Surface Ocean Lower Atmosphere Research Articles

Impacts of ocean biogeochemistry on atmospheric chemistry

Ocean biogeochemistry involves the production and consumption of an array of organic compounds and halogenated trace gases that influence the composition and reactivity of the atmosphere, air quality, and the climate system. Some of these molecules affect tropospheric ozone and secondary aerosol formation and impact the atmospheric oxidation capacity on both regional and global scales. Other emissions undergo transport to the stratosphere, where they contribute to the halogen burden and influence ozone. The oceans also comprise a major sink for highly soluble or reactive atmospheric gases. These issues are an active area of research by the SOLAS (Surface Ocean Lower Atmosphere) community. This article provides a status report on progress over the past decade, unresolved issues, and future research directions to understand the influence of ocean biogeochemistry on gas-phase atmospheric chemistry. Common challenges across the subject area involve establishing the role that biology plays in controlling the emissions of gases to the atmosphere and the inclusion of such complex processes, for example involving the sea surface microlayer, in large-scale global models.

Ocean negative carbon emissions: A new UN Decade program

Ocean negative carbon emissions: A new UN Decade program

From Monodisciplinary via Multidisciplinary to an Interdisciplinary Approach Investigating Air-Sea Interactions – a SOLAS Initiative

Understanding the physical and biogeochemical interactions and feedbacks between the ocean and atmosphere is a vital component of environmental and Earth system research. The ability to predict and respond to future environmental change relies on a detailed understanding of these processes. The Surface Ocean-Lower Atmosphere Study (SOLAS) is an international research platform that focuses on the study of ocean-atmosphere interactions, for which Future Earth is a sponsor. SOLAS instigated a collaborative initiative process to connect efforts in the natural and social sciences related to these processes, as a contribution to the emerging Future Earth Ocean Knowledge-Action Network (Ocean KAN). This is imperative because many of the recent changes in the Earth system are anthropogenic. An understanding of adaptation and counteracting measures requires an alliance of scientists from both domains to bridge the gap between science and policy. To this end, three SOLAS research areas were targeted for a case study to determine a more effective method of interdisciplinary research: valuing carbon and the ocean’s role; air-sea interactions, policy and stewardship; and, air-sea interactions and the shipping industry.

Harnessing remote sensing to address critical science questions on ocean-atmosphere interactions

Earth observing systems have proven to be a unique source of long-term synoptic information on numerous physical, chemical and biological parameters on a global scale. Merging this information for integrated studies that peruse key questions about the ocean-atmosphere interface is, however, very challenging. Such studies require interdisciplinary frameworks and novel insights into ways to address the problem. We present here a perspective review on how current and emerging remote sensing technologies could help address two scientific questions within the Surface Ocean-Lower Atmosphere Study (SOLAS) science plan: (1) to what extent does upper-ocean biology affect the composition and radiative properties of the marine boundary layer; and (2) to what extent does upper-ocean turbulence drive fluxes of mass and energy at the air-sea interface. We provide a thorough review of how these questions have been addressed and discuss novel potential avenues using multiplatform space-borne missions, from visible to microwave, active and passive sensors.

Surface ocean-lower atmosphere study: Scientific synthesis and contribution to Earth system science

The domain of the surface ocean and lower atmosphere is a complex, highly dynamic component of the Earth system. Better understanding of the physics and biogeochemistry of the air–sea interface and the processes that control the exchange of mass and energy across that boundary define the scope of the Surface Ocean-Lower Atmosphere Study (SOLAS) project. The scientific questions driving SOLAS research, as laid out in the SOLAS Science Plan and Implementation Strategy for the period 2004–2014, are highly challenging, inherently multidisciplinary and broad. During that decade, SOLAS has significantly advanced our knowledge. Discoveries related to the physics of exchange, global trace gas budgets and atmospheric chemistry, the CLAW hypothesis (named after its authors, Charlson, Lovelock, Andreae and Warren), and the influence of nutrients and ocean productivity on important biogeochemical cycles, have substantially changed our views of how the Earth system works and revealed knowledge gaps in our understanding. As such SOLAS has been instrumental in contributing to the International Geosphere–Biosphere Programme (IGBP) mission of identification and assessment of risks posed to society and ecosystems by major changes in the Earth’s biological, chemical and physical cycles and processes during the Anthropocene epoch. SOLAS is a bottom-up organization, whose scientific priorities evolve in response to scientific developments and community needs, which has led to the launch of a new 10-year phase. SOLAS (2015–2025) will focus on five core science themes that will provide a scientific basis for understanding and projecting future environmental change and for developing tools to inform societal decision-making.

Autonomous Surface Vehicle Measurements of the Ocean’s Response to Tropical Cyclone Freda

Abstract On 31 December 2012, an instrumented autonomous surface vehicle (ASV; Wave Glider) transiting across the Pacific from Hawaii to Australia as part of the Pacific Crossing (PacX) project came very close (46 km) to the center of a category 3 Tropical Cyclone (TC), Freda, experiencing winds of up to 37 and significant wave heights close to 10 m. The Wave Glider was instrumented for surface ocean–lower atmosphere (SOLA) measurements, including atmospheric pressure, surface winds and temperature, sea surface temperature, salinity, dissolved oxygen, fluorescence (chlorophyll-a and turbidity), and surface-wave directional spectra. Such measurements in close proximity to a tropical cyclone are rare. This study presents novel observations of the ocean’s response in three quadrants of TC Freda, collected from the instrumented glider. Evolution of the wind, the directional wave field, the sea surface temperature, and the Stokes drift profile (calculated from the wave directional spectrum) as Freda passed near the vehicle are examined. Results are discussed in the context of the recent coupled wind-wave modeling and large eddy simulation (LES) modeling of the marine boundary layer in Hurricane Frances (Sullivan et al. 2012). Processes by which cold nutrient-rich waters are entrained and mixed from below into the mixed layer as the TC passes near the Wave Glider are presented and discussed. The results of this encounter of an autonomous surface vehicle with TC Freda supports the use of ASVs for regular TC (hurricane) monitoring to complement remote sensing and “hurricane hunter” aircraft missions.

