Interhemispheric transport of metallic ions within ionospheric sporadic E layers by the lower thermospheric meridional circulation

Mapping Intimacies ◽

10.5194/acp-2020-820 ◽

2020 ◽

Author(s):

Bingkun Yu ◽

Xianghui Xue ◽

Christopher J. Scott ◽

Jianfei Wu ◽

Xinan Yue ◽

...

Keyword(s):

Large Scale ◽

Climate Model ◽

Meridional Circulation ◽

Strong Support ◽

Metallic Ions ◽

Meridional Transport ◽

Summer Circulation ◽

Sporadic E Layers ◽

Sporadic E ◽

Interhemispheric Transport

Abstract. Long-lived metallic ions in the Earth's atmosphere/ionosphere have been investigated for many decades. Although the seasonal variation in ionospheric sporadic E layers was first observed in the 1960s, the mechanism driving the variation remains a long-standing mystery. Here we report a study of ionospheric irregularities using scintillation data from COSMIC satellites and identify a large-scale horizontal transport of long-lived metallic ions, combined with the simulations of the Whole Atmosphere Community Climate Model with the chemistry of metals and ground-based observations from two meridional chains of stations from 1975–2016. We find that the lower thermospheric meridional circulation influences the meridional transport and seasonal variations of metallic ions within sporadic E layers. The winter-to-summer, meridional velocity of ions is estimated to vary between −1.08 and 7.45 m/s at altitudes of 107–118 km between 10°–60° N latitude. Our results not only provide strong support for the lower thermospheric meridional circulation predicted by a whole atmosphere chemistry-climate model, but also emphasise the influences of this winter-to-summer circulation on the large-scale interhemispheric transport of composition in the thermosphere/ionosphere.

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Interhemispheric transport of metallic ions within ionospheric sporadic <i>E</i> layers by the lower thermospheric meridional circulation

Atmospheric Chemistry and Physics ◽

10.5194/acp-21-4219-2021 ◽

2021 ◽

Vol 21 (5) ◽

pp. 4219-4230

Author(s):

Bingkun Yu ◽

Xianghui Xue ◽

Christopher J. Scott ◽

Jianfei Wu ◽

Xinan Yue ◽

...

Keyword(s):

Large Scale ◽

Climate Model ◽

Meridional Circulation ◽

Strong Support ◽

Metallic Ions ◽

Meridional Transport ◽

Summer Circulation ◽

Sporadic E Layers ◽

Sporadic E ◽

Interhemispheric Transport

Abstract. Long-lived metallic ions in the Earth's atmosphere (ionosphere) have been investigated for many decades. Although the seasonal variation in ionospheric “sporadic E” layers was first observed in the 1960s, the mechanism driving the variation remains a long-standing mystery. Here, we report a study of ionospheric irregularities using scintillation data from COSMIC satellites and identify a large-scale horizontal transport of long-lived metallic ions, combining the simulations of the Whole Atmosphere Community Climate Model with the chemistry of metals and ground-based observations from two meridional chains of stations from 1975–2016. We find that the lower thermospheric meridional circulation influences the meridional transport and seasonal variations of metallic ions within sporadic E layers. The winter-to-summer meridional velocity of ions is estimated to vary between −1.08 and 7.45 m/s at altitudes of 107–118 km between 10–60∘ N. Our results not only provide strong support for the lower thermospheric meridional circulation predicted by a whole atmosphere chemistry–climate model, but also emphasize the influences of this winter-to-summer circulation on the large-scale interhemispheric transport of composition in the thermosphere–ionosphere.

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Type-1 echoes from the mid-latitude E-Region ionosphere

Annales Geophysicae ◽

10.1007/s00585-997-0908-2 ◽

1997 ◽

Vol 15 (7) ◽

pp. 908-917 ◽

Cited By ~ 1

Author(s):

C. Haldoupis ◽

D. T. Farley ◽

K. Schlegel

Keyword(s):

Doppler Radar ◽

Spectral Component ◽

Equatorial Electrojet ◽

Metallic Ions ◽

Sporadic E Layers ◽

E Region ◽

Sporadic E ◽

The Right

Abstract. This paper presents more data on the properties of type-1 irregularities in the nighttime mid-latitude E-region ionosphere. The measurements were made with a 50-MHz Doppler radar system operating in Crete, Greece. The type-1 echoes last from several seconds to a few minutes and are characterized by narrow Doppler spectra with peaks corresponding to wave phase velocities of 250–350 m/s. The average velocity of 285 m/s is about 20% lower than nominal E-region ion-acoustic speeds, probably because of the presence of heavy metallic ions in the sporadic-E-layers that appear to be associated with the mid-latitude plasma instabilities. Sometimes the type-1 echoes are combined with a broad spectrum of type-2 echoes; at other times they dominate the spectrum or may appear in the absence of any type-2 spectral component. We believe these echoes are due to the modified two-stream plasma instability driven by a polarization electric field that must be larger than 10 mV/m. This field is similar in nature to the equatorial electrojet polarization field and can arise when patchy nighttime sporadic-E-layers have the right geometry.

