scholarly journals Measurements of the stratospheric Density and Temperature Profiles in Hanoi by a Rayleigh Lidar

2014 ◽  
Vol 24 (3) ◽  
pp. 247
Author(s):  
Nguyen Xuan Tuan ◽  
Dinh Van Trung ◽  
Nguyen Thanh Binh ◽  
Bui Van Hai
Keyword(s):  
Density Profile ◽  
Atmospheric Model ◽  
Ideal Gas ◽  
Temperature Profiles ◽  
Molecular Density ◽  
Ideal Gas Law ◽  
Lidar Measurements ◽  
Long Time ◽  
Atmospheric Molecule ◽  
Rayleigh Lidar

The molecular density and temperature profiles of the stratosphere in Hanoi are measured by a Rayleigh lidar. The profiles have the spatial resolution of 120 m and the temporal resolution of 1h. Their bottom height and top height are 20 km and 57 km, respectively. The atmospheric molecule density profile is directly derived from the correction-range lidar signal. The temperature profile is deduced from the molecular density profile based on the assumptions of the hydrostatic equilibrium and the ideal-gas law. Lidar measurements show good agreement with the molecular density and the temperature profiles from the MSISE-90 atmospheric model. Maximum errors of the density and temperature are found to be \(\pm 0.9\)\% and \(\pm 3.4\)~K, respectively.The position and the temperature  of the stratopause in Hanoi are determined to be about 49 km and 270 K. Database of lidar in a long time might reveal the characteristic and the structure of the stratosphere in Hanoi, Vietnam.

scholarly journals Measurement of the Upper Tropospheric Density and Temperature Profiles in Hanoi Using a Raman Lidar

2016 ◽  
Vol 24 (3S2) ◽  
pp. 52-62
Author(s):  
Nguyen Xuan Tuan ◽  
Dinh Van Trung ◽  
Nguyen Thanh Binh ◽  
Bui Van Hai
Keyword(s):  
Atmospheric Model ◽  
Nitrogen Molecule ◽  
Ideal Gas ◽  
Temperature Profiles ◽  
Raman Lidar ◽  
Density Profiles ◽  
Molecular Density ◽  
Upper Troposphere ◽  
Ideal Gas Law ◽  
Lidar Measurements

The nitrogen molecular density and temperature profiles of the upper troposphere are measured by a Raman lidar system in Hanoi over the range from 3 km to 19 km. The spatial and temporal resolutions of profiles are 60 m and 1h, respectively. The nitrogen molecular density profiles are directly calculated from the range-corrected lidar signal. The temperature profiles are derived from the molecular density profile based on the assumptions of the hydrostatic equilibrium, the ideal-gas law and a fixed nitrogen molecule ratio in the atmosphere. The results of our lidar measurements show good agreement with the MSISE-90 atmospheric model. The maximum errors of density and temperature measurements are 6% and 7%, respectively. We estimated the height of tropopause in Hanoi about 16 km from the derived temperature profile. The measured density and temperature profiles from this Raman lidar can be used for studying the trends and characteristics of the upper troposphere in Hanoi.

scholarly journals Rayleigh lidar observation of tropical mesospheric inversion layer: a comparison between dynamics and chemistry

2018 ◽  
Vol 176 ◽  
pp. 03003
Author(s):  
K. Ramesh ◽  
S. Sridharan ◽  
K. Raghunath
Keyword(s):  
Inversion Layer ◽  
Green Laser ◽  
Ideal Gas ◽  
Vital Role ◽  
Temperature Profiles ◽  
Vertical Temperature ◽  
Atmospheric Research ◽  
Ideal Gas Law ◽  
Rayleigh Lidar ◽  
532 Nm

The Rayleigh lidar at National Atmospheric Research Laboratory, Gadanki (13.5°N, 79.2°E), India operates at 532 nm green laser with ~600 mJ/pulse since 2007. The vertical temperature profiles are derived above ~30 km by assuming the atmosphere is in hydrostatic equilibrium and obeys ideal gas law. A large mesospheric inversion layer (MIL) is observed at ~77.4-84.6 km on the night of 22 March 2007 over Gadanki. Although dynamics and chemistry play vital role, both the mechanisms are compared for the occurrence of the MIL in the present study.

