The Maunakea Spectroscopic Explorer Book 2018

(Abridged) This is the Maunakea Spectroscopic Explorer 2018 book. It is intended as a concise reference guide to all aspects of the scientific and technical design of MSE, for the international astronomy and engineering communities, and related agencies. The current version is a status report of MSE's science goals and their practical implementation, following the System Conceptual Design Review, held in January 2018. MSE is a planned 10-m class, wide-field, optical and near-infrared facility, designed to enable transformative science, while filling a critical missing gap in the emerging international network of large-scale astronomical facilities. MSE is completely dedicated to multi-object spectroscopy of samples of between thousands and millions of astrophysical objects. It will lead the world in this arena, due to its unique design capabilities: it will boast a large (11.25 m) aperture and wide (1.52 sq. degree) field of view; it will have the capabilities to observe at a wide range of spectral resolutions, from R2500 to R40,000, with massive multiplexing (4332 spectra per exposure, with all spectral resolutions available at all times), and an on-target observing efficiency of more than 80%. MSE will unveil the composition and dynamics of the faint Universe and is designed to excel at precision studies of faint astrophysical phenomena. It will also provide critical follow-up for multi-wavelength imaging surveys, such as those of the Large Synoptic Survey Telescope, Gaia, Euclid, the Wide Field Infrared Survey Telescope, the Square Kilometre Array, and the Next Generation Very Large Array.Comment: 5 chapters, 160 pages, 107 figure

EUREC4A-OA experiment: Air-Sea Flux Mast Data

All data from MAST Flux on board ATALANTE during EURECA-OA CampaignAs part of the EUREC4A-OA project (H. Bellenger, S. Speich, LMD), which is the French oceanographic component of the larger EUREC4A field experiments, the “flux mast” national instrument was installed on the Reseach Vessel R/V Atalante from Genavir. The flux mast holds instruments that measure atmospheric turbulence and meteorological variables. The collected data are used to estimate the turbulent fluxes of momentum and heat at the air-sea interface. Specifically, the flux mast instruments measure air pressure, air temperature, humidity, air refraction index, H2O, the three components of the wind vector, and the upward and downward solar and infrared radiation fluxes. The fluxes calculated are the latent and sensible heat fluxes, and the friction velocity

IAOOS microlidar-on-buoy development and first atmospheric observations obtained during 2014 and 2015 arctic drifts

International audienceThe in situ tests of first ever autonomous aerosol and cloud backscatter LIDAR (light detection and ranging) systems implemented on buoys for Arctic observations has been achieved in 2015 within the French EQUIPEX IAOOS project. The environmental and operational constraints were met by adopting a concept of a fibered microjoule lidar system using a laser diode. Two systems have been developed with and without polarization analysis capability. A specific optical design was used for polarization discrimination. These systems were integrated in buoys and tested in the Arctic in 2014 and 2015 at latitudes higher than 80°N. Data were transmitted through an Iridium space link. Measurements have been obtained 90% of the time from the non-polarized system in 2014 over 8 months as the first fully equipped buoy drifted from the Barneo Russian camp close to the North Pole toward Svalbard. A polarized system was then tested over a short period in winter 2015 north of Svalbard during the Norwegian campaign N-ICE. In April and May 2014, the unattended lidar measurements showed a large occurrence of aerosols and haze. The average attenuated scattering ratio for non-cloudy profiles during this period was about 2.2. Aerosols could reach an altitude of 5km on average, whereas over the rest of the period low level clouds (below 1000 m) were prevailing with an average attenuated scattering ratio of about 103. The main features of the developed lidar instruments and first results are presented here

OCARINA : a new platform dedicated to measurements of Air-Sea fluxes

OCARINA (Ocean Coupled with Atmosphere : Recherche Instrumentale sur Navire Annexe) is a small moving platform deployed from a research vessel. Turbulent fluxes, radiation fluxes, and wave state can all be derived from the instruments embedded on OCARINA, which include a sonic anemometer, an inertial platform, a CT probe, and other sensors. OCARINA was recently deployed during the FROMVAR experiment in Mer d'Iroise. It was successfully operated in winds up to 12 m/s and waves up to 4 m. The platform and datasets will be presented. Turbulent fluxes estimated with OCARINA data will be compared to data collected on the host vessel

