A new insight into the vertical neutral-ion coupling between the mesopause and equatorial ionosphere F-region

Abstract. This letter reports unique observations, illustrating the vertical coupling between the daytime mesopause and F-region of the ionosphere over the magnetic dip equatorial station Trivandrum (8.5° N, 76.5° E, 0.5° N dip lat.) in India. For the "first time", it has been shown that the temporal variations in the mean daytime mesopause temperatures (MPT), during geomagnetically quiet days corroborate well with that of the base height changes (h'F) of the ionospheric F-region. However, there exist some characteristic time delays between these two, which vary from 0 to 90 min. The MPTs are measured using the unique Multi-Wavelength Dayglow Photometer while the h'Fs are derived using a co-located digital Ionosonde. The observed time delays are attributed to the intercompeting roles between the diffusion and wave-dynamical processes in modulating the transport of atomic oxygen at these altitudes.

[1]  H. Rishbeth,et al.  Day-by-day modelling of the ionospheric F2-layer for year 2002 , 2009 .

[2]  D. Marsh,et al.  Temporal variations of atomic oxygen in the upper mesosphere from SABER , 2010 .

[3]  T. Pant,et al.  A comparative study of daytime mesopause temperatures obtained using unique ground based optical and meteor wind radar techniques over the magnetic equator , 2005 .

[4]  Can molecular diffusion explain Space Shuttle plume spreading? , 2010 .

[5]  J. Forbes.  Dynamics of the Thermosphere , 2007 .

[6]  A. Coster,et al.  Unexpected connections between the stratosphere and ionosphere , 2010 .

[7]  R. Sridharan,et al.  First results on daytime mesopause OH rotational temperatures using ground-based photometry from equatorial latitudes , 1999 .

[8]  C. Bruma,et al.  Planetary wave signatures in the equatorial atmosphere – ionosphere system , and mesosphere-E-and F-region coupling , 2006 .

[9]  Anne K. Smith,et al.  Physics and chemistry of the mesopause region , 2004 .

[10]  J. Meriwether.  High latitude airglow observations of correlated short-term fluctuations in the hydroxyl meinel 8-3 band intensity and rotational temperature , 1975 .

[11]  S. Sridharan,et al.  Variabilities of mesospheric tides and equatorial electrojet strength during major stratospheric warming events , 2009 .

[12]  A. D. Danilov,et al.  Eddy diffusion studies in the lower thermosphere , 1996 .

[13]  Rolando R. Garcia,et al.  The effect of breaking gravity waves on the dynamics and chemical composition of the mesosphere and lower thermosphere , 1985 .

[14]  J. Russell,et al.  The "wave turbopause" , 2007 .

[15]  T. Pant,et al.  Highly localized cooling in daytime mesopause temperature over the dip equator during counter electrojet events: First results , 2007 .

[16]  M. Taylor,et al.  Large amplitude perturbations in mesospheric OH Meinel and 87‐Km Na lidar temperatures around the autumnal equinox , 2001 .

[17]  D. Marsh,et al.  Interaction of chemical heating and the diurnal tide in the mesosphere , 2003 .

[18]  Jorge L. Chau,et al.  Quiet variability of equatorial E × B drifts during a sudden stratospheric warming event , 2009 .

[19]  S. Thampi,et al.  Investigation on the mesopause energetics and its possible implications on the equatorial MLTI processes through coordinated daytime airglow and radar measurements , 2007 .

[20]  M. Larsen,et al.  Two‐dimensional turbulence, space shuttle plume transport in the thermosphere, and a possible relation to the Great Siberian Impact Event , 2009 .

[21]  K. K. Kumar,et al.  Vertical propagation characteristics and seasonal variability of tidal wind oscillations in the MLT region over Trivandrum (8.5° N, 77° E): first results from SKiYMET Meteor Radar , 2006 .

[22]  J. Forbes,et al.  Intra‐annual variability of the low‐latitude ionosphere due to nonmigrating tides , 2008 .

[23]  R. P. Lowe,et al.  Atomic oxygen profiles (80–94 km) derived from Wind Imaging Interferometer/Upper Atmospheric Research Satellite measurements of the hydroxyl airglow: 1. Validation of technique , 2003 .

[24]  T. Pant,et al.  Atmosphere‐Ionosphere coupling observed over the dip equatorial MLTI region through the quasi 16‐day wave , 2007 .

[25]  M. Mlynczak,et al.  A detailed evaluation of the heating efficiency in the middle atmosphere , 1993 .