A continuation of the National Aeronautics and Space Administration’s (NASA) truncated Convective Processes Experiment – Aerosols and Winds (CPEX-AW) field program flown out of St. Croix, USVI, in the summer of 2021, CPEX – Cabo Verde (CPEX-CV) deployed NASA’s DC-8 from Sal Island, Cabo Verde in September 2022, equipped with a unique and comprehensive suite of active and passive remote sensing and in-situ capabilities that, in combination with the availability of similar spaceborne observations, allowed for the measurements of tropospheric aerosols, winds, temperature, water vapor, and clouds and precipitation. The tropical northern East Atlantic Ocean is a data sparse region that, in boreal summer, offers a unique location to study convective lifecycles and processes in a variety of thermodynamic, dynamic, and aerosol environments, such as within persistent (e.g., Intertropical Convergence Zone, ITCZ) and periodic (e.g., African easterly waves and tropical cyclones) large-scale forcing, local terrain effects (e.g., land-ocean transition off western Africa), and aerosol-cloud interactions (e.g., Saharan air layer). In addition to observing the interaction between large-scale environmental forcing and convective systems, the payload is uniquely capable of observing the smaller-scale processes within the near-environment of convection, including those within the marine boundary layer (e.g., cold pools), the inflow/outflow of the storm, and dust-cloud interactions, that affect convective initiation and lifecycle, as well as other poorly resolved/understood properties of these systems.

CPEX-AW and -CV were a part of a joint observing effort with the European Space Agency (ESA) and their partner laboratories and universities called the Joint Aeolus Tropical Atlantic Campaign (JATAC) out of Cabo Verde to validate ESA’s Aeolus satellite. As part of the CPEX-CV – JATAC collaboration in September 2022, the NASA DC-8 carried out coincident underpasses of the Aeolus satellite on four of the thirteen CPEX-CV research flights, performed four overpasses of the ASKOS ground site at Mindelo, and two coordinated flights with the Slovenian WT-10 in situ aircraft that also encompassed a coincident flight under Aeolus and over the Mindelo ground site. Here, we summarize the CPEX-CV science objectives, mission architecture, scientific targets observed on flights flown during the September 2022 campaign, and highlights of the data collected planned to be released to the community in early April 2023 with a focus on collaborative efforts between CPEX-CV and JATAC.

How to cite: Nowottnick, E., Zawislak, J., Nehrir, A., McCarty, W., Piña, A., Reid, J., Chen, S.-H., Rowe, A., Sakaeda, N., Chen, S., Zipser, E., Pu, Z., Robinson, C., Ferrare, R., Hristova-Veleva, S., Ziemba, L., Thornhill, L., Bedka, K., Kavaya, M., and Tanelli, S. and the CPEX-CV/JATAC Team: Overview of NASA’s Convective Processes Experiment – Cabo Verde (CPEX-CV) in the East Atlantic in September 2022 and Collaboration with the Joint Aeolus Tropical Atlantic Campaign (JATAC), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-8956, https://doi.org/10.5194/egusphere-egu23-8956, 2023.

During June 2022, the Cyprus Institute (CyI) took part in the ASKOS experiment in Mindelo, Cape Verde, with several of Unmanned Aerial Vehicles (UAVs), fitted with a number of in-situ aerosol instruments able to profile the Saharan Air Layer between the surface and an altitude of 5,300 m. In addition to ASKOS objectives, transnational access project Diurnal vAriation of the vertically resolved siZe distribution in the Saharan Air Layer  (DAZSAL) was also carried out at the same time. The campaign aimed at validating the Aeolus L2A product in the presence of dust and marine aerosols, estimating the influence on Aeolus products of non-spherical particles, evaluating the impact of particle orientation, and study the diurnal cycle of the dust size-distribution at high altitude. In this presentation we will present and discuss the scientific objectives, the context, the Unmanned Aerial Systems (UASs) that we developed in-house, and the instruments used, together with their limitations, calibration methods, uncertainties, challenges and difficulties encountered. We will also discuss the logistical and planning challenges that such a campaign entails.

Operations took place from the Cesaria Evora International Airport. The instruments deployed on-board the UAVs permitted to evaluate the height-resolved particle size-distribution between 0.1 and 40 µm and detect cases of particle orientation, to complement the observations with ground-based remote sensing set out by NOA and TROPOS. Moreover, 24 high-altitude dust samples were collected on impactors, for further analysis by Scanning Electron Microscopy. In total, 25 scientific flights were performed on 12 flying days (almost half of which at night). Five flights were conducted during Aeolus overpasses. Weather has been a determining factor for both the ground-based remote sensing operations and the UAS operation, and airport traffic has been another constraint that needed to be accounted for, in the UAS operation.

