The MACC-II 2007–2008 reanalysis: atmospheric dust evaluation and characterization over Northern Africa and Middle East

Cuevas, E.; Camino, C.; Benedetti, Angela; Basart, Sara; Terradellas, Enric; Recio, José María Baldasano; Morcrette, J.-J.; Marticoréna, B.; Goloub, P.; Mortier, Augustin; Berjón, A.; Hernandéz, Y.; Gil-Ojeda, Manuel; Schulz, Mıchael

doi:10.5194/acpd-14-27797-2014

Cited by 15 publications

(14 citation statements)

References 142 publications

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“…The parameterization has the potential to solve a long‐standing issue in simulating dust storms. In particular, it may compensate for the too low AOD over summertime West Africa in large‐scale dust models compared to observations [e.g., Johnson et al , ; Ridley et al , ; Guirado et al , ; Cuevas et al , ]. It has potential to solve a long‐standing issue in simulating dust storms.…”

Section: Resultsmentioning

confidence: 99%

Modeling haboob dust storms in large‐scale weather and climate models

et al. 2016

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Recent field campaigns have shown that haboob dust storms, formed by convective cold pool outflows, contribute a significant fraction of dust uplift over the Sahara and Sahel in summer. However, in situ observations are sparse and haboobs are frequently concealed by clouds in satellite imagery. Furthermore, most large-scale weather and climate models lack haboobs, because they do not explicitly represent convection. Here a 1 year long model run with explicit representation of convection delivers the first full seasonal cycle of haboobs over northern Africa. Using conservative estimates, the model suggests that haboobs contribute one fifth of the annual dust-generating winds over northern Africa, one fourth between May and October, and one third over the western Sahel during this season. A simple parameterization of haboobs has recently been developed for models with parameterized convection, based on the downdraft mass flux of convection schemes. It is applied here to two model runs with different horizontal resolutions and assessed against the explicit run. The parameterization succeeds in capturing the geographical distribution of haboobs and their seasonal cycle over the Sahara and Sahel. It can be tuned to the different horizontal resolutions, and different formulations are discussed with respect to the frequency of extreme events. The results show that the parameterization is reliable and may solve a major and long-standing issue in simulating dust storms in large-scale weather and climate models.

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Section: Resultsmentioning

confidence: 99%

Modeling haboob dust storms in large‐scale weather and climate models

et al. 2016

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“…The main global source of atmospheric dust in the winter months is Bodélé depression, northeast of Lake Chad (Washington et al, ). Northeastern trade winds (the Harmattan) in winter and early spring transport the dust over West Africa and over the Gulf of Guinea (Cuevas et al, ; Ridley et al, ). This main transport pathway is well seen in all four products.…”

Section: Evaluation and Comparisonmentioning

confidence: 99%

“…Satellite measurements of dust have proven to be very useful in identifying sources (Ginoux et al, ), transport (Yu et al, ), and relevant meteorological processes (Knippertz & Todd, ) and in characterizing diurnal (Schepanski et al, ) and seasonal cycles as well as multiyear trends (Zhang & Reid, ). In addition, they are now routinely used to evaluate and improve regional and global models (Cuevas et al, ) and are assimilated to yield near‐real‐time forecasts (Benedetti et al, ). The most commonly derived aerosol parameter from space is the aerosol optical depth (AOD) at 500/550 nm, which is a measure of how much light is absorbed and scattered by dust at visible wavelengths.…”

Section: Introductionmentioning

confidence: 99%

A Decadal Data Set of Global Atmospheric Dust Retrieved From IASI Satellite Measurements

et al. 2019

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Aerosol is an important component of the Earth's atmosphere, affecting weather, climate, and diverse elements of the biosphere. Satellite sounders are an essential tool for measuring the highly variable distributions of atmospheric aerosol. Here we present a new algorithm for estimating atmospheric dust optical depths and associated retrieval uncertainties from spectral radiance measurements of the Infrared Atmospheric Sounding Interferometer (IASI). The retrieval is based on the calculation of a dust index and on a neural network trained with synthetic IASI spectra. It has an inherent high sensitivity to dust and efficiently discriminates dust from other aerosols. In particular, over remote dust‐free areas, the retrieved levels of optical depth have a low bias. Over sea, noise levels are markedly lower than over land. Performance over deserts is comparable to that of other land surfaces. We use ground‐based coarse mode aerosol measurements from the AErosol RObotic NETwork to validate the new product. The overall assessment is favorable, with standard deviations in line with estimated uncertainties, low biases, and high correlation coefficients. However, a systematic relative bias occurs between sites dominated by African and Asian dust sources respectively, likely linked to differences in mineralogy. The retrieval has been performed on over a decade of IASI data, and the resulting data set is now publicly available. We present a global seasonal dust climatology based on this record and compare it with those obtained from independent satellite measurements (Moderate Resolution Imaging Spectroradiometer and a third‐party IASI product) and dust optical depth from the ECMWF model.

