Research projects - Environmental Processes cluster

The list below may also include a small number of archived projects. In due course, these will be listed separately.

Cambridge Volcanology Group

A collection of JScripts for retrieval of gas column amounts using DOAS methodology: This document presents a collection of DOASIS JScript projects designed to collect spectra from Ocean Optics™ spectrometers and to retrieve column amounts of absorbing gases using DOAS methodology (Platt and Stutz, 2008). To investigate the gas content of the plume, it is necessary to collect spectra of dark current and electronic offset, and scattered sunlight passing through both the plume and background atmosphere (with no plume present).
Book: Eruptions that shook the world: A primary aim of this book is to examine the claims that volcanism shaped prehistoric and historic social trajectories. To do this, we need to look at how volcanoes act on a very large scale, and how often do they do it. The book also delves into the deeper geological record to explore the links between volcanism and mass extinctions identified in the fossil record.
Climate and dust: Dust is an airborne suspension of very fine mineral particles derived primarily from surface soils or injected into the atmosphere during volcanic eruptions. Particles are initially generated from weathering, geomorphic processes, and from explosive volcanism. Dust is an important constituent of tropospheric aerosol, which consists of a mixture of sulphate aerosol, black carbon and organic carbon, nitrate and mixed particles such as sea salt and mineral dust. Dust, and the other components of tropospheric aerosol, affect climate in a variety of ways; this impact is measured in terms of changes in radiative forcing, i.e. the implied perturbation of the Earth’s energy budget caused by changes in the aerosol budget. There is an urgent need to better understand how dust impacts climate to refine model simulations of present, past and future climates.
Climatic, palaeoenvironmental and human impacts of super-volcanic eruptions: The Youngest Toba Tuff (YTT) eruption of Toba volcano in Northern Sumatra, Indonesia, around 74,000 years ago was one of the largest in the entire geological record and impacted climate on the global scale. The effect was a cooling of surface temperatures due to the generation of a globally-dispersed stratospheric sulphate aerosol veil. Catastrophists link the eruption to the onset of a glacial period and a corresponding ‘bottleneck’ in human genetic diversity, akin to a near-mass extinction of our early ancestors. Others believe the global climatic effects from the eruption were less severe. Given that the eruption potentially had a massive impact on early human dispersal patterns and evolution, in addition to extreme forcing of global climate, remarkably little is known about the eruption source parameters and the effect on local environments. The research is intended to provide a strong linkage between modelling, volcanology and field data (palaeoenvironments and Quaternary geology).
Fourier transform spectroscopy of the gas plume of Masaya volcano, Nicaragua: We have now obtained field observations of volcanic gases with a portable fourier transform infrared (FTIR) spectrometer at a number of volcanoes since our first measurements at Mount Etna in 1994. Information concerning the chemistry and dynamics of the gas phase in Masaya magma is crucial in understanding the control of degassing on eruptive style, and assessment of the environmental impacts of the volcanic gases.
Hazards from airborne silicate microparticles: Long-term exposure to high concentrations of airborne dust and other fine silicate particles is known to cause detrimental health effects, such as pneumoconiosis (Desert Lung Syndrome). There is a high occurrence of pneumoconiosis in the population living in Indus Valley near Leh, Ladakh, which receives frequent dust storms. In addition, the people here base their lives around agriculture and most tasks are still carried out through manual labour. The high altitude of the valley (> 3500 m) means that it is persistently dry so dust emission is high. Communities work together during spring months to clear irrigation channels and work manure into their fields. In doing so, they are exposed to chronically high dust levels. Research Associate Dr Adam Durant recently participated in a field study investigating the health effects from exposure to mineral dust aerosol on the local population in and around Leh, Ladakh.
Heterogeneous ice nucleation in atmospheric clouds: Clouds are an integral part of the Earth system and influence the dynamics and radiative balance of the atmosphere. Ice formation is catalysed by particles in the atmosphere (ice nuclei) and directly influences cloud processes such as precipitation/sedimentation. However, there is large uncertainty in heterogeneous ice nucleation rates due to a lack of empirical observations, both in situ (they are extremely challenging to make) and in the laboratory. Furthermore, there is a complete lack of ice nucleation measurements for volcanic clouds. Taking this as motivation, a series of experiments were carried out to quantify heterogeneous ice nucleation rates in liquid water drops.
