EUREC&amp;lt;sup&amp;gt;4&amp;lt;/sup&amp;gt;A's HALO

Konow, Heike; Ewald, Florian; George, Geet; Jacob, M.; Klingebiel, Marcus; Kölling, T.; Luebke, Anna; Mieslinger, Theresa; Pörtge, Veronika; Radtke, Jule; Schäfer, Michal; Schulz, Hauke; Vogel, Robert; Wirth, Maria; Bony, Sandrine; Crewell, Susanne; Ehrlich, A.; Forster, Linda; Giez, Andreas; Gödde, F.; Gross, S. P.; Gutleben, Manuel; Hagen, Martin; Hirsch, Lutz; Jansen, Friedhelm; Lang, Theresa; Mayer, B.; Mech, Mario; Prange, Marc; Schnitt, Sabrina; Vial, Jessica; Walbröl, Andreas; Wendisch, Manfred; Wolf, K.; Zinner, Tobias; Zöger, Martin; Ament, Felix; Stevens, Björn

doi:10.5194/essd-2021-193

Cited by 8 publications

(9 citation statements)

References 18 publications

(33 reference statements)

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“…Furthermore, the HALO campaign Elucidating the role of clouds-circulation coupling in climate (EUREC 4 A) specified in Bony et al (2017) and , which was conducted early 2020 and equipped with the same devices aboard HALO (Konow et al, 2021), adds a large set of tropical marine cloud observations. EUREC 4 A data, which are currently being processed, comprise measurements during the dry season and allow a seasonal comparison.…”

Section: Discussionmentioning

confidence: 99%

Horizontal geometry of trade-wind cumuli – aircraft observations from shortwave infrared imager versus radar profiler

Dorff

Konow

Ament

2021

Preprint

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Abstract. This study elaborates how aircraft-based horizontal geometries of trade-wind cumulus clouds differ whether a one-dimensional (1D) profiler or a two-dimensional (2D) imager is used. While nadir profiling devices are limited to 1D realisation of the cloud transect size with limited representativeness of horizontal cloud extension, 2D imagers enhance our perspectives by mapping the horizontal cloud field. Both require high-resolution to detect the lower end of the cloud size spectrum. In this regard, the payload aboard the High Altitude and Long Range Research Aircraft (HALO) achieves a comparison and also a synergy of both measurement systems. Using the NARVAL-II campaign, we combine HALO observations from a 35.2 GHz cloud and precipitation radar (1D) and from the hyperspectral 2D imager specMACS, having a 30 times higher along-track resolution and compare their cloud masks. We examine cloud size distributions in terms of sensitivity to sample size, resolution and the considered field of view (2D or 1D). This specifies impacts on horizontal cloud sizes derived from the across-track perspective of the high-resolution imager in comparison to the radar curtain. We assess whether and how the trade-wind field amplifies uncertainties in cloud geometry observations along 1D transects through directional cloud elongation. Our findings reveal that each additional dimension, no matter of the device, causes a significant increase of observed clouds. The across-track field yields the highest increase in the cloud sample. The radar encounters difficulties to characterize the trade-wind cumuli size distribution. More than 60 % of clouds are subgrid scale for the radar. While the radar cannot resolve clouds shorter than 200 m and has a lower sensitivity, the amount of small invisible clouds leads to deviations in the size distribution. Double power law characteristics in the imager based cloud size distribution do not occur in radar observations. Along-track measurements do not necessarily cover the predominant cloud extent and inferred geometries lack of representativeness. Trade-wind cumuli show horizontal patterns similar to ellipses with a mean aspect ratio of 3 : 2. Instead of circular estimations based on the 1D transect, elliptic fits maintain the cloud area size distribution. Increasing wind speed tends to stretch clouds more and tilts them into the wind field, which makes transect measurements more representative along this axis.

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Section: Discussionmentioning

confidence: 99%

Horizontal geometry of trade-wind cumuli – aircraft observations from shortwave infrared imager versus radar profiler

Dorff

Konow

Ament

2021

Preprint

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“…Scenes are flagged as probably cloudy if either ceilometer or radar sensed a cloud. These occurrences are mainly due to sensor beam mismatch, platform motions, or sensitivity differences between the ceilometer and radar (see discussion in Konow et al, 2021). Confident cloudy scenes refer to measurements in which both radar and ceilometer sensed a cloud.…”

