VERTICAL DISTRIBUTION OF SODIUM IN THE UPPER ATMOSPHERE

1961 ◽  
Vol 39 (7) ◽  
pp. 976-982 ◽  
Author(s):  
W. R. Bullock ◽  
D. M. Hunten
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
Peak Height ◽  
Upper Atmosphere ◽  
Large Decrease ◽  
Vertical Distributions ◽  
Abundance Variation

The sodium twilight has been observed over the period October 1958 to December 1959 with a birefringent photometer. Abundances and vertical distributions have been found for 120 twilights. The abundance variation is similar to that found previously but is more nearly symmetrical about the solstices. A small seasonal variation in peak height is found, 3 to 5 kilometers with maximum in March. In general, changes in abundance cannot be correlated with changes in distribution; however, a few exceptions to this were found in June and July, when a large overnight increase in abundance accompanied a large decrease in the height of the whole distribution.

scholarly journals Observed and predicted characteristics of equatorial F1 layer during solar minimum

2014 ◽  
Vol 32 (5) ◽  
pp. 571-580 ◽  
Author(s):  
C.-C. Lee
Keyword(s):  
Seasonal Variation ◽  
Diurnal Variation ◽  
Solar Minimum ◽  
Shape Parameter ◽  
Early Morning ◽  
Peak Height ◽  
Time Range ◽  
Occurrence Probability ◽  
Peak Density

Abstract. This study aims to assess the predictability of IRI-2012 on the equatorial F1 layer during solar minimum. The observed characteristics of F1 layer by the Jicamarca digisonde are compared with the model outputs. The results show that the time range for F1-layer appearance of observation is longer than that of IRI-2012, by at least 1 h in the early morning and later afternoon. In IRI-2012, there are three options for the occurrence probability of F1 layer: IRI-95, Scotto-97 no L, and Scotto-97 with L options. The first option predicts the probability well, but the last two underestimate the probability. The peak density of F1 layer (NmF1) of observation is very close to that of IRI-2012. For the F1 peak height (hmF1), the modeled values are smaller than the observed ones. The observed seasonal variation of hmF1 is not found in the modeled results. Nevertheless, the observed diurnal variation of hmF1 is similar to the modeled results with the B0 choices of Bil-2000 and ABT-2009. Regarding the shape parameter, the values of D1 (the shape parameter of F1 layer in observation) are much greater than the values of C1 (the shape parameter of F1 layer in IRI-2012). The D1 values are 3–6 times the C1 values. The diurnal variation of D1 is similar to that of C1, but the seasonal variation of D1 is not.

Daily inundation induced seasonal variation in the vertical distribution of soil water salinity in an estuarine mangrove forest under a tropical monsoon climate

2020 ◽  
Vol 35 (4) ◽  
pp. 638-649
Author(s):  
Akira Komiyama ◽  
Sasitorn Poungparn ◽  
Suthathip Umnouysin ◽  
Chadtip Rodtassana ◽  
Shogo Kato ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
Soil Water ◽  
Mangrove Forest ◽  
Water Salinity ◽  
Monsoon Climate ◽  
Tropical Monsoon ◽  
The Vertical Distribution

scholarly journals Observations of the summertime atmospheric pollutants vertical distributions and the corresponding ozone production in Shanghai, China

2017 ◽  
Author(s):  
Chengzhi Xing ◽  
Cheng Liu ◽  
Shanshan Wang ◽  
Ka Lok Chan ◽  
Yang Gao ◽  
...  
Keyword(s):  
Vertical Distribution ◽  
Pearson Correlation ◽  
A Priori ◽  
Lower Troposphere ◽  
Sensitivity Study ◽  
Atmospheric Pollutants ◽  
Ozone Production ◽  
Optical Absorption Spectroscopy ◽  
Lidar Measurements ◽  
Vertical Distributions