Impacts of Mt. Erebus volcano (Antarctica) on the atmospheric environment: Mt. Erebus is one of the largest active volcanoes on Earth. It reaches nearly 4 km above sea level, and is renowned in volcanological circles for its persistently active lava lake, which is sited in the summit crater. Despite its remote location, an extensive monitoring programme is in place. The Cambridge Volcanology Group has participated in annual field campaigns on Erebus since 2003, with the principal contribution being spectroscopic measurements of gas emissions from the lava lake.
Large Volume Explosive Eruption database: This project is aimed at generating the most complete possible record of the >VEI 7 (>30km3 of products) eruptions that have occurred in the world.
Linking cloud microphysics and volcanic sedimentation: Explosive volcanic eruptions, such as the 18 May 1980 eruption of Mount St. Helens, USA, can generate ash clouds that reach the stratosphere and deposit tephra 1000s km from the volcano. Predicting how long the particles remain airborne and where ash-fall may occur is an essential component of hazard mitigation performed by volcanic ash transport and dispersion models. The majority of these models calculate sedimentation rates based on gravitational settling of single particles and often have difficulty reproducing the observed sedimentation of the finest size fraction (<100 microns) 100-1000s km downwind from the volcano. This discrepancy results from particle aggregation, a poorly understood process, which is also responsible for forming distal mass deposition maxima observed 100s km from the volcano in many recent ash deposits. To stimulate advances in the understanding of volcanic cloud sedimentation, the development of several sedimentological databases has been undertaken.
Mechanisms and implications of the 2011 eruption of Nabro volcano, Eritrea: The 2011 eruption of Nabro volcano in Eritrea is of great scientific interest and has had substantial impacts in the remote part of Afar in which it is located. The main aims of the project are to arrive at a detailed synthesis of the nature and causes of the eruption, to evaluate the events in the context of understanding restless calderas worldwide, and to compare and contrast activity of Nabro with the fissural basaltic systems that have been the focus of research by the NERC Afar Consortium.
Physico-chemical properties of tropospheric volcanic emissions: Volcanoes are a major source of gases and particles to the atmosphere. Quantifying fluxes of volcanic gases, such as sulphur dioxide, is important for understanding the potential impacts on climate and local ecosystems, and hazards to human health. Sulphur dioxide emission is routinely monitored using ground-based and satellite remote sensing techniques to estimate fluxes and predict changes in eruptive activity. However, conversion rates of sulphur dioxide to sulphate aerosol are poorly constrained for tropospheric volcanic plumes, which can severely impact these measurements downwind from the volcano. Direct in situ measurement of volcanic emissions can be used to validate and improve remote sensing techniques. However, these data are sparse and the bulk of measurements comprise aircraft sampling carried out ~20-30 years ago, an approach now considered to be extremely hazardous. Funding was secured to perform a proof-of-concept study using state-of-the-art remotely-operated altitude-controlled meteorological (CMET) balloons as a platform to measure gases in volcanic plumes.
Retrieval of aerosol properties from MICROTOPS II sunphotometer data: Volcanoes represent one of the most important global sources of gases and particles to the atmosphere. Their emissions provide important information about the physical and chemical conditions of subsurface magma, and have impacts on the atmospheric and terrestrial environments, human health, and climate. Volcanoes present particularly harsh and challenging conditions to work in, and remote sensing techniques often provide the only safe means for data collection. Differential Optical Absorption Spectroscopy has played a key role in monitoring and in quantifying the global budget of several significant gaseous species (SO2, BrO, NO2, ClO etc.) emitted by volcanoes. In contrast, little work has been carried out on volcanic aerosol, except perhaps for important studies of Pinatubo and El Chichón eruptions and their resulting global climatic changes.
Volcanic degassing: The objectives of this research are: (1) To develop novel remote sensing techniques for surveillance of volcanic gases and aerosols; (2) To develop comprehensive models for volcanic degassing; (3) To understand the atmospheric chemistry and transport of volcanic plumes; and (4) To understand the impacts of volcanic gases and aerosols on human health and terrestrial ecosystems.
Volcanological and geophysical research on Paektu volcano, Democratic People’s Republic of Korea: Mount Paektu (aka Paektusan, Changbaishan, Changbai, Baitoushan, Baekdu and Baegdu!) is a fascinating volcano straddling the border between DPRK (North Korea) and China. We have been developing an ambitious project to carry out field-based geophysical and volcanological studies of the volcano on the DPRK side of the border.

