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

Abstract

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.

The relationship between precipitation and its spatial pattern in the trades observed during EUREC4A

“…(2021). Here, we exploit observational data from the C‐band radar Poldirad that was deployed on Barbados to provide a detailed view of the upstream precipitating trade‐wind convection (Hagen et al ., 2021). Furthermore, we include observations of vertically integrated water vapour from GNSS receivers (Bock et al ., 2021) at the Barbados Cloud Observatory (Stevens et al ., 2016).…”

“…This dataset and the radar's deployment in the EUREC$$$ {}^4 $$$A field campaign are described in detail in Hagen et al . (2021). For our analyses we examine the scans between the 25 and 175 km range (see Figure 2) as the radar beam remains below about 3 km height up to this range and the frequency of strong echoes is approximately constant, and to limit effects of sea clutter.…”

“…Additionally, the Poldirads' radar beams showed an elliptical shape that caused the cells to appear stretched in the azimuthal direction, resulting in an overestimation of the size of the rain cells. For an estimation of this effect, please see Hagen et al . (2021, appendix A).…”

“…The data used in this publication were gathered in the EUREC$$$ {}^4 $$$A field campaign and are published by Hagen et al . (2021) and Bock et al . (2021) and available on the EUREC$$$ {}^4 $$$A AERIS database via https://doi.org/10.25326/217 and https://doi.org/10.25326/79.…”

“…To address our questions, we investigate scenes of trade‐wind convection scanned by the C‐band polarization diversity radar (Poldirad; Hagen et al ., 2021) during the EUREC$$$ {}^4 $$$A field campaign (Stevens et al ., 2021), which took place in January and February 2020 in the western tropical North Atlantic near Barbados. In these scenes, we analyse how trade‐wind precipitation fields are organised into spatial patterns and how this relates to the scenes' precipitation amount and intensity.…”