PRESCRIBE workshop Bremen, May 15 –16, 2013 1 / 66 Report from the EU ACCENT Plus and ICACGP Workshop Pollution studied by REmote Sensing of Conurbations/urban conglomerations/ megacities and Retrieved from observations made by Instrumentation on space BasEd platforms - PRESCRIBE Bremen, May 15 –16, 2013 PRESCRIBE workshop Bremen, May 15 –16, 2013 2 / 66 Preface ACCENT Plus (Atmospheric Composition Change: the European NeTwork-Policy Support and Science) is an Instrument within the European Union, EU Framework Programme 7, FP7, being a coordination and support action. It ran from 2010 to the end of 2014 and follows on its successful and larger predecessor the ACCENT (Atmospheric Composition Change: the European NeTwork) project. ACCENT Plus has focussed on some key selected issues of particular significance for environmental policymaking. iCACGP (international Commission on Atmospheric Chemistry and Global Pollution) is one of the Commissions in IAMAS (International Association of Meteorology and Atmospheric Sciences), which in turn is one of the associations within IUGG (International Union of Geodesy and Geophysics) under the non-governmental ICSU (International Council for Science) family. iCACGP was initiated in the international Geophysics year in 1957. iCACGP promotes research on chemistry and the composition of troposphere related to global pollution and climate change. It aims to initiate, facilitate research programs which by necessity require international cooperation and collaboration. It co-sponsors the international research project IGAC (International Global Atmospheric Chemistry) together with the International Geosphere- Biosphere Programme (IGBP), and the international SOLAS (Surface Ocean Lower Atmosphere Study) together with IGBP (International Geosphere Biosphere Programme), the Scientific Committee on Oceanic Research (SCOR) and the World Climate Research Programme (WCRP). SOLAS and IGAC are currently in the process of migrating to Future Earth. The latter is a new transdisciplinary research initiative building on the Earth System Science Partnership (ESSP), which under the auspices of the International Council for Science (ICSU) addressed, the integrated study of the Earth System, the ways that it is changing, and the implications for global and regional sustainability. The rapid growth of population since the industrial revolution and in particular since the second world war has the growth of conurbations, urban conglomerations and mega cities, or major pollution centres, MPC, coupled with an increasing standard of living. MPC are an increasingly important source of global air pollution. The population is predicted to reach around 10 Billion with 75% living in urban areas by 2050. Our knowledge and understanding of the impact of MPC on air pollution and feedback with climate change is not adequate. An adequate knowledge of the emissions of key pollutants and their precursors by MPC is a pre requisite to improve our understanding of the processes, which determine the transport and transformation of pollution within the troposphere, and provides an important part of the evidence base required for policymaking. The remote sounding of trace atmospheric composition from space based platforms provides a unique and only feasible approach to deliver global comparable knowledge about the tropospheric trace constituents yield in top down estimates of emissions from MPC and subsequent transport and transformation. The development of and use of remote sensing to quantify atmospheric trace constituents and assess both natural phenomena and tropospheric pollution has been one of the milestones of the past two decades in atmospheric research for the provision of the data for numerical environmental and climate predictions. This began in Europe with the preparation form 1984 to 1988 of the SCIAMACHY (SCanning Imaging Absorption spectrometer for Atmospheric ChemistrY) project and subsequent successful proposal, submitted in July 1988, for a passive solar remote sensing PRESCRIBE workshop Bremen, May 15 –16, 2013 3 / 66 instrument for the ESA’s first Polar Orbiting Earth Observation Mission, POME-1: the research part of the later renamed Envisat. The spin off originally called SCIA-mini was selected for ERS-2 and after descoping became GOME (Global Ozone Monitoring Experiment), which began measurements on board ERS-2 after its launch in 1995. SCIAMACHY flew aboard Envisat, which operated successfully from 2002 to 2012. Subsequently GOME-2 was developed and flies on the EUMETSAT/ESA Metop series: the first being launched in 2006 and the second in 2012. The successful retrieval of cloud and aerosol parameters from space based platforms also developed rapidly over the past two decades using a variety of