Wooster M.J.,King's College London |
Wooster M.J.,National Center for Earth Observation |
Perry G.L.W.,University of Auckland |
Zoumas A.,King's College London
Biogeosciences | Year: 2012
Borneo (Indonesia) is Earth's third largest island, and the location of both extensive areas of rainforest and tropical peatlands. It is the site of both regular (seasonal) biomass burning associated with deforestation, land cover change and agricultural production preparations, and occasional, but much more severe, extreme fire episodes releasing enormous volumes of carbon from burning vegetation and peat. These extreme fire episodes are believed to result from anthropogenic practices related to (the still ongoing) forest degradation and clearance activities, whose impact with regard to fire is magnified by the effects of El Niño related drought. Since 2000, data from the MODIS Earth Observation satellite instruments have been used to study fire on Borneo, but earlier large fire events remain less well documented. Here we focus on a series of large fire episodes prior to the MODIS era, and specifically a 20 yr period covering both the two strongest El Niño events on record (1997-1998 and 1982-1983), along with an unprecedented series of more frequent, but weaker, El Niños. For the five El Niños occurring between 1980 and 2000, we develop quantitative measures of the fire activity across Borneo based on active fire counts derived from NOAA AVHRR Global Area Coverage (GAC) Earth Observation satellite data. We use these metrics to investigate relationships between the strength and timing of the El Niño event, the associated drought, and the fire activity. During each El Niño, we find areas of major fire activity confined within two or three fire sub-seasons (separated by monsoons) and focused in parts of South and Central Kalimantan, and sometimes also in East and/or West Kalimantan. For each El Niño we investigate various lag correlations, and find relationships of similar strength between monthly rainfall deficit and fire, but of more variable strength between indices of El Niño strength (ENSO indices) and rainfall deficit. The two strongest El Niño episodes (1982-1983 and 1997-1998) are accompanied by the most abundant fires (two and three times the active fire count seen in the next largest fire year), and the strongest correlations between measures of El Niño strength, rainfall and fire. We find the most significant positive statistical association between an ENSO index and fire activity to be that between the 16-month (first and second fire sub-seasons) cumulative NINO3 anomaly and the simultaneously recorded active fire count (r Combining double low line 0.98, based on the five El Niño episodes between 1980 and 2000), although we find a negative association of equal strength between the cumulative NINO4 index and active fire count when considered over the entire two year duration of each El Niño episode (first, second and third fire sub-seasons). Our results confirm that the El Niño phenomenon, via its effect on precipitation, is a primary large-scale, short-term climatic factor that has a strong control on the magnitude of the fire activity resulting from the numerous land cover changes, agricultural preparation practices and human-caused ignitions occurring annually across Borneo. The results also suggest that ENSO forecasting maybe a realistic means of estimating the extent and magnitude of this fire activity some months in advance, thus offering some potential for forecasting effects on the remaining forest and peatland resource and the regional atmosphere. © 2012 Author(s).
Dacre H.F.,University of Reading |
Hawcroft M.K.,University of Reading |
Stringer M.A.,University of Reading |
Hodges K.I.,National Center for Earth Observation
Bulletin of the American Meteorological Society | Year: 2012
Extratropical cyclones play a significant role in determining the day-to-day weather conditions in many parts of the world through their associated wind and precipitation patterns. The atlas has been created to explore the mean structure and evolution of the 200 most intense North Atlantic cyclones identified in 20 winters of the ERAInterim reanalysis data. The method used to create the composite fields is described in section 2. In sections 3 and 4, vertical and horizontal composites of cyclone structure for cyclones generated in the North Atlantic regions are used to subjectively identify features such as the relative positions of cold, warm, and occluded fronts and their associated wind and cloud patterns. At the same time, development of a closed isobar forms and the central pressure falls; cyclonic circulation and system-relative wind speeds around the cyclone center increase. The system-relative winds are computed by subtracting the propagation speed of the cyclone from the gridded winds for each individual cyclone before compositing.
