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Recent ARSF-supported Science: 2009

2009 Normal UK flying

2009 Overseas flying

GB09-01 Geraint Vaughan: Evaluation of remote sensing turbulence measurements by comparison of aircraft and wind profiler measurements.

The ability of radar wind profilers to detect atmospheric turbulence is well known - turbulence causes enhanced spectral width of the echoes which is related to the variance of velocity within the sampling volume. Moving from a qualitative detection to a quantitative measurement however has proved difficult. SEAES have a joint programme of research with the Met Office to retrieve better quantitative information from wind profiler spectra and to use these for improved parameterisation of boundary layer turbulence in the Met Office forecast models. The AIMMS probe on the Dornier provides a means to measure turbulence directly, and in a quantitative manner. We propose here to conduct a number of flights of the ARSF Dornier in the vicinity of the Capel Dewi field site near Aberystwyth in Wales, where the UK MST radar is located and where the UFAM boundary layer wind profiler will be deployed for the experiment. Between them these radars measure from 100 m to 20 km altitude but the focus of this work will be on the boundary layer and lower free troposphere. As a secondary objective we will conduct an intercomparison between in situ ozone measurements and ozone lidar observations from Capel Dewi.

GB09-02 Martin Gallagher: Measurements of turbulent entrainment and impacts of cloud droplet dynamics using a new ultra high-speed spectrometer.

The effect of turbulent entrainment of air into clouds is key to understanding their microphysical evolution and lifetime. Turbulent entrainment can potentially alter super-saturation fields experienced by droplets within the cloud and so influence their growth times. SEAES have ongoing collaborative programmes to provide improved cloud measurement databases in order to test the accuracy of various predicted cloud parameters for both numerical weather prediction as well as global climate models. The focus of this work will be to use the ARSF Dornier to collect measurements of high resolution turbulence, cloud droplet size distributions and droplet interarrival times in cumulus clouds over Cardington. Measurements will be collected using upgraded versions of instruments previously flown on the ARSF aircraft, a fast forward scattering spectrometer probe (SFSSP) and the AIMMS turbulence probe. The aim is to characterise turbulent velocity distributions at multiple levels within a range of clouds, to investigate the effect of entrainment and detrainment at those levels on the spatial structure of the liquid phase and droplet growth rates. A high quality database will result which will be used for cloud model simulations in collaboration with the UK Met Office who support this work.

GB09-03 Peter Stansbury: Monitoring Morecambe Bay Using LiDAR to Develop a Model of Intertidal Morphodynamics to Support Coastal Emergency Response and Flood Defence.

Morecambe Bay consists of extensive intertidal sandflats and mudflats covering a 310 km2 area with a tidal range of 8 - 10m. LiDAR Intensity data provides an opportunity to monitor the changes of the intertidal bed in greater detail than previously achieved before. Channels, water wells, mudflats and sandflats will be mapped down to 1m in horizontal resolution; these are important features as they can be hazardous and their location is thus important for the Bay Search and Rescue Team (BSAR). An assessment of the intertidal features depicted in LiDAR and Aerial Photography will be compared to lower resolution Radar data (ASAR/TerraSAR-X) to assess the effects of upscaling. The LiDAR data will be used to create a baseline bathymetry in the TELEMAC modelling. Historical ERA40 and present data (tides, wave and surges) from the Proudman Oceanographic Laboratory (POL) and river discharge data from the Centre of Ecology and Hydrology (CEH) will be used to try and relate changes in the morphodynamics with coastal and river hydrodynamics, particularly major storm events generating storm surge, high river flows, big waves etc. The model created in TELEMAC will be run backwards from the present day and predicted bathymetries validated against historical map data and remotely sensed imagery. The outputs of the study will feed into the Water Framework Directive to try and understand the impacts of morphodynamics on saltmarsh ecology; inform BSAR and contribute to the Flood Risk Management Research Consortium (FRMRC) and the Tyndall Coastal Simulator (CoastS).

GB09-04 Sarah Taylor: Assessing the impact of environment factors on invasive potential of Rhododendron ponticum in western Britain: implications for climate change.