Evolving research directions in Surface Ocean - Lower Atmosphere (SOLAS) science

Environmental context Understanding the exchange of energy, gases and particles at the ocean–atmosphere interface is critical for the development of robust predictions of, and response to, future climate change. The international Surface Ocean–Lower Atmosphere Study (SOLAS) coordinates multi-disciplinary ocean–atmosphere research projects that quantify and characterise this exchange. This article details five new SOLAS research strategies – upwellings and associated oxygen minimum zones, sea ice, marine aerosols, atmospheric nutrient supply and ship emissions – that aim to improve knowledge in these critical areas. Abstract This review focuses on critical issues in ocean–atmosphere exchange that will be addressed by new research strategies developed by the international Surface Ocean–Lower Atmosphere Study (SOLAS) research community. Eastern boundary upwelling systems are important sites for CO2 and trace gas emission to the atmosphere, and the proposed research will examine how heterotrophic processes in the underlying oxygen-deficient waters interact with the climate system. The second regional research focus will examine the role of sea-ice biogeochemistry and its interaction with atmospheric chemistry. Marine aerosols are the focus of a research theme directed at understanding the processes that determine their abundance, chemistry and radiative properties. A further area of aerosol-related research examines atmospheric nutrient deposition in the surface ocean, and how differences in origin, atmospheric processing and composition influence surface ocean biogeochemistry. Ship emissions are an increasing source of aerosols, nutrients and toxins to the atmosphere and ocean surface, and an emerging area of research will examine their effect on ocean biogeochemistry and atmospheric chemistry. The primary role of SOLAS is to coordinate coupled multi-disciplinary research within research strategies that address these issues, to achieve robust representation of critical ocean–atmosphere exchange processes in Earth System models.

Surface Ocean–Lower Atmosphere Processes

No system exists in isolation, and the ocean is no different. Understanding the mechanics directing a system as complicated as the ocean takes an interdisciplinary effort and well‐controlled studies. The Surface Ocean–Lower Atmosphere Study (SOLAS) program is an international effort to make sense of the physical and biogeochemical interactions that take place between the air and the sea. Having scientists ready to dissect these interactions will be increasingly important as the world begins to consider deliberately manipulating the system in an attempt to combat climate change. The AGU Monograph Surface Ocean–Lower Atmosphere Processes, edited by Corinne Le Quéré and Eric S. Saltzman, looks at the increasingly important interactions occurring at the boundary between these two systems. In this interview, Eos talks to Corinne Le Quéré.

Cycling of PCBs and HCB in the Surface Ocean-Lower Atmosphere of the Open Pacific

Surface ocean and lower atmosphere samples were collected on the R/V Revelle during a scientific cruise from San Diego, CA to New Zealand via Samoa and the South Pacific Gyre (SPG) from 12/2006 to 1/2007. Samples were analyzed for polychlorinated biphenyls (PCBs) and hexachlorobenzene (HCB). summation operator(ICES)PCBs gaseous concentrations (ICES: International Council for the Exploration of the Sea) ranged from 28-103 pg m(-3) in the northern hemisphere (NH) and 1.5-36 pg m(-3) in the southern hemisphere (SH), whereas dissolved seawater concentrations were between 0.2-15 pg L(-1) in the NH and 0.3-7.8 pg L(-1) in the SH. Both gas ([PCBs](gas)) and dissolved phase concentrations ([PCBs](sw_dis)) displayed highest concentrations near North America and lowest in the SPG. In the NH, [HCB](gas) ranged from 42-89 pg m(-3), higher than the average in the SH (31 pg m(-3)), while [HCB](sw_dis) were comparable in both hemispheres (NH: 0.4-1.6 pg L(-1), SH: 0.4-0.8 pg L(-1)). Fugacity ratio calculations suggest PCBs were volatilizing from surface waters to the overlying atmosphere, and air-water exchange fluxes were approximately 0.5 to approximately 30.4 ng m(-2) d(-1). This is the first study reporting the degassing of PCBs from the open ocean into the air. Previous studies deduced net deposition of PCBs into the Atlantic and Arctic Oceans. As has been observed for other oceans, HCB was at/near air-water equilibrium. A mass balance model was used to interpret the short-term variations in [PCBs](gas) in the SPG, which was not observed for HCB. It is suggested that hydroxyl radical depletion reaction and air-water gas exchange together controlled the variation in [PCBs](gas).

Influence of the ITCZ on H2O2 in near surface waters in the equatorial Atlantic Ocean

H2O2 was measured in the upper water column (0–200 m) along a west‐east transect through the Equatorial Atlantic as part of the German SOLAS (Surface Ocean Lower Atmosphere) cruise Meteor 55 (M55). Vertical profiles of H2O2 showed characteristic exponential decay consistent with light profiles and rainwater inputs. Integrated (0–100 m) water column H2O2 inventories ranged from 1.1–8.9 mmol m−2 with the highest values in the Amazon Plume. H2O2 inventories were also higher at the Equatorial Upwelling and after heavy rain showers in the region of the Inter Tropical Convergence Zone (ITCZ). Analysis of rain water samples collected during the cruise gave a volume weighted mean of 10.8 μmol L−1 (range 1.5–22.3 μmol L−1). This work highlights the importance of rainwater as a major source for H2O2 in the surface waters under the ITCZ.