instruments. The nadir sounding thermal infrared instruments such as the AIRS (Atmospheric Infrared Sounder), on NASA AQUA in 2002 and later the IASI (Infrared Atmospheric Sounding Interferometer) on MetOp series have as their primary objective the measurement of the temperature but also yield some unique trace gas data products from the mid and upper troposphere. Driven by the need to observe the diurnal variation of pollution, and the global tropospheric composition, the field is growing. New missions are planned e.g. the realisation of the GeoSCIA concept and first geostationary the EU Copernicus/ESA/EUMETSAT Sentinel 4 and the follow on to GOME-2, the EU Copernicus/ESA/EUMETSAT Sentinel 5 and the ESA Sentinel 5 Precursor. It was therefore very appropriate and timely that ACCENT Plus as a European contribution to the iCACGP, commission a workshop with the title: “Pollution studied by REmote Sensing of Conurbations/urban conglomerations/ megacities and Retrieved from observations made by Instrumentation on space BasEd platforms – PRESCRIBE. This workshop was organised at the University of Bremen for ACCENT Plus and was attended by an international team of scientific experts, taking place on the 15 and 16th May 2015. The organisation team led by myself and Andreas Richter had key support work from Geraldine Schmiechen, Petra Horn, Heiko Schellhorn, Enno Peters, Folkard Wittrock and Lars Jeschke at IUP-UB Bremen and the ACCENT Plus project office. The report was collated and written by Andreas Richter and I with contributions from all PRESCRIBE participants and support from Folkard Wittrock, Enno Peters, and Geraldine Schmiechen from the Institute of Environmental Physics/Institute of Remote Sensing of the University of Bremen. My thanks go to all who worked hard to facilitate the smooth running of the PRESCRIBE meeting and the report. The resulting report is a uniquely valuable and comprises a status reviewing the progress made in remote sensing the pollution from megacities and making proposals for the future. John P. Burrows Bremen 31st December 2014 PRESCRIBE workshop Bremen, May 15 –16, 2013 4 / 66 Executive Summary As one of the key activities of ACCENT Plus and as a European contribution to the International Commission on Atmospheric Chemistry and Global Pollution, ICACGP, a workshop was held in Bremen on the 15th and 16th of May 2013 with the title: “Pollution studied by REmote Sensing of Conurbations/megacities and Retrieved from observations made by Instrumentation on space BasEd platforms – PRESCRIBE”. The objective of the PRESCRIBE workshop was to establish the status of current and planned measurements from space, the development of retrieval algorithms and their data products, as well as our understanding of the needs for the research community and policymakers. At the workshop, the current status of research was reviewed and the successes were assessed. Some key requirements, which will guide the future evolution of space based observations of pollutants for numerical environmental prediction, monitoring environmental and climate change, and the verification of international environmental policy, were established. Specifically, the following was reviewed: the relevant observational capabilities available in the past, present and in the near future from planned missions; some outstanding achievements thus far in terms of measurement and quantification of the outflow and increasing emissions of pollutants and trace constituents (gases and aerosols); the current state of pollution / tropospheric chemistry observations from space instrumentation; the use of satellite data for attribution of pollution sources and their changes; the potential global and regional impacts resulting from further industrialisation, urbanisation, and land use change etc. Highlights from some of the recent retrieved data products and applications were presented. It was recognised that the past three decades have been a golden age of development of passive and active remote sensing of atmospheric constituents. The challenge now is to achieve an adequate fit for purpose global observing system. In principle the ground work and definition of needs has been developed under the auspices of the WMO. The main challenge is to achieve an adequate temporal sampling at adequate spatial resolution. In this context there is a clear need for new satellite platforms driven by the scientific needs and for the development of the new and improved remote sensing instrumentation required for future generations of observation systems. The latter are needed for example to meet the objectives of the EU Copernicus programme. In particular the recent establishment in late 2014 by the EU of the next phase of its Copernicus Atmospheric Monitoring Service