How to cite: Marenco, F., Kezoudi, M., Papetta, A., Keleshis, C., Ryder, C., Ratcliffe, N., Kandler, K., Girdwood, J., Stopford, C., Wienhold, F., Gao, R.-S., Marinou, E., Amiridis, V., Baars, H., Mocnik, G., and Sciare, J.: Unmanned Aerial Vehicles for the Joint Aeolus Tropical Atlantic Campaign, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17089, https://doi.org/10.5194/egusphere-egu23-17089, 2023.

Aeolus, ESA’s space mission, provides vertical profiles of the HLOS wind component in the troposphere and the lower stratosphere. In addition, ALADIN thanks to its HSLR configuration retrieves and provides profiles of extinction/backscatter coefficients of aerosols and clouds (known as spin-off or L2A products), at the ultraviolet region of the spectrum (355nm). However, ALADIN’s design enables the detection only of the returned co-polar component of the transmitted light. This inherent limitation hampers the ability of ALADIN to provide realistic optical products (i.e., underestimated backscatter coefficient profiles) when non-spherical particles (e.g., dust, volcanic ash, cirrus ice crystals) are probed, a deficiency for the case of Earth Observation of highly depolarizing targets with negative impacts on applications of Data Assimilation (DA) and Numerical Weather Prediction (NWP). 

The ESA L2A+ (Enhancing Aeolus L2A for depolarizing targets and impact on aerosol research and NWP) project kicked off in November 2022, with an overarching objective to develop a refined Aeolus L2A aerosol product (L2A+) and test its application for enhancing aerosol research. The generation of the refined L2A+ Aeolus aerosol optical product will be based, among others, on an integrated approach of novel algorithms (i.e., AEL-FM/AEL-PRO), model outputs (i.e., CAMS), advanced EO-based products (i.e., MSG, MODIS-MIDAS), existing climatologies (ESA-LIVAS), and AOD retrievals from Aeolus itself. The product will be thoroughly compared with L2A and validated against quality-assured measurements from the ESA-ASKOS/JATAC experiment in Cape Verde. 

With respect to the overarching objectives on aerosol research, L2A+ aims to (1) examine the impact of L2A and L2A+ on aerosol assimilation and dust transport models, (2) assess the impact of Aeolus on NWP, (3) highlight the benefit of the Aeolus joint aerosol and wind assimilation for simulating dust deposition fields, (4) assess the climatological value of L2A+ for aerosol databases such as the ESA-LIVAS long-term climate dataset, and (5) assess the impact of the novel L2A+ product on aerosol assimilation, towards improved dust transport modelling and for further enhancing NWP. 

The ESA-L2A+ project focuses on the broader the Western Sahara and the Tropical Atlantic Ocean, while due to the extensive wealth of available observational data collected in the framework of the European Space Agency (ESA) ASKOS Tropical Campaign in Cape Verde, which are needed for a complete and descriptive assessment analysis of the project outputs and the evaluation of the enhanced L2A+ product, the developments and experiments will be performed for September 2021. 

Preliminary results from the project will be presented. 

The L2A+ team acknowledges support by ESA in the framework of the "Enhancing Aeolus L2A for depolarizing targets and impact on aerosol research and NWP project (4000139424/22/I-NS). 

How to cite: Georgiou, T., Proestakis, E., Gkikas, A., Rizos, K., Drakaki, E., Kampouri, A., Tsikerdekis, A., Baars, H., Floutsi, A. A., Benedetti, A., and Amiridis, V.: Enhancing Aeolus L2A for depolarizing targets and impact on aerosol research and NWP, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-17110, https://doi.org/10.5194/egusphere-egu23-17110, 2023.

