Table of Contents
HALO as a Cloud Observatory
HALO is configured to function as an airborne cloud observatory with a great variety of remote-sensing instruments on board along with a dropsonde launching system. For greater detail, refer to Stevens et al (2019). The instruments have been listed in the table below.
| Name | Instrument | Quantities measured & derived products | Type | Detailed description of instrument | Campaigns |
|---|---|---|---|---|---|
| BAHAMAS (not shown in image) | Multiple sensors all over the aircraft fuselage such as five hole probe on boom, diode laser, etc. | Aircraft state variables, position, three-dimensional turbulent winds, humidity, temperature and pressure | In-situ | DLR website | All |
| Dropsondes | Vaisala RD-94 sondes with AVAPS receiver on HALO (EUREC4A used RD-41) | Vertical profiles of: Temperature Relative Humidity Horizontal wind speed and direction Derived Products: Divergence Vorticity Vertical velocity Moist static energy Integrated water vapour (Precipitable water) | In-situ | Wang et al (2015) | 8-channel receiver for EUREC4A; 4-channel for campaigns earlier |
| HAMP Cloud Radar | Ka-band (35 GHz) mono-static, pulsed magnetron radar | Vertical profiles of: Radar reflectivity Linear Depolarization ratio 1) Derived products: Cloud objects Cloud fraction | Active remote-sensing | Ewald et al (2019) | All |
| HAMP Radiometers | Microwave radiometers in: K-band (22- 31 GHz) V-band (50 - 58 GHz) W-band (90 GHz) F-band (119 GHz) and G-band (183 GHz) | Brightness Temperature Derived products: Liquid water path Rain water path Water vapour profiling Water condensate (liquid/ice) path Temperature profiling | Passive remote-sensing | Mech et al (2014) | All |
| SMART | Visible and near-infrared (300 to 1000 nm) 2- to 3-nm spectral resolution [full width half maximum (FWHM)] Shortwave infrared (1000 to 2200 nm) 10- to 15-nm spectral resolution (FWHM) | Downwelling irradiance Upwelling radiance and irradiance Derived products: Cloud fraction Cloud droplet density | Passive remote-sensing | Wendisch et al (2016) | NARVAL2, NAWDEX, EUREC4A |
| specMACS | Cameras: Visible and near-infrared (400 to 1,000 nm) Shortwave infrared (1,000 to 2,500 nm) 2D polarized (RGGB + polarization Bayer Pattern) | Spectrally resolved line image Derived products: Cloud top temperature Cloud mask (cloud fraction) 3D cloud field along flight path | Passive remote-sensing | Ewald et al (2016) | NARVAL2, NAWDEX; Two lens-system with FoV overlap for EUREC4A |
| WALES | High spectral resolution lidar Multi-wavelength water vapor differential absorption lidar (DIAL) Four wavelengths near 935 nm Aerosol channels 532 and 1064 nm with depolarization | Vertical profiles of: Backscatter Extinction Derived products: Water vapour mixing ratio profiles Cloud top mask Aerosol optical depth Ice water content | Active remote-sensing | Wirth et al (2009) | All |
| Velox | Thermal Infrared Wavelength Imager | Passive Remote-sensing | EUREC4A |
N.B.: The list of derived products is not an exhaustive list, and most of the listed ones are not from a single instrument, but are estimates of quantities using synergistic measurements from the various instruments on board.
Campaigns and Data
Campaigns
For campaigns see Observation Campaigns in the Tropics
Data Access
Unified Dataset
There is a unified dataset, developed by Konow et al (2018), available for all NARVAL campaigns and the NAWDEX campaign together, which integrates the data from the HAMP instruments along with the dropsonde data, over a uniform grid of 30 m resolution in the vertical. The dataset also includes auxiliary data from BAHAMAS. Along with the data, quick looks for all flights have been uploaded to the CERA database as auxiliary data. These datasets are available at:
Liquid water path
Using the microwave measurements on board HALO, in combination with the cloud radar and lidar measurements, Jacob et al (2019) have calculated the liquid water path (LWP) and rain water path (RWP), using artificial neural network techniques for the NARVAL1 South and NARVAL2 campaigns. The dataset also includes integrated water vapor (IWV), along with auxiliary data from the radar and lidar. These are also available through the CERA database at:
WALES Data
All WALES data is available through the DLR Institute for Atmospheric Physics in the HALO database at:
German Aerospace Center (2016).
SpecMACS Data
Although the data is not published yet, data from SpecMACS is available at the MACS-LMU server. Please contact Tobias Kölling (LMU) regarding any queries about these data.
SMART Data
Available from the HALO database here