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Large-scale transport into the Arctic: the roles of the midlatitude jet and the Hadley Cell

Atmospheric Chemistry and Physics ◽

10.5194/acp-19-5511-2019 ◽

2019 ◽

Vol 19 (8) ◽

pp. 5511-5528 ◽

Cited By ~ 3

Author(s):

Huang Yang ◽

Darryn W. Waugh ◽

Clara Orbe ◽

Guang Zeng ◽

Olaf Morgenstern ◽

...

Keyword(s):

Large Scale ◽

Climate Model ◽

Source Region ◽

Meridional Flow ◽

Hadley Cell ◽

The Arctic ◽

Boreal Summer ◽

Boreal Winter ◽

Meridional Transport ◽

Fixed Lifetime

Abstract. Transport from the Northern Hemisphere (NH) midlatitudes to the Arctic plays a crucial role in determining the abundance of trace gases and aerosols that are important to Arctic climate via impacts on radiation and chemistry. Here we examine this transport using an idealized tracer with a fixed lifetime and predominantly midlatitude land-based sources in models participating in the Chemistry Climate Model Initiative (CCMI). We show that there is a 25 %–45 % difference in the Arctic concentrations of this tracer among the models. This spread is correlated with the spread in the location of the Pacific jet, as well as the spread in the location of the Hadley Cell (HC) edge, which varies consistently with jet latitude. Our results suggest that it is likely that the HC-related zonal-mean meridional transport rather than the jet-related eddy mixing is the major contributor to the inter-model spread in the transport of land-based tracers into the Arctic. Specifically, in models with a more northern jet, the HC generally extends further north and the tracer source region is mostly covered by surface southward flow associated with the lower branch of the HC, resulting in less efficient transport poleward to the Arctic. During boreal summer, there are poleward biases in jet location in free-running models, and these models likely underestimate the rate of transport into the Arctic. Models using specified dynamics do not have biases in the jet location, but do have biases in the surface meridional flow, which may result in differences in transport into the Arctic. In addition to the land-based tracer, the midlatitude-to-Arctic transport is further examined by another idealized tracer with zonally uniform sources. With equal sources from both land and ocean, the inter-model spread of this zonally uniform tracer is more related to variations in parameterized convection over oceans rather than variations in HC extent, particularly during boreal winter. This suggests that transport of land-based and oceanic tracers or aerosols towards the Arctic differs in pathways and therefore their corresponding inter-model variabilities result from different physical processes.

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Relative concentrations of molecular and metallic ions in midlatitude intermediate and sporadic-E layers

Geophysical Research Letters ◽

10.1029/2004gl020604 ◽

2004 ◽

Vol 31 (19) ◽

Cited By ~ 31

Author(s):

P. A. Roddy

Keyword(s):

Metallic Ions ◽

Sporadic E Layers ◽

Sporadic E

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Large-Scale Tropospheric Transport in the Chemistry Climate Model Initiative (CCMI) Simulations

10.5194/acp-2017-1038 ◽

2017 ◽

Cited By ~ 2

Author(s):

Clara Orbe ◽

Huang Yang ◽

Darryn W. Waugh ◽

Guang Zeng ◽

Olaf Morgenstern ◽

...

Keyword(s):

Large Scale ◽

Climate Model ◽

Atmospheric Transport ◽

Global Scale ◽

Atmospheric Composition ◽

The Arctic ◽

Free Running ◽

The Mean ◽

The Tropics ◽

Interhemispheric Transport

Abstract. Understanding and modeling the large-scale transport of trace gases and aerosols is important for interpreting past (and projecting future) changes in atmospheric composition. Here we show that there are large differences in the global-scale atmospheric transport properties among models participating in the IGAC SPARC Chemistry-Climate Model Initiative (CCMI). Specifically, we find up to 40 % differences in the transport timescales connecting the Northern Hemisphere (NH) midlatitude surface to the Arctic and to Southern Hemisphere high latitudes, where the mean age ranges between 1.7 years and 2.6 years. We show that these differences are related to large differences in vertical transport among the simulations and, in particular, to differences in parameterized convection over the oceans. While stronger convection over NH midlatitudes is associated with slower transport to the Arctic, stronger convection in the tropics and subtropics is associated with faster interhemispheric transport. We also show that the differences among simulations constrained with fields derived from the same reanalysis products are as large as (and, in some cases, larger than) the differences among free-running simulations, due to larger differences in parameterized convection. Our results indicate that care must be taken when using simulations constrained with analyzed winds to interpret the influence of meteorology on tropospheric composition.