scholarly journals Polar middle atmosphere temperature climatology from Rayleigh lidar measurements at ALOMAR (69° N)

2008 ◽  
Vol 26 (7) ◽  
pp. 1681-1698 ◽  
Author(s):  
A. Schöch ◽  
G. Baumgarten ◽  
J. Fiedler
Keyword(s):  
Middle Atmosphere ◽  
Lidar Data ◽  
Temperature Profiles ◽  
Raman Lidar ◽  
Data Set ◽  
Unique Data ◽  
Falling Sphere ◽  
Lidar Measurements ◽  
Atmosphere Temperature ◽  
Rayleigh Lidar

Abstract. Rayleigh lidar temperature profiles have been derived in the polar middle atmosphere from 834 measurements with the ALOMAR Rayleigh/Mie/Raman lidar (69.3° N, 16.0° E) in the years 1997–2005. Since our instrument is able to operate under full daylight conditions, the unique data set presented here extends over the entire year and covers the altitude region 30 km–85 km in winter and 30 km–65 km in summer. Comparisons of our lidar data set to reference atmospheres and ECMWF analyses show agreement within a few Kelvin in summer but in winter higher temperatures below 55 km and lower temperatures above by as much as 25 K, due likely to superior resolution of stratospheric warming and associated mesospheric cooling events. We also present a temperature climatology for the entire lower and middle atmosphere at 69° N obtained from a combination of lidar measurements, falling sphere measurements and ECMWF analyses. Day to day temperature variability in the lidar data is found to be largest in winter and smallest in summer.

scholarly journals High spectral resolution lidar using spherical Fabry-Perot to measure aerosol and atmospheric molecular density

2018 ◽  
Vol 176 ◽  
pp. 01016
Author(s):  
Caraty Yann ◽  
Hauchecorne Alain ◽  
Keckhut Philippe ◽  
Mariscal Jean-François ◽  
Dalmeida Eric
Keyword(s):  
Spectral Resolution ◽  
High Spectral Resolution ◽  
Temperature Profiles ◽  
Thermal Drift ◽  
Molecular Density ◽  
Fabry Perot ◽  
Validity Range ◽  
Optical Alignment ◽  
Rayleigh Lidar ◽  
High Spectral Resolution Lidar

In theory, the HSRL method should expand the validity range of the atmospheric molecular density and temperature profiles of the Rayleigh LIDAR in the UTLS below 30 km, with an accuracy of 1 K, while suppressing the particle contribution. We tested a Spherical Fabry-Perot which achieves these performances while keeping a big flexibility in optical alignment. However, this device has some limitations (thermal drift and a possible partial depolarisation of the backscattered signal).

Gravity wave analysis using OH airglow and Rayleigh lidar at the Haute-Provence observatory

2020 ◽  
Author(s):  
Thurian Le Du
Keyword(s):  
Gravity Waves ◽  
Lower Stratosphere ◽  
Temperature Inversion ◽  
Short Wave ◽  
Temperature Profiles ◽  
Wave Analysis ◽  
Vertical Temperature ◽  
Clear Sky ◽  
Lidar Measurements ◽  
Rayleigh Lidar

<div> <div> <div> <p>In the frame of the European H2020 project ARISE, a short wave infrared (SWIR) InGaAs camera has been operated at the Haute-Provence Observatory. This camera allows continuous observations during clear-sky nighttime of the OH airglow layer centered at 87 km. These observations were collocated with Rayleigh lidar measurements providing vertical temperature profiles from the lower stratosphere to the altitude of the OH layer around the mesopause. Spectral analysis of OH images and temperature fluctuations allows us to identify and characterize gravity waves, their activity observed from the OH camera and the lidar, appear to be modified with the presence of a temperature inversion described by this one.</p> </div> </div> </div>

Making sense of sensemaking: using the sensemaking epistemic game to investigate student discourse during a collaborative gas law activity

2021 ◽  
Author(s):  
Kevin H. Hunter ◽  
Jon-Marc G. Rodriguez ◽  
Nicole M. Becker
Keyword(s):  
Problem Solving ◽  
Conceptual Understanding ◽  
Ideal Gas ◽  
Interactive Simulation ◽  
Structural Components ◽  
Student Discourse ◽  
Coding Scheme ◽  
Making Sense ◽  
Ideal Gas Law ◽  
The Ideal