Cambridge Coastal Research Unit

A hierarchical approach to the examination of the relationship between biodiversity and ecosystem service flows across coastal margins (CBESS): The fundamental aim of the CBESS project is to establish links between biodiversity and ecosystem service provision from salt marshes and intertidal sediments over different scales of measurement.
A large-scale flume experiment to determine wave dissipation and transformation over coastal vegetation under extreme hydrodynamic loading (a HYDRALAB IV project): The multiple services provided by salt marsh ecosystems to the local, regional, and global community are being increasingly recognised and valued. At the same time, however, such ecosystems are under increasing pressure from sea-level rise, changes to wind wave climates, and more direct anthropogenic pressures such as grazing, which alter their functioning and potentially threaten their survival over the longer term. To build coastal vegetation into coastal protection schemes, the dynamics that control the sustainability of such an approach need to be fully understood.
Coastal Settlements at Risk: A summary of this project will be online shortly.
Establishing a global database of surface elevation change and accretion rates in coastal wetlands: The effects of rising sea-levels on coastal regions and the increased vulnerability of the coastal zone due to the high concentration of natural and socio-economic resources highlight the need for regional to global assessments. Global vulnerability assessment (GVA) studies have been the main sources of quantitative information on the potential impacts of sea-level rise. However, one of the principal limitations of GVAs, which has compromised their reliability and consistency, has been the lack of appropriate data sources. To fill this significant gap in coastal research, a new global coastal database has been developed within the framework of the EU DINAS - COAST project. The database provides the input data for the Dynamic Interactive Vulnerability Analysis (DIVA) tool which is the main product of the project. DIVA identifies coastal units that are particularly vulnerable to sea level rise and adverse human interventions and allows for the evaluation of a range of response options.
European approaches to managed re-alignment: Managed realignment means the deliberate process of realigning river, estuary and/or coastal defences. Whilst Managed Realignment has been a topical issue for many years now, there have been few examples of the practice being implemented. There is an urgent need for a better understanding of issues associated with Managed Realignment, and how it could be better delivered through future flood defence planning. This research project sets out to answer several questions.
Flooding and Environmental Challenges for Venice and its Lagoon: State of Knowledge 2003: A research project focussing on the flooding and environmental challenges for Venice and its Lagoon. The project is an initiative by the Venice in Peril Fund (the British Committee for the preservation of Venice). The mission is to promote the objective study and review of information concerning key aspects of the flooding and environmental issues relevant to Venice, in an international dimension.
Mapping corals reef habitats in the Amirantes and southern Seychelles: The presence of many drowned reefs and shallow banks, rather than sea level reefs, on the Seychelles Bank, the Amirantes and the Mascarene Plateau in the western Indian Ocean suggests environmental controls may prevent coral reefs reaching their growth potential in this region. The objective of this research will be to provide the first modern maps of all these locations for incorporation into marine ecosystem management plans in the Seychelles. It is anticipated that the findings will be incorporated into the wider plans for the conservation of marine biodiversity in the western Indian Ocean region.
North Sea storm surges: Storm surges in the southern North Sea pose a complex, persistent and perhaps growing threat to the surrounding coastline of NW Europe. Within a broader project looking at 'Coastal Settlements at Risk', research has focussed on the uncertainties associated with numerical modelling of extreme coastal flooding.
Quantifying the saltmarsh vegetation canopy: Recent concern over the possibility of increased flood risk (as a result of global and accompanying regional climatic changes) on the low-lying coasts of North-east Europe (including, e.g., the UK East coast) requires a better understanding of the natural sea-defence capacity of intertidal areas. This project involved (a) the testing and validating an innovative digital photograph technique for the measurement and parameterisation of saltmarsh vegetation 'roughness'/'density', and (b) the provision of information on the relationships between wave attenuation and vegetation 'roughness'/'density' on a macro-tidal saltmarsh.
The changing flora, fauna and sedimentation of the West Norfolk coast: This research theme centres on monitoring the possible effects of flood-defence activity on the flora, fauna and sedimentation patterns of the West Norfolk coast. This area offers a mosaic of maritime habitats considered internationally important for wildlife conservation and bird migration.
The relationships between vegetation characteristics and the sea defence value of saltmarsh ecosystems: Global and accompanying regional climatic changes are likely to increase flood and erosion risk on the low-lying coasts of many shores in the near future. To manage such risks, a better understanding of the natural sea-defence capacity of intertidal areas is required. While, at the time of the this study, preceding studies (e.g. Möller and Spencer (2003), Möller et al. (2001)) had indicated that such environments can reduce flood risk by significantly attenuating waves over hydraulically rough vegetated surfaces, no study had, as yet, systematically investigated the relative importance of different types of intertidal vegetation and/or seasonal changes to this bed roughness effect.
The sea-defence function of micro-tidal temperate coastal wetlands: Global environmental change poses a growing challenge for the management of low-lying coastal environments. The challenge is to (a) recognise and quantify the ecological functions of such environments, and (b) develop management approaches that allow those functions to be maintained in the context of global change. Meeting this challenge is particularly important on micro-tidal shorelines, where the ecological sensitivity to sea level rise and changing climatic conditions (e.g. storm frequency and intensity) is likely to be high. Previous studies have focused on tidal coasts and salt marsh or mangrove vegetation and have highlighted relationships between coastal wetland vegetation type, water depths, and observed wave energy reduction. Prior to this study, however, no data was available on the sea-defence function of coastal grasslands and reed beds, where irregular inundation by meteorologically driven storm surges dominates over tidal inundation. This has now been made possible.
Understanding estuarine hydrodynamics for decision making in data poor coastal environments: Coastal zones and estuaries provide ecosystem services at local, national and international levels. Consequently, decision makers implement broadly impacting and costly regulatory actions using available scientific resources. Developing countries face further resource challenges necessitating effective science for management. Baseline data collection, rule based, and numerical models are proposed and investigated in this project, characterising a poorly studied macro-tidal estuary of central Mozambique.
Understanding large-scale coastal morphology: a study of Winterton Ness, UK: The better understanding and prediction of geomorphological processes that govern the long-term natural and/or human induced changes at the coastal zone lies at the centre of this project. This research assess the use of digital photogrammetry as an analytical tool for the study of the dynamics of large-scale coastal features such as the East Anglian nesses (in particular, its use for determining changes in sediment volume (i.e. sediment budgets), as well as reviewing existing theories of ness evolution in the light of newly available morphological data; and developing alternative tools (computer visualisation/animation) for use by coastal managers to assess morphological change of large-scale features.
Wave dynamics over saltmarsh surfaces: Coastal marshes constitute a delicately balanced system between hydrodynamic forcing on the one hand and ecological, sedimentological, and morphological responses on the other. Equally, however, the marsh surface itself exerts an influence on tidal currents and incident waves. The aim of this research is to quantify changes in significant wave heights and total spectral energy across densely vegetated macro-tidal saltmarshes of different morphological characteristics.

