HAMP – the microwave package on the High Altitude and LOng range research aircraft (HALO)

Mech, Mario; Orlandi, Emiliano; Crewell, Susanne; Ament, Felix; Hirsch, Lutz; Hagen, Martin; Peters, Gerhard; Stevens, Björn

doi:10.5194/amt-7-4539-2014

Cited by 77 publications

(72 citation statements)

References 54 publications

(44 reference statements)

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“…Further studies will extend the algorithm to cloudy cases and to temperature and relative humidity profiling. In addition, the method will be applied, not only to ground-based measurements, but also to airborne data (Mech et al, 2014), which will allow the study of meteorological phenomena to be completed from the airborne point of view.…”

Section: Discussionmentioning

confidence: 99%

Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

et al. 2016

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Abstract. Continuous monitoring of atmospheric humidity profiles is important for many applications, e.g., assessment of atmospheric stability and cloud formation. Nowadays there are a wide variety of ground-based sensors for atmospheric humidity profiling. Unfortunately there is no single instrument able to provide a measurement with complete vertical coverage, high vertical and temporal resolution and good performance under all weather conditions, simultaneously. For example, Raman lidar (RL) measurements can provide water vapor with a high vertical resolution, albeit with limited vertical coverage, due to sunlight contamination and the presence of clouds. Microwave radiometers (MWRs) receive water vapor information throughout the troposphere, though their vertical resolution is poor. In this work, we present an MWR and RL system synergy, which aims to overcome the specific sensor limitations. The retrieval algorithm combining these two instruments is an optimal estimation method (OEM), which allows for an uncertainty analysis of the retrieved profiles. The OEM combines measurements and a priori information, taking the uncertainty of both into account. The measurement vector consists of a set of MWR brightness temperatures and RL water vapor profiles. The method is applied to a 2-month field campaign around Jülich (Germany), focusing on clear sky periods. Different experiments are performed to analyze the improvements achieved via the synergy compared to the individual retrievals. When applying the combined retrieval, on average the theoretically determined absolute humidity uncertainty is reduced above the last usable lidar range by a factor of ∼ 2 with respect to the case where only RL measurements are used. The analysis in terms of degrees of freedom per signal reveal that most information is gained above the usable lidar range, especially important during daytime when the lidar vertical coverage is limited. The retrieved profiles are further evaluated using radiosounding and Global Position Satellite (GPS) water vapor measurements. In general, the benefit of the sensor combination is especially strong in regions where Raman lidar data are not available (i.e., blind regions, regions characterized by low signal-to-noise ratio), whereas if both instruments are available, RL dominates the retrieval. In the future, the method will be extended to cloudy conditions, when the impact of the MWR becomes stronger.

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Section: Discussionmentioning

confidence: 99%

Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

et al. 2016

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“…Over a stretch of thousands of kilometers convection was confined to a shallow (topping at 1.5-3 km) marine layer, above which the atmosphere was very dry and cloud free. The microwave instrumentation is described in more detail by Mech et al (2014). 10).…”

Section: Anchoring Investigations On the Edge Of The Itczmentioning

confidence: 99%

The Barbados Cloud Observatory: Anchoring Investigations of Clouds and Circulation on the Edge of the ITCZ

Stevens

Farrell

Hirsch

et al. 2016

Bulletin of the American Meteorological Society

164

202

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Clouds over the ocean, particularly throughout the tropics, are poorly understood and drive much of the uncertainty in model-based projections of climate change. In early 2010, the Max Planck Institute for Meteorology and the Caribbean Institute for Meteorology and Hydrology established the Barbados Cloud Observatory (BCO) on the windward edge of Barbados. At 13°N the BCO samples the seasonal migration of the intertropical convergence zone (ITCZ), from the well-developed winter trades dominated by shallow cumulus to the transition to deep convection as the ITCZ migrates northward during boreal summer. The BCO is also well situated to observe the remote meteorological impact of Saharan dust and biomass burning. In its first six years of operation, and through complementary intensive observing periods using the German High Altitude and Long Range Research Aircraft (HALO), the BCO has become a cornerstone of efforts to understand the relationship between cloudiness, circulation, and climate change.

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“…Together with microwave radiometers in the K, V, W, F, and G-band the MIRA36 is part of HAMP (Mech et al 2014).…”

Section: The Halo Aircraft and Its Instrumentationmentioning

confidence: 99%

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

et al. 2017

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Trade-wind cumuli constitute the cloud type with the highest frequency of occurrence on Earth, and it has been shown that their sensitivity to changing environmental conditions will critically influence the magnitude and pace of future global warming. Research over the last decade has pointed out the importance of the interplay between clouds, convection and circulation in controling this sensitivity. 123Surv Geophys (2017) 38:1529-1568 https://doi.org/10.1007/s10712-017-9428-0 cumuli at cloud base is very sensitive to changes in environmental conditions, while process models suggest the opposite. To understand and resolve this contradiction, we propose to organize a field campaign aimed at quantifying the physical properties of tradecumuli (e.g., cloud fraction and water content) as a function of the large-scale environment. Beyond a better understanding of clouds-circulation coupling processes, the campaign will provide a reference data set that may be used as a benchmark for advancing the modelling and the satellite remote sensing of clouds and circulation. It will also be an opportunity for complementary investigations such as evaluating model convective parameterizations or studying the role of ocean mesoscale eddies in air-sea interactions and convective organization.

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HAMP – the microwave package on the High Altitude and LOng range research aircraft (HALO)

Cited by 77 publications

References 54 publications

Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

The Barbados Cloud Observatory: Anchoring Investigations of Clouds and Circulation on the Edge of the ITCZ

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

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