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“…Clear skies and high atmospheric stability make IZO a suitable site for atmospheric monitoring and calibration activities under free-tropospheric conditions. Moreover, this station also allows us to measure under Saharan Air Layer (SAL) conditions (Rodríguez et al, 2011(Rodríguez et al, , 2015Cuevas et al, 2013Cuevas et al, , 2015Barreto et al, 2014b), which is an advantage for characterizing photometers in a wide range of AOD and AE values. This station is a member of the WMO-GAW programme and is one of the two directsun calibration sites of the AERONET network (Pappalardo et al, 2014) and AERONET station, managed by the Atmospheric Physics Group (GFAT) at the Andalusian Institute for Earth System Research (IISTA-CEAMA).…”

Section: Measurement Sitesmentioning

confidence: 99%

The new sun-sky-lunar Cimel CE318-T multiband photometer – a comprehensive performance evaluation

et al. 2016

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Abstract. This paper presents the new photometer CE318-T, able to perform daytime and night-time photometric measurements using the sun and the moon as light source. Therefore, this new device permits a complete cycle of diurnal aerosol and water vapour measurements valuable to enhance atmospheric monitoring to be extracted. In this study we have found significantly higher precision of triplets when comparing the CE318-T master instrument and the Cimel AErosol RObotic NETwork (AERONET) master (CE318-AERONET) triplets as a result of the new CE318-T tracking system. Regarding the instrument calibration, two new methodologies to transfer the calibration from a reference instrument using only daytime measurements (Sun Ratio and Sun-Moon gain factor techniques) are presented and discussed. These methods allow the reduction of the previous complexities inherent to nocturnal calibration. A quantitative estimation of CE318-T AOD uncertainty by means of error propagation theory during daytime revealed AOD uncertainties (u D AOD ) for Langley-calibrated instruments similar to the expected values for other reference instruments (0.002-0.009). We have also found u D AOD values similar to the values reported in sun photometry for field instruments (∼ 0.015). In the case of the night-time period, the CE318-T-estimated standard combined uncertainty (u N AOD ) is dependent not only on the calibration technique but also on illumination conditions and the instrumental noise. These values range from 0.011-0.018 for Lunar Langley-calibrated instruments to 0.012-0.021 for instruments calibrated using the Sun Ratio technique. In the case of moon-calibrated instruments using the Sun-Moon gain factor method and suncalibrated using the Langley technique, we found u N AOD ranging from 0.016 to 0.017 (up to 0.019 in 440 nm channel), not dependent on any lunar irradiance model.A subsequent performance evaluation including CE318-T and collocated measurements from independent reference instruments has served to assess the CE318-T performance as well as to confirm its estimated uncertainty. Daytime AOD evaluation, performed at Izaña station from March to June 2014, encompassed measurements from a reference CE318-T, a CE318-AERONET master instrument, a Precision Filter Radiometer (PFR) and a Precision Spectroradiometer (PSR) prototype, reporting low AOD discrepancies between the four instruments (up to 0.006). The nocturnal AOD evaluation was performed using CE318-T-and starphotometer-collocated measurements and also by means of a day/night coherence transition test using the CE318-T masPublished by Copernicus Publications on behalf of the European Geosciences Union. Á. Barreto et al.: The new sun-sky-lunar Cimel CE318-T multiband photometerter instrument and the CE318 daytime data from the CE318-AERONET master instrument. Results showed low discrepancies with the star photometer at 870 and 500 nm channels (≤ 0.013) and differences with AERONET daytime data (1 h after and before sunset and sunrise) in agreement with the estimated u N AOD value...

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The MACC-II 2007–2008 reanalysis: atmospheric dust evaluation and characterization over Northern Africa and Middle East

Cited by 15 publications

References 142 publications

Modeling haboob dust storms in large‐scale weather and climate models

Modeling haboob dust storms in large‐scale weather and climate models

A Decadal Data Set of Global Atmospheric Dust Retrieved From IASI Satellite Measurements

The new sun-sky-lunar Cimel CE318-T multiband photometer – a comprehensive performance evaluation

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