A Significant Increase in Detection of High-resolution Emission Spectra Using a Three-dimensional Atmospheric Model of a Hot Jupiter

Abstract The advent of high-resolution spectroscopy (R ≳ 25,000) as a method for characterization of exoplanet atmospheres has expanded our capability to study nontransiting planets, vastly increasing the number of planets accessible for observation. Many of the most favorable targets for atmospheric characterization are hot Jupiters, where we expect large spatial variation in physical conditions such as temperature, wind speed, and cloud coverage, making viewing geometry important. Three-dimensional models have generally simulated observational properties of hot Jupiters assuming edge-on viewing, which can be compared to observations of transiting planets, but neglected the large fraction of planets without nearly edge-on orbits. As the first investigation of how orbital inclination manifests in high-resolution emission spectra from three-dimensional models, we use a general circulation model to simulate the atmospheric structure of Upsilon Andromedae b, a typical nontransiting hot Jupiter with high observational interest, due the brightness of its host star. We compare models with and without clouds, and find that cloud coverage intensifies spatial variations by making colder regions dimmer and relatedly enhancing emission from the clear, hotter regions. This increases both the net Doppler shifts and the variation of the continuum flux amplitude over the course of the planet’s orbit. In order to accurately capture scattering from clouds, we implement a generalized two-stream radiative transfer routine for inhomogeneous multiple scattering atmospheres. As orbital inclination decreases, four key features of the high-resolution emission spectra also decrease in both the clear and cloudy models: (1) the average continuum flux level, (2) the amplitude of the variation in continuum with orbital phase, (3) net Doppler shifts of spectral lines, and (4) Doppler broadening in the spectra. Models capable of treating inhomogeneous cloud coverage and different viewing geometries are critical in understanding results from high-resolution emission spectra, enabling an additional avenue to investigate these extreme atmospheres.

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3-D model simulations of dynamical and microphysical interactions in pyroconvective clouds under idealized conditions

Atmospheric Chemistry and Physics ◽

10.5194/acp-14-7573-2014 ◽

2014 ◽

Vol 14 (14) ◽

pp. 7573-7583 ◽

Cited By ~ 11

Author(s):

P. Reutter ◽

J. Trentmann ◽

A. Seifert ◽

P. Neis ◽

H. Su ◽

...

Keyword(s):

High Resolution ◽

Cloud Condensation Nuclei ◽

Three Dimensional ◽

Atmospheric Model ◽

Cloud Microphysics ◽

Aerosol Concentration ◽

Cloud Droplets ◽

Cloud Development ◽

Microphysical Processes ◽

D Model

Abstract. Dynamical and microphysical processes in pyroconvective clouds in mid-latitude conditions are investigated using idealized three-dimensional simulations with the Active Tracer High resolution Atmospheric Model (ATHAM). A state-of-the-art two-moment microphysical scheme building upon a realistic parameterization of cloud condensation nuclei (CCN) activation has been implemented in order to study the influence of aerosol concentration on cloud development. The results show that aerosol concentration influences the formation of precipitation. For low aerosol concentrations (NCN = 200 cm−3), rain droplets are rapidly formed by autoconversion of cloud droplets. This also triggers the formation of large graupel and hail particles, resulting in an early onset of precipitation. With increasing aerosol concentration (NCN = 1000 cm−3 and NCN = 20 000 cm−3) the formation of rain droplets is delayed due to more but smaller cloud droplets. Therefore, the formation of ice crystals and snowflakes becomes more important for the eventual formation of graupel and hail, which is delayed at higher aerosol concentrations. This results in a delay of the onset of precipitation and a reduction of its intensity with increasing aerosol concentration. This study is the first detailed investigation of the interaction between cloud microphysics and the dynamics of a pyroconvective cloud using the combination of a high-resolution atmospheric model and a detailed microphysical scheme.