Atmospheric Processes

Aerosols and Climate: Aerosols play an important role in the climate system, both directly and in interaction with clouds. Aerosol effects have been studied in several international projects as described here.
Air quality in airport approaches: impact of emissions from aircraft in ground run and flight: Development of infrastructure and the urban environment must be carefully managed if it is not to jeopardise air quality. To satisfy planning statutes and national and international directives, the impact of a major airport development on air quality as well as noise levels must be assessed. Accurate predictions of aircraft emission transport require innovative measurement and modelling techniques that account for these complicating factors. The Department has been contributing to work in this area through application of optical remote sensing to measurement of aircraft during take-off and landing.
Climate outlooks and Agent Based Simulation of Adaptation in Africa (CLOUD): Arguably the next grand challenge for climate research lies not with improvement of physical models, but in the improved assessment of the possible impacts of climate change on society. In order to make believable climate forecasts for the next 50-100 years we need accurate and robust dynamic models of the response of socio-economic systems to climate change, and the associated feedback into the climate system. With the recent rise in computing power, a new paradigm for modelling social systems is emerging:- agent based modelling is a technique arising from artificial intelligence, which attempts to give a direct representation to each person, or larger organization within the system being modelled, by allocating a set of behavioural rules for the conduct of each agent. Such a model forms a testbed for hypotheses about how climate change and its perception within society may affect both adaptation to change and the future climate, in much the same way that a global circulation model allows testing of hypotheses about the physics of the atmosphere and ocean.
Effects of Volcanoes in the Atmosphere: This project examines the various ways in which volcanoes affect atmospheric processes.
Long-term weathering studies on St. Paul's Cathedral, London: This project concerns research to monitor the rate of surface loss of the stone at this site since 1980. We conclude that air pollution control in London appears to be benefiting buildings.
Stratospheric-Topospheric Coupling: Stratosphere and troposphere are coupled by mass exchange and due to dynamical processes. Mainly, the vertical propagation characteristics of planetary waves were studied to understand variability of climate in the troposphere.

