DOI: 10.5281/zenodo.15737726
title: Helicopter-borne observations of atmospheric clouds, aerosol, and dynamics over the Azores - the ACORES campaign.

description: Description of ACTOS data

ACORES campaign 2017

Introduction 

In July 2027, the helicopter-borne measurement platform ACTOS (Airborne Cloud Turbulence Observation System, Siebert et al., 2006) was deployed over the island of Graciosa (Azores) to investigate the interaction of clouds, aerosol particles and atmospheric dynamics under the influence of different air masses.

This document describes selected parameters of the data set that enable each user to gain an initial impression of the measurement situation and perform basic data analyses. The data is stored here with the native temporal resolution of 100 Hz. With a typical flight speed of 20 m/s, this means that the spatial resolution is typically 20 cm. Turbulence data with even higher resolution is available for individual flights, but this requires individual post-processing and is available on request and within the framework of cooperation agreements. The same applies in part to cloud droplet, aerosol particle,    and other data as mentioned in Siebert et al., (2021)

Contact

All data and more detailed information are available from the author: siebert@tropos.de

Location

All flights have been operated around the airport of Graciosa with the coordinates 39° 5’ 32” N and 028° 1’ 47” W about 26 m above mean sea level; the maximum distance to the airport was about 20 nautical miles and the maximum height was 10.000 feet (about 3000 m).

Parameter






Paramter name



Description



Unit



Measurement Device



 





 



 



 



 



 





Date/Time  



Date and Time



UTC



GPS



 





zb



Barometric height



m



Pressure device



 





pp



Static pressure



hPa



Pressure device



 





TT



Static temperature



°C



PT-100



 





PT



Potential temperature



K



PT-100 / Pressure device



 





T_UFT



(Fast) temperature



°C



Ultrafast thermometer



 





PVM_LWC



Liquid water content



g / m3



PVM-100A



 





PVM_PSA



Particle surface area



cm2 / m3



“”



 





PVM_Reff



Effective radius



micron



“”



 





CDP_Reff



Effective radius



micron



CDP-2



 





CDP_LWC



Liquid water content



g / m3



“”



 





CDP_N



Droplet number concentration



# / cm3



“”



 





DP_a



absolute humidity



g / m3



Dewpoint mirror  



 





DP_TD



Dewpoint temperature



°C



“”



 





DP_TT



Static temperature



°C



“”



 





UU



Horizontal wind speed



m / s



Ultrasonic anemometer & inertial navigation unit 



 





DD



Wind direction



°



“”



 





wHP



Fluctuations of vertical wind



m / s



“”



 





a_LI



absolute humidity



g / m3



Open Path infrared hygrometer



 





N_F1



fast aerosol particle concentration



# / cm3



MCPC



 





N_TSI



slow aerosol particle concentration



# / cm3



TSI CPC



 





Lat



Latitude



rad



GPS



 





Lon



Longitude



rad



“



 





 

 

 All devices are explained in the given references

 

Literature

H. Siebert, H. Franke, K. Lehmann, R. Maser, E. W. Saw, D. Schell, R. A. Shaw, and M. Wendisch: Probing fine-scale dynamics and microphysics of clouds with helicopter-borne measurements. Bull. Am.Meteor. Soc., 87:1727 – 1738, 2006.

H. Siebert, K. E. Szodry, U. Egerer, B. Wehner, K. C. S. Henning, J. Lückerath, O. Welz, K. Weinhold, F. Lauermann, M. Gottschalk, A. Ehrlich, M. Wendisch, P. Fialho, S. Viviani, G. Roberts, S. Schum, R. A. Shaw, C. Mazzoleni, J. Nowak, S. Malinowski, K. Karpinska, W. Kumala, and D. Czyzewska: Observations of aerosol, cloud, turbulence, and radiation properties at the top of the marine boundary layer over the Eastern North Atlantic Ocean: The ACORES campaign. Bull. Amer. Meteor. Soc., pages E123 – E147, 2021.