Section: Cloud Maskmentioning

confidence: 99%

Ground- and ship-based microwave radiometer measurements during EUREC4A

Schnitt

Foth

Kalesse

et al. 2023

Preprint

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Abstract. During the EUREC4A field study, microwave radiometric measurements were performed at Barbados Cloud Observatory (BCO) and aboard the RV Meteor and RV Maria S Merian. We present retrieved Integrated Water Vapor (IWV), Liquid Water Path (LWP) and temperature and humidity profiles as a unified, quality-controlled, multi-site dataset on a three second temporal resolution for a core period between January 19, 2020 and February 14, 2020 in which all instruments were operational. 14-channel K- and V-band measurements were performed at BCO and aboard the RV Meteor, and combined radar-radiometer measurements of a W-band Doppler radar with a single-channel radiometer instrument were conducted at 89 GHz onboard the RV Meteor and RV Maria S Merian. Mean IWV of 31.8 kgm−2 matches independent radiosoundings at BCO with a rootmean-square difference of 1.1 kgm−2. Mean LWP conditions in confident cloudy, non-precipitating conditions ranged between 66.5 gm−2 at BCO to 40.4 gm−2 aboard the RV Maria S Merian. Aboard the ships, 90 % of LWP was below 120 gm−2 with an uncertainty of 30 % at LWP of 50 gm−2. Up to 30 % of confident cloudy profiles ranged below the LWP detection limit due to optically thin clouds. The data set comprises of processed raw-data (Level 1), full quality-controlled post-processed instrument data (Level 2), a unified temporal resolution (Level 3), and a ready-to-use multi-site time series of IWV and LWP (Level 4), available to the public via AERIS (https://doi.org/10.25326/454, Schnitt et al., 2023). The data set complements the airborne LWP measurements conducted during EUREC4A and provides a benchmark tool for model-observation studies.

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“…Figure 15 shows the CFAD from the HALO cloud radar (Mech et al, 2014;Ewald et al, 2019;Konow et al, 2021) while HALO was flying on its standard circle (Fig. 1) on an altitude of 11. since the HALO radar has been calibrated by independent means (Ewald et al, 2019).…”

Section: Vertical Reflectivity Distributionmentioning

confidence: 99%

Deployment of the C-band radar Poldirad on Barbados during EUREC<sup>4</sup>A

Hagen

Ewald

Groß

et al. 2021

Preprint

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Abstract. The German polarimetric C-band weather radar Poldirad (Polarization Diversity Radar) was deployed for the international field campaign EUREC4A (ElUcidating the RolE of Cloud-Circulation Coupling in ClimAte) on the island of Barbados. Poldirad was operated on Barbados from February until August 2020. Focus of the installation was monitoring clouds and precipitation in the trade wind region east of Barbados. Different scanning modes were used with a temporal sequence of 5 minutes and a maximum range of 375 km. In addition to built-in quality control performed by the radar signal processor, it was found that the copoloar correlation coefficient ρHV can be used to remove contamination of radar products by sea clutter. Radar images were available in real-time for all campaign participants and onboard of research aircraft. Examples of mesoscale precipitation patterns, rain rate accumulation, diurnal cycle, and vertical distribution are given to show the potential of the radar measurements for further studies on the life cycle of precipitating shallow cumulus clouds and other related aspects. Poldirad data from the EUREC4A campaign are available on the EUREC4A AERIS database: https://doi.org/10.25326/218 (Hagen et al., 2021a) for raw data and https://doi.org/10.25326/217 (Hagen et al., 2021b) for gridded data.

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EUREC<sup>4</sup>A's HALO

Cited by 8 publications

References 18 publications

Horizontal geometry of trade-wind cumuli – aircraft observations from shortwave infrared imager versus radar profiler

Horizontal geometry of trade-wind cumuli – aircraft observations from shortwave infrared imager versus radar profiler

Ground- and ship-based microwave radiometer measurements during EUREC4A

Deployment of the C-band radar Poldirad on Barbados during EUREC<sup>4</sup>A

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EUREC&lt;sup&gt;4&lt;/sup&gt;A's HALO

Cited by 8 publications

References 18 publications

Horizontal geometry of trade-wind cumuli – aircraft observations from shortwave infrared imager versus radar profiler

Horizontal geometry of trade-wind cumuli – aircraft observations from shortwave infrared imager versus radar profiler

Ground- and ship-based microwave radiometer measurements during EUREC4A

Deployment of the C-band radar Poldirad on Barbados during EUREC&lt;sup&gt;4&lt;/sup&gt;A

Contact Info

Product

Resources

About

EUREC<sup>4</sup>A's HALO

Deployment of the C-band radar Poldirad on Barbados during EUREC<sup>4</sup>A