Abstract. Ground based Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) and lidar measurements were performed in Shanghai, China during May 2016 to investigate the summertime atmospheric pollutants vertical distribution. In this study, vertical profiles of aerosol extinction coefficient, nitrogen dioxide (NO2) and formaldehyde (HCHO) concentrations were retrieved from MAX-DOAS measurement using the Heidelberg Profile (HeiPro) algorithm, while vertical distribution of ozone (O3) was obtained from an ozone lidar. Sensitivity study of the MAX-DOAS aerosol profile retrieval shows that the a priori aerosol profile shape has significant influences on the aerosol profile retrieval. Aerosol profiles retrieved from MAX-DOAS measurements with Gaussian a priori demonstrate the best agreements with simultaneous lidar measurements and vehicle-based tethered-balloon observations among all a priori aerosol profiles. MAX-DOAS measured tropospheric NO2Vertical Column Densities (VCDs) show a good agreement with OMI satellite observations with Pearson correlation coefficient (R) of 0.95. In addition, measurements of the O3 vertical distribution indicate that the ozone productions do not only occur at surface level but also at higher altitudes (about 1.1 km). Planetary boundary layer (PBL) height, horizontal and vertical wind fields information were integrated to discuss the ozone formation at upper altitudes. The results reveal that enhanced ozone concentrations at ground and upper altitudes are not directly related to horizontal and vertical transportations. Similar patterns of O3 and HCHO vertical distributions were observed during this campaign, which implies that the ozone productions near to the surface and at higher altitudes are mainly influenced by the abundance of volatile organic compounds (VOCs) in the lower troposphere.

scholarly journals The upper atmospheres of Uranus and Neptune

2020 ◽  
Vol 378 (2187) ◽  
pp. 20190478 ◽  
Author(s):  
Henrik Melin
Keyword(s):  
Magnetic Field ◽  
Joule Heating ◽  
Critical Role ◽  
Upper Atmosphere ◽  
Heating Rates ◽  
James Webb Space Telescope ◽  
Vertical Distributions ◽  
Auroral Current ◽  
First Time ◽  
The Magnetic Field

We review the current understanding of the upper atmospheres of Uranus and Neptune, and explore the upcoming opportunities available to study these exciting planets. The ice giants are the least understood planets in the solar system, having been only visited by a single spacecraft, in 1986 and 1989, respectively. The upper atmosphere plays a critical role in connecting the atmosphere to the forces and processes contained within the magnetic field. For example, auroral current systems can drive charged particles into the atmosphere, heating it by way of Joule heating. Ground-based observations of H 3 + provides a powerful remote diagnostic of the physical properties and processes that occur within the upper atmosphere, and a rich dataset exists for Uranus. These observations span almost three decades and have revealed that the upper atmosphere has continuously cooled between 1992 and 2018 at about 8 K/year, from approximately 750 K to approximately 500 K. The reason for this trend remain unclear, but could be related to seasonally driven changes in the Joule heating rates due to the tilted and offset magnetic field, or could be related to changing vertical distributions of hydrocarbons. H 3 + has not yet been detected at Neptune, but this discovery provides low-hanging fruit for upcoming facilities such as the James Webb Space Telescope and the next generation of 30 m telescopes. Detecting H 3 + at Neptune would enable the characterization of its upper atmosphere for the first time since 1989. To fully understand the ice giants, we need dedicated orbital missions, in the same way the Cassini spacecraft explored Saturn. Only by combining in situ observations of the magnetic field with in-orbit remote sensing can we get the complete picture of how energy moves between the atmosphere and the magnetic field. This article is part of a discussion meeting issue ‘Future exploration of ice giant systems’.

Seasonal variation of near surface black carbon and satellite derived vertical distribution of aerosols over a semi-arid station in India

2017 ◽  
Vol 184 ◽  
pp. 77-87 ◽  
Author(s):  
Raja Obul Reddy Kalluri ◽  
Balakrishnaiah Gugamsetty ◽  
Rama Gopal Kotalo ◽  
Siva Kumar Reddy Nagireddy ◽  
Chakradhar Rao Tandule ◽  
...  
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
Black Carbon ◽  
Near Surface ◽  
Semi Arid

scholarly journals Vertical distribution of pre-settled sandeel (Ammodytes marinus) in the North Sea in relation to size and environmental variables

2003 ◽  
Vol 60 (6) ◽  
pp. 1342-1351 ◽  
Author(s):  
Henrik Jensen ◽  
Peter J Wright ◽  
Peter Munk
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
North Sea ◽  
Distribution Patterns ◽  
Food Concentration ◽  
The North ◽  
Vertical Distributions ◽  
The North Sea ◽  
Drift Trajectory ◽  
Vertical Positioning

Abstract Vertical distribution patterns of larval and juvenile sandeels were investigated at four locations in the North Sea. Sandeels between 6 and 65 mm were found to depths of 80 m, with vertical distributions dependent on both length and environmental factors. At one location with a stratified water column, the highest densities were found during the day in midwater where food concentration was also highest. In areas without marked vertical hydrographic gradients, larvae were relatively more abundant in surface waters during the day. At all locations, larvae of all sizes were generally more homogeneously distributed in the water column during night than during day. The extent of vertical migration, as measured by the standard deviation of the mean depth, increased generally with length. Gear avoidance was evident for larvae ≥20 mm. Catch efficiency generally depended on both length class and surface light intensity. A simulated drift pattern of larvae, based on ADCP current measurements from two locations, predicts that the horizontal drift trajectory would only be affected slightly by the vertical positioning of the larvae in the water column during the time of sampling. The implication of vertical migrations for dispersal of larvae away from the spawning grounds is discussed.

