Atmospheric Science with InSight

Abstract

In November 2018, for the first time a dedicated geophysical station, the InSight lander, will be deployed on the surface of Mars. Along with the two main geophysical pack-The InSight Mission to Mars II Edited by William B. Banerdt and Christopher T. Russell B A.

Scientific Observations With the InSight Solar Arrays: Dust, Clouds, and Eclipses on Mars

“…Renno et al (2004) noticed a similar periodicity in ground heat flux measurements during a dust devil survey in Arizona but attributed it to a kind of dust‐convection feedback where lofted dust reduces the solar input on the ground, resulting in less dust lifting, and so on. However, little other evidence for such a feedback exists, and since regularity in the Martian PBL has already been noted in the spacing of dust devils (Fenton & Lorenz, 2015), and the cellular structure of the PBL is evident in large‐eddy simulations (e.g., Spiga et al, 2018), this is our preferred explanation. With a cellular pattern with a characteristic wavelength of the order of the PBL thickness (2–10 km) and advection speeds of the order of 5–10 m/s, quasiperiodic variations in other meteorological properties with periods of a few hundred seconds might be expected and indeed have been observed in the Viking windspeed and seismometer record (Lorenz et al, 2017).…”

“…Indeed, such clouds have been visible in camera images acquired in sunset and postsunset imaging campaigns after Sol 140—Figure 12 shows one example. In their discussion of prelanding meteorological expectations, Spiga et al (2018) noted that InSight is at low enough latitude to be in the Mars aphelion cloud belt, and orbital observations cited there support the expectation of visible clouds forming from about L s = 0° (InSight Sol 117) and increasing up to northern summer solstice ( L s = 90°, InSight Sol 320).…”

“…The second effect is the amount of dust suspended in the atmosphere, usually expressed as a vertical column‐integrated optical depth (“tau”). This has been measured at intervals of typically a few sols from measurements of near‐Sun sky brightness from the imagers on InSight (Spiga et al, 2018), as on previous Mars missions (e.g., Lemmon et al, 2015). The initial value was around 0.7, but this grew dramatically over Sols 40–60 to a peak of 1.9 associated with a large dust storm and then declined back to a near steady state of 0.7 or so—see Banfield et al (2020) and Lisano and Bernard (2014).…”

“…The current data from these arrays provide a useful window on the Martian environment that can be exploited for scientific purposes, supplementing the dedicated atmospheric science payload on InSight (e.g., Spiga et al, 2018). On previous missions, the engineering performance of solar arrays has been reported (e.g., for Pathfinder/Sojourner, Landis, 1996; Crisp et al, 2004; for Phoenix, Coyne et al, 2009; for the Mars Exploration Rovers, Stella et al, 2008, 2009), but after the initial report of dust settling on Sojourner, the environmental insights afforded by solar array data have received relatively little comment, although see Lorenz and Jackson (2015) for the potential of similar data at Mars analog sites on Earth.…”

Calibration of the HP3 Radiometer on InSight

“…In situ radiometers can also be used to derive thermophysical properties of the observed ground, such as thermal inertia (e.g., Fergason et al, ; Golombek et al, ; Grott et al, ; Vasavada et al, ). The InSight lander also has a comprehensive suite of meteorological sensors, which enable atmospheric science that is enhanced by the RAD data (Banfield et al, ; Spiga et al, ).…”