NARVAL SouthLutz Hirsch, Friedhelm Jansen

Sensor Synergy

While Radars and Lidars provide excellent spatial resolution but only ambiguous information on the microphysical conditions in the sampled volume, radiometers have only poor or no spatial resolution but deliver integral constraints in the observed column as for example the liquid water path or ice/water partitioning.

Thus the information provided by these active and passive sensors is complementary to large extend.

The two plots below show examples of the second research flight.

•The first plot shows an intercomparison of the HAMP radar (reflectivity) and the WALES Lidar (backscatter ratio):

The Cloud Radar gives insights about internal cloud structure. The Lidar detects cloud top boundaries and provides aerosol and water vapor information (not displayed here) at the cloud environment.

•The second plot shows an intercomparison of the HAMP radar and the brightness temperatures of the different radiometers:

The brightness temperature peaks at 20 GHz indicate liquid water (emission) whereas drops at 183 GHz are due to cloud ice (scattering).

Summary

8 flights: 4 flights between Germany and Barbados 1 local flight 3 flights „middle of atlantic“

65 flight hours approx. 60 hours of measurements

7 cloudsat overpasses

77 dropsondes launched

HAMP (HALO Microwave Package)

advanced set of microwave remote cloud sensing instrumentation operated on board of HALO.HAMP consists of

• an active cloud radar • a suite of passive radiometers in different frequency

bands.

Cloud Radar MIRA-36 monostatic, pulsed, magnetron, Ka-Band, Doppler radar at 35.5 GHz with two receivers to provide a co- and cross-polarization channel.

Output parameters: radar reflectivity, Doppler velocity, spectral width, linear depolarization ratio

Radiometers

5 passive microwave radiometers are separated into three nadir pointing modules •K-band receiver (22-32 GHz, 7 channels) used for humidity profiling•V-band (51-59 GHz, 7 channels) for temperature profiling•direct detection radiometer at a window channel at 90 GHz•Heterodyne receiver with four channels (118.75 ± 8.5 to ± 1.4 GHz, double sideband)•single heterodyne receiver with seven channels (183.31 ± 12.5 to ± 0.6 GHz, double sideband)

DLR WALES: combined H2O/Aerosol LIDAR

•4 wavelength H2O DIAL at 935 nm to cover whole troposphere and lower stratosphere

•Additional aerosol channels with depolarization and direct extinction measurement capability

Water Vapor

•H2O mixing ratio profile covering whole troposphere(typical resolution: 200 m vertical / 6 km horizontal)

Aerosol

•Backscatter coefficient at 532 nm and 1064 nm (935 nm)

- Color ratio (532 nm / 1064 nm) of backscatter

•Aerosol depolarization at 532 nm and 1064 nm

•Aerosol extinction at 532 nm (assumption free HSRL)

•Aerosol classification

•Geometrical mapping with a spatial resolution of 15 m vertical / 200 m horizontal (40 m possible)

NARVAL: Next Generation Aircraft Remote Sensing for Validation Studies

Overarching Themes:

•Precipitation in shallow marine convection

•Ability of HAMP-WALES to characterize the vertical structure of the atmosphere

NARVAL SOUTH was designed to help connect long-term measurements on Barbados (see Barbados Cloud Observatory) to the behavior of the broader trades.

Specific scientific questions: •precipitation efficiency of isolated versus cloud clusters•link of clouds to humidity structure of the lower atmosphere

Seen as part of the long term effort to better characterize clouds and convection as they evolve in the trades and enter the ITCZ.

Interpretative basis for Earth Care (planned) and CloudSat / CALIPSO (existing)

AcknowledgementsNARVAL is a joined research initiative by:

DLR Oberpfaffenhofen, MPI-M Hamburg, Universität Hamburg, Universität zu Köln, Universität Heidelberg, Universität Leipzig, FZ Jülich funded by DFG, MPG and DLR.

Plots in this poster are provided by these partners.

The logistics during this campaign was supported by DLR and CIMH (Caribbean Institute for Meteorology and Hydrology)

Fig.01: HAMP instruments from below the aircraft without Bellypod installed

Fig.02: WALES (Water Vapour Lidar Experiment in Space)

Fig.02: Summary of flight-tracks, cloudsat overpasses and dropsonde launchers during NARVAL-South