Sulfur speciation, vertical distribution, and seasonal variation in a northern hardwood forest soil, U.S.A

1995 ◽  
Vol 25 (2) ◽  
pp. 234-243 ◽  
Author(s):  
B.R. Dhamala ◽  
M.J. Mitchell
Keyword(s):  
Seasonal Variation ◽  
Vertical Distribution ◽  
Forest Soil ◽  
Specific Activity ◽  
Soil Depth ◽  
Mineral Soil ◽  
Hardwood Forest ◽  
Northern Hardwood Forest ◽  
Northern Hardwood ◽  
Sulfur Speciation

Sulfur biogeochemistry of a northern hardwood forest soil in Bear Brook Watershed, Maine, was studied utilizing 35S in situ. The objectives of study were to characterize different S pools, their vertical distribution, and seasonal variation. Soil cores were used at the field and treated with 35SO42−. The distribution of total and C-bonded S followed a typical pattern of decreasing concentration with soil depth. More than 86% of total 35S added was retained by the soil. Most of the 35S activity was in the organic S pool (up to 73 and 20% of total 35S in C-bonded S and ester-sulfate forms, respectively) in both the forest floor and the mineral soil horizons. Ester sulfate increased with depth from 5.3 to 25.5% of total S. During the summer the relative importance of mineralization to immobilization decreased. Inorganic sulfate was the smallest S pool. However, higher specific activity and turnover rate of the inorganic 35SO42− pool than organic 35S pool indicated that S concentration and solution flux were more regulated by abiotic (adsorption and desorption) than biotic (mineralization and immobilization) processes.

scholarly journals Cloud vertical distribution from combined surface and space radar–lidar observations at two Arctic atmospheric observatories

2017 ◽  
Vol 17 (9) ◽  
pp. 5973-5989 ◽  
Author(s):  
Yinghui Liu ◽  
Matthew D. Shupe ◽  
Zhien Wang ◽  
Gerald Mace
Keyword(s):  
Vertical Distribution ◽  
Climate Models ◽  
Cloud Fraction ◽  
The Arctic ◽  
Active Sensors ◽  
Annual Cycles ◽  
Cloud Property ◽  
Microphysical Properties ◽  
Cloud Water Content ◽  
Vertical Distributions

Abstract. Detailed and accurate vertical distributions of cloud properties (such as cloud fraction, cloud phase, and cloud water content) and their changes are essential to accurately calculate the surface radiative flux and to depict the mean climate state. Surface and space-based active sensors including radar and lidar are ideal to provide this information because of their superior capability to detect clouds and retrieve cloud microphysical properties. In this study, we compare the annual cycles of cloud property vertical distributions from space-based active sensors and surface-based active sensors at two Arctic atmospheric observatories, Barrow and Eureka. Based on the comparisons, we identify the sensors' respective strengths and limitations, and develop a blended cloud property vertical distribution by combining both sets of observations. Results show that surface-based observations offer a more complete cloud property vertical distribution from the surface up to 11 km above mean sea level (a.m.s.l.) with limitations in the middle and high altitudes; the annual mean total cloud fraction from space-based observations shows 25–40 % fewer clouds below 0.5 km than from surface-based observations, and space-based observations also show much fewer ice clouds and mixed-phase clouds, and slightly more liquid clouds, from the surface to 1 km. In general, space-based observations show comparable cloud fractions between 1 and 2 km a.m.s.l., and larger cloud fractions above 2 km a.m.s.l. than from surface-based observations. A blended product combines the strengths of both products to provide a more reliable annual cycle of cloud property vertical distributions from the surface to 11 km a.m.s.l. This information can be valuable for deriving an accurate surface radiative budget in the Arctic and for cloud parameterization evaluation in weather and climate models. Cloud annual cycles show similar evolutions in total cloud fraction and ice cloud fraction, and lower liquid-containing cloud fraction at Eureka than at Barrow; the differences can be attributed to the generally colder and drier conditions at Eureka relative to Barrow.

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