Landscape ecology

Biogeochemistry and Climate Change Research Training Network (GREENCYCLES): The GREENCYCLES Biogeochemistry and Climate Change project, an EC-funded FP6 Marie Curie Research Training Network (2005-2008), coordinated by Andrew Friend, is a direct response to this challenge. The GREENCYCLES project aims to improve our understanding of the biological controls on the growth of atmospheric greenhouse gases through a collaborative research programme across 13 European research laboratories. The network also has the important aim of training the next generation of Earth system scientists by sponsoring and supervising 13 PhD student projects and 5 post-doc projects.
Dendroecology of Fagus sylvatica in Northern Greece: The radial growth of Fagus sylvatica L. has been investigated throughout much of the species distribution (e.g. Lebourgeois et al, 2005), but not in Greece. This region is important as it contains the trailing edge of the range, and because the Balkan peninsula is the contact zone between F. sylvatica and F. orientalis. At other locations along the trailing edge, increased sensitivity to drought and growth declines have been detected (e.g. Jump et al, 2006). The project aims to quantify factors controlling radial growth and investigate spatial and temporal patterns of growth.
Detecting signatures of natural selection in the human genome with geographically explicit models: The purpose of this project is to exploit recently available datasets on worldwide human genetic diversity to test for possible targets of natural selection in the genome. Demographic, geographically explicit inference frameworks have been developed for the analysis of the genetic data. Using this tool, we have reconstructed the expansion out of Africa by anatomically modern humans, taking into account climatic changes over the last 120k years.
Geology, ecology, hydrology & management of Chalk springs: This research theme centres on the water supply, water quality, macro-invertebrate communities and management status of coldwater springs within East Anglia. Special emphasis has been placed on certain key species of flatworms (Planarians) and caddis-flies (Trichoptera) sensitive to water quality and temperature.
GREENCYCLESII: Anticipating climate change and biospheric feedbacks within the Earth system to 2200: There is a pressing need to improve our understanding of climate processes and their impacts in order to develop appropriate adaptation and mitigation measures. The GREENCYCLESII Anticipating climate change and biospheric feedbacks within the Earth system to 2200 project, an EC-funded FP7 Marie Curie Initial Training Network (2010-2013), coordinated by Andrew Friend, is a direct response to this challenge.
Holocene environmental change in southern Portugal: The absence of lakes and freshwater wetlands in southern Portugal has constrained the use of traditional pollen analytical studies from which inferences can be made about the history of climate and human activity based on the region's vegetation history. Alternative pollen-bearing sediments, such as estuarine material, have the potential to provide palaeoecological data, both in terms of the wider vegetation history of the estuarine catchments and the changing nature of the ecology of the estuarine wetlands themselves. However, sediment accumulation in estuaries is influenced by factors such as changing sea-level, possible tectonic activity, sediment accommodation space and input from both terrestrial and marine sources. These factors, is turn, may reflect both the climatic and anthropogenic history of the area. It is a challenge, therefore, to discriminate between the different environmental signals contained within these types of sediment.
Monitoring Mediterranean ecosystem changes: Land use change has been identified as a major contributor to loss of biodiversity, and models of global biome change predict that mediterranean-type ecosystems will probably experience large losses by the end of the twenty-first century. Olive groves represent one of the iconic landscapes of the Mediterranean, but in recent decades have undergone rapid land use change. There is a need to establish the impact of changes in cultivation practices on the biodiversity of olive groves and shrubland communities both at the local scale, by means of ground-based fieldwork, and at the landscape and regional scales by means of remote sensing. In this way the longer term effects of agricultural intensification and abandonment of more marginal land can be evaluated.
The Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP): ISI-MIP is a community-driven modelling effort with the goal of providing cross-sectoral global impact assessments, based on the newly developed climate scenarios (RCPs: Representative Concentration Pathways) and socio-economic scenarios (SSPs: Shared Socio-Economic Pathways). Based on these common background scenarios, quantitative estimates of impacts and uncertainties for different sectors and from multiple impacts models are being derived. From this, policy relevant and society-focused metrics are being calculated.
The use of airborne LiDAR to characterise Mediterranean forest communities: Mediterranean semi-natural forest communities are amongst the most transformed, fragmented and threatened of landscapes worldwide and yet are also some of the least protected with extent of habitat conversion exceeding that of habitat protection. The need for the conservation of this habitat is increasingly recognised but this requires detailed habitat surveying and mapping. This work is based on the use of airborne laser scanning (LiDAR: Light Detection and Ranging) to characterise the 3-dimensional structure of the forest communities of southern Portugal, based on a field area in the Serra region of the western Algarve.
Tools for writing models: Software for the future: Much research in computer science has been carried out to aid the development of efficient, correct, and easily extendible computer programs. This project is a collaborative effort between the Cambridge Computer Laboratory and the Cambridge Centre for Climate Science, aiming to apply state-of-the-art programming research to facilitate the development of advanced climate models.

