Paper: Hopcroft et al 2015

Title: Last glacial maximum radiative forcing from mineral dust aerosols in an Earth System model

For a fuller description of the paper itself, go to the end of this web page.

Each simulation published in this paper corresponds to a unique 5 or 6 character code on the web pages.
The following table lists the name of the simulation as used in the paper, and the corresponding code name

The webpage gives you the ability to examine the published simulations, but you can also download the raw (netcdf) files to perform your own analysis. Detailed instructions on how to use the webpages and access the data can be found here: Using_BRIDGE_webpages.pdf

You can have make you own analysis and plots by going here

Simulation Name as in PaperSimulation name on web pages
PI-CLASSICxjlah
LGM-CLASSICxjlag
PI-DEADxjlal
LGM-DEADxjlak
PI-CLASSIC extra outputxjlax
LGM-CLASSIC extra outputxjlaw
PI-DEAD extra outputxjlaz
LGM-DEAD extra outputxjlay
PI-CLASSIC double-call radxjlap
LGM-CLASSIC double-call radxjlao
PI-DEAD double-call radxjlar
LGM-DEAD double-call radxjlaq


This is a fuller description of paper

We performed atmosphere-aerosol-vegetation simulations with HadGEM2-A for the pre-industrial and last glacial maximum using two different emissions schemes for mineral dust. CLASSIC: which is used in HadGEM2-ES and DEAD which is used in CCSM4.

NameHopcroft et al
Brief DescriptionWe performed atmosphere-aerosol-vegetation simulations with HadGEM2-A for the pre-industrial and last glacial maximum using two different emissions schemes for mineral dust. CLASSIC: which is used in HadGEM2-ES and DEAD which is used in CCSM4.
Full Author ListPeter O. Hopcroft, Paul J. Valdes, Stephanie Woodward and Manoj M. Joshi
Title Last glacial maximum radiative forcing from mineral dust aerosols in an Earth System model
Year2015
JournalJournal of Geophysical Research
Volume120
Issue
Pages8186-8205
DOI10.1002/2015JD023742
Contact's NamePeter O. Hopcroft
Contact's emailpeter.hopcroft@bristol.ac.uk
AbstractThe mineral dust cycle in preindustrial (PI) and Last Glacial Maximum (LGM) simulations with the Coupled Model Intercomparison Project Phase 5 model Hadley Centre Global Environment Model 2-Atmosphere (HadGEM2-A) is evaluated. The modeled global dust cycle is enhanced at the LGM, with larger emissions in the Southern Hemisphere, consistent with some previous studies. Two different dust uplift schemes within HadGEM2 both show a similar LGM/PI increase in total emissions (60% and 80%) and global loading (100% and 75%), but there is a factor of 3 difference in the top of the atmosphere net LGM-PI direct radiative forcing (?1.2 W m?2 and ?0.4 W m?2, respectively). This forcing is dominated by the short-wave effects in both schemes. Recent reconstructions of dust deposition fluxes suggest that the LGM increase is overestimated in the Southern Atlantic and underestimated over east Antarctica. The LGM dust deposition reconstructions do not strongly discern between these two dust schemes because deposition is dominated by larger (2?6 ?m diameter) particles for which the two schemes show similar loading in both time periods. The model with larger radiative forcing shows a larger relative emissions increase of smaller particles. This is because of the size-dependent friction velocity emission threshold and different size distribution of the soil source particles compared with the second scheme. Size dependence of the threshold velocity is consistent with the theory of saltation, implying that the model with larger radiative forcing is more realistic. However, the large difference in radiative forcing between the two schemes highlights the size distribution at emission as a major uncertainty in predicting the climatic effects of dust cycle changes.