Agency: GTR | Branch: NERC | Program: | Phase: Other Grant | Award Amount: 906.70K | Year: 2014
NEODAAS is funded by NERC and managed by NCEO to support UK research scientists with remote sensing data and information. It has the capability to automatically receive, archive, process and map global data from multiple polar-orbiting sensors in near-real time, including MERIS, MODIS, SeaWiFS and AVHRR, allowing the support of global studies. NEODAAS also receives and procesess data from multiple geostationary satellites and their instruments including SEVIRI, VISSR, GOES and MTSAT.
Agency: GTR | Branch: NERC | Program: | Phase: Other Grant | Award Amount: 949.96K | Year: 2014
The essential objectives for NCEO are: 1. Innovative data assimilation for Earth state representation, its model-mediated assessment and interrogation, with significant NWP-related impact. 2. Historical and new observations of Earth System evolution and impact in operational and business services using critical long-term data sets. 3. Model-data evaluation and policy impact for global ESM and component models 4. Provision of instrument, data facilities, key tools and training for use by the wider NERC community with impact from NERC technology applications. The NCEO Corporate team provides strategic and day to day management of NCEO and oversight of strategic projects. The Corporate team consists of the NERC Directorate team concerned with scientific support,training, communications, innovation and impact, outreach and admin, and the NCEO Executive Team which consists of the Director and Divisional Directors to provide strategic direction.
Agency: GTR | Branch: NERC | Program: | Phase: Other Grant | Award Amount: 1.14M | Year: 2014
The key science questions addressed by NCEOs Land and Composition in the Earth System Group are focussed on improving our understanding of the terrestrial carbon cycle and the interaction of emission from the surface with the atmospheric composition of key reactive and long-lived gases. We generate long term global EO datasets and advance retrieval methods to generate improved or novel datasets from existing and upcoming sensors and use them in combination with atmospheric models and data assimilation methods to infer information on surface fluxes and to test and improve the representation of the underlying processes in land surface models. The current work of the group addresses questions related to the state and dynamics of terrestrial carbon and how is it likely to change, the carbon cycle - climate feedbacks and related changes in strength, the assessment of regional CO2 and CH4 budgets, key processes that control the height-resolved ozone distribution and regional changes and its trend, the quantification of trace gas emissions from vegetation and fires.
Thomas R.Q.,Virginia Polytechnic Institute and State University |
Williams M.,University of Edinburgh |
Williams M.,National Center for Earth Observation
Geoscientific Model Development | Year: 2014
Carbon (C) and nitrogen (N) cycles are coupled in terrestrial ecosystems through multiple processes including photosynthesis, tissue allocation, respiration, N fixation, N uptake, and decomposition of litter and soil organic matter. Capturing the constraint of N on terrestrial C uptake and storage has been a focus of the Earth System Modeling community. However, there is little understanding of the trade-offs and sensitivities of allocating C and N to different tissues in order to optimize the productivity of plants. Here we describe a new, simple model of ecosystem C-N cycling and interactions (ACONITE), that builds on theory related to plant economics in order to predict key ecosystem properties (leaf area index, leaf C : N, N fixation, and plant C use efficiency) based on the outcome of assessments of the marginal change in net C or N uptake associated with a change in allocation of C or N to plant tissues. We simulated and evaluated steady-state ecosystem stocks and fluxes in three different forest ecosystems types (tropical evergreen, temperate deciduous, and temperate evergreen). Leaf C : N differed among the three ecosystem types (temperate deciduous < tropical evergreen < temperature evergreen), a result that compared well to observations from a global database describing plant traits. Gross primary productivity (GPP) and net primary productivity (NPP) estimates compared well to observed fluxes at the simulation sites. Simulated N fixation at steady-state, calculated based on relative demand for N and the marginal return on C investment to acquire N, was an order of magnitude higher in the tropical forest than in the temperate forest, consistent with observations. A sensitivity analysis revealed that parameterization of the relationship between leaf N and leaf respiration had the largest influence on leaf area index and leaf C : N. A parameter governing how photosynthesis scales with day length had the largest influence on total vegetation C, GPP, and NPP. Multiple parameters associated with photosynthesis, respiration, and N uptake influenced the rate of N fixation. Overall, our ability to constrain leaf area index and allow spatially and temporally variable leaf C : N can help address challenges simulating these properties in ecosystem and Earth System models. Furthermore, the simple approach with emergent properties based on coupled C-N dynamics has potential for use in research that uses data-assimilation methods to integrate data on both the C and N cycles to improve C flux forecasts.
