Julia Crook
Research Fellow
Telephone number:
+44(0) 113 34
39085
Email address: j.a.crook08@leeds.ac.uk
Room: 9.127
Biography
I am a member of the Climate Change and Impacts Research Group. Although I am currenly on maternity leave I am part of the Integrated Assessment of Geoengineering Project and will be running the Met Office Unified Model and analysing its output for this.
I have recently submitted my PhD which I started in 2008. Details of my PhD project are given below. Before this I was at UEA doing an MSc in Climate Change. From 1990-2006 I worked as a software engineer working on telecoms products and a variety of control and management systems, writing and testing code, and project managing a team of software engineers.
Qualifications
- BA Natural Sciences, University of Cambridge
- MSc Surface Chemistry, University of Bristol
- MSc Climate Change, University of East Anglia
Memberships/Fellowships
American Geophysical Union
Project details
Project title
Quantifying zonal patterns of climate feedbacks and their role in polar amplification.
Supervisors
Funding
NERC
Project outline
Climate feedbacks are processes in the climate system which respond to surface temperature change and either amplify or dampen that response through radiative flux changes, e.g. snow and ice albedo, water vapour, lapse rate, and cloud feedback. Earth's climate feedback strength is not well constrained by models or observations. Models give a wide range of surface temperature responses to a doubling of CO2 (global mean of 2.0 to 4.5 °C) due to their differences in feedback strengths. Although all models suggest high latitudes will warm more than the tropics, the extent of this polar amplification varies considerably between models. It is believed that beyond about 2°C of global mean warming certain irreversible tipping points will be reached, such as the collapse of the Greenland and Antarctic ice shelves, and the melting of the permafrost. The former will result in large sea level rises and the latter will result in the release of methane, a greenhouse gas which is about 20 times more powerful than CO2, further exacerbating the warming. Ecosystems will be damaged resulting in extinctions of many species including the polar bear. The point at which such dangerous climate changes occur depends on the feedback strength and polar amplification. Therefore a better understanding of regional feedback strength and polar amplification is essential in making accurate projections of future climate change.
Most feedback studies have looked at global mean feedbacks. Using the linear model of feedback and the Earth's energy budget, this project has quantified the modelled zonal mean feedback strengths rather than just global means. The contribution to the 2xCO2 equilibrium temperature response from each feedback, the forcing and the horizontal heat convergence were also determined. A comparison of the 20th century temperature response in models and observations was made. The breakdown of this modelled temperature response in terms of forcing, feedback and heat storage/transport allowed me to suggest why some models do not reproduce the observed temperature response well. Finally a comparison of surface albedo feedback in models and observations was made using several satellite datasets.