Hydrology, Water and Landscape

Discrete simulation systems for environmental modelling: Many systems that are encountered in environmental modelling consist of set of discrete entities that we might be able to represent directly in making computational models of the environment, for instance physical systems, for example particle-based flows, such as debris avalanches, or the transport of grains in a river-bed. In addition to these intrinsically discrete aspects of the environment, there are nearly continuous things that we are forced to model discretely simply because of computational restrictions. Here the primary example is fluid flow, including the atmosphere and ocean, but also flow in streams and rivers. Arguably we need to try to model all of these aspects together in order to be able to form a clear view of how the environment will evolve over time, including interactions between physical, ecological and social systems. As a way of achieving such a goal we aim to build up a suite of discrete simulation models that span the disciplines in a way that gives us a unified environmental modelling system.
Effect of Climate and Land Use Change on River Hydrology of Thailand: A summary of this project will be online shortly.
FLOBAR1 - Floodplain Biodiversity and Restoration: A summary of this project will be online shortly.
FLOBAR2 - Floodplain Biodiversity and Restoration: Integrated natural science and socio-economic approaches to catchment management: A summary of this project will be online shortly.
Integrating Agent-Based Models of Subsistence Farming with Individual-Based Models of Trees and Dynamic Models of Water Distribution: Subsistence farming communities are dependent on the landscape to provide the resource base upon which their societies can be built. We present an integrated modelling system to represent land use change that couples three simple process models:- An agent based model of subsistence farming; an individual-based model of tree growth; and a spatially extended version of TOPMODEL for the prediction of distributed soil moisture and stream discharge. In this way we can, for example, investigate how demographic changes and associated removal of forest cover influence agricultural production through changes in ground water availability and how land-use change affects river regimes and influences flood frequency and magnitude.
River Basin Governance Research and Network (RiBaGo): RiBaGo is interested in studying institutional structures for water management in the European and Chinese contexts, in order to help understand key water governance challenges, and attempts to solve them, over time. It is analysing drivers, constraints and processes of integration in river basin management in both the EU and China (Integrated River Basin Management; IRBM).
The Cambridge Arsenic Project: A global interdisciplinary study of arsenic contamination of groundwater, surface water and soils: its occurrence, causes, impacts and mitigation. The project aims to investigate the geographical and other aspects of the problems of arsenic in groundwater that is used for drinking and in irrigation. The study aims principally to synthesise existing material and identify research and other needs that will improve the predictability of arsenic contamination and indicate the best ways of avoiding or reducing the impacts.