Rhododendron ponticum (L) is a non-native shrub that has invaded a range of natural habitats since its introduction into Britain 240 years ago. Rhododendron dominates a habitat; shading out indigenous vegetation and preventing natural regeneration in woodlands, leading to irreparable deterioration and reduced biodiversity of the invaded habitat. Dense rhododendron occupation in woodland is particularly difficult to map, as access is physically restricted and traditional mapping methods cannot penetrate the woodland canopy. Hence new techniques are required to identify the location and extent of current invasions. This project will use airborne remotelysensed data to map existing rhododendron sites and a landscape-level model to predict future rhododendron expansion over 20 and 50 years by a combination of vegetative layering and seed dispersal. Ecological Site Classification, which classifies a site in terms of its climate and soil quality, will be used to assess the hypothesis that rhododendron population characteristics are affected by landscape-level environmental factors, in order to model potential impact of climate change. This could be applied to the worldwide problem of predicting which species could become invasive. The data will also be assessed in terms of its suitability to predict the spread of the pathogen Phytophthora in wild rhododendron populations.

GB09-05 Alan Blackburn: Reedbed mapping and monitoring with hyperspectral and LiDAR imagery.

Reedbeds are a UK Biodiversity Action Plan habitat and have been identified as a priority project for many regional Biodiversity Partnerships across the UK. There is no up-to-date detailed information as to the current distribution of this habitat within the UK and this inhibits a number of organisations in their conservation work. Satellite data (e.g. Landsat) is of limited use because of the small spatial areas often covered by reedbeds and their intricate juxtaposition with other terrestrial and aquatic habitats. This project will investigate the potential of using high spatial resolution hyperspectral and LiDAR data as a means of providing accurate maps of reedbeds and for quantitative assessments of habitat quality. We propose to acquire ARSF hyperspectral and LiDAR data for two sites in Cumbria, where reedbeds are growing naturally in a range of environmental/habitat contexts and a site in Lancashire, an extensive managed reedbed. Using field surveys and sampling, the first Cumbria site and the Lancashire site will be used to develop/train our methods and the second Cumbria site will be used as an independent test, for accuracy assessment. The project will assess the feasibility of hyperspectral and LiDAR sensing for operational reedbed mapping and monitoring in the UK.

GB09-07 Andreas Baas: Combined LiDAR and hyper-spectral remote sensing of coastal dune fields.

This application is for the acquisition of airborne LiDAR and hyper-spectral data to produce co-ordinated high-resolution DEMs and plant-type distribution maps of coastal dune fields in the UK, which are then compared within a quantitative statistical analysis framework to simulated landscapes generated by a 3D computer model.

The context of this remote sensing request is a recently started 2-year research project funded by The Leverhulme Trust that aims to compare quantitatively the state and development of vegetated dune systems as simulated in a cellular automaton (CA) computer model with that of real dunes developing in coastal and semi-arid environments around the world. This project explores the boundaries and scales of applicability and relevance of the CA modelling approach, while the comparison itself tests an innovative combination of earth observation methods and data sets with newly developed landscape state descriptors.

The quantitative framework of comparison between simulations and real-world dune fields is achieved through statistical landscape metrics that are calculated from 1 m resolution DEMs and collocated distribution maps of different functional plant-types. The proposed airborne remotes sensing of coastal dune fields in the UK can provide the empirical data required for extracting landscape metrics that can be compared with simulations.

GB09-08 Jacobus Baas: Integrated field & numerical modelling of rapid & gradual morphological change in the river-estuarine transition zone.

