Potential temperature
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Sensitivity of boundary-layer variables to PBL schemes in the WRF model based on surface meteorological observations, lidar, and radiosondes during the HygrA-CD campaign Open
Air quality forecast systems need reliable and accurate representations of the planetary boundary layer (PBL) to perform well. An important question is how accurately numerical weather prediction models can reproduce conditions in diverse …
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Persistent inversion dynamics and wintertime PM10 air pollution in Alpine valleys Open
International audience
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Global and Full-Depth Ocean Temperature Trends during the Early Twenty-First Century from Argo and Repeat Hydrography Open
The early twenty-first century’s warming trend of the full-depth global ocean is calculated by combining the analysis of Argo (top 2000 m) and repeat hydrography into a blended full-depth observing system. The surface-to-bottom temperature…
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Parameterization of Frontal Symmetric Instabilities. I: Theory for Resolved Fronts Open
A parameterization is proposed for the effects of symmetric instability (SI) on a resolved front. The parameterization is dependent on external forcing by surface buoyancy loss and/or down-front winds, which reduce potential vorticity (PV)…
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Atmospheric boundary‐layer characteristics from ceilometer measurements. Part 1: A new method to track mixed layer height and classify clouds Open
The use of Automatic Lidars and Ceilometers (ALC) is increasingly extended beyond monitoring cloud base height to the study of atmospheric boundary layer (ABL) dynamics. Therefore, long‐term sensor network observations require robust algor…
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Why does tropical convective available potential energy (CAPE) increase with warming? Open
Recent work has produced a theory for tropical convective available potential energy (CAPE) that highlights the Clausius‐Clapeyron (CC) scaling of the atmosphere's saturation deficit as a driver of increases in CAPE with warming. Here we t…
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A case study of convectively sourced water vapor observed in the overworld stratosphere over the United States Open
On 27 August 2013, during the Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys field mission, NASA's ER‐2 research aircraft encountered a region of enhanced water vapor, extending over a dep…
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Upward transport into and within the Asian monsoon anticyclone as inferred from StratoClim trace gas observations Open
Every year during the Asian summer monsoon season from about mid-June to early September, a stable anticyclonic circulation system forms over the Himalayas. This Asian summer monsoon (ASM) anticyclone has been shown to promote transport of…
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Profiles of second- to fourth-order moments of turbulent temperature fluctuations in the convective boundary layer: first measurements with rotational Raman lidar Open
The rotational Raman lidar (RRL) of the University of Hohenheim (UHOH) measures atmospheric temperature profiles with high resolution (10 s, 109 m). The data contain low-noise errors even in daytime due to the use of strong UV laser light …
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Ship- and island-based atmospheric soundings from the 2020 EUREC <sup>4</sup> A field campaign Open
To advance the understanding of the interplay among clouds, convection, and circulation, and its role in climate change, the Elucidating the role of clouds–circulation coupling in climate campaign (EUREC4A) and Atlantic Tradewind Ocean–Atm…
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The power of vertical geolocation of atmospheric profiles from GNSS radio occultation Open
High‐resolution measurements from Global Navigation Satellite System (GNSS) radio occultation (RO) provide atmospheric profiles with independent information on altitude and pressure. This unique property is of crucial advantage when analyz…
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Climate intercomparison of GPS radio occultation, RS90/92 radiosondes and GRUAN from 2002 to 2013 Open
Observations from the GPS radio occultation (GPSRO) satellite technique and from the newly established GCOS Reference Upper Air Network (GRUAN) are both candidates to serve as reference observations in the Global Climate Observing System (…
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What are the Best Thermodynamic Quantity and Function to Define a Front in Gridded Model Output? Open
Fronts can be computed from gridded datasets such as numerical model output and reanalyses, resulting in automated surface frontal charts and climatologies. Defining automated fronts requires quantities (e.g., potential temperature, equiva…
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Assessment of Observational Evidence for Direct Convective Hydration of the Lower Stratosphere Open
In situ and remote sensing observations of water vapor are analyzed to assess the evidence for direct convective hydration of the lower stratosphere. We have examined several hundred balloon‐borne and airborne in situ measurements of lower…
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The impact of overshooting deep convection on local transport and mixing in the tropical upper troposphere/lower stratosphere (UTLS) Open
In this study we examine the simulated downward transport and mixing of stratospheric air into the upper tropical troposphere as observed on a research flight during the SCOUT-O3 campaign in connection with a deep convective system. We use…
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The <span>A</span>tlantic <span>W</span>ater boundary current north of <span>S</span>valbard in late summer Open
