Aphelion Equatorial Mesospheric Clouds Observed By Mcs
M. Slipski, A. Kleinböhl, D. M. Kass, Jet Propulsion Laboratory, California Institute Of Technology, Pasadena,
Ca, Usa. (Marek.J.Slipski@Jpl.Nasa.Gov).

Introduction And Background
Clouds In The Middle Atmosphere (>50 Km) Of Mars
Have Been Observed By Many Instruments In The Past Few
Decades [1, 2, 3, 4] And Are Important For Better Understanding The Vertical Transport Of Volatiles, Dynamical
Phenomena, And Coupling Processes Between The Lower
And Middle Atmopshere.
One Population Has Been Consistently Observed In The
Equatorial Region During Aphelion Season [5, 6]. While
They Are Fairly Well-Studied, Certain Characteristics, Such
As A Clear Pause In Cloud Formation Near Northern Summer
Solstice, Are Not Well Understood. They Are Generally
Clustered Around 2-3 Longitudes Between About 20◦ S To
20◦ N And Are Most Frequently Observed From Ls=0-180◦ ,
With Noticeably Less Formation From Ls=60-100◦ . Many
Clouds In This Population Have Been Spectroscopically
Confirmed To Be Co2 Ice [1, 4, 6].