Numerical simulations of the decay of Martian global dust storms

Conference · Thu Aug 30 04:00:00 EDT 1990 · Journal of Geophysical Research; (United States)

OSTI ID:5445266

Murphy, J R ^[1]; Toon, O B; Haberle, R M; Pollack, J B ^[2]

---

1. Univ. of Washington, Seattle (USA)
2. NASA Ames Research Center, Moffett Field, CA (USA)

The decay of Martian global (great) dust storms is investigated. One-dimensional (vertical, static atmosphere) and two-dimensional (latitude-height, steady state circulation) simulations carried out with an aerosol transport-microphysical model indicate that atmospheric motions play a significant role in the observed decay of global dust storms. Spacecraft observations (Mariner 9, Viking) of the 1971 and the two 1977 planet-encircling dust storms have provided suggestions about some characteristics of storm decay. Specifically, the dust particle size distribution is inferred to have remained essentially unchanged for particles with radii between 1 and 10 {mu}m during decay of the 1971 storm, and surface visible opacity declined quasi-exponentially with time in northern mid-latitudes during the decay of the two 1977 storms. The results from this investigation indicate that two- or three-dimensional dynamical processes play a significant role in the observed decay features of Martian global dust storms. The most important processes are the lofting of dust by vertical motions in the dust source region of the southern hemisphere subtropics and a continuing advective resupply of atmospheric dust into the dust sink regions of the northern hemisphere. This work has implications for Viking data analyses and future Mars observer observations and requires that the particle size distribution be treated as a time and latitude dependent quantity.

• OSTI ID: 5445266
• Report Number(s): CONF-9001119--
• Conference Information: Journal Name: Journal of Geophysical Research; (United States) Journal Volume: 95:B9
• Country of Publication: United States
• Language: English

Related Subjects

640107* -- Astrophysics & Cosmology-- Planetary Phenomena
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ATMOSPHERES
COMPUTERIZED SIMULATION
DISASTERS
DUSTS
DYNAMICS
GLOBAL ASPECTS
MARS PLANET
MATHEMATICAL MODELS
MECHANICS
ONE-DIMENSIONAL CALCULATIONS
PARTICLE SIZE
PLANETARY ATMOSPHERES
PLANETS
SIMULATION
SIZE
STORMS
TIME DEPENDENCE
TWO-DIMENSIONAL CALCULATIONS