Atlantic Multidecadal Variability: Surface and Subsurface Thermohaline Structure and Hydroclimate Impacts

The Atlantic Multidecadal Oscillation (AMO), a sea surface temperature mode of natural variability with dominant timescales of 30 -70 years and largest variations centered on the northern North Atlantic latitudes is one of the principal climate signals that have earned considerable attention in the recent decades, due to its multilateral impact on both local and remote weather and climate and its importance in predicting extreme events, such as drought development over North America. A 3-dimensional structure of the AMO is constructed based on observations and coupled, ocean-atmosphere 20th century climate simulations. The evolution of modeled, decadal-to-multidecadal variability and its hydroclimate impact is also investigated between two successive model versions participating in the CMIP3 and CMIP5 projects. It is found that both model versions underestimate low frequency variability in the 70-80 and 30-40 year ranges, while overestimating variability in higher frequencies (10-20 year range). In addition, no significant improvements are noted in the simulation of AMO's hydroclimate impact. A subsurface, vertically integrated heat content index (0-1000m) is proposed in an effort to capture the thermal state of the ocean and to understand the origin of AMO variability, especially its surface-subsurface link on decadal- to- multidecadal timescales in the North Atlantic basin. The AMO-HC index exhibits stronger oscillatory behavior and shorter timescales in comparison to the AMO-SST index, while leading the latter by about 5 years. A cooling of the North Atlantic subsurface is discernible in the recent years (mid-2000s -present), a feature that is almost absent at the ocean surface and could have tremendous implications in predicting future North Atlantic climate and in relation to the recent hiatus in the rise of global surface temperatures that was noted in the latest Intergovernmental Panel on Climate Change assessment report. Finally, AMO's decadal variability is shown linked to Gulf Stream's northward surges and the low-frequency NAO, as envisioned by Vinhelm Bjerknes in 1964. A cycle encompassing the low-frequency NAO, Gulf Stream's poleward excursions and the associated shifts in surface winds and SSTs over the subpolar North Atlantic is proposed as a possible mechanism for AMO's origin and a principal target for future research

Earth observation in service of the 2030 Agenda for Sustainable Development

This paper reviews the key role that Earth Observations (EO) play in achieving the Sustainable Development Goals (SDGs) as articulated in the 2030 Agenda document and in monitoring, measuring, and reporting on progress towards the associated targets. This paper also highlights how the Group on Earth Observations (GEO) would contribute to ensure the actual use of EO in support of the 2030 Agenda; and how the Global Earth Observations System of Systems meets requirements for efficient investments in science and technology and a good return on investment, which is elaborated in the Addis Ababa Action Agenda on development financing. Through a number of examples, we first discuss how extensive EO use would: provide a substantial contribution to the achievements of the SDGs by enabling informed decision-making and by allowing monitoring of the expected results; improve national statistics for greater accuracy, by ensuring that the data are “spatially-explicit” and directly contribute to calculate the agreed SDG Targets and Indicators support the fostering of synergy between the SDGs and multilateral environmental agreements by addressing cross-cutting themes such as climate and energy; and facilitate countries’ approaches for working across different development sectors, which is, according to the special adviser on the 2030 Agenda, a key challenge to achieve the SDGs. We then focus on the role that GEO could play in enabling actual use of EO in support of the 2030 Agenda by directly addressing the Strategic Development Goal 17 on partnerships

National Open Data Cubes and Their Contribution to Country-Level Development Policies and Practices

The emerging global trend of satellite operators producing analysis-ready data combined with open source tools for managing and exploiting these data are leading to more and more countries using Earth observation data to drive progress against key national and international development agendas. This paper provides examples from Australia, Mexico, Switzerland, and Tanzania on how the Open Data Cube technology has been combined with analysis-ready data to provide new insights and support better policy making across issues as diverse as water resource management through to urbanization and environmental–economic accounting