In the frame of the Joint Aeolus Tropical Atlantic Campaigns, an airborne field campaign took place in Sal island of Cape-Verde from the 8^th to 21^st of September 2021, as part of the French CADDIWA mission. During this campaign, the SAFIRE F20 research aircraft equipped with in situ and remote sensing instruments performed nine 3 to 4 hour long flights sampling tropical environment underneath AEOLUS satellite tracks and performing exploration flights within the convective cloud systems of tropical disturbances. In this study, an overview of the available aerosol and cloud in situ dataset is given first, presenting the instrumental and methodological approaches relevant to the collection of data from a set of four instruments: the UHSAS (aerosol size range : 40 – 1000 nm,  Cai et al. 2008), the SPP-300 (aerosol 0.3 – 20 µm, Baumgardner 1992) and the CDP-2 (droplets 2-50 µm, Lance et al. 2010) scattering probes, and the 2D-S imager (10-1280 µm, Lawson et al. 2006). Then a detailed microphysical analysis is conducted on two case studies: a tropical perturbation referred to as Pierre-Henri in this study (unnamed/numbered by NOAA National Hurricane Center (NHC)), sampled during F20 flight #7/8, and the Tropical Storm Rose (# AL172021 according to NOAA NHC) sampled during flights #12/13. The analysis includes a discussion on the main microphysical properties such as Particle Size Distribution (PSD), Ice Water Content (IWC) retrieved at different locations in the cloud convective systems, complemented by 95GHz reflectivity and Doppler vertical velocity measured by the airborne cloud radar RASTA (Delanoe et al. 2013). The data supporting this study is illustrated in the figure below: the vertical velocity (derived from 3 Doppler non colinear measurements of the radar) and PSD time series are given on top of two samples ice crystal images taken by the 2DS imager at different location in the TS Rose. A newly developed image classification algorithm (Jaffeux et al. 2022) is applied to the 2D-S data to derive statistics on the ice particles morphological properties, yielding to a discussion on the microphysical ice growth processes occurring in these systems.

How to cite: Coutris, P., Febvre, G., Jaffeux, L., Bazantay, C., Aubry, C., Caudoux, C., Delanoë, J., Schwarzenboeck, A., and Flamant, C.: Overview and first analysis of the in situ microphysical measurement dataset collected during the CADDIWA mission, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-13084, https://doi.org/10.5194/egusphere-egu23-13084, 2023.

The Joint Aeolus Tropical Atlantic Campaigns (JATAC) 2021 and 2022 deployed on the US Virgin Islands and Cabo Verde, respectively, with science objectives related to the life cycle of convective systems, the long-range transport of dust and its impact on air quality, and the satellite calibration/validation of current and the preparation of future ESA and NASA missions (Aeolus, EarthCARE, AOS, WIVERN). The NASA components of JATAC, Convective Processes Experiment-Aerosols and Winds (CPEX-AW) and CPEX–Cabo Verde (CPEX-CV), included a focus on the complex multi-scale processes and interactions that lead to convective development and its upscale growth: Understanding the environmental conditions supporting the development of tropical cyclones (TCs) remains a research and operational challenge, owing in part to limited observations of the lifecycle of convective activity that eventually become TCs. In the Atlantic basin, early stages of TC development favor the region off the west coast of Africa as African Easterly Waves move offshore and provide, at times, favorable conditions for TC development. CPEX-CV provided airborne measurements in this region, with a total of 13 research flights throughout September 2022. The payload included a triple-frequency precipitation radar, Doppler wind lidar, and dropsondes, among other remote sensing and in situ instrumentation, offering a rare 4-D look at tropical oceanic convective systems and their environment.

To support the campaign goals, we developed the JPL CPEX-AW/CV portal (https://cpex-aw.jpl.nasa.gov), which integrates model forecasts with multi-parameter satellite and airborne observations from a variety of instruments. The portal provides an interactive system for multi-scale visualization and on-line analysis, allowing for the interrogation of a large number of variables for flight planning and execution and for post-campaign analysis, including the large-scale context of the detailed airborne observations. In this presentation, the portal will be used to provide an initial investigation into the evolution of a tropical wave observed during CPEX-CV. The 16 September 2022 flight targeted a growing convective system associated with a broad circulation, the wave structure itself, an Aeolus validation underflight, and dust over Mindelo in coordination with other JATAC measurements. While the wave was not forecasted to immediately develop into a TC downstream, the convection sampled on the western edge of the wave was intense with lightning, although did not grow upscale into a large organized mesoscale convective system during or immediately after the flight. A focus of this initial portal-based analysis is on gradients in environmental moisture, evolution of environmental wind shear in the vicinity of the precipitation, and the presence (or absence) of large-scale convergence as we suspect some combination of these factors limited the initial development of this convective system into a tropical cyclone. Potential later large-scale ties to the development of Hurricane Ian in the Caribbean will also be explored with the portal as it provided a useful tool for this purpose.

How to cite: Hristova-Veleva, S., Rowe, A., Zipser, E., Zawislak, J., Li, P. P., Knosp, B., Vu, Q., and Eriksen, J.: Investigating the evolution of a tropical wave observed during JATAC/CPEX-CV using the campaign data portal, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10983, https://doi.org/10.5194/egusphere-egu23-10983, 2023.

