Ice Sheet Influences on Tropical Climate (Ref: OP19_32)

Records of the past climate in the tropics are generally interpreted within the context of either changing orbital configuration, which alters the amount of energy received from the sun, or changing greenhouse gas concentrations. However, a recent study (Jones et al. 2018, Nature) has shown that the growth and decay of Northern Hemisphere ice sheets can also change the climate in the tropics. Our understanding of the dynamics of how this happens is at present very limited. This project will begin to probe the details of how changes in the high latitudes can influence the lower latitudes.

Key questions include: how can the seasonal cycle be changed by ice sheets which are present in the same configuration all year round? What are the dynamical mechanisms, such as changes in the monsoons or mean westerly winds, that underlie the way ice sheets alter the climate? Are there spatial patterns that typify these changes? How does the shape of the ice sheet affect its influence?

Numerical models of the physical climate and vegetation distribution will be used to investigate these and other questions. These models can be used in idealised configurations, to understand the basic dynamics, or in more focussed experiments to understand specific phenomena, for example, how the South American Monsoon changed. Using vegetation and isotope models we can further understand how the climatological changes may be recorded in palaeo-proxy archives.

Skills obtained in this project will include: understanding of the dynamics of the climate, using computational models on High Performance computing facilities and analysis of large data sets – Big Data.
Key Research Gaps and Questions:
How do the large ice sheets that grew during ice ages affect the climate in the tropics?

What are the physical mechanisms that enable ice sheets located north of 45N to alter the climate south of 20N and even into the Southern Hemisphere?
Prerequisites:
Some basic experience with numerical analysis software e.g. Python, MATLAB, NCL or similar is a must. Experience of computing in a Unix environment would be helpful.

For more information, please contact William Roberts ([Email Address Removed])