Identifying Sources of Aeolian Mineral Dust: Present and Past - Mineral Dust: A Key Player in the Earth System - page 50

Chapter 3
Identifying Sources of Aeolian Mineral Dust:
Present and Past
Daniel R. Muhs, Joseph M. Prospero, Matthew C. Baddock,
and Thomas E. Gill
Abstract Aeolian mineral dust is an important component of the Earth's envi-
ronmental systems, playing roles in the planetary radiation balance, as a source
of fertilizer for biota in both terrestrial and marine realms and as an archive
for understanding atmospheric circulation and paleoclimate in the geologic past.
Crucial to understanding all of these roles of dust is the identification of dust
sources. Here we review the methods used to identify dust sources active at present
and in the past. Contemporary dust sources, produced by both glaciogenic and
non-glaciogenic processes, can be readily identified by the use of Earth-orbiting
satellites. These data show that present dust sources are concentrated in a global
dust belt that encompasses large topographic basins in low-latitude arid and semiarid
regions. Geomorphic studies indicate that specific point sources for dust in this zone
include dry or ephemeral lakes, intermittent stream courses, dune fields, and some
bedrock surfaces. Back-trajectory analyses are also used to identify dust sources,
through modeling of wind fields and the movement of air parcels over periods of
several days. Identification of dust sources from the past requires novel approaches