Beyond students’ ability to manipulate variables and solve problems, chemistry instructors are also interested in students developing a deeper conceptual understanding of chemistry, that is, engaging in the process of sensemaking. The concept of sensemaking transcends problem-solving and focuses on students recognizing a gap in knowledge and working to construct an explanation that resolves this gap, leading them to “make sense” of a concept. Here, we focus on adapting and applying sensemaking as a framework to analyze three groups of students working through a collaborative gas law activity. The activity was designed around the learning cycle to aid students in constructing the ideal gas law using an interactive simulation. For this analysis, we characterized student discourse using the structural components of the sensemaking epistemic game using a deductive coding scheme. Next, we further analyzed students’ epistemic form by assessing features of the activity and student discourse related to sensemaking: whether the question was framed in a real-world context, the extent of student engagement in robust explanation building, and analysis of written scientific explanations. Our work provides further insight regarding the application and use of the sensemaking framework for analyzing students’ problem solving by providing a framework for inferring the depth with which students engage in the process of sensemaking.

scholarly journals Induction of Changes in Internal Gas Pressure of Bulky Plant Organs by Temperature Gradients

1990 ◽  
Vol 115 (2) ◽  
pp. 308-312 ◽  
Author(s):  
Kenneth A. Corey ◽  
Zhi-Yi Tan
Keyword(s):  
Bath Temperature ◽  
Ideal Gas ◽  
Gas Pressure ◽  
Temperature Gradients ◽  
Maximum Pressure ◽  
Plant Organs ◽  
Ideal Gas Law ◽  
Increasing Temperature ◽  
Pressure Changes

Water manometers were connected to fruits of tomato (Lycopersicon esculentum Mill.) and pepper (Capsicum annuum L.), and then fruits were submerged in water baths providing initial temperature gradients between fruit and water of 0 to 19C. Apple (Malus domestics Borkh.) fruits, carrot (Daucus carota L.) roots, witloof chicory (Cichorium intybus L.) roots, rhubarb Rheum rhabarbarum L.) petioles, and pokeweed (Phytolacca americana L.) stems were subjected to water bath temperature gradients of 5C. Internal partial vacuums developed in all organs within minutes of imposing the gradients. The maximum partial vacuums in tomato and pepper fruits increased with increasing temperature gradients. Uptake of water accompanied changes in internal pressure reaching maxima of 17% (w/w) and 2% (w/w) of pepper and tomato fruits, respectively, after 22 hours. Maximum pressure changes achieved in bulky organs deviated from those predicted by the ideal gas law, possibly due to concomitant changes in gas pressure upon replacement of intercellular spaces with water and dissolution of CO2. Partial vacuums also developed in pepper fruits, rhubarb petioles, and pokeweed stems following exposure to air 15C cooler than initial organ temperatures. Results point to the role of temperature gradients in the transport of liquids and gases in plant organs.

scholarly journals A new method to derive middle atmospheric temperature profiles using a combination of Rayleigh lidar and O<sub>2</sub> airglow temperatures measurements

2012 ◽  
Vol 30 (1) ◽  
pp. 27-32 ◽  
Author(s):  
A. Taori ◽  
A. Jayaraman ◽  
K. Raghunath ◽  
V. Kamalakar
Keyword(s):  
Temperature Profile ◽  
Atmospheric Temperature ◽  
New Method ◽  
Temperature Profiles ◽  
Vertical Temperature ◽  
Lidar System ◽  
Mesospheric Temperature ◽  
Simultaneous Measurements ◽  
Rayleigh Lidar ◽  
First Time

Abstract. The vertical temperature profiles in a typical Rayleigh lidar system depends on the backscatter photon counts and the CIRA-86 model inputs. For the first time, we show that, by making simultaneous measurements of Rayleigh lidar and upper mesospheric O2 temperatures, the lidar capability can be enhanced to obtain mesospheric temperature profile up to about 95 km altitudes. The obtained results are compared with instantaneous space-borne SABER measurements for a validation.

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