Dr Graham Mann

Profile

Dr Mann has 23 years academic research experience in atmospheric science, with a h-index of 50, with 94 publications in leading peer-reviewed journals including 29 published in the last 5 years. 

Dr. Graham Mann joined the University of Leeds in 1994, completing his PhD in 1998 supervised by Stephen Mobbs, modelling the size distribution of wind-borne snow particles and their interaction with the atmospheric boundary layer, a CASE studentship with the British Antarctic Survey (BAS). The research involved applying a bin-resolved time-dependent boundary layer model to simulate the variation in snow particle size distribution, comparing to optical particle counter measurements and particle size distributions from gummed particle impaction BAS measurements from the STABLE-2 field campaign in Antarctic winter 1991.  The project, a collaboration between Stephen Mobbs and John King and Phil Anderson at BAS, revealed how the sublimation (evaporation from the solid phase) of the blowing snow particles greatly exceeds that from the surface, and provides an influential water vapour source and heat sink to the lower boundary layer, the model simulations exploring the influences on humidity and temperature profiles.

After his PhD, Dr. Mann continued this research as a PDRA via a NERC standard grant, to understand how the acceleration of wind over Antarctic ice shelf topography causes variability in snow accumulation, and consequences for the siting and potential biasing of ice core measurements. The project was another Leeds-BAS collaboration led by Stephen Mobbs, and involved comparing simulations to observations from the Lyddan Ice Rise near Halley on the Brunt Ice Shelf, John King, Phil Anderson again the collaborating BAS scientists, with David Vaughan taking the field measurements (during Antarctic summers 1998, 1999 and 2000).

In 2003, Dr. Mann began researching the composition of the stratosphere as an EU-funded PDRA with Ken Carslaw, the MAPSCORE project involving microphysical modelling of Arctic polar stratospheric clouds (PSCs). The project coupled a global 3D stratospheric chemistry transport model SLIMCAT with a new PSC microphysics module (DLAPSE) to understand how inter-annual Arctic vortex variability affects the growth and sedimentation of nitric acid containing PSCs. These sedimenting PSCs remove nitric acid from the Arctic stratosphere during winter, the "denitrification" then prolonging ozone loss in polar spring.

In 2005, Dr Mann became a permanent Research Scientist with Prof. Carslaw funded by the National Centre for Atmosphere Science (NCAS), where his research initially involved developing a new aerosol microphysics module for the in-development UK Chemistry and Aerosol sub-model of the UK Met Office Unified Model (UM).  The first phase of the research (from 2005-2010) involved creating the new "GLOMAP-mode" scheme , essentially a faster "parametrised version" of the existing sectional aerosol microphysics module "GLOMAP-bin", both running within the Leeds tropospheric chemistry transport model TOMCAT.

The 2nd phase of the research (2010-2015) saw Dr. Mann then leading the activity to ensure GLOMAP-mode became fully incorporated into the UM, and subsequently applied for a range of tropospheric aerosol science within the UM-UKCA community composition-climate model. With UKCA now a core sub-model of the joint NERC-Met Office "UK Earth System Model (UKESM)", GLOMAP-mode is active in all configurations of UKESM, for example including for the CMIP6 deck UKESM simulations in 2017/2018.  

Since 2013, Dr. Mann's research interests have shifted back to the stratosphere, and to think how the GLOMAP-mode aerosol microphysics module could be applied within UM-UKCA and UKESM to understand the composition of the stratospheric aerosol layer and its enhancement by volcanic eruptions and potential particle or sulphur injection for "stratospheric solar radiation management" (strat-SRM) geoengineering purposes.

Dr. Mann is now a Lecturer in Atmospheric Science, and leads the 1st year foundation modules in Maths and Physics: "Foundation Maths for Environmental Social Science" (SOEE1483) and Foundation Physics for Environmental Science (SOEE1541).  Dr. Mann research-directs several PDRA and PhD researchers within ICAS, and advises scientists at other UK Universities, and internationally, who are applying GLOMAP-mode within a range of different host models, including the European global modelling system for CAMS (Copernicus Atmospheric Monitoring Service), one of six services that together form Copernicus, the EU’s Earth observation programme.