Rivers and coasts are highly sensitive to anticipated future increases in the frequency of extreme weather events. High-magnitude river floods and storm surges may cause rapid change in the physical structure (morphology) of the river/sea bed through erosion, transportation and redeposition of gravel, sand and mud. The environmental stress thus caused may persist for a long time after the event. This project investigates the morphological evolution of the river-estuary transition zone (RETZ), where river flows and river floods interact with tides and storm surges. The Dyfi River (West Wales) will be used as a test bed for investigating the impact of river flood events and storm surges on the morphology of shallow, dynamic and wave-protected RETZs, by means of integrated numerical modelling and field surveys. The state-of-the-art techniques used for field surveying will include LIDAR, Multibeam profiling, RTK GPS, 3D Terrestrial Laser Scanning and Blimp photography. This combination of techniques covers a necessarily wide range of spatial and temporal scales of morphological change. The requested LIDAR surveys of the Dyfi (Machynlleth to Aberdyfi) in 2009 and 2011 are vitally important for obtaining quasi-instantaneous whole-system morphologies during low tides, when most of the Dyfi estuary is subaerially exposed, and for quantifying morphological change on time scales of several years and at (sub)metre-scale spatial resolutions.

GB09-09 Kate Welham: Understanding human use of the historic environment: combining aerial and geophysical remote sensing techniques to improve feature detection in archaeological landscapes.

Traditional archaeological techniques are predominantly site-based, limited by available technologies and the cost of large scale intervention. Therefore they are unable to provide landscape perspective which is vital to understanding the context of known sites and prospecting for new features. The majority of archaeological sites, particularly those in areas of intensive agricultural production, have no upstanding remains and are identified only when changes in soil moisture and vegetation become visible on aerial photography in drought conditions. To improve detection of these important remains, this project pioneers the use of a multi-sensor approach to surveying the historic environment. Through systematic processing and analysis of lidar elevation and intensity data in combination with hyper-spectral and thermal imaging, it is hypothesised that feature recognition rates will be substantially improved under sub-optimal environmental conditions. The locations for this study, a Bronze Age ceremonial landscape at Knowlton, and two Iron Age/Romano-British hillforts at Hambledon and Hod Hill (all in Dorset), have been selected to provide a quantity and range of features identified through aerial photography and confirmed by excavation and geophysical survey in two areas of different land use. Both sites provide the opportunity to expand the methods trialled on data rich areas to the rest of the historic landscape which is currently poorly understood.

GB09-10 Jadu Dash: Development and validation of terrestrial chlorophyll index product for Sentinel 2 and Sentinel 3 missions.

Accurate estimation of vegetation chlorophyll content provides information needed to both understand and monitor vegetation condition. Various methods have been developed over the last three decades to estimate chlorophyll content spatially using remotely sensed data. The development of MERIS Terrestrial Chlorophyll Index (MTCI) provided the opportunity to estimate chlorophyll content at global scale using data from the Envisat MERIS sensor and we now have an extremely valuable archive of global terrestrial chlorophyll content (2002-8). The follow-on ESA missions such as Sentinel 2 and 3 (planned for launch in 2012) will have sensors with bands suitable for use in a chlorophyll index. This project aims to develop and validate new algorithms for the estimation of chlorophyll content prior to the launch of these sensors. This will ensure the continuity of the global coverage of chlorophyll content database and will help the scientific community develop the routine and robust monitoring program it needs for ecosystem understanding and management. Data provided by the NERC ARSF will support chlorophyll index algorithm development and thus involve the ARSF in the NERC's new technology theme.

GB09-11 Tim Malthus: Red squirrel habitat mapping using remote sensing.

The red squirrel (Sciurus vulgaris) is the only squirrel species native to the UK. Intensive tree felling (17th and 18th centuries) and the introduction of grey squirrel (Sciurus carolinensis) in the 1870s have resulted in a marked reduction in red squirrel populations. The species is now considered endangered, is listed in the UK Biodiversity Action Plan and is also under legal protection (Wildlife and Countryside Act 1981). Long-term management of red squirrel habitats is a key goal of the UK Strategy for Red Squirrel Conservation. Red squirrels are thought to adapt better to large (> 200ha) conifer forests, while grey squirrels prefer broadleaves or mixed forests. For a particular habitat to be suitable for red squirrels, a variety of different conifer species and tree ages is necessary to ensure food supply. Thus, food availability and differences in the dietary preferences of red and grey squirrels is an additional tool that could be used for red squirrel conservation. Attempts made so far to map red squirrel habitat have relied on the National Inventory of Forests and Woodlands (NIFW), but this is inaccurate in many cases (i.e. not updated) and limited since only conifers and broadleaves are mapped, without providing further details of tree species, an essential aspect for effective red squirrel habitat management. Tree species classification requires high spectral and spatial resolution data, and airborne sensors or high resolution satellite data may provide an advantage over coarser resolution satellite data to achieve reasonably accurate tree species classifications (Martin et. al., 1998; Leckie et. al., 2005). A hierarchical approach to classification will be developed using a combination of LiDAR and EAGLE/HAWK data to generate tree species classification and canopy structure maps, which will be then tested as descriptors of red squirrel variables related to food and cover for incorporation into habitat suitability models.

