24 pages, 7 figures, 10 tables, 2 appendices, supplementary material https://doi.org/10.1016/j.pocean.2019.102136, Mass transports for the thermocline, intermediate, deep and abyssal layers in the Atlantic Ocean, at 30°S and for 2003 and 2011, have been estimated using data from GO-SHIP hydrographic transoceanic sections and applying three inverse models with different constraints. The uppermost layers comprise South Atlantic Central Water (SACW) and Antarctic Intermediate Water (AAIW), with a net northward transport in the range of 12.1–14.7 Sv in 2003 and 11.7–17.7 Sv in 2011, which can be considered as the northward returning limb of the Meridional Overturning Circulation (MOC). The western boundary Brazil Current transports twice as much SACW in 2003 (−20.2 ± 0.7 Sv) than in 2011 (−9.7 ± 0.7 Sv). A poleward current consisting of AAIW and Upper Circumpolar Deep Water (UCDW) flows beneath the Brazil Current. The eastern boundary Benguela Current, characterized by a high mesoscale eddy activity, transports 15.6 ± 0.9 Sv in 2003 and 11.2 ± 0.8 Sv in 2011, east of the Walvis Ridge. In the ocean interior, the northward flow is mainly located east of the Mid Atlantic Ridge (MAR) where Agulhas Rings (ARs), observed in both 2003 and 2011, transport warm and salty water from the Indian to the Atlantic Ocean. For the deep layers, the southward transport of North Atlantic Deep Water (NADW) occurs as the Deep Western Boundary Current and also in the eastern basin. The western and eastern basins transport similar amounts of NADW to the south during both years, although the eastern pathway changes substantially between both years. The total NADW transport, which is also considered the MOC, is in the range 16.3–24.5 Sv in 2003 and 17.1–29.6 Sv in 2011, hence with no significant change, This study has been performed as part of projects: US CLIVAR Repeat Hydrography Program, which is now part of the International GO-SHIP project, with US funding from the US National Oceanic and Atmospheric Administration (NOAA) Climate Program Office, and National Science Foundation Geoscience Division, BOUNDARY (ProID2017010083) funded by RIS-3, PO Feder Canarias, VA-DE-RETRO (CTM2014-56987-P) and SAGA (RTI2018-100844-B-C31) funded by the Spanish Government. [...] EM was supported by NERC national capability funding through the ORCHESTRA (NE/N018095/1) and CLASS (NE/R015953/1) projects, Peer Reviewed

19 pages, 14 figures, 1 table, supporting information https://doi.org/10.1002/joc.6247, We combine daily in situ precipitation data with meteorological reanalysis data in order to explore the contribution of cut-off low systems to the seasonal and inter-annual rainfall variations over Baghdad from 2005 to 2016. During these 12 years (average rainfall of 131 ± 67 mm/year), 38 rainy cut-off lows brought 43% of the total precipitation, with extreme inter-annual variations. Indeed, precipitation associated with autumn cut-off lows was the principal factor that turned an arid into a wet year: during the three most arid years cut-off lows contributed about 25% of the average rainfall (10 out of 40 mm/year) while during the three wettest years they contributed near 67% (171 out of 254 mm/year). The extreme-rain cut-off low systems displayed analogous synoptic characteristics: upper-atmosphere divergence, upwards vertical motions in the middle atmosphere, and lower-atmosphere winds into central Iraq at times when the surface Red Sea and Persian Gulf waters were warmer than the surface air. During those days previous to an extreme event, the surface waters cooled substantially and the amount of precipitable water increased largely, suggesting high latent heat transfer. In order to characterize those conditions that favour rainfall, we focus on the November 18–20, 2013 cut-off low system, which led to the largest flooding and wettest year in Baghdad between 2005 and 2016. The distribution of properties in the middle (500 hPa) and upper (250 hPa) troposphere shows that the region was affected by intense horizontal divergence and upwards motions, coinciding with a surface low over the Arabian Peninsula that caused intense northwards winds over the Persian Gulf and brought substantial moisture to central Iraq. The analysis of several stability indexes indicates that convective instability played a secondary role during the episode., This work has been supported by projects VA‐DE‐RETRO (CTM2014‐56987‐P), FLUXES (CTM2015‐69392‐C3‐3‐R), TECBIOMET (CTM2017‐89565‐C2‐1‐P), and SAGA (RTI2018‐100844‐B‐C33), funded by the Spanish government. Ali Raheem Al‐Nassar wishes to thank the Iraqi Ministry of Higher Education and Scientific Research and the Mustansiriyah University for their support to carry out this research, With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

