Bodélé: "More or Less" a major dust source

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Recently I am help doing a study on dust transport and deposition
concerning central and northern Libya. [A geochemical study](http://dx.doi.org/10.1016/j.atmosenv.2006.02.020) by my mentors suggest
that some of the dust in Hun and Sebha, even some in the coastal
areas, may be from the Bodélé, which is the largest source of dust in
Libya. [This preprint article on
PNAS](http://dx.doi.org/10.1073/pnas.0711850106), therefore, is of
special interest to me.

However, if the authors of the paper are right about the transport
mode of dust from Bodélé, our story may prove wrong. The authors
claim that the prevailing direction of the dust transport from this
area is towards the west in winter, which is also the maximum of dust
output in a year in the area. But our study area shows a constrasting
trend: lowest dust deposition both by ground data and remote sensing,
in winter, and it is to the north of Bodélé. The summer
transportation, if any, may contribute very little to our study area,
limited both by transport and production.

The MODIS brightness temperature difference (BTD) data is being
derived, which can provide us a picture of dust plumes for major dust
events. We are also looking at the geochemical properties and
meteorological data around the area. Combining these data, hopefully,
can provide more information on the transport mode in our study.

In the PNAS paper, the authors point out that the Bodélé area may be a
"tipping element" in the context of climate change, due to its
dominant position in the output of dust and its location. Some
climate models suggest that the area may become wetter, yet the wind
will be strengthened. As a result, it is really difficult to tell how
the dust output will be influenced by climate change at the moment.
Will we have more or less dust from Bodélé? This will be an
interesting problem, as dust from this area interacts with many
large-scale systems. It is a wonder, considering that the Bodélé
Depression is so small. The difficulty is that we only have inaccurate
model and incomplete data for this area, and for the North Africa.
New remote sensing technology such as
[SEVIRI](http://www.esa.int/esapub/bulletin/bullet111/chapter4_bul111.pdf)
(imagine quasi-MODIS resolution images every 15 minutes, very cool) may partly solve
the problem, but more geochemical and meteorological data are
essential to answer the complex dust question.

Washington, R., Bouet, C., Cautenet, G., Mackenzie, E., Ashpole, I., Engelstaedter, S., Lizcano, G., Henderson, G., Schepanski, K., & Tegen, I. (2009). Tipping Elements in Earth Systems Special Feature: Dust as a tipping element: The Bodele Depression, Chad Proceedings of the National Academy of Sciences DOI: 10.1073/pnas.0711850106

OHARA, S., CLARKE, M., & ELATRASH, M. (2006). Field measurements of desert dust deposition in Libya Atmospheric Environment, 40 (21), 3881-3897 DOI: 10.1016/j.atmosenv.2006.02.020