An Airborne Time of Flight Aerosol Mass Spectrometer
Lead Research Organisation:
University of Manchester
Department Name: Earth Atmospheric and Env Sciences
Abstract
The atmosphere is known to contain large amounts of particulate matter. Numbers can range from several tens of thousands of particles per cubic centimetre of polluted air to mere hundreds in more remote locations. As well as being known to affect human health, they have a significant control on the earth's climate, as they can scatter and absorb solar radiation. They are also thought to indirectly affect climate by dictating the properties of clouds and hence their microphysical and optical properties. However, many of the processes and properties that govern large parts of the lifecycle of aerosols in the atmosphere remain quantitatively uncertain, or in some cases unknown, and this must be addressed to improve predictions of aerosol effects. This is being achieved through laboratory and field measurement programmes and model development, the latter requiring field measurements to test their validity. Part of our lack of understanding and the lack of available model data is due to difficulties in accurately measuring the size and composition of particles in a variety of environments. This is particularly true of the organic fraction, which normally consists of a highly complex mixture of different chemical species. Current models tend to under-predict the amounts of organics in by a large factor, especially in the upper atmosphere, where measurements are scarce. Traditionally methods for measuring particle compositions are offline and so need significant time for sample collection. This is unsuitable for aircraft work, where measurements taken over the course of minutes or less are desired. The UK Facility for Airborne Atmospheric Measurements currently uses an Aerodyne Aerosol Mass Spectrometer (AMS) on many of its activities to measure particle compositions and sizes in real time. While this instrument has proved highly useful in studying aerosol compositions in polluted environments, it lacks the sensitivity to be able to study background particles, especially at higher altitudes within the troposphere or when studying aerosol composition in rapidly changing environments such as pollution plumes and cloud systems. We are proposing to develop this instrument further, using technology proven on the ground, to allow us to probe areas of uncertainty in the aerosol lifecycle such as organic aerosols within the free troposphere; the evolution of aerosols within the atmosphere after emission and aerosol-cloud interaction in greater detail than was possible previously. We will then show its capability and versatility in a series of demonstration experiments that focus on two areas of current scientific uncertainty: the composition of aerosols at many altitudes within the free troposphere, especially their organic content, and the evolution of aerosols within the atmosphere shortly after emission in pollution plumes. The instrument is also capable of probing the chemical nature of the particles that act as sites for cloud droplet formation. We will show its effectiveness at doing this using a size selecting inlet already installed on the FAAM to sample cloud droplets. These experiments will demonstrate the power of the new instrument and, as importantly, will highlight how the new instrument can probe aerosol processes in the atmosphere in the future.
Organisations
Publications
Heald C
(2011)
Exploring the vertical profile of atmospheric organic aerosol: comparing 17 aircraft field campaigns with a global model
in Atmospheric Chemistry and Physics
Haywood J
(2008)
Overview of the Dust and Biomass-burning Experiment and African Monsoon Multidisciplinary Analysis Special Observing Period-0
in Journal of Geophysical Research: Atmospheres
Haslett S
(2019)
Remote biomass burning dominates southern West African air pollution during the monsoon
in Atmospheric Chemistry and Physics
Franklin J
(2014)
A case study of aerosol scavenging in a biomass burning plume over eastern Canada during the 2011 BORTAS field experiment
in Atmospheric Chemistry and Physics
Esteve A
(2014)
A study on the sensitivities of simulated aerosol optical properties to composition and size distribution using airborne measurements
in Atmospheric Environment
Darbyshire E
(2019)
The vertical distribution of biomass burning pollution over tropical South America from aircraft in situ measurements during SAMBBA
in Atmospheric Chemistry and Physics
Dandou A
(2017)
Investigation of Turbulence Parametrization Schemes with Reference to the Atmospheric Boundary Layer Over the Aegean Sea During Etesian Winds
in Boundary-Layer Meteorology
Crosier J
(2007)
Technical Note: Description and Use of the New Jump Mass Spectrum Mode of Operation for the Aerodyne Quadrupole Aerosol Mass Spectrometers (Q-AMS)
in Aerosol Science and Technology
Crosier J
(2007)
Chemical composition of summertime aerosol in the Po Valley (Italy), northern Adriatic and Black Sea
in Quarterly Journal of the Royal Meteorological Society
Description | - new airborne capability for online aerosol chemical measurement - assessment of European particle emissions databases - quantification of African biomass burning aerosol abundances - determination of south American pollution over the subtropical Pacific Ocean - Assessment of biogenic secondary organic aerosol over Borneo - Quantification of pollution aerosol over the Arctic region - Quantifying emissions of biomass burning aerosol over Canada and Brazil |
Exploitation Route | The findings have been widely used to test models of air pollution. This is one of the most widely used data sets from the FAAM aircraft. |
Sectors | Aerospace, Defence and Marine,Agriculture, Food and Drink,Energy,Environment,Transport |
Description | This grant supported the development of a new instrument, the aerosol mass spectrometer, on the NERC-Met Office Facility for Airborne Atmospheric Measurements (FAAM). The instrument development has not in itself led to significant impact but has massively increased the capability of the aircraft. It has flown on over 30% of the aircraft missions flown since 2004 and has delivered a wealth of data to a wide community of researchers and users including testing pollution and visibility model performance for the Met Office; assessing emissions over the UK for DEFRA, constraining numerical weather prediction models in Europe, Africa and Brazil, and contributing to global constraint of climate models through a number of major comparison exercises. |
First Year Of Impact | 2004 |
Sector | Energy,Environment,Transport |
Impact Types | Societal,Economic,Policy & public services |