EU09-01 Jonathan Carrivick: LGM and Holocene volcanic activity at Kverkfjöll, Iceland.

Rapid deglaciation produces considerable landscape instability. The relative role of landscaping processes that have persisted through the Holocene in the Icelandic central highlands is contentious. This is due to the paucity of terrestrial information on the timing, rate and style of deglaciation in northern Iceland, which in turn is perhaps due to the presence of an LGM ice sheet divide over this area that would have produced negligible ice sheet flow velocities and hence negligible glacial erosion. Additionally, volcanic activity either during or closely following the LGM, and indeed throughout the Holocene, may previously have been supposed to have obliterated any terrestrial evidence of glacial activity. We intend to use volcaniclastic edifices and sequences produced by such LGM and Holocene volcanic activity to inform the debate on deglaciation in the Icelandic central highlands and to suggest a model of changing volcanic activity due to deglaciation; i.e to present field evidence of a deglacial control on eruptive behaviour. This project therefore has a single overall aim; to test the hypothesis that deglaciation has exerted control on volcanic activity in north-central Iceland. This aim will be achieved by firstly documenting ice-volcano interactions via the variety of subglacial and subaerial volcanic sequences and lithofacies at Kverkfjöll, north-central Iceland. Secondly we will present a stratigraphy-based interpretation of landscape evolution at Kverkfjöll over an area of > 250 km2 through opportunistic use of high-resolution topography (LiDAR) data and through our intensive and extensive field observations and measurements. This project will also produce an improved understanding of the timing, rate and style of deglaciation in the central Icelandic highlands.

EU09-02 David Rippin: Mapping glacier debris cover thickness and extent using aerial photography, LiDAR and spectral emissivity.

The ablation zones of many glaciers are mantled by debris, and this is becoming more common as glaciers thin under a warming climate, and debris previously held within ice is exposed at the surface. It is widely recognised that a debris cover plays a major role on surface melt-rates of these glaciers, with ablation under debris increasing with debris thickness, up to a maximum thickness of ~1-2 cm, after which it decreases. Debris thickness is thus an important control on glacier mass balance. While the spatial extent of supraglacial debris can be measured using satellites, this is often problematic and requires substantial manual intervention. Further, debris thickness determination is, to date, best done using field surveys, which are slow and fraught with difficulties. Accurate determination of debris extent and thickness is thus difficult, yet of great importance because of its role in glacier energy balance. This project will utilise an integrated remote sensing dataset to:

EU09-03 /WI09-01 Geoffrey Wadge: Water and terrain of the Soufriere Hills Volcano, Montserrat.

Montserrat is a small, British-dependent island with a currently active volcano and limited water supply. Our proposed flight will help to better understand the interplay between the volcano and the hydrology of the island. This improved knowledge will help to better evaluate the volcanic hazards facing the islanders and secure the long-term water supply for the island. There are three main objectives. Firstly, to acquire a high-resolution, bare-ground lidar DEM that will permit the definition of the surface hydrological network, illuminate better the structural fabric of the island, provide the base for numerical hazardous process models (e.g. pyroclastic flows) and permit more accurate correction of gravity and resistivity measurements. Secondly, to determine the locations and flow rates of near-shore submarine groundwater springs. Thirdly, to collect samples of the water in the volcano's plume directly and thence to determine flux and the relative contributions of meteoric and magmatic water (using H isotopes). This work is linked to other projects that will provide the analytical framework to make sense of the measurements and to make full use of the results for the people of Montserrat.