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Signatures of Clouds in Hot Jupiter Atmospheres: Modeled High-resolution Emission Spectra from 3D General Circulation Models

The Astrophysical Journal ◽

10.3847/1538-4357/abdc22 ◽

2021 ◽

Vol 909 (1) ◽

pp. 85

Author(s):

Caleb K. Harada ◽

Eliza M.-R. Kempton ◽

Emily Rauscher ◽

Michael Roman ◽

Isaac Malsky ◽

...

Keyword(s):

High Resolution ◽

General Circulation ◽

Emission Spectra ◽

General Circulation Models ◽

Hot Jupiter

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Implications of three-dimensional chemical transport in hot Jupiter atmospheres: Results from a consistently coupled chemistry-radiation-hydrodynamics model

Astronomy and Astrophysics ◽

10.1051/0004-6361/201937153 ◽

2020 ◽

Vol 636 ◽

pp. A68 ◽

Cited By ~ 11

Author(s):

Benjamin Drummond ◽

Eric Hébrard ◽

Nathan J. Mayne ◽

Olivia Venot ◽

Robert J. Ridgway ◽

...

Keyword(s):

Large Scale ◽

Three Dimensional ◽

Chemical Species ◽

Emission Spectra ◽

Chemical Transport ◽

Radiation Hydrodynamics ◽

Atmospheric Flow ◽

Hot Jupiters ◽

Chemical Structures ◽

Hot Jupiter

We present results from a set of simulations using a fully coupled three-dimensional (3D) chemistry-radiation-hydrodynamics model and investigate the effect of transport of chemical species by the large-scale atmospheric flow in hot Jupiter atmospheres. We coupled a flexible chemical kinetics scheme to the Met Office Unified Model, which enables the study of the interaction of chemistry, radiative transfer, and fluid dynamics. We used a newly-released “reduced” chemical network, comprising 30 chemical species, that was specifically developed for its application in 3D atmosphere models. We simulated the atmospheres of the well-studied hot Jupiters HD 209458b and HD 189733b which both have dayside–nightside temperature contrasts of several hundred Kelvin and superrotating equatorial jets. We find qualitatively quite different chemical structures between the two planets, particularly for methane (CH4), when advection of chemical species is included. Our results show that consideration of 3D chemical transport is vital in understanding the chemical composition of hot Jupiter atmospheres. Three-dimensional mixing leads to significant changes in the abundances of absorbing gas-phase species compared with what would be expected by assuming local chemical equilibrium, or from models including 1D – and even 2D – chemical mixing. We find that CH4, carbon dioxide (CO2), and ammonia (NH3) are particularly interesting as 3D mixing of these species leads to prominent signatures of out-of-equilibrium chemistry in the transmission and emission spectra, which are detectable with near-future instruments.

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High Resolution Microscopy of Multi-Layered Biological Crystals

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005319x ◽

1982 ◽

Vol 40 ◽

pp. 80-83

Author(s):

H.A. Cohen ◽

T.W. Jeng ◽

W. Chiu

Keyword(s):

High Resolution ◽

Low Dose ◽

Three Dimensional ◽

Data Interpretation ◽

Two Dimensional ◽

Biological Objects ◽

Density Maps ◽

Density Map ◽

Complex Crystal ◽

High Resolution Microscopy

This tutorial will discuss the methodology of low dose electron diffraction and imaging of crystalline biological objects, the problems of data interpretation for two-dimensional projected density maps of glucose embedded protein crystals, the factors to be considered in combining tilt data from three-dimensional crystals, and finally, the prospects of achieving a high resolution three-dimensional density map of a biological crystal. This methodology will be illustrated using two proteins under investigation in our laboratory, the T4 DNA helix destabilizing protein gp32*I and the crotoxin complex crystal.

