More than 90% of the heat energy accumulation in the climate system between 1971 and the present has been in the ocean. Thus, the ocean plays a crucial role in determining the climate of the planet. Observing the oceans is problematic even under the most favourable of conditions. Historically, shipboard ocean sampling has left vast expanses, particularly in the Southern Ocean, unobserved for long periods of time. Within the past 15 years, with the advent of the global Argo array of pro ling oats, it has become possible to sample the upper 2,000 m of the ocean globally and uniformly in space and time. The primary goal of Argo is to create a systematic global network of pro ling oats that can be integrated with other elements of the Global Ocean Observing System. The network provides freely available temperature and salinity data from the upper 2,000 m of the ocean with global coverage. The data are available within 24 hours of collection for use in a broad range of applications that focus on examining climate-relevant variability on seasonal to decadal timescales, multidecadal climate change, improved initialization of coupled ocean-atmosphere climate models and constraining ocean analysis and forecasting systems.

Indian Ocean hides Global Warming Marine scientists proof additional heat uptake during the past decades May 18, 2015/Miami/Kiel. Why has the global temperature rise paused during the past two decades? A team of scientists from the US and the German GEOMAR Helmholtz Centre for Ocean Research Kiel was able to now show that the heat content of the Indian Ocean has risen substantially since late 1990s although the global temperature showed only little changes.

The Argo Program has been implemented and sustained for almost two decades, as a global array of about 4000 profiling floats. Argo provides continuous observations of ocean temperature and salinity versus pressure, from the sea surface to 2000 dbar. The successful installation of the Argo array and its innovative data management system arose opportunistically from the combination of great scientific need and technological innovation. Through the data system, Argo provides fundamental physical observations with broad societally-valuable applications, built on the cost-efficient and robust technologies of autonomous profiling floats. Following recent advances in platform and sensor technologies, even greater opportunity exists now than 20 years ago to (i) improve Argo's global coverage and value beyond the original design, (ii) extend Argo to span the full ocean depth, (iii) add biogeochemical sensors for improved understanding of oceanic cycles of carbon, nutrients, and ecosystems, and (iv) consider experimental sensors that might be included in the future, for example to document the spatial and temporal patterns of ocean mixing. For Core Argo and each of these enhancements, the past, present, and future progression along a path from experimental deployments to regional pilot arrays to global implementation is described. The objective is to create a fully global, top-to-bottom, dynamically complete, and multidisciplinary Argo Program that will integrate seamlessly with satellite and with other in situ elements of the Global Ocean Observing System (Legler et al., 2015). The integrated system will deliver operational reanalysis and forecasting capability, and assessment of the state and variability of the climate system with respect to physical, biogeochemical, and ecosystems parameters. It will enable basic research of unprecedented breadth and magnitude, and a wealth of ocean-education and outreach opportunities.

a b s t r a c tAs part of an effort to monitor changes in inorganic carbon chemistry of the coastal ocean, near-synoptic cruises are being conducted in the Northern Gulf of Mexico and along the East Coast of the United States.Here we describe observations obtained on a cruise in the summer of 2012 and compare them with results from a cruise following a similar track in 2007. The focus is on describing spatial patterns of aragonite saturation state (Ω Ar ). This parameter is an indicator of ecosystem health, in particular for calcifying organisms. The results show large-scale regional trends from different source waters at the northeastern and southwestern edges of the domain, along with the modulating effects of remineralization/respiration and riverine inputs. The broader patterns and changes over five years along the coast can be well described by the impacts of large-scale circulation, notably changes in source water contributions. Changes in the well-buffered Loop Current and Gulf Stream with high Ω Ar impact the waters in the southern part of the study area. The less buffered southward coastal currents with low Ω Ar originating from the Labrador Sea and Gulf of St. Lawrence impact the Ω Ar patterns in the Northern regions. The expected 2% average decrease in Ω Ar in the surface mixed layer due to increasing atmospheric CO 2 levels over the 5-year period is largely overshadowed by local and regional variability from changes in hydrography and mixed layer dynamics.Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).