In July 2017, Dr. Mann led a major grant success for the University of Leeds, bringing in £0.8 million of research funding via the "MeteorStrat" project in collaboration with Prof. John Plane in the School of Chemistry and Prof. Ben Murray and Prof. Martyn Chipperfield in the School of Earth and Environment. The research will quantify how the stratospheric aerosol and ozone layers are influenced by particles formed during the burn-up of cosmic dust particles in the outer atmosphere. Meteoric smoke particles (MSPs) form as small meteroids ablate, which are then continuously (but slowly) entrained down into the stratosphere, alongside also small "meteoric fragments" which, unlike MSPs, are not ablation-generated, but instead "break off" the meteroids as they burn up during atmospheric entry.

The research aligns directly with recent in-situ observations which have confirmed findings from the late 1990s that most particles in the stratospheric aerosol layer contain refractory core of meteoric origin. That many of the sulphuric acid particles that comprise the stratospheric aerosol layer contain refractory cores has important implications for how readily PSCs form, particularly in the Arctic, and the project brings together several research strands from Dr. Mann's research.

Dr. Mann also continues to lead the co-ordination of the development of the GLOMAP-mode aerosol microphysics module, which is now included in several modelling frameworks including the TOMCAT chemistry transport model (Mann et al., 2010), the UKCA sub-model in the UK Met Office Unified Model (MetUM) (see Bellouin et al., 2013), the UK Earth System Model UKESM (Mulcahy et al., 2020) and the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasting (ECMWF). 

Responsibilities

• Lead of stratospheric aerosol research group
• Research-direction of several PDRAs and PhD students
• Module Leader

Research interests

Dr. Mann is a member of the steering committee for the World Climate Research Programme (WCRP) initiative on stratospheric aerosol: Stratospheric Sulphur and its Role in Climate “SSiRC”. Dr. Mann also co-leads the “ISA-MIP” model intercomparison for interactive stratospheric aerosol models. A senior member of the aerosol modelling group (http://www.see.leeds.ac.uk/aerosol) in the Institute for Climate and Atmospheric Science (ICAS) within the School of Earth Environment, he leads the development of the GLOMAP-mode aerosol microphysics module, which is now included in several modelling frameworks including the TOMCAT chemistry transport model (Mann et al., 2010), the UKCA sub-model in the UK Met Office Unified Model (MetUM) (see Bellouin et al., 2013), the UK Earth System Model UKESM (Mulcahy et al., 2020) and the Integrated Forecast System (IFS) of the European Centre for Medium-Range Weather Forecasting (ECMWF). 

Dr. Mann has over 10 years postgraduate research supervision experience since his first PhD student (Matt Woodhouse), with several CASE studentships with the UK Met Office, recent projects including “Nitrate aerosol: Implications for European climate and air quality” (Leeds-York DTP) and Met Office partnership project “The role of volcanic ash in the global dispersion of the aerosol cloud from major tropical eruptions” (50% funded by the EU’s Copenicus EO programme).

Dr. Mann is lead PI on the £0.8m project “Meteoric Influences on stratospheric aerosol and polar clouds (MeteorStrat)” (NERC standard grant NE/R011222/1), and co-I on the recent NERC consortium projects on the climate hiatus (“Securing Multidisciplinary UndeRstanding and Prediction of Hiatus and Surge events”, NERC highlight topic: NE/N006038/1) and the North Atlantic climate system (The North Atlantic Climate System Integrated Study, NERC multi-centre Long-Term Science Program NE/N018001/1).

Whilst the UKESM core team have focused to integrate the model’s component modules, Dr. Mann has continued to make major contributions to the project’s success, NCAS PI for the “Aerosol and Chemistry Efficiency (ACE)” JWCRP project enacting hybrid OpenMP-MPI within UKCA, unlocking crucial throughput enhancements for UKESM. More recently he his contributions have focused on GLOMAP’s incorporation into the European modelling system via the global aerosol development consortium within the EU-funded Copernicus Atmospheric Monitoring Service (CAMS), one of six services that together form Copernicus, the EU’s Earth observation programme.

• MeteorStrat (Meteoric influences on stratospheric aerosol and clouds)

Qualifications

• PhD, Atmospheric Science, University of Leeds
• BSc, Applied Mathematics, University of Warwick

Professional memberships

• Member of the European Geosciences Union
• Member of the American Geophysics Union
• Member of the Royal Meteorological Society

Student education

In session 2020-2021, Dr. Mann is module leader for two undergraduate modules, which span all 6 degree programmes within the School of Earth and Environment.