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Common volume coherent and incoherent scatter radar observations of mid-latitude sporadic E-layers and QP echoes

Annales Geophysicae ◽

10.5194/angeo-22-3277-2004 ◽

2004 ◽

Vol 22 (9) ◽

pp. 3277-3290 ◽

Cited By ~ 54

Author(s):

D. L. Hysell ◽

M. F. Larsen ◽

Q. H. Zhou

Keyword(s):

Large Scale ◽

Incoherent Scatter Radar ◽

Coherent Scatter ◽

Electrostatic Waves ◽

Incoherent Scatter ◽

Scatter Radar ◽

Dual Beam ◽

Sporadic E Layers ◽

E Region ◽

Sporadic E

Abstract. Common-volume observations of sporadic E-layers made on 14-15 June 2002 with the Arecibo incoherent scatter radar and a 30MHz coherent scatter radar imager located on St. Croix are described. Operating in dual-beam mode, the Arecibo radar detected a slowly descending sporadic E-layer accompanied by a series of dense E-region plasma clouds at a time when the coherent scatter radar was detecting quasi-periodic (QP) echoes. Using coherent radar imaging, we collocate the sources of the coherent scatter with the plasma clouds observed by Arecibo. In addition to patchy, polarized scattering regions drifting through the radar illuminated volume, which have been observed in previous imaging experiments, the 30MHz radar also detected large-scale electrostatic waves in the E-region over Puerto Rico, with a wavelength of about 30km and a period of about 10min, propagating to the southwest. Both the intensity and the Doppler shifts of the coherent echoes were modulated by the wave.

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Large-scale tropospheric transport in the Chemistry–Climate Model Initiative (CCMI) simulations

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-7217-2018 ◽

2018 ◽

Vol 18 (10) ◽

pp. 7217-7235 ◽

Cited By ~ 18

Author(s):

Clara Orbe ◽

Huang Yang ◽

Darryn W. Waugh ◽

Guang Zeng ◽

Olaf Morgenstern ◽

...

Keyword(s):

Large Scale ◽

Climate Model ◽

Atmospheric Transport ◽

Global Scale ◽

Atmospheric Composition ◽

The Arctic ◽

Free Running ◽

The Mean ◽

The Tropics ◽

Interhemispheric Transport

Abstract. Understanding and modeling the large-scale transport of trace gases and aerosols is important for interpreting past (and projecting future) changes in atmospheric composition. Here we show that there are large differences in the global-scale atmospheric transport properties among the models participating in the IGAC SPARC Chemistry–Climate Model Initiative (CCMI). Specifically, we find up to 40 % differences in the transport timescales connecting the Northern Hemisphere (NH) midlatitude surface to the Arctic and to Southern Hemisphere high latitudes, where the mean age ranges between 1.7 and 2.6 years. We show that these differences are related to large differences in vertical transport among the simulations, in particular to differences in parameterized convection over the oceans. While stronger convection over NH midlatitudes is associated with slower transport to the Arctic, stronger convection in the tropics and subtropics is associated with faster interhemispheric transport. We also show that the differences among simulations constrained with fields derived from the same reanalysis products are as large as (and in some cases larger than) the differences among free-running simulations, most likely due to larger differences in parameterized convection. Our results indicate that care must be taken when using simulations constrained with analyzed winds to interpret the influence of meteorology on tropospheric composition.

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Interaction of plasma cloud with external electric field in lower ionosphere

Annales Geophysicae ◽

10.5194/angeo-28-719-2010 ◽

2010 ◽

Vol 28 (3) ◽

pp. 719-736 ◽

Cited By ~ 3

Author(s):

Y. S. Dimant ◽

M. M. Oppenheim

Keyword(s):

Electric Fields ◽

Large Scale ◽

Three Dimensional ◽

Lower Ionosphere ◽

Ionosphere Plasma ◽

Sporadic E Layers ◽

D Region ◽

Mhd Modeling ◽

Sporadic E ◽

Meteor Plasma

Abstract. In the auroral lower-E and upper-D region of the ionosphere, plasma clouds, such as sporadic-E layers and meteor plasma trails, occur daily. Large-scale electric fields, created by the magnetospheric dynamo, will polarize these highly conducting clouds, redistributing the electrostatic potential and generating anisotropic currents both within and around the cloud. Using a simplified model of the cloud and the background ionosphere, we develop the first self-consistent three-dimensional analytical theory of these phenomena. For dense clouds, this theory predicts highly amplified electric fields around the cloud, along with strong currents collected from the ionosphere and circulated through the cloud. This has implications for the generation of plasma instabilities, electron heating, and global MHD modeling of magnetosphere-ionosphere coupling via modifications of conductances induced by sporadic-E clouds.

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