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Abstract. This study delves into the small-scale temperature structure inside the turbulent convection Π Chamber under three temperature differences (10, 15, and 20 K) at Rayleigh number Ra∼109 and Prandtl number Pr≈0.7. We performed high-frequency measurements (2 kHz) with the UltraFast Thermometer (UFT) at selected points along the vertical axis. The miniaturized design of the sensor with a resistive platinum-coated tungsten wire, 2.5 µm thick and 3 mm long, mounted on a miniature wire probe, allowed for vertically undisturbed temperature profiling through the chamber's depth spanning from 8 cm above the bottom to 5 cm below the top. The collected data, consisting of 19 and 3 min time series, were used to investigate the variability of the temperature field within the chamber, aiming to better address scientific questions related to its primary objective: understanding small-scale aerosol–cloud interactions. The analyses reveal substantial variability in both variance and skewness of temperature distributions near the top and bottom plates and in the bulk (central) region, which were linked to local thermal plume dynamics. We also identified three spectral regimes termed “inertial range” (slopes of ∼-7/5), “transition range” (slopes of ∼-3), and “dissipative range”, characterized by slopes of ∼-7. Furthermore, the analysis showed a power law relationship between the periodicity of large-scale circulation (LSC) and the temperature difference. Notably, the experimental results are in good agreement with direct numerical simulation (DNS) conducted under similar thermodynamic conditions, illustrating a comparative analysis of this nature. 

Abstract Simplifying the atmosphere into discrete layers, such as the Marine Atmospheric Boundary Layer (MABL) and its surface, mixed, and detrainment layers, as well as the Saharan Air Layer (SAL) aloft, is necessary in maritime meteorological modeling and data analysis. However, data reduction risks losing critical information. The ONR Moisture and Aerosol Gradients/Physics of Inversion Evolution (MAGPIE) experiment, centered on Ragged Point Barbados around August 2023, July 2024, and February 2025 used Synthetic Aperture Radar (SAR), High Spectral Resolution Lidar (HSRL), Doppler and Raman lidars coupled with ground-based instrumentation, as well as the CIRPAS/NOAA aircraft to document the four-dimensional variability and large to fine scale budgets of atmospheric state, clouds, sea salt, and dust. Results span three areas: 1) Regime identification: SAR winds and geostationary imagery easily identify MABL regimes that can be reproduced in large eddy simulations; 2) Vertical exchange: Lidar and aircraft show that cloud organization of MABL regimes are related to vertical exchange from the near surface through cloud water vapor halos, especially at regime boundaries. Copious dust was also found in the MABL; and 3) SAL stratification: The concept of the monolithic or multi-layer of Saharan Air is often realized as ultrafine Saharan Air Layer(s) stratified under influence by large scale forcing, shear, diabatic heating, and likely more complex coupled processes. These insights inform multiscale modeling to bridge MABL 'grey zone' processes too large for parameterization in large-domain models, yet too fine to be explicitly resolved due to computational constraints.