Towards delivering on the Sustainable Development Goals using Earth observations

With less than a decade left to attain the Sustainable Development Goals (SDGs), this communication aims to improve understanding of the enabling environment that is essential for Earth observations (EO) to be fully adopted within the institutional settings that drive the implementation of the SDGs and the Global Indicator Framework, an effective review mechanism for tracking progress at global to national and local levels. This paper also serves as an introduction to the Remote Sensing of Environment's Special Issue (SI) on Earth Observation for the Sustainable Development Goals. The seventeen contributions published in this SI showcase the application of EO data, methods, and tools to support countries in target setting for the SDGs, including baseline determination, as well as tracking of progress on SDG implementation and informing sustainable development planning and decision making. The majority of published articles focus on Goals 6 (Clean Water and Sanitation), 14 (Life below Water) and 15 (Life on Land). We also present our own analysis of existing EO systems available to generate data for SDG indicators addressed via the SI contributions, including main resolution characteristics, and assess factors that hinder the full integration of EO solutions for the SDGs within country processes, institutions of government, and policies. We conclude that an urgent need exists for the EO community to work more closely with local and regional governments and other relevant stakeholders to promote the operationalization of EO solutions for implementing the 2030 Agenda at global to local levels. Our review also illustrates the need for transitioning towards new EO for SDG frameworks that are focused on the knowledge element of the data-information-knowledge-wisdom paradigm, rather than the data and information aspects

Monitoring water-related ecosystems with Earth observation data in support of Sustainable Development Goal (SDG) 6 reporting

Lack of national data on water-related ecosystems is a major challenge to achieving the Sustainable Development Goal (SDG) 6 targets by 2030. Monitoring surface water extent, wetlands, and water quality from space can be an important asset for many countries in support of SDG 6 reporting. We demonstrate the potential for Earth observation (EO) data to support country reporting for SDG Indicator 6.6.1, ‘Change in the extent of water-related ecosystems over time’ and identify important considerations for countries using these data for SDG reporting. The spatial extent of water-related ecosystems, and the partial quality of water within these ecosystems is investigated for seven countries. Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat 5, 7, and 8 with Shuttle Radar Topography Mission (SRTM) are used to measure surface water extent at 250 m and 30 m spatial resolution, respectively, in Cambodia, Jamaica, Peru, the Philippines, Senegal, Uganda, and Zambia. The extent of mangroves is mapped at 30 m spatial resolution using Landsat 8 Operational Land Imager (OLI), Sentinel-1, and SRTM data for Jamaica, Peru, and Senegal. Using Landsat 8 and Sentinel 2A imagery, total suspended solids and chlorophyll-a are mapped over time for a select number of large surface water bodies in Peru, Senegal, and Zambia. All of the EO datasets used are of global coverage and publicly available at no cost. The temporal consistency and long time-series of many of the datasets enable replicability over time, making reporting of change from baseline values consistent and systematic. We find that statistical comparisons between different surface water data products can help provide some degree of confidence for countries during their validation process and highlight the need for accuracy assessments when using EO-based land change data for SDG reporting. We also raise concern that EO data in the context of SDG Indicator 6.6.1 reporting may be more challenging for some countries, such as small island nations, than others to use in assessing the extent of water-related ecosystems due to scale limitations and climate variability. Country-driven validation of the EO data products remains a priority to ensure successful data integration in support of SDG Indicator 6.6.1 reporting. Multi-country studies such as this one can be valuable tools for helping to guide the evolution of SDG monitoring methodologies and provide a useful resource for countries reporting on water-related ecosystems. The EO data analyses and statistical methods used in this study can be easily replicated for country-driven validation of EO data products in the future

The group on earth observations carbon and greenhouse gas initiative

An improved understanding of the global carbon cycle is important to the success of efforts to mitigate climate change, such as agreed in the Paris meeting of the UN Conference of the Parties in 2016. Climate change mitigation and adaptation requires action by individual countries, municipalities, cities, and their citizens. These actions require a diverse range of information. Current efforts responding to the need for these carbon observations are, however, fragmented. There is a need to coordinate observations on carbon, GHG measurements, and ecosystem processes related to carbon cycle dynamics. The GEO Carbon and Greenhouse Gas Initiative (GEO-C) was launched to further support continuity and coherence of the ongoing efforts and facilitate their cooperation and interoperability. The GEO-C Initiative (1) supports the development of a holistic cross-domain, global carbon cycle and GHG monitoring system that provides long-term, high quality, and open access; (2) engages with users and policy makers and ensures the fitness for purpose of the observation and reporting system; and (3) aims to establish a common terminology (including scientists and decision makers) involved in addressing GHG emissions. This chapter describes the background of the GEO-GHG initiative and describes the main aims of the initiative and first steps toward implementation