along an extended path that is highly-unstable than along the same path under conditions of greater stability.

Single-molecule spectromicroscopy: a route towards sub-wavelength refractometry

2015 ◽  
Vol 184 ◽  
pp. 263-274 ◽  
Author(s):  
T. A. Anikushina ◽  
M. G. Gladush ◽  
A. A. Gorshelev ◽  
A. V. Naumov
Keyword(s):  
Refractive Index ◽  
Single Molecule ◽  
Low Temperatures ◽  
Radiative Lifetime ◽  
Spatially Resolved ◽  
Local Fluctuations ◽  
Novel Approach ◽  
Spectral Linewidth ◽  
Spatial Fluctuations ◽  
Sub Wavelength

We suggest a novel approach for spatially resolved probing of local fluctuations of the refractive index n in solids by means of single-molecule (SM) spectroscopy. It is based on the dependence T1(n) of the effective radiative lifetime T1 of dye centres in solids on n due to the local-field effects. Detection of SM zero-phonon lines at low temperatures gives the values of the SM natural spectral linewidth (which is inversely proportional to T1) and makes it possible to reveal the distribution of the local n values in solids. Here we demonstrate this possibility on the example of amorphous polyethylene and polycrystalline naphthalene doped with terrylene. In particular, we show that the obtained distributions of lifetime limited spectral linewidths of terrylene molecules embedded into these matrices are due to the spatial fluctuations of the refractive index local values.

scholarly journals Water Vapor Sorption Characteristics of Powder Type Organic Sorbent in a Moist Air Fluidized Bed.

2001 ◽  
Vol 67 (660) ◽  
pp. 2105-2112 ◽  
Author(s):  
Hideo INABA ◽  
Takahisa KIDA ◽  
Akihiko HORIBE ◽  
Kiyohiro KAMEDA ◽  
Tamio OKAMOTO ◽  
...  
Keyword(s):  
Water Vapor ◽  
Fluidized Bed ◽  
Water Vapor Sorption ◽  
Vapor Sorption ◽  
Moist Air ◽  
Powder Type ◽  
Sorption Characteristics

scholarly journals The lightness of water vapor helps to stabilize tropical climate

2020 ◽  
Vol 6 (19) ◽  
pp. eaba1951 ◽  
Author(s):  
Seth D. Seidel ◽  
Da Yang
Keyword(s):  
Water Vapor ◽  
Longwave Radiation ◽  
Tropical Climate ◽  
Climate Feedback ◽  
Tropical Atmosphere ◽  
Radiative Effect ◽  
Buoyancy Effect ◽  
Moist Air ◽  
Dry Air ◽  
Earth’S Climate

Moist air is lighter than dry air at the same temperature, pressure, and volume because the molecular weight of water is less than that of dry air. We call this the vapor buoyancy effect. Although this effect is well documented, its impact on Earth’s climate has been overlooked. Here, we show that the lightness of water vapor helps to stabilize tropical climate by increasing the outgoing longwave radiation (OLR). In the tropical atmosphere, buoyancy is horizontally uniform. Then, the vapor buoyancy in the moist regions must be balanced by warmer temperatures in the dry regions of the tropical atmosphere. These higher temperatures increase tropical OLR. This radiative effect increases with warming, leading to a negative climate feedback. At a near present-day surface temperature, vapor buoyancy is responsible for a radiative effect of 1 W/m2 and a negative climate feedback of about 0.15 W/m2 per kelvin.

The Refractive Index of Moist Air in the 3-μm Region

Metrologia ◽  
1982 ◽  
Vol 18 (2) ◽  
pp. 49-52 ◽  
Author(s):  
Hirokazu Matsumoto
Keyword(s):  
Refractive Index ◽  
Moist Air

scholarly journals <i>A Tale of Two Dust Storms</i>: analysis of a complex dust event in the Middle East

2019 ◽  
Vol 12 (9) ◽  
pp. 5101-5118 ◽  
Author(s):  
Steven D. Miller ◽  
Louie D. Grasso ◽  
Qijing Bian ◽  
Sonia M. Kreidenweis ◽  
Jack F. Dostalek ◽  
...  
Keyword(s):  
Water Vapor ◽  
Mineral Dust ◽  
Weather Prediction ◽  
Detection Threshold ◽  
Dust Storms ◽  
Moist Air ◽  
Air Mass ◽  
Dry Air ◽  
Environmental Controls ◽  
Dust Detection

Abstract. Lofted mineral dust over data-sparse regions presents considerable challenges to satellite-based remote sensing methods and numerical weather prediction alike. The southwest Asia domain is replete with such examples, with its diverse array of dust sources, dust mineralogy, and meteorologically driven lofting mechanisms on multiple spatial and temporal scales. A microcosm of these challenges occurred over 3–4 August 2016 when two dust plumes, one lofted within an inland dry air mass and another embedded within a moist air mass, met over the southern Arabian Peninsula. Whereas conventional infrared-based techniques readily detected the dry air mass dust plume, they experienced marked difficulties in detecting the moist air mass dust plume, becoming apparent when visible reflectance revealed the plume crossing over an adjacent dark water background. In combining information from numerical modeling, multi-satellite and multi-sensor observations of lofted dust and moisture profiles, and idealized radiative transfer simulations, we develop a better understanding of the environmental controls of this event, characterizing the sensitivity of infrared-based dust detection to column water vapor, dust vertical extent, and dust optical properties. Differences in assumptions of dust complex refractive index translate to variations in the sign and magnitude of the split-window brightness temperature difference commonly used for detecting mineral dust. A multi-sensor technique for mitigating the radiative masking effects of water vapor via modulation of the split-window dust-detection threshold, predicated on idealized simulations tied to these driving factors, is proposed and demonstrated. The new technique, indexed to an independent description of the surface-to-500 hPa atmospheric column moisture, reveals parts of the missing dust plume embedded in the moist air mass, with the best performance realized over land surfaces.

Theoretical and calculational aspects of the radio refractive index of water vapor

Radio Science ◽  
1982 ◽  
Vol 17 (5) ◽  
pp. 1251-1257 ◽  
Author(s):  
R. J. Hill ◽  
R. S. Lawrence ◽  
J. T. Priestley
Keyword(s):  
Refractive Index ◽  
Water Vapor
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