During the CADDIWA (Cloud-Atmospheric Dynamics-Dust Interaction in West Africa) airborne campaign that took place in September 2021, three tropical disturbances initiated from African Easterly Waves were sampled. Two of them reached the Tropical Storm state and were named Rose and Peter by the National Hurricane Center. The last one, later named Pierre-Henri, failed to develop. After a validation of reanalysis data for september 2021 against the data collected during the campaign, a comparative study of the three events will be conducted using ERA5, satellite and campaign data, with a focus on energy budgets. Several processes that may be catalysts or inhibiters for tropical cyclogenesis (AEW-Monsoon -, AEW-AEW -, dust-dynamics interaction ...) will especially be discussed. 

How to cite: Jonville, T., Flamant, C., Lavaysse, C., Delanoë, J., Richard, P., Bounissou, S., Cazenave, Q., Colomb, H., Caudoux, C., Peyrillé, P., and Cornillault, E.: Development of Tropical Cyclones from African Easterly Waves : comparative study of three African Easterly Wave events during the CADDIWA campaign, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1087, https://doi.org/10.5194/egusphere-egu23-1087, 2023.

Wind profiles in the lower troposphere influence the processes driving cloud formation and dissipation. For example, dendritic cumulus and linear sheets formations are governed by different factors including wind direction and velocity. Trade winds and local dynamic processes influence the formation of cumulus and stratocumulus.

Using multiple case studies where the ALADIN lidar observes the different cloud patterns mentioned above, we will see how AEOLUS retrieves winds and clouds and what are the links between them. This study will be backed by visible MODIS observations and Calipso-GOCCP data to confirm the presence of clouds and their types. The focus will be around the JATAC area (Cape Verde, June to September 2021 and 2022), especially in the boundary layer, where our knowledge about the interactions between the wind and clouds are yet to be improved.

How to cite: Titus, Z. and Chepfer, H.: Studying interactions between low clouds and wind profiles using ALADIN/AEOLUS data, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-9467, https://doi.org/10.5194/egusphere-egu23-9467, 2023.

Tropical storms, especially when they develop into hurricanes, are among the most destructive natural disasters. They are the subject of numerous studies, in particular to better understand their dynamics on meteorological scales in order to better predict them and reduce their impacts. We have been able to understand the role of African easterly waves in the formation of tropical storms in the Cape Verde region. However, the role of desert dust originating from the Sahara remains poorly understood due to their multiple and antagonistic effects in stabilizing the atmosphere by heating and reinvigorating convection through cloud icing as well as the lack of observation and limited simulation capabilities.

The CADDIWA (Clouds-Atmospheric Dynamics-Dust Interactions in West Africa) project aims to better understand the effects of desert dust on the atmospheric circulation off Senegal. The CADDIWA airborne campaign, took place from September 5 to 23, 2021 operating the SAFIRE Falcon 20 in the tropical environment of the Cape Verde Islands. During the campaign, the tropical storm Rose was observed on September 18 and 19, 2021. The goal of this PhD project is to exploit current very high resolution modeling capabilities combined with new observations to understand the dynamical and microphysical processes responsible for the development of Tropical Storm Rose. The first results of a large-eddy simulation of Tropical Storm Rose will be presented as well as its evaluation by comparison with available airborne and satellite observations.

How to cite: Feger, G., Dauhut, T., and Chaboureau, J.-P.: The role of desert dust in the development of the Tropical Storm Rose, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-938, https://doi.org/10.5194/egusphere-egu23-938, 2023.

As support to the operational field campaign of the CADDIWA field experiment, the coupled regional model WRF-CHIMERE in forecast mode during the summer 2021. The simulation domain covers West Africa and the East Atlantic and allows the modeling of dust emissions and their transport to the Atlantic. On this route, we find Cape Verde which was used as a base for measurements during the CADDIWA campaign. The forecast consists of meteorological variables and mineral dust concentrations on a horizontal grid with a resolution of 30 km and from the surface to 200 hPa. Each day, the simulation starts the day before (D-1) and up to 4 days ahead (D+4). For each day, we thus have 6 different calculations, with logically a better precision the closer we get to the analysis (D-1). This presentation will show a quantification of the variability of the forecast of mineral dust according to the modelled lead. This quantification will also be done according to the interactions between clouds, aerosols and radiation.

How to cite: Menut, L.: Meteorology and mineral dust forecast variability during the CADDIWA campaign, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1162, https://doi.org/10.5194/egusphere-egu23-1162, 2023.