Arctic aerosol and cloud measurements in the frame of the Ice-Atmosphere-Ocean Observing System (IAOOS) project

International audienceIn the frame of the French IAOOS Equipex project, a new observational network is to be developed for the ocean-ice-atmosphere survey over the Arctic starting in 2015 to better understand interactions and in particular the role of aerosols and clouds in the Arctic. Eye-safe lidar measurements will allow to profile aerosols and clouds for the atmospheric part, with the objective to perform regular measurements and characterize their vertical structure and optical properties complementing satellite observations. Radiation and meteorological parameters will simultaneously be measured at the surface. A first buoy has been prototyped and deployed in April 2014 at the Barneo site set by the Russian teams at the North Pole. Measurements with the first autonomous backscatter lidar ever deployed in the arctic have been taken from April to end of November 2014 before the buoy was lost. A second set of data were acquired during the N-ICE campaign north of Svalbard during winter 2015. Up to four profiles a day (10 mn sequence each) have been performed allowing a good sampling with respect to meteorological analyses. Observations have shown that the occurrence of low level clouds was higher than 90% during summer. New deployments are planned in summer 2015 as the start of the IAOOS network. The project is presented, instruments are described and first results are discussed

Arctic aerosol and cloud measurements performed during IAOOS 2014

International audienceBetter understanding of atmosphere-ice-ocean interactions and in particular of the role of aerosols and clouds in this Earth system is of prime importance in the Arctic. In the frame of the French IAOOS Equipex project, a new observational network is planned to be developed for ocean-ice-atmosphere climate survey over the Arctic, starting in 2015, to complement satellite observations. Eye-safe lidar measurements will allow us to profile aerosols and clouds for the atmospheric part, with the objective to perform regular measurements and characterize the vertical structure and optical properties. Radiation and meteorological parameters will be measured at the surface. A first buoy has been prototyped and deployed in April 2014 at the Barneo site set by the Russian teams at the North Pole. Measurements with the first autonomous backscatter lidar ever deployed in the arctic have been taken from April to end of November 2014 before the buoy was lost. Four profiles a day have been performed allowing a good sampling of cloud variability. Observations have shown that the occurrence of low level clouds was higher than 90% during summer. The project is presented, instrument performance is described and first results are discussed

A new platform for the determination of air-sea fluxes (OCARINA): Overview and first results

International audienceThe present paper describes a new type of floating platform that was specifically designed for estimating air-sea fluxes, investigating turbulence characteristics in the atmospheric surface boundary layer, and studying wind-wave interactions. With its design, it can be deployed in the open ocean or in shallow water areas. The system is designed to be used from a research vessel. It can operate for ~10 hours as a drifting wave rider and three hours under power. Turbulence and meteorological instrument packages are placed at a low altitude (1-1.5 m). It was deployed for validation purposes during the FROMVAR 2011 experiment off the west coast of Brittany (France). Wind friction velocity and surface turbulent buoyancy flux were estimated using eddy-covariance, spectral, bulk and profile methods. The comparisons of the four methods show a reasonable agreement except for the spectral buoyancy flux. This suggests that the platform design is correct. Also the wind measured at a fixed height above the sea shows spectral coherence with wave heights, such that wind and swell are in phase, with largest wind values on top of swell crests. This result in qualitative agreement with current model predictions supports the capability of OCARINA to investigate wind-swell interactions

A new device to follow temporal variations of oxygen demand in deltaic sediments: the LSCE benthic station