Data from a shipboard hydrographic/velocity survey carried out in September 2013 of the region north of Svalbard in the Nansen Basin are analyzed to characterize the Atlantic Water (AW) boundary current as it flows eastward along the conti…
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Observations of PAN and its confinement in the Asian summer monsoonanticyclone in high spatial resolution Open
This paper presents an analysis of trace gases in the Asian summer monsoon (ASM) region on the basis of observations by the CRISTA infrared limb sounder taken in low-earth orbit in August 1997. The spatially highly resolved measurements of…
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Vertical Profiles of Ozone Concentration Collected by an Unmanned Aerial Vehicle and the Mixing of the Nighttime Boundary Layer over an Amazonian Urban Area Open
The nighttime boundary layer was studied in an urban area surrounded by tropical forest by use of a copter-type unmanned aerial vehicle (UAV) in central Amazonia during the wet season. Fifty-seven vertical profiles of ozone concentration, …
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Atmospheric boundary‐layer characteristics from ceilometer measurements. Part 2: Application to London's urban boundary layer Open
Long‐term measurements of mixed layer height (Z ML ) are possible with advances in detecting Z ML based on Automatic Lidars and Ceilometers (ALC) observations. Six years of ALC measurements in central London are analysed using the CABAM (“…
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Characterisation of boundary layer turbulent processes by the Raman lidar BASIL in the frame of HD(CP) <sup>2</sup> Observational Prototype Experiment Open
Measurements carried out by the University of Basilicata Raman lidar system (BASIL) are reported to demonstrate the capability of this instrument to characterise turbulent processes within the convective boundary layer (CBL). In order to r…
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New Definition of Potential Spicity by the Least Square Method Open
A differentiable function whose contours are orthogonal to potential density ( σ ) contours does not exist. However, such a function, called potential spicity ( π ), can be defined in the least square sense; these two functions form a prac…
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The Atmospheric Boundary Layer during Wintertime Persistent Inversions in the Grenoble Valleys Open
This study addresses the atmospheric boundary layer dynamics in the Grenoble valleys during persistent inversions, for 5 months during the 2006-2007 winter. During a persistent inversion, the boundary layer contains a layer with a positive…
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Global Climatologies of Fronts, Airmass Boundaries, and Airstream Boundaries: Why the Definition of “Front” Matters Open
Climatologies of fronts, airmass boundaries, and airstream boundaries can be calculated using automated approaches on gridded data. Such approaches may require choices to define a front, including a quantity (or quantities) to diagnose the…
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Quantifying horizontal and vertical tracer mass fluxes in an idealized valley during daytime Open
The transport and mixing of pollution during the daytime evolution of a valley boundary layer is studied in an idealized way. The goal is to quantify horizontal and vertical tracer mass fluxes between four different valley volumes: the con…
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Why is the Tropical Cyclone Boundary Layer Not “Well Mixed”? Open
Plausible diagnostics for the top of the tropical cyclone boundary layer include (i) the top of the layer of strong frictional inflow and (ii) the top of the “well mixed” layer, that is, the layer over which potential temperature θ is appr…
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Environmental Controls on Tropical Sea Breeze Convection and Resulting Aerosol Redistribution Open
Sea breeze fronts propagate inland from the coastline, driving convective initiation and aerosol redistribution. Forecasting sea breezes is challenging due to uncertainties in the initial conditions, as well as the covariance and interacti…
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Concurrent Sensitivities of an Idealized Deep Convective Storm to Parameterization of Microphysics, Horizontal Grid Resolution, and Environmental Static Stability Open
This study investigated the sensitivity of idealized deep convective storm simulations to microphysics parameterization, horizontal grid spacing (Δx), and environmental static stability. Three different bulk microphysics schemes in the Wea…
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Response of the Atmospheric Boundary Layer to Submesoscale Sea Surface Temperature Fronts Open
Submesoscale sea surface temperature fronts are ubiquitous throughout much of the global ocean; however, the response of the marine atmospheric boundary layer (MABL) to the ocean submesoscale is not well understood. In this manuscript larg…
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Tropical continental downdraft characteristics: mesoscale systems versus unorganized convection Open
Downdrafts and cold pool characteristics for strong mesoscale convective systems (MCSs) and isolated, unorganized deep precipitating convection are analyzed using multi-instrument data from the DOE Atmospheric Radiation Measurement (ARM) G…
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Nocturnal low-level clouds in the atmospheric boundary layer over southern West Africa: an observation-based analysis of conditions and processes Open
During the West African summer monsoon season, extended nocturnal stratiform low-level clouds (LLCs) frequently form in the atmospheric boundary layer over southern West Africa and persist long into the following day affecting the regional…