The near‐global mesospheric potassium layer: Observations and modeling

Dawkins, E. C. M.; Plane, J. M. C.; Chipperfield, Martyn P.; Feng, Wuhu

doi:10.1002/2015jd023212

Cited by 19 publications

(46 citation statements)

References 74 publications

(122 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Lidar observations have shown that K column abundance varies semiannually, with maxima in summer and winter and minima at the equinoxes [ Mégie et al ., ; Eska et al ., ; Friedman et al ., ]. More recently, satellite‐based observations have demonstrated that the semiannual variability is global in extent except at very high latitudes [ Dawkins et al ., , ]. Dawkins et al .…”

Section: Introductionsupporting

confidence: 73%

“…Dawkins et al . [] investigated the relationship between temperature and K density by employing the National Center for Atmospheric Research (NCAR) Whole Atmosphere Community Climate Model with potassium chemistry (WACCM‐K) [ Plane et al ., , ], and their results validated the temperature dependence of the Plane et al . [] K chemistry model.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Structure and seasonal variations of the nocturnal mesospheric K layer at Arecibo

Yue

Friedman

et al. 2017

JGR Atmospheres

View full text Add to dashboard Cite

We present the seasonal variations of the nocturnal mesospheric potassium (K) layer at Arecibo, Puerto Rico (18.35°N, 66.75°W) from 160 nights of K Doppler lidar observations between December 2003 and January 2010, during which the solar activity is mostly low. The background temperature is also measured simultaneously by the lidar and shows a strong semiannual oscillation with maxima occurring during equinoxes at all altitudes. The annual mean K density profile is approximately Gaussian with a peak altitude of 91.7 km. The K column abundance and the centroid height have strong semiannual variations, with maxima at the solstices. Both parameters are negatively correlated to the mean background temperature with a correlation coefficient < −0.5. The root‐mean‐square (RMS) width has a distinct annual oscillation with the largest width occurring in May. The seasonal variation of the centroid height is similar to that of the Fe layer at the same site. The seasonal temperature variation indicates significant enhanced wave‐induced downward transport for both species during spring and autumn. This explains the metal layer centroid height and column abundance variations at Arecibo and provides a general mechanism to account for the seasonal variations in the centroid height of all metal species measured at low‐latitude and midlatitude sites.

show abstract

Section: Introductionsupporting

confidence: 73%

Section: Introductionmentioning

confidence: 99%

Structure and seasonal variations of the nocturnal mesospheric K layer at Arecibo

Yue

Friedman

et al. 2017

JGR Atmospheres

View full text Add to dashboard Cite

show abstract

“…Overall, the results presented here demonstrate that the unusual behavior of K compared to Na and Fe is present at diurnal [ Feng et al ., ], seasonal [ Dawkins et al ., ], and longer timescales (this study). The model predicts that K is the only one of these three metals that will provide a sensitive indicator of long‐term changes in the MLT region.…”

Section: Discussionmentioning

confidence: 56%

Solar cycle response and long‐term trends in the mesospheric metal layers

et al. 2016

Self Cite

View full text Add to dashboard Cite

The meteoric metal layers (Na, Fe, and K)—which form as a result of the ablation of incoming meteors—act as unique tracers for chemical and dynamical processes that occur within the upper mesosphere/lower thermosphere region. In this work, we examine whether these metal layers are sensitive indicators of decadal long‐term changes within the upper atmosphere. Output from a whole‐atmosphere climate model is used to assess the response of the Na, K, and Fe layers across a 50 year period (1955–2005). At short timescales, the K layer has previously been shown to exhibit a very different seasonal behavior compared to the other metals. Here we show that this unusual behavior is also exhibited at longer timescales (both the ~11 year solar cycle and 50 year periods), where K displays a much more pronounced response to atmospheric temperature changes than either Na or Fe. The contrasting solar cycle behavior of the K and Na layers predicted by the model is confirmed using satellite and lidar observations for the period 2004–2013.

show abstract

“…These spaceborne spectrometers typically were on board satellites with Sun-synchronous and polar orbits and a maximum scanned latitude of up to 82 • that retrieved densities for Mg and/or Mg + (see, e.g., Joiner and Aikin, 1996;Correira et al, 2008;Scharringhausen et al, 2008;Langowski et al, 2015), K (see, e.g., Dawkins et al, 2014) and Na (see, e.g., Fussen et al, 2004;Casadio et al, 2007;Fan et al, 2007;Gumbel et al, 2007;Fussen et al, 2010;Hedin and Gumbel, 2011;Langowski et al, 2016). Along with the measurements, global atmospheric models for the metal layers in the MLT have been developed for Na (Marsh et al, 2013a), Fe (Feng et al, 2013), Mg (Langowski et al, 2015), K Dawkins et al, 2015), and Si atoms, molecules and ions.…”

Section: Introductionmentioning

confidence: 99%

Comparison of global datasets of sodium densities in the mesosphere and lower thermosphere from GOMOS, SCIAMACHY and OSIRIS measurements and WACCM model simulations from 2008 to 2012

Langowski¹,

Savigny²,

Burrows³

et al. 2017

Atmos. Meas. Tech.

Self Cite

View full text Add to dashboard Cite

Abstract. During the last decade, several limb sounding satellites have measured the global sodium (Na) number densities in the mesosphere and lower thermosphere (MLT). Datasets are now available from Global Ozone Monitoring by Occultation of Stars (GOMOS), the SCanning Imaging Absorption spectroMeter for Atmospheric CHartography (SCIAMACHY) (both on Envisat) and the Optical Spectrograph and InfraRed Imager System (OSIRIS) (on Odin). Furthermore, global model simulations of the Na layer in the MLT simulated by the Whole Atmosphere Community Climate Model, including the Na species (WACCM-Na), are available. In this paper, we compare these global datasets.The observed and simulated monthly averages of Na vertical column densities agree reasonably well with each other. They show a clear seasonal cycle with a summer minimum most pronounced at the poles. They also show signs of a semi-annual oscillation in the equatorial region. The vertical column densities vary from 0.5 × 10 9 to 7 × 10 9 cm −2 near the poles and from 3 × 10 9 to 4 × 10 9 cm −2 at the Equator. The phase of the seasonal cycle and semi-annual oscillation shows small differences between the Na amounts retrieved from different instruments. The full width at half maximum of the profiles is 10 to 16 km for most latitudes, but significantly smaller in the polar summer. The centroid altitudes of the measured sodium profiles range from 89 to 95 km, whereas the model shows on average 2 to 4 km lower centroid altitudes. This may be explained by the mesopause being 3 km lower in the WACCM simulations than in measurements. Despite this global 2-4 km shift, the model captures well the latitudinal and temporal variations. The variation of the WACCM dataset during the year at different latitudes is similar to the one of the measurements. Furthermore, the differences between the measured profiles with different instruments and therefore different local times (LTs) are also present in the model-simulated profiles. This capturing of latitudinal and temporal variations is also found for the vertical column densities and profile widths.

show abstract

The near‐global mesospheric potassium layer: Observations and modeling

Cited by 19 publications

References 74 publications

Structure and seasonal variations of the nocturnal mesospheric K layer at Arecibo

Structure and seasonal variations of the nocturnal mesospheric K layer at Arecibo

Solar cycle response and long‐term trends in the mesospheric metal layers

Comparison of global datasets of sodium densities in the mesosphere and lower thermosphere from GOMOS, SCIAMACHY and OSIRIS measurements and WACCM model simulations from 2008 to 2012

Contact Info

Product

Resources

About