RV Meteor#
METEOR is Germany’s third largest research vessel and is used for basic research in a number of scientific disciplines, including the study of the atmosphere, the water column, marine organisms and the ocean floor. The METEOR is the property of the Federal Republic of Germany, represented by the Federal Ministry of Education and Research (BMBF), which financed the building of the vessel.
The work programme is divided into three parts. First, the continues sampling of atmospheric and upper ocean conditions during the three Atlantic transects; Second, it continues ocean measurements at the centre points of the transects with the deployed gliders and Wire-Walkers and finally stations about every degree travelled for CTD/MSS and biogeochemistry measurements with simultaneous drone measurements in the atmospheric boundary layer.
Instrument#
Cloud Radar
The cloud radar operates at 3.2 millimeter wavelength (94GHz). The radar provides range profiles of radar moments (e.g. radar reflectivity, mean Doppler velocity, spectral width) that contain information about scatterers in the atmosphere such as cloud particles, raindrops, ice particles, snowflakes and insects. The radar utilises FMCW signals and therefore has a high range resolution down to a few meters, time resolution is a few seconds. Doppler and polarimetric capabilities of the radar make a good basis for a classification of particles and a quantitative characterisation of hydrometeors.
CPICS
The Continuous Plankton Imaging and Classification System (CPICS) will be mounted to the GEOMAR CTD-Frame. It is fully self-contained and has a depth rating of 6000m for vertical deep profiles.
CTD and biogeochemical measurements
Repeated 1500m CTD profiles and micro-structure (MSS) measurements in the upper ocean carried throughout the working area, roughly every degree. Measurements will be used to determine stratification and current velocity to quantify internal wave energy and energy flux.
Concentration measurements of inorganic and organic nitrogen and phosphorus compounds, rate measurements of primary productivity, nitrogen fixation, and phosphonate utilization using stable-isotope incubations, with and without nutrient supplementation, microbial community analyses using state-of-art metagenomic and transcriptomic sequencing, and cell specific activity measurements of keystone microbial groups using nanoSIMS, will be carried out at CTD stations and with specific full depths CTDs.
Drones
Four coordinate drones will measure humidity, temperature, pressure, 3-D winds, area averaged mesoscale kinematics and up-/downdraft at every station in the atmospheric boundary layer. The drones will measure in a radius of about 10km around the ship up to a height of 1.5km.
Flux Measurements
Flux measurements determine latent and sensible heat fluxes. The flux station will be installed on the top mast. In addition, an ocean viewing thermal camera at the front of the ship will be used to determine the ocean temperature of the undisturbed water.
LICHT Raman Lidar
The Raman lidar of the MPI-M offers continuous vertical profiles for atmospheric properties. Backscatter profiles at 3 wave lengths (0.355, 0.532 and 1.064 um) inform on cloud-base altitude and offer a qualitative aerosol vertical distribution. Additional information on depolarization reveals non-spherical particles shapes to identify ice-clouds and mineral dust layers. Most important is excited backscatter in off wavelengths (Raman) frequencies near 0.355 and 0.532um. This added information offers quantitative profiles for aerosol extinction as well as for profiles of temperature and water vapor.
Ocean Glider
Deployment and recovery of ocean gliders equipped with microstructure sensors measuring shear and temperature profiling the upper 100 m and 1000 m of the water column. The gliders are capable of sampling continuously for an approximately four-week period. They will be deployed at the easter, central and western transect, to capture background conditions, and will be used to repeatedly sample specific features such as fronts, and internal wave spectra. They have typical horizontal speeds (under low current conditions) of 0.8 km/hour. The shallow gliders will be configured to sample up to the water surface to collect very near surface turbulence and thermal structure on the upcasts.
RPG-HATPRO Microwave Radar
The microwave RPG-HATPRO (Humidity and Temperature PROfiler) is a micro-wave detector for measuring humidity and temperature profiles in the earth’s troposphere. The radiometer is a passive remote-sensing instrument measuring the sky’s brightness temperatures at absorption lines of atmospheric water vapor (22.23 - 31.4 GHz) and oxygen (51.26 - 58.0 GHz) as well as window channels between those spectral lines. Apart from humidity and temperature profiles, the system also retrieves integrated quantities like integrated water vapor (IWV) and liquid water path (LWP) in the troposphere.
Radiosondes
Radiosonde launches are planned at every three hours. The radiosondes establish vertical atmospheric profiles of wind, temperature and humidity. With the receiving system of the University of Hamburg profiles during ascent and descent can be recorded, before the radiosonde signal will be lost due to the curvature of the earth. The radiosondes will be coordinated with launches at the BCO site, on Barbados.
SEA-POL
SEA-POL radar measures dual-polarisation data over a range in excess of 200 km. The radar operates at C-band (5.65 GHz) and has a 4.3m stabilised antenna system, kinematic and microphysical structure of precipitation events.
Sunphotometer
Sunphotometer instruments of MPI-M/NASA and IOPAN collect atmospheric column properties for aerosol and water vapor. Samples are collected in a laborintensive handheld operation and are only possible when the sun is not obscured by clouds. Each evening data are transmitted to AERONET from where sampled data and derived products (e.g. fine-mode fraction) can be viewed or downloaded within hours.
UCTD
Underway measurements with the ship-board ADCPs and an underway CTD (UCTD) will be used to provide velocity and stratification information for the upper water column. The data will be used to measure submesoscale currents and internal wave shear and strain.
Wind lidar
Wind lidar systems will measure vertical profiles of the horizontal wind and turbulent momentum fluxes in the lower atmosphere at a high temporal and range resolution. The set-up includes one lidar pointing vertically and one lidar horizontal.
WireWalker
Wirewalker will vertically profile, along a cable between Surface and 750m depth. It is equipped with a Plankton and Particle camera (Underwater Vision Profiler 6-HF), CTD, Chlorophyll, Microstructure turbulence probe and Oxygen sensor. Deployment is planned together with Gliders.