METEOR-20240828

METEOR-20240828#

Summary#

RV Meteor’s scientific party is finally complete! With an exchange at sea this morning just outside the harbor in Praia, Cape Verde, STRINQS has finally joined BOWTIE and PICCOLO on the ship. STRINQS will deploy four drones from Meteor to investigate the role of boundary layer processes in organizing the mesoscale structure of the ITCZ. Due to repeated air freight delays, the drones did not arrive in Mindelo in time for Meteor’s departure and we had leave both without the drones and without the STRINQS personnel. With the eventual arrival of the drones and our planned return to the northern edge of the ITCZ, as well as the critical support of Meteor’s Captain and the German research ship coordination center (Leitstelle), we were able to arrange to pick them up in Praia. We also picked up some needed parts for the SEA-POL radar, which were delivered to Praia from Colorado, USA. Repairs are underway in hopes of reviving SEA-POL’s dual polarization capabilities.

Now that STRINQS is on board, they will perform simultaneous but spatially separated soundings and leverage the capability of arrayed drones in order to derive area-averaged mesoscale vertical velocity. The drones will also provide high-resolution atmospheric soundings of temperature, humidity, pressure, and 3D winds up to a height of 1.5 km. These measurements will be used to understand the variability of turbulent fluxes within and above the mixed layer, of updrafts and downdrafts, as well as of cold-pools. The capacity to take detailed measurements in the atmospheric boundary layer fills a gap in our observations.

We did not have our usual daily briefing and science discussion today due to the exchange in Praia. Yesterday, Anna Trosits presented about the instrument suite she is managing from Uni Leipzig. They are running four remote-sensing instruments on board the Meteor: a W-band cloud radar, a microwave radiometer, a wind lidar, and a micro rain radar. The cloud radar utilizes a stabilization platform in which the radar is free-swinging on a two-axis mount, to account for the ship’s motion. It is sensitive to small droplets and so is able to detect clouds, but attenuates rapidly in rain. This is very complementary to the SEA-POL radar, which is blind to clouds but detects rain. The microwave radiometer is a passive instrument that measures emissions from atmospheric gases to retrieve profiles of temperature and humidity, column-integrated water vapor, and liquid water path. The micro rain radar operates at 24 GHz and, since it is un-stabilized, is used primarily to indicate whether or not it is raining. In post-processing, the group from Leipzig will combine data from these instruments along wth data from MPI-M’s ceilometer using the CloudNet retrieval algorithm. This will permit calculations of liquid water concentration, ice water concentration, effective radius of liquid and ice particles, droplet number concentration, and hydrometeor identification.

Looking forward, today and tomorrow we are returning to the Pirata buoy at 11.5N and 23W to retrieve drifters and gliders that we deployed on August 18th. After meeting EarthCare and HALO on August 31st, we will head west towards the central Atlantic.

Remarks#

  • Radiosondes were launched on the normal 3-hourly schedule. We did not launch the 12Z sonde at 9:50 LT as we were at the harbor at Praia, but launched an extra radiosonde at 11:50 LT.

  • We retrieved SEA-POL parts, drones, and STRINQS personnel from Praia today. Our measurements were off while we were in the harbor.

  • We plan to meet HALO and EarthCare on 31.08.

Plans#

  • 28.08 10:30 LT - 30.08 08:00 LT: Steam to Pirata buoy at 11.5N, 23 W to retrieve drifters and gliders.

  • 30.08 16:00 LT - 31.08 14:00 LT: Steam EarthCare orbit towards 9N, 23.07 W to meet EarthCare and HALO.

  • 31.08 15:00 LT - 06.09 19:00 LT: Steam to central Atlantic buoy at 8N, 38W, performing MSS, CTD, and SEA-POL circles every 6 hours.

Events#

Time (Local)

Comment

10:00

Picked up parts, drones, and personnel in Praia.
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