Perspectives and Integration in SOLAS Science

Why a chapter on Perspectives and Integration in SOLAS Science in this book? SOLAS science by its nature deals with interactions that occur: across a wide spectrum of time and space scales, involve gases and particles, between the ocean and the atmosphere, across many disciplines including chemistry, biology, optics, physics, mathematics, computing, socio-economics and consequently interactions between many different scientists and across scientific generations. This chapter provides a guide through the remarkable diversity of cross-cutting approaches and tools in the gigantic puzzle of the SOLAS realm. Here we overview the existing prime components of atmospheric and oceanic observing systems, with the acquisition of ocean–atmosphere observables either from in situ or from satellites, the rich hierarchy of models to test our knowledge of Earth System functioning, and the tremendous efforts accomplished over the last decade within the COST Action 735 and SOLAS Integration project frameworks to understand, as best we can, the current physical and biogeochemical state of the atmosphere and ocean commons. A few SOLAS integrative studies illustrate the full meaning of interactions, paving the way for even tighter connections between thematic fields. Ultimately, SOLAS research will also develop with an enhanced consideration of societal demand while preserving fundamental research coherency. The exchange of energy, gases and particles across the air-sea interface is controlled by a variety of biological, chemical and physical processes that operate across broad spatial and temporal scales. These processes influence the composition, biogeochemical and chemical properties of both the oceanic and atmospheric boundary layers and ultimately shape the Earth system response to climate and environmental change, as detailed in the previous four chapters. In this cross-cutting chapter we present some of the SOLAS achievements over the last decade in terms of integration, upscaling observational information from process-oriented studies and expeditionary research with key tools such as remote sensing and modelling. Here we do not pretend to encompass the entire legacy of SOLAS efforts but rather offer a selective view of some of the major integrative SOLAS studies that combined available pieces of the immense jigsaw puzzle. These include, for instance, COST efforts to build up global climatologies of SOLAS relevant parameters such as dimethyl sulphide, interconnection between volcanic ash and ecosystem response in the eastern subarctic North Pacific, optimal strategy to derive basin-scale CO2 uptake with good precision, or significant reduction of the uncertainties in sea-salt aerosol source functions. Predicting the future trajectory of Earth’s climate and habitability is the main task ahead. Some possible routes for the SOLAS scientific community to reach this overarching goal conclude the chapter

Ethylene and methane in the upper water column of the subtropical Atlantic

The vertical distributions of ethylene and methane in the upper water column ofthe subtropical Atlantic were measured along a transect from Madeira to the Caribbean andcompared with temperature, salinity, oxygen, nutrients, chlorophyll-a, and dissolved organiccarbon (DOC).Methane concentrations between 41.6 and 60.7 nL L−1 were found in the upper 20 m ofthe water column giving a calculated average flux of methane into the atmosphere of 0.82 µgm−2 h−1. Methane profiles reveal several distinct maxima in the upper 500 m of the watercolumn and short-time variations which are presumably partly related to the vertical migrationof zooplankton.Ethylene concentrations in near surface waters varied in the range of 1.8 to 8.2 nL L−1.Calculated flux rates for ethylene into the atmosphere were in the range of 0.41 to 1.35 µgm−2 h−1 with a mean of 0.83 µg m−2 h−1. Maximum concentrations of up to 39.2 nL L−1were detected directly below the pycnocline in the western Atlantic. The vertical distributionsof ethylene generally showed one maximum at the pycnocline (about 100 m depth) whereelevated concentrations of chlorophyll-a, dissolved oxygen, and nutrients were also found;no ethylene was detected below 270 m depth. This suggests that ethylene release is mainlyrelated to one, probably phytoplankton associated, source, while for methane, enhanced netproduction occurs at various depth horizons. For surface waters, a simple correlation betweenethylene and chlorophyll-a or DOC concentrations could not be observed. No considerablediurnal variation was observed for the distribution and concentration of ethylene in the upperwater column