EU09-04 Samantha Lavender: Inter-comparison and Validation Campaign in Support of MERIS.

The proposal is in support of an inter-comparison and validation campaign that will occur in the Baltic off the coast of Sweden. The aim is to understand the patchiness of the water and how this influences the process of comparing in-situ matchups to ocean colour satellite data that has a pixel size of 300m. In-situ data, airborne imagery and satellite imagery should ideally be acquired at the same time. The airborne imagery will undergo the same processing as (or as close as possible to) the satellite imagery. Results will be published in the scientific peer-reviewed literature.

EU09-05 Katherine Arrel: Modelling meltwater production and hydrogeomorphology in an Arctic river basin.

The overall aim of this project is to undertake an interdisciplinary study of snow and glacier melt, meltwater discharge, and proglacial floodplain dynamics for an Arctic river system. Whilst these three components have been studied separately elsewhere, quantification of their interactions still remain under-developed. This research gap is especially important in the Arctic where there are strong seasonal cycles in meltwater runoff and highly responsive physicochemical habitats. Thus there is an urgent requirement for accurate prediction of 1) Climate change effects on Arctic hydrogeomorphological processes; namely shifts in runoff patterns, sediment fluxes, and stream temperature dynamics; and 2) the effect of these on river freshwater biota. Integrated modelling will be performed to couple: (1) heat exchange processes and snow and ice melt on Kårsaglaciaren, northern Sweden (2) river discharge and sediment transport of the Kårsavagge proglacial river, and (3) stream temperature dynamics. Field measurements will be made to inform the development, validation and integration these models. These data will comprise (i) Kårsaglaciaren surface topography (LiDAR) and snow-ice interface, (ii) Meteorological data via an Automatic Weather Station (AWS) and regional records, (iii) Upper Kårsavagge ground surface topography (LiDAR), (iv) River bed substrate and hydraulics, and stream temperature.

EU09-06 David Graham: Glacier response to a changing climate in southern Iceland.

Three inter-related themes will provide new datasets for the rigorous evaluation of the timing and mechanisms of glacial response to climatic forcing at a range of contemporary ice masses. Global warming is predicted to have a pronounced effect on terrestrial ice masses but predictions of how ice masses will respond to future warming depend on rigorous understanding of the relationship between climatic change and recent glacier activity. The mass balance of glaciers in southern Iceland is closely coupled to North Atlantic Ocean-Atmosphere circulation and these glaciers are therefore highly sensitive barometers of regional climatic change. Consequently, proglacial landforms in southern Iceland are archives of North Atlantic climate change and provide an important resource for the evaluation of both the timing and mechanisms of ice mass response to recent climatic forcing. Proglacial areas in southern Iceland have been subject to regular aerial survey since the 1940s providing important insights into both the timing and mechanisms of glacial retreat. However, since the Icelandic mapping agency ceased routine aerial photography, this fundamental avenue of research has been curtailed.

EU09-07 Jeff Evans: Glacial, geomorphological and ecological change in a sub-arctic alpine environment (northern Sweden).

The environment of N Sweden is responding to the rapid circumpolar increase in air temperature in the late 20th Century, and General Circulation Models predict that future warming will continue to be disproportionally experienced in high northern latitude regions. Measurements on glaciers in the Tarfala region of N Sweden indicate a prolonged period of negative mass balance associated with 20th Century warming, with significant impacts on glacier thermal regime, dynamics and hydrology. In the context of this change, three related research themes have been developed for the Tarfala region. The first will contribute to the extensive dataset for this part of the sub-arctic, providing a key resource for future research. The second will provide evidence on the processes of glacier movement at the bed (key to our understanding of fast ice flow), and their role in controlling the drainage of large glaciers and ice sheets in response to climate change. The third will investigate the proglacial sediments and landforms associated with polythermal valley glaciers, which record the nature of past climate events and glacier dynamics. Such evidence will help interpret the significance of ancient landforms and better understand the links between past climate change and glacier response, with implications for the mechanisms and rate of ice mass evolution in a warming climate.