28 pages, We present the historical development of the nutrient stream concept, from the initial ideas on the nutrient‐bearing stratum and the transport of inorganic nutrients by the Gulf Stream to the large‐scale inorganic and organic connections in the entire Atlantic Ocean. We mostly analyze and discuss available literature but also present some novel calculations using cruise data and the velocity fields from numerical re‐analysis data. We first examine and discuss the structure of the Gulf Nutrient Stream, the significance of boundary exchange, and the importance of epipycnal and diapycnal processes. We then move to explore the subtropical and remote pathways into the Gulf Nutrient Stream, including the effect of the returning limb of the global overturning circulation, and end up reviewing the concept of nutrient irrigation of the subpolar gyre and its relevance in the spring–fall maintenance of the spring bloom. We close the chapter with some thoughts on the role of streams in the Earth system, as the key conduit for recycling properties within any ocean subsystem while simultaneously connecting the different subsystems, hence bringing about the complexity of the living planet, This research has been supported by the Spanish government through project VA-DE-RETRO (reference number CTM2014-56987-P). Ignasi VallèsCasanova and Dorleta Orúe-Echeverria have been supported by scholarships from the Spanish government, respectively from the FPI and FPU programs

11 pages, 7 figures, 4 tables, supplementary material https://doi.org/10.1016/j.ijheatmasstransfer.2020.120185.-- This article is a publication of the Unidad Océano y Clima of the Universidad de Las Palmas de Gran Canaria, a R+D+I CSIC-associate unit, The large uncertainties in the forecasting of future global climatic conditions endorse the need of developing simple yet credible predicting tools. Here we propose a three-zone steady-state radiative model that maximizes latitudinal heat fluxes and considers the potential effect of the Earth's declination. The model is formulated as a set of five equations and six unknowns (zonal temperatures and widths, and the latitudinal heat transport) that requires specifying the reflected (albedo) and back-to-Earth (greenhouse) radiation fractions and obliges turning the low-latitude temperature into an additional parameter. The results do depend on the Earth declination, with changes of 0.5/1.5 K in the intermediate/high zones, which is interpreted as potentially affecting the greenhouse and high-latitude albedo coefficients. Therefore, we focus on identifying the effects of changes in these parameters – properly selected to represent last-glacial-maximum, modern and end-of the-century conditions. The main change is a large rise of the high-latitude temperature, favored both by a decrease in the high-latitude albedo and an increase in the greenhouse factor. For the other variables, the temporal changes in albedo and greenhouse gases compete among them, resulting in one trend from glacial to modern times and a reversal between preindustrial times and the end of the 21st century (currently a warming-narrowing of the intermediate region and the widening of both the low- and high-latitude zones); however, we note that an increase in the low-latitude temperature would tend to alleviate these changes. Despite its simplicity, the model leads to realistic global trends, becoming a useful simple tool for exploring the sensitivity of the Earth's heat distribution to changes in radiative fluxes and endorsing the validity of the maximum latitudinal-heat-transport premise, This work has been funded by the Spanish Government through projects VA-DE-RETRO (Ministerio de Economía y Competitividad, ref. no. CTM2014-56987-P) and SAGA (Ministerio de Ciencia, Innovación y Universidades, ref. no. RTI2018-100844-B-C33), With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)