ACRIDICON–CHUVA Campaign: Studying Tropical Deep Convective Clouds and Precipitation over Amazonia Using the New German Research Aircraft HALO

Abstract

Between 1 September and 4 October 2014, a combined airborne and ground-based measurement campaign was conducted to study tropical deep convective clouds over the Brazilian Amazon rain forest. The new German research aircraft, High Altitude and Long Range Research Aircraft (HALO), a modified Gulfstream G550, and extensive ground-based instrumentation were deployed in and near Manaus (State of Amazonas). The campaign was part of the German–Brazilian Aerosol, Cloud, Precipitation, and Radiation Interactions and Dynamics of Convective Cloud Systems–Cloud Processes of the Main Precipitation Systems in Brazil: A Contribution to Cloud Resolving Modeling and to the GPM (Global Precipitation Measurement) (ACRIDICON– CHUVA) venture to quantify aerosol–cloud–precipitation interactions and their thermodynamic, dynamic, and radiative effects by in situ and remote sensing measurements over Amazonia. The ACRIDICON–CHUVA field observations were carried out in cooperation with the second intensive operating period of Green Ocean Amazon 2014/15 (GoAmazon2014/5). In this paper we focus on the airborne data measured on HALO, which was equipped with about 30 in situ and remote sensing instruments for meteorological, trace gas, aerosol, cloud, precipitation, and spectral solar radiation measurements. Fourteen research flights with a total duration of 96 flight hours were performed. Five scientific topics were pursued: 1) cloud vertical evolution and life cycle (cloud profiling), 2) cloud processing of aerosol particles and trace gases (inflow and outflow), 3) satellite and radar validation (cloud products), 4) vertical transport and mixing (tracer experiment), and 5) cloud formation over forested/deforested areas. Data were collected in near-pristine atmospheric conditions and in environments polluted by biomass burning and urban emissions. The paper presents a general introduction of the ACRIDICON– CHUVA campaign (motivation and addressed research topics) and of HALO with its extensive instrument package, as well as a presentation of a few selected measurement results acquired during the flights for some selected scientific topics.

EUREC4A: A Field Campaign to Elucidate the Couplings Between Clouds, Convection and Circulation

“…For this purpose, the core of the EUREC 4 A field campaign will be the deployment of two research aircraft (Fig. 2): The French ATR-42 operated by the Service des Avions Français Instrumentés pour la Recherche en Environnement (SAFIRE), which will fly in the lowertroposphere with a payload of up to two tons and will be equipped with both remote sensing instrumentation and a suite of in situ sensors (Table 1), and the German HALO (High Altitude and Long Range Research Aircraft) operated by the Deutsches Zentrum für Luft-and Raumfahrt (DLR), which has a payload of up to three tons, a range of up to 8000 km, and a ceiling of up to 15 km, an advanced instrumentation (Table 2) and the ability to launch dropsondes (see for instance Wendisch et al 2016). In addition to these aircraft, we will use the Barbados Cloud Observatory (BCO), buoys, drifters plus several research vessels deployed in the area and equipped with radiosondes and additional remote sensing instruments to complement surface, atmospheric and ocean measurements (Sect.…”

Classification of Arctic, midlatitude and tropical clouds in the mixed-phase temperature regime

“…The instrument platform was HALO (High Altitude and Long Range Research Aircraft), a Gulfstream V aircraft operated by DLR (Deutsches Luftund Raumfahrtszentrum/German Aerospace Centre). Based in Manaus, Brazil, ACRIDICON-CHUVA was aimed at convective clouds over tropical rainforest and deforested areas (see Table 5; for details, see Wendisch et al, 2016). The campaign comprises 14 flights, 11 of which contained clouds in the mixed-phase temperature regime.…”

Comparing Airborne and Satellite Retrievals of Optical and Microphysical Properties of Cirrus and Deep Convective Clouds using a Radiance Ratio Technique

“…All concentration data are corrected concerning the air compression upstream of the underwing cloud probe at the high flight speeds inherent with airborne measurements on board of HALO (Weigel et al, 2016). The robust performance of the specific CCP instrument used in this study was demonstrated by Frey et al (2011) for tropical convective outflow, Molleker et al…”

“…Here, the terminology of r eff,z is used to describe the in situ effective radius sampled at a specific vertical layer z, while the effective radius retrieved using a remote sensing technique r eff represents a bulk value. The number size distribution measured by the CCP has been converted into the 25 particle effective radius with 1 Hz temporal resolution (Weigel et al, 2016). A binning method is applied to gain the profile of cirrus effective radius with a 20 m vertical resolution.…”

“…The Cloud Combination Probe (CCP) incorporates two separate instruments, the Cloud Droplet Probe (CDP) and the greyscale Cloud Imaging Probe (CIPgs) (Weigel et al, 2016). This way the CCP overall covers a size diameter range from 2 µm to 960 µm, including large aerosol particles, liquid cloud droplets and small frozen hydrometeors (Klingebiel et al, 2015).…”