Dr Graham Mann

Dr Graham Mann

Profile

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 3rd year "Frontiers in Environmental Science Research" module (SOEE 3710), core for students on the Environmental Science and Meteorology and Climate Science degree programmes. He now also leads the 1st year foundation modules in Maths and Physics: "Maths for Environmental Social Scientists" (SOEE1420) and Physics for Environmental Scientists (SOEE1540).  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 several different host models, including the flagship European atmospheric monitoring system "Composition-IFS".

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.

With 20 years experience in atmospheric science research at the University of Leeds, Dr. Mann has ~60 publications in leading international peer-reviewed journals (at July 2017) including 40 in Atmospheric Chemistry and Physics, 5 in the Journal of Geophysical Research, 4 in Geophysical Research Letters, 2 in Nature and 1 in PNAS. He is also a Topical Editor for the international Geoscientific Model Development journal.

Dr. Mann also continues to lead the onward development of the GLOMAP-mode aerosol microphysics module, a core element of several community models including the TOMCAT chemistry transport model, the UM-UKCA composition-climate model, UK Earth System Model (UKESM) and the Copernicus Atmospheric Monitoring System C-IFS.  He co-ordinates GLOMAP coding developments with several groups at the UK Met Office and ECMWF and is code-owner in TOMCAT, UM-UKCA and C-IFS.

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 Scientific Steering Committee of the SPARC “Stratospheric Sulphur and its Role in Climate” initiative (SSIRC) and the Bern International Space Science Institute team on stratospheric aerosol. UK co-lead for the CMIP6 MIPs “VolMIP” and “GeoMIP”, Dr. Mann also co-leads the modelling component of SSiRC, leading the co-ordination of multi-model experiments on major volcanic eruptions for models which treat stratospheric aerosol interactively. Dr. Mann also co-convened two stratospheric aerosol and volcano-climate impacts sessions at 2016 and 2018 EGU, and is lead convenor for the session at EGU 2019. With University of Leeds scientists increasingly contributing to stratospheric aerosol research internationally, the annual workshop for SSiRC is planned to be held in Leeds in spring 2020.

<h4>Research projects</h4> <p>Any research projects I'm currently working on will be listed below. Our list of all <a href="https://environment.leeds.ac.uk/dir/research-projects">research projects</a> allows you to view and search the full list of projects in the faculty.</p>

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 2018-2019, Dr. Mann is module leader for three undergraduate modules, which span all 6 degree programmes within the School of Earth and Environment.

  1. Maths for Environmental Social Scientists
  2. Physics for Environmental Scientists
  3. Frontiers in Environmental Science Research

The 3rd year "Frontiers in Environmental Science Research" module is core for students on the Environmental Science and Meteorology & Climate Science degree programmes, whilst the 1482 and 1540 are 1st year foundation modules in Maths and Physics. The 1482 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 1540 module provides similarly to ensure all students on the Environmental Science and Geological Sciences degree programmes have good understanding of Physics to A-level standard. 

In 2018-2019 Dr. Mann will be lead supervisor for a 3rd year dissertation project into marine biogenic influences on climate (and the CLAW hypothesis) and in 2017-2018 supervised dissertation project investigating meteorological influences on air pollution in Leeds. He also 2nd-marked dissertation projects on biochar (lead supervisor Alex Rap) and climate change in the Mediterranean (lead supervisor Amanda Maycock). 

In 2018-2019 Dr. Mann is lead supervisor for a Meteorology and Climate Science MRes project to investigate the 1960s stratosphere, and how the March 1963 Agung eruption may have effected faster removal of radionuclides (increasing fallout), the eruption occurring shortly before the ban on atmospheric nuclear testing took effect in October 1963.  This research topic also provides an applied example of basic statistical techniques for one of the coursework elements of the 1482 module

Dr. Mann's current PhD students include:

  • 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-present. 
  • Hana Pearce, "Nitrate aerosol: implications for European air quality and climate", (lead supervisor, co-supervisor Dr. Stephen Arnold), NERC DTP PhD studentship 2014-present
  • 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-present (submitted Aug 2018)

Previous PhD studentships include:

  • Tim Keslake, "Investigating the impact of fires on atmospheric composition using reactive gas and aerosol assimilation", (co-supervisor, lead supervisor Prof. Martyn Chipperfield), NCEO PhD studentship 2013-2017.
  • 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.
  • 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.
  • 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.

Research groups and institutes

  • Institute for Climate and Atmospheric Science

Current postgraduate research students

<h4>Postgraduate research opportunities</h4> <p>We welcome enquiries from motivated and qualified applicants from all around the world who are interested in PhD study. Our <a href="https://environment.leeds.ac.uk/research-opportunities">research opportunities</a> allow you to search for projects and scholarships.</p>