ATMOSPHERIC DENSITY PROFILES FROM THE SURFACE TO 70,000 FEET

Abstract. GPS radio occultation (RO) data have proved to be a great tool for atmospheric monitoring and studies. In the past decade, they were frequently used for analyses of the internal gravity waves in the upper troposphere and lower stratosphere region. Atmospheric density is the first quantity of state gained in the retrieval process and is not burdened by additional assumptions. However, there are no studies elaborating in detail the utilization of GPS RO density profiles for gravity wave analyses. In this paper, we introduce a method for density background separation and a methodology for internal gravity wave analysis using the density profiles. Various background choices are discussed and the correspondence between analytical forms of the density and temperature background profiles is examined. In the stratosphere, a comparison between the power spectrum of normalized density and normalized dry temperature fluctuations confirms the suitability of the density profiles' utilization. In the height range of 8–40 km, results of the continuous wavelet transform are presented and discussed. Finally, the limits of our approach are discussed and the advantages of the density usage are listed.

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Eye-safe 21-μm Ho lidar for measuring atmospheric density profiles

Optics Letters ◽

10.1364/ol.15.000302 ◽

1990 ◽

Vol 15 (6) ◽

pp. 302 ◽

Cited By ~ 28

Author(s):

Nobuo Sugimoto ◽

Newton Sims ◽

Kinpui Chan ◽

Dennis K. Killinger

Keyword(s):

Atmospheric Density ◽

Density Profiles

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Density representation of Long's equation

Nonlinear Processes in Geophysics ◽

10.5194/npg-14-273-2007 ◽

2007 ◽

Vol 14 (3) ◽

pp. 273-283 ◽

Cited By ~ 3

Author(s):

M. Humi

Keyword(s):

Gravity Waves ◽

Atmospheric Density ◽

Density Profiles ◽

Atmospheric Flow ◽

First Order ◽

The Stability ◽

New Equation ◽

New Formulation ◽

Stream Function Formulation ◽

New Criteria

Abstract. Long's equation describes two dimensional stratified atmospheric flow over terrain. Its solutions using regular first order perturbations and linear approximation were investigated analytically and numerically by many authors. Special attention was paid to the properties of the gravity waves that have been predicted to be generated as a result. In this paper we derive a new representation of this equation in terms of the atmospheric density. This new equation is used then to study the steady state that results from some ideal upstream density profiles and the generation of gravity waves. Furthermore we compare the new formulation with the stream function formulation of Long equation and develop new criteria for the stability of the flow.

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Analysis of internal gravity waves with GPS RO density profiles

Atmospheric Measurement Techniques Discussions ◽

10.5194/amtd-7-8311-2014 ◽

2014 ◽

Vol 7 (8) ◽

pp. 8311-8338

Author(s):

P. Šácha ◽

U. Foelsche ◽

P. Pišoft

Keyword(s):

Global Positioning System ◽

Gravity Waves ◽

Recent Decade ◽

Internal Gravity Waves ◽

Atmospheric Density ◽

Retrieval Process ◽

Density Profiles ◽

Height Range ◽

Upper Troposphere ◽

Global Positioning

Abstract. GPS (Global Positioning System) radio occultation (RO) data proved to be a great tool for atmospheric monitoring and studies. In the recent decade, they were frequently used for analyses of the internal gravity waves in the upper troposphere lower stratosphere region. Atmospheric density is the first quantity of state gained in the retrieval process and is not burdened by any additional assumptions. However, there are no studies elaborating in details the utilization of GPS RO density profiles for gravity waves analyses. In the presented paper, we introduce a method for the density background separation and a methodology for internal gravity waves analysis using the density profiles. Various background choices are discussed and the correspondence between analytical forms of the density and temperature background profiles is examined. In the stratosphere, the comparison between the power spectrum of normalized density and normalized dry temperature fluctuations confirms the suitability of the density profiles utilization. In the height range of 8–40 km, results of the continuous wavelet transform are presented and discussed. Finally, the limits of our approach are discussed and the advantages of the density usage are listed.

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Measurement of vertical atmospheric density profile from the X-ray Earth occultation of the Crab Nebula with Insight-HXMT

10.5194/amt-2021-406 ◽

2022 ◽

Author(s):

Daochun Yu ◽

Haitao Li ◽

Baoquan Li ◽

Mingyu Ge ◽

Youli Tuo ◽

...

Keyword(s):

Energy Range ◽

Density Profile ◽

Crab Nebula ◽

Model Parameters ◽

Atmospheric Density ◽

Altitude Range ◽

Density Profiles ◽

X Ray ◽

Posterior Probability Distribution ◽

The Crab Nebula

Abstract. The X-ray Earth occultation sounding (XEOS) is an emerging method for measuring the neutral density in the lower thermosphere. In this paper, the X-ray Earth occultation (XEO) of the Crab Nebula is investigated by using the Insight-HXMT. The pointing observation data on the 30th September, 2018 recorded by the Low Energy X-ray telescope (LE) of Insight-HXMT are selected and analyzed. The extinction lightcurves and spectra during the X-ray Earth occultation process are extracted. A forward model for the XEO lightcurve is established and the theoretical observational signal for lightcurve is predicted. A Bayesian data analysis method is developed for the XEO lightcurve modeling and the atmospheric density retrieval. The posterior probability distribution of the model parameters is derived through the Markov Chain Monte Carlo (MCMC) algorithm with the NRLMSISE-00 model and the NRLMSIS 2.0 model as basis functions and the best-fit density profiles are retrieved respectively. It is found that in the altitude range of 105–200 km, the retrieved density profile is 88.8 % of the density of NRLMSISE-00 and 109.7 % of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 1.0–2.5 keV based on XEOS method. In the altitude range of 95–125 km, the retrieved density profile is 81.0 % of the density of NRLMSISE-00 and 92.3 % of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 2.5–6.0 keV based on XEOS method. In the altitude range of 85–110 km, the retrieved density profile is 87.7 % of the density of NRLMSISE-00 and 101.4 % of the density of NRLMSIS 2.0 by fitting the lightcurve in the energy range of 6.0–10.0 keV based on XEOS method. The measurements of density profiles are compared with the NRLMSISE-00/NRLMSIS 2.0 model simulations and the previous retrieval results with RXTE satellite. Finally, we find that the retrieved density profile from Insight-HXMT based on the NRLMSISE-00/NRLMSIS 2.0 models is qualitatively consistent with the previous retrieved results from RXTE. This study demonstrate that the XEOS from the X-ray astronomical satellite Insight-HXMT can provide an approach for the study of the upper atmosphere. The Insight-HXMT satellite can join the family of the XEOS. The Insight-HXMT satellite with other X-ray astronomical satellites in orbit can form a space observation network for XEOS in the future.

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