Agency: GTR | Branch: NERC | Program: | Phase: Other Grant | Award Amount: 1.14M | Year: 2014
In NCEOs Radiation and Climate Groups, the work is divided between two teams. The first focuses on energy and water cycles. The second on developing and exploiting datasets of Essential Climate Variables. The key long term science goal of the first team is improved understanding and quantification of key processes contributing to the energy and water cycles, aimed at elucidating the relative importance of the various interactions between the cycles over a range of temporal and spatial scales. Work here includes the scientific analysis of relatively long-term existing data records (e.g. GERB, HIRS, SSMI), the exploitation of new, emerging data from instruments such as GPM, and the development of tools to exploit future relevant missions (e.g. EarthCare). The Integrated Climate Data Model Systems team aims to develop and apply relatively mature ECV datasets to significant questions in climate science and climate modelling, where these observations have a central contribution to make in advancing understanding of the Earth system. The current focus of the team is on sea surface temperature, ocean colour, aerosols and clouds, giving it an ocean-atmosphere perspective based on passive optical and thermal sensors.
Agency: GTR | Branch: NERC | Program: | Phase: Other Grant | Award Amount: 588.53K | Year: 2014
The Centre for Environmental Data Archival (CEDA) provides the infrastructure to deliver a range of computer-based data management and research services for NCEO and wider NERC environmental science, including those related to big data initiatives. The main NCEO-funded activites include: 1. The NERC Earth Observation Data Centre (NEODC) which is the NERC designated data,centre for earth observation science, responsible for the active curation and dissemination of relevant NERC environmental data holdings. 2. The academic component of the facility for Climate and Environmental Monitoring from Space (CEMS-A), providing data access and research services on behalf of NCEO. Both NEODC and CEMS exploit the JASMIN super computing environment located at CEDA/STFC.
Agency: GTR | Branch: NERC | Program: | Phase: Other Grant | Award Amount: 452.16K | Year: 2014
The NCEOs Instrumentation and Radiative Basis work encompasses 1. Support to NCEO and wider NERC community via access to significant remote sensing instrumentation, facilities and measurement expertise, along with training and tools, flexibly deployable to support NERC science. 2. Development of underpinning knowledge on EO radiative transfer, that can provide the NERC community with significant steps forward in abilities to exploit EO data. 3. Access to relevant EO data and geophysical products in a near real-time manner for science studies, and to deliver services and abilities to obtain data and geophysical knowledge required on short timescales, for example for supporting science campaigns or study of rapidly changing events. Work coordinates and complements activities of the Field Spectroscopy Facility (FSF) and NERC Earth Observation Data and Acquisition and Analysis Service (NEODAAS).
Agency: GTR | Branch: NERC | Program: | Phase: Other Grant | Award Amount: 1.36M | Year: 2014
Data assimilation activities: 1. Provide NCEO and the NERC community with accessible core models equipped for data assimilation which can be used for Earth System Science investigations and Observing System Simulation Experiments. 2. Interrogate UK Earth System components and derive data-consistent global state and model parameter estimates for initialisation and driving of models. 3. Investigate new techniques that will enable DA to meet the science challenges of tomorrow, including work with the Met Office and other meteorological forecast centres to ensure NCEO DA work has impact and to promote critical mass in key research and development areas.