1. Foundation Maths for Environmental Social Science (SOEE1483)
2. Foundation Physics for Environmental Science (SOEE1541)

The 1483 module provides for students on the Sustainability & Environmental Management and Environment & Business degree programmes, who either didn't take A-level Maths, or did not get a good grade at that particular time.  The 1541 module provides similarly to ensure all students on the Environmental Science degree programme have good understanding of Physics to A-level standard. 

In 2020-2021 Dr. Mann is also lead supervisor for two Masters research projects (http://homepages.see.leeds.ac.uk/~amtgwm/Mann_MRes2021projects_1960sStratosphere.pdf ) to understand the stratospheric aerosol layer in the 1960s, within the MRes in Climate and Atmospheric Science programme ( http://homepages.see.leeds.ac.uk/~earrn/mrescas/ )

The projects link with Dr. Mann’s research interests to understand the broader composition of the 1960s stratosphere, including the US government High Altitude Sampling Program (HASP) of global aircraft surveys and balloon measurments in the stratosphere that continued through that decade, and the sustained US Air Force Cambridge Laboratory program of weekly ozone-sonde launches from sites spanning the tropics and mid-latitudes.

Today’s generation of interactive stratospheric aerosol models have the potential to understand what the observed concentrations of radiostrontium and radiocarbon in the period after the October 1963 partial test ban on atmospheric nuclear testing can teach us about stratospheric aerosol transport and sedimentation.  With the 1963 stratosphere strongly affected by the volcanic aerosol cloud from the major tropical eruption of Agung in March 1963, these measurements also have within them variations caused by the radiative heating and increased sedimentation (larger effective radius) caused by the Agung aerosol cloud.

This environmental monitoring research topic has provided an environmental science example for coursework on correlation and regression for the Foundation Maths module and as a history of science essay within the Foundation Physics module.

Examples of Dr. Mann's recent PhD students are:

• Sarah Shallcross, "Assessing the role of ash in the global dispersion of the stratospheric aerosol cloud from the 1991 Mount Pinatubo eruption", (lead supervisor, co-supervisors Dr. Anja Schmidt, Dr. Ryan Neely), co-funded PhD studentship (SEE and CAMS43) 2016-2020 https://etheses.whiterose.ac.uk/28125/
• Lauren Marshall, "Effects of volcanic eruption source parameters on radiative forcing and sulfate deposition", (co-supervisor, lead supervisor Dr. Anja Schmidt), NERC DTP PhD studentship, 2014-2018 http://etheses.whiterose.ac.uk/22551/
• Hana Pearce, "Nitrate aerosol: implications for European air quality and climate", (lead supervisor, co-supervisor Dr. Stephen Arnold), NERC DTP PhD studentship 2014-2018 https://etheses.whiterose.ac.uk/25173/

Dr, Mann has supervised also these other former PhD students:

• Tim Keslake, "Investigating the impact of fires on atmospheric composition using reactive gas and aerosol assimilation", (2^nd Leeds supervisor, lead supervisor Prof. Martyn Chipperfield), NCEO PhD studentship 2013-2017 http://etheses.whiterose.ac.uk/20837/
• Anja Schmidt, "'Modelling tropospheric volcanic aerosol: from aerosol microphysical processes to Earth system impacts.", (3rd Leeds supervisor, lead supervisors Prof. Marge Wilson and Prof. Ken Carslaw, co-supervisor Thor Thordarson, Univ. Edinburgh), Univ. Leeds PhD studentship 2007-2011 https://www.springer.com/gp/book/9783642348389
• Matt Woodhouse, "Oceanic dimethyl sulphide emissions and dust deposition in the climate system" (lead supervisor, co-supervisor Prof. Ken Carslaw, CASE supervisor Olivier Boucher), UK-SOLAS Knowledge Transfer PhD studentship 2006-2010 http://homepages.see.leeds.ac.uk/~amtgwm/Woodhouse_PhDthesis_submitted.pdf
• Paul Manktelow, "Understanding the complex behaviour of tropospheric sulfate in a global aerosol microphysics model" (co-supervisor, lead supervisor Prof. Ken Carslaw), NERC quota PhD studentship 2005-2009 http://homepages.see.leeds.ac.uk/~amtgwm/Manktelow_PhDthesis_corrected.pdf

Research groups and institutes

• Institute for Climate and Atmospheric Science
• Atmospheric Chemistry and Aerosols

Current postgraduate researchers

• Saffron Heddell