@article {RN109,
	title = {Air-Sea Fluxes With a Focus on Heat and Momentum},
	journal = {Frontiers in Marine Science},
	volume = {6},
	year = {2019},
	pages = {430},
	type = {Journal Article},
	abstract = {Turbulent and radiative exchanges of heat between the ocean and atmosphere (hereafter heat fluxes), ocean surface wind stress, and state variables used to estimate them, are Essential Ocean Variables (EOVs) and Essential Climate Variables (ECVs) influencing weather and climate. This paper describes an observational strategy for producing 3-hourly, 25-km (and an aspirational goal of hourly at 10-km) heat flux and wind stress fields over the global, ice-free ocean with breakthrough 1-day random uncertainty of 15 W m{\textendash}2 and a bias of less than 5 W m{\textendash}2. At present this accuracy target is met only for OceanSITES reference station moorings and research vessels (RVs) that follow best practices. To meet these targets globally, in the next decade, satellite-based observations must be optimized for boundary layer measurements of air temperature, humidity, sea surface temperature, and ocean wind stress. In order to tune and validate these satellite measurements, a complementary global in situ flux array, built around an expanded OceanSITES network of time series reference station moorings, is also needed. The array would include 500{\textendash}1000 measurement platforms, including autonomous surface vehicles, moored and drifting buoys, RVs, the existing OceanSITES network of 22 flux sites, and new OceanSITES expanded in 19 key regions. This array would be globally distributed, with 1{\textendash}3 measurement platforms in each nominal 10{\textdegree} by 10{\textdegree} box. These improved moisture and temperature profiles and surface data, if assimilated into Numerical Weather Prediction (NWP) models, would lead to better representation of cloud formation processes, improving state variables and surface radiative and turbulent fluxes from these models. The in situ flux array provides globally distributed measurements and metrics for satellite algorithm development, product validation, and for improving satellite-based, NWP and blended flux products. In addition, some of these flux platforms will also measure direct turbulent fluxes, which can be used to improve algorithms for computation of air-sea exchange of heat and momentum in flux products and models. With these improved air-sea fluxes, the ocean{\textquoteright}s influence on the atmosphere will be better quantified and lead to improved long-term weather forecasts, seasonal-interannual-decadal climate predictions, and regional climate projections.},
	keywords = {air-sea heat flux, autonomous surface vehicle, ICOADS, latent heat flux, ocean wind stress, OceanSITES, satellite-based ocean monitoring system, surface radiation},
	issn = {2296-7745},
	doi = {10.3389/fmars.2019.00430},
	url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00430},
	author = {Cronin, Meghan F. and Gentemann, Chelle L. and Edson, James and Ueki, Iwao and Bourassa, Mark and Brown, Shannon and Clayson, Carol Anne and Fairall, Chris W. and Farrar, J. Thomas and Gille, Sarah T. and Gulev, Sergey and Josey, Simon A. and Kato, Seiji and Katsumata, Masaki and Kent, Elizabeth and Krug, Marjolaine and Minnett, Peter J. and Parfitt, Rhys and Pinker, Rachel T. and Stackhouse, Paul W. and Swart, Sebastiaan and Tomita, Hiroyuki and Vandemark, Douglas and Weller, A. Robert and Yoneyama, Kunio and Yu, Lisan and Zhang, Dongxiao}
}
@article {RN108,
	title = {Integrated Observations of Global Surface Winds, Currents, and Waves: Requirements and Challenges for the Next Decade},
	journal = {Frontiers in Marine Science},
	volume = {6},
	year = {2019},
	pages = {425},
	type = {Journal Article},
	abstract = {Ocean surface winds, currents, and waves play a crucial role in exchanges of momentum, energy, heat, freshwater, gases, and other tracers between the ocean, atmosphere, and ice. Despite surface waves being strongly coupled to the upper ocean circulation and the overlying atmosphere, efforts to improve ocean, atmospheric, and wave observations and models have evolved somewhat independently. From an observational point of view, community efforts to bridge this gap have led to proposals for satellite Doppler oceanography mission concepts, which could provide unprecedented measurements of absolute surface velocity and directional wave spectrum at global scales. This paper reviews the present state of observations of surface winds, currents, and waves, and it outlines observational gaps that limit our current understanding of coupled processes that happen at the air-sea-ice interface. A significant challenge for the coming decade of wind, current, and wave observations will come in combining and interpreting measurements from (a) wave-buoys and high-frequency radars in coastal regions, (b) surface drifters and wave-enabled drifters in the open-ocean, marginal ice zones, and wave-current interaction {\textquotedblleft}hot-spots,{\textquotedblright} and (c) simultaneous measurements of absolute surface currents, ocean surface wind vector, and directional wave spectrum from Doppler satellite sensors.},
	keywords = {absolute surface velocity, air-sea interactions, Doppler oceanography from space, ocean surface winds, surface waves},
	issn = {2296-7745},
	doi = {10.3389/fmars.2019.00425},
	url = {https://www.frontiersin.org/article/10.3389/fmars.2019.00425},
	author = {Villas B{\^o}as, Ana B. and Ardhuin, Fabrice and Ayet, Alex and Bourassa, Mark A. and Brandt, Peter and Chapron, Betrand and Cornuelle, Bruce D. and Farrar, J. T. and Fewings, Melanie R. and Fox-Kemper, Baylor and Gille, Sarah T. and Gommenginger, Christine and Heimbach, Patrick and Hell, Momme C. and Li, Qing and Mazloff, Matthew R. and Merrifield, Sophia T. and Mouche, Alexis and Rio, Marie H. and Rodriguez, Ernesto and Shutler, Jamie D. and Subramanian, Aneesh C. and Terrill, Eric J. and Tsamados, Michel and Ubelmann, Clement and van Sebille, Erik}
}