International audienceA new benthic station equipped with oxygen microelectrodes and environmental sensors was developed by Laboratoire des Sciences du Climat et de L'Environnement (LSCE) and Division Technique of the Institut National des Sciences de L'Univers (DT‐ INSU) to perform in situ time series monitoring of sediment oxygen demand, linked to the mineralization of organic matter. The time series typically cover periods of 2‐ 3 months, with a base frequency of 1 set of oxygen profiles per day. The profiling head assessed the lateral heterogeneity of the sediment oxygen demand at the beginning of the time series over a 0.8‐ m long rectangle to discriminate spatial and temporal variability. A continuous recalibration is performed using a moored oxygen optode anchored to the benthic station together with a set of environmental sensors. These sensors (turbidity, temperature, salinity, and oxygen) can trigger a high‐ frequency profiling mode to investigate the fate of particulate organic matter delivered during floods, resuspension, and deposition events. Deployments of the benthic station were performed in the Rhone River subaqueous delta (Mediterranean Sea). We show that “stable” periods (when neither floods nor storms occur) were characterized by a stable oxygen demand. In the case of resuspension events, an increase of the sediment oxygen demand by a factor of 2‐ 3 with a relaxation time of 1 day was observed, indicating that the new benthic station can adequately capture the impact of resuspension events on the oxygen demand in deltaic sediments

Temporal and spatial variability of water vapor isotopic composition in the lower troposphere: insights from ultralight aircraft measurements

International audienceThe lower troposphere is where the surface evapotranspiration flux has a strong impact on the atmospheric water vapor isotopic composition, enabling the investigation of the hydro-ecological features of a specific study area. Even though several studies investigated in the last decade the spatial and temporal variability of tropospheric water vapor isotopic composition with ships, aircrafts, satellites and at fixed locations at ground level, vertical profiles and spatial observations acquired within the same time window in the lower troposphere (<3000 m) are still rare. As part of the ground validation of the EU H2020 LEMON project, we used an UltraLight Aircraft (ULA) equipped with a flight-enabled CRDS water vapor isotopes analyzer to probe the vertical and spatial structure of the lower troposphere in Ardèche, Southern France, between 17 and 23 September 2021. In total, 16 flights with different flight strategies were performed for a total flight time of ~20 hours. The flight patterns were mainly designed to obtain representative vertical profiles of the water vapor column below 3000 m for comparison with ground-based LIDAR and to obtain precise estimates of the humidity and water vapor isotopic composition at specific altitude levels, spanning an area of approximately 10 km x 10 km. Due to the flexibility of the ULA, it was also possible to fly several times throughout the day, allowing to study the daytime temporal evolution of the water vapor column within the boundary layer. In general, vertical profile measurements showed evidence of strong mixing process throughout the lower atmospheric column, with both input from free tropospheric layer and surface evapotranspiration. Water vapor stratification, characterized by a large vertical gradient of the isotopic composition, was observed during early morning flights with increased steepness of the vertical isotopic profile along the day. In some cases, flights focused on horizontal and spatial gridding of water vapor isotopic composition showed variation of more than 10‰ for dD in ~5 km2 and in less than 0.12 hours. We Powered by TCPDF (www.tcpdf.org)hypothesize this large horizontal variability to be related to development of thermals within the boundary layer. Our next step will be to summarize the spatial and temporal variability of water vapor isotopic composition for allowing a fair comparison between high-resolution isotope- enabled general circulation models, remote sensing and water vapor observations in the boundary layer

IAOOS (Ice - Atmosphere - Arctic Ocean Observing System, 2011-2019)

6th International Workshop on Sea-Ice Modelling and Data Assimilation, 2014 September 15-16, Toulouse, FranceInternational audienceThe key to documenting and understanding change in the Arctic is continuous monitoring. The high cost of Arctic operations thus makes observationsby satellite or with long-endurance, refurbishable, autonomous platforms a cost effective solution to continuously observe on-going changes in nearreal-time. IAOOS (Ice Atmosphere Ocean Observing System, http://www.iaoos-equipex.upmc.fr, http://iaoos.ipev.fr/) is a nine-year France-fundedproject (2011-2019), developed by LOCEAN and LATMOS, which objective is to provide and maintain an integrated observing system over the ArcticOcean that collects synoptic and near real time information related to the state of the atmosphere, the snow, the sea-ice and the ocean