1 / 6

1. Variability in dust

North African dust: Natalie Mahowald and others. 1. Variability in dust. Reconciling small scale to large scale. Diurnal to synoptic variability. Decadal variability. Glacial to interglacial. Jones et al., 2003; Mahowald et al., 2002,2005, 2006.

allegra-yates
Télécharger la présentation

1. Variability in dust

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. North African dust: Natalie Mahowald and others 1. Variability in dust Reconciling small scale to large scale Diurnal to synoptic variability Decadal variability Glacial to interglacial Jones et al., 2003; Mahowald et al., 2002,2005, 2006

  2. Currently looking at what station visibility data tells us about dust trends, and reasons for sources (Mahowald et al, in prep) In this data: NAO, El Nino not particularly important Precip Land use, grazing Winds Important over north africa

  3. Anthropogenic impacts on dust Understanding regional impact of possible land use dust sources in North Africa Global picture of changes from preindustrial to future due to climate, land use and vegetation changes (co2 fertilization) Yoshioka et al., 2005; Mahowald and Luo, 2003

  4. CAM3/SOM Dust radiative feedback impacts on precip Not including long wave in CCSM3 enhances double ITCZ (not shown) 2. Impacts of dust onto climate/precipitation • Impacts on Sahel precip. • SSTs ~50% of observed precip change • Vegetation changes Not significant • Model can’t capture dust changes observed, but observed dust changes (when forced onto model) cause ~30% change in observed precip in Sahel • Dust could be important feedback on Sahel precip Yoshioka et al., submitted

  5. 3. Impact of changing iron deposition on ocean biogeochemistry: Including iron limitation, and nitrogen fixation, using CCSM3 dust changes for different time periods, we see large response to climate: Much more uptake of CO2 in LGM. More uptake of CO2 in preindustrial than current Less uptake of CO2 in doubled-CO2 climate than today. Moore, et al. accepted using ocean ecosystem model in CCSM

  6. Young Scientist Network Goal: To foster global collaborations among young scientists on integrative research to better understand the role of humans in perturbing biogeochemistry and climate. • 1st workshop in June, 2005 in Breckenridge, Colorado, 52 participants from 17 countries, 33 also attended CCSM workshop • 2nd Workshop planned for September 9-10, 2006: Mexico City “Urbanization Interactions with Climate and Biogeochemistry” Organizational Committee: N. Mahowald, M. Scholze, K. Hibbard, P. Rayner, R. Dawson, A. Balogun. Organized by NCAR-ASP. Funded by AIMES, NCAR-SERE, NCAR-ASP, NSF, MPI and participant organizations www.asp.ucar.edu/ess

More Related