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Electron crystallographic determination of the 3-D structure of staurolite at atomic resolution

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010008701x ◽

1991 ◽

Vol 49 ◽

pp. 540-541

Author(s):

Kenneth H. Downing ◽

Hu Meisheng ◽

Hans-Rudolf Went ◽

Michael A. O'Keefe

Keyword(s):

High Resolution ◽

Three Dimensional ◽

High Resolution Electron Microscopy ◽

Atomic Resolution ◽

Dimensional Structure ◽

Structure Information ◽

Resolution Electron ◽

Scattering Effects ◽

High Resolution Images ◽

Effects Of Radiation

With current advances in electron microscope design, high resolution electron microscopy has become routine, and point resolutions of better than 2Å have been obtained in images of many inorganic crystals. Although this resolution is sufficient to resolve interatomic spacings, interpretation generally requires comparison of experimental images with calculations. Since the images are two-dimensional representations of projections of the full three-dimensional structure, information is invariably lost in the overlapping images of atoms at various heights. The technique of electron crystallography, in which information from several views of a crystal is combined, has been developed to obtain three-dimensional information on proteins. The resolution in images of proteins is severely limited by effects of radiation damage. In principle, atomic-resolution, 3D reconstructions should be obtainable from specimens that are resistant to damage. The most serious problem would appear to be in obtaining high-resolution images from areas that are thin enough that dynamical scattering effects can be ignored.

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Three-Dimensional Immunoelectron Microscopy of Yeast Cells by a New High-Resolution Replica Method

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100119594 ◽

1985 ◽

Vol 43 ◽

pp. 562-563

Author(s):

Hirano T. ◽

M. Yamaguchi ◽

M. Hayashi ◽

Y. Sekiguchi ◽

A. Tanaka

Keyword(s):

High Resolution ◽

Plasma Polymerization ◽

Three Dimensional ◽

Freeze Fracture ◽

Replica Method ◽

Yeast Cells ◽

Dynamic Aspect ◽

Replica Technique ◽

Gaseous Hydrocarbon ◽

Transmission Electron

A plasma polymerization film replica method is a new high resolution replica technique devised by Tanaka et al. in 1978. It has been developed for investigation of the three dimensional ultrastructure in biological or nonbiological specimens with the transmission electron microscope. This method is based on direct observation of the single-stage replica film, which was obtained by directly coating on the specimen surface. A plasma polymerization film was deposited by gaseous hydrocarbon monomer in a glow discharge.The present study further developed the freeze fracture method by means of a plasma polymerization film produces a three dimensional replica of chemically untreated cells and provides a clear evidence of fine structure of the yeast plasma membrane, especially the dynamic aspect of the structure of invagination (Figure 1).

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Nano-probe x-ray analysis and high-resolution imaging on planar defects in high-pressure synthesized infinite-layer superconductor

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100171377 ◽

1994 ◽

Vol 52 ◽

pp. 728-729

Author(s):

Y. Y. Wang ◽

H. Zhang ◽

V. P. Dravid ◽

H. Zhang ◽

L. D. Marks ◽

...

Keyword(s):

High Pressure ◽

High Resolution ◽

Atomic Structure ◽

Emission Spectra ◽

High Resolution Electron Microscopy ◽

Planar Defects ◽

X Ray ◽

Infinite Layer ◽

Resolution Electron ◽

Resolution Imaging

Azuma et al. observed planar defects in a high pressure synthesized infinitelayer compound (i.e. ACuO2 (A=cation)), which exhibits superconductivity at ~110 K. It was proposed that the defects are cation deficient and that the superconductivity in this material is related to the planar defects. In this report, we present quantitative analysis of the planar defects utilizing nanometer probe xray microanalysis, high resolution electron microscopy, and image simulation to determine the chemical composition and atomic structure of the planar defects. We propose an atomic structure model for the planar defects.Infinite-layer samples with the nominal chemical formula, (Sr1-xCax)yCuO2 (x=0.3; y=0.9,1.0,1.1), were prepared using solid state synthesized low pressure forms of (Sr1-xCax)CuO2 with additions of CuO or (Sr1-xCax)2CuO3, followed by a high pressure treatment.Quantitative x-ray microanalysis, with a 1 nm probe, was performed using a cold field emission gun TEM (Hitachi HF-2000) equipped with an Oxford Pentafet thin-window x-ray detector. The probe was positioned on the planar defects, which has a 0.74 nm width, and x-ray emission spectra from the defects were compared with those obtained from vicinity regions.

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