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Sensitivity of Mediterranean thermohaline circulation to gateway depth: A model investigation

Bahjat Alhammoud, Paul T. Meijer, Henk A. Dijkstra
2010 Paleoceanography  
Citation: Alhammoud, B., P. T. Meijer, and H. A. Dijkstra (2010), Sensitivity of Mediterranean thermohaline circulation to gateway depth: A model investigation, Paleoceanography, 25, PA2220,  ...  Alhammoud et al., unpublished results, 2007) . We suggest it would be very interesting to explore whether this behavior can be confirmed from observations.  ...  Jungclaus and Mellor [2000] ; the eastward flow of the Atlantic water along the African coast as described by Millot [1999] ; and the northward recirculation in the easternmost part of the basin [Alhammoud  ... 
doi:10.1029/2009pa001823 fatcat:cmtxhsv2hrhcdfyugjzidpo37m

Patterns of Precipitation and Convection Occurrence over the Mediterranean Basin Derived from a Decade of Microwave Satellite Observations

Bahjat Alhammoud, Chantal Claud, Beatriz Funatsu, Karine Béranger, Jean-Pierre Chaboureau
2014 Atmosphere  
Author Contributions Led design of the study and writing of the manuscript (Bahjat Alhammoud and Chantal Claud), processing of the AMSU-B datasets (Bahjat Alhammoud and Beatriz M.  ...  Funatsu) and assembly of the HOAPS and ERA-Interim datasets (Bahjat Alhammoud).  ... 
doi:10.3390/atmos5020370 fatcat:vjkfjs4f2rdjtpabzihlzfzdey

Sentinel-2A MSI and Landsat-8 OLI radiometric cross comparison over desert sites

Julia A. Barsi, Bahjat Alhammoud, Jeffrey Czapla-Myers, Ferran Gascon, Md. Obaidul Haque, Morakot Kaewmanee, Larry Leigh, Brian L. Markham
2018 European Journal of Remote Sensing  
The Sentinel-2A and Landsat-8 satellites carry on-board moderate resolution multispectral imagers for the purpose of documenting the Earth's changing surface. Though they are independently built and managed, users will certainly take advantage of the opportunity to have higher temporal coverage by combining the datasets. Thus it is important for the radiometric and geometric calibration of the MultiSpectral Instrument (MSI) and the Operational Land Imager (OLI) to be compatible.
more » ... n of MSI to OLI has been accomplished using multiple techniques involving the use of pseudo-invariant calibration sites (PICS) using direct comparisons as well as through use of PICS models predicting top-ofatmosphere reflectance. A team from the University of Arizona is acquiring field data under both instruments for vicarious calibration of the sensors. This paper shows that the work done to date by the Landsat and Sentinel-2 calibration teams has resulted in stable radiometric calibration for each instrument and consistency to~2.5% between the instruments for all the spectral bands that the instruments have in common. ARTICLE HISTORY
doi:10.1080/22797254.2018.1507613 fatcat:xjibavq6rvebjkq3mlc3ntrvse

Impact of the spatial distribution of the atmospheric forcing on water mass formation in the Mediterranean Sea

Karine Béranger, Yann Drillet, Marie-Noëlle Houssais, Pierre Testor, Romain Bourdallé-Badie, Bahjat Alhammoud, Alexandra Bozec, Laurent Mortier, Pascale Bouruet-Aubertot, Michel Crépon
2010 Journal of Geophysical Research  
The structure of the AW boundary current in the Levantine basin resembles that described by Alhammoud et al. [2005] .  ... 
doi:10.1029/2009jc005648 fatcat:lutxigxn65gv3jqkg7ry4dhe5i

Copernicus Sentinel-2A Calibration and Products Validation Status

Ferran Gascon, Catherine Bouzinac, Olivier Thépaut, Mathieu Jung, Benjamin Francesconi, Jérôme Louis, Vincent Lonjou, Bruno Lafrance, Stéphane Massera, Angélique Gaudel-Vacaresse, Florie Languille, Bahjat Alhammoud (+11 others)
2017 Remote Sensing  
As part of the Copernicus programme of the European Union (EU), the European Space Agency (ESA) has developed and is currently operating the Sentinel-2 mission that is acquiring high spatial resolution optical imagery. This paper provides a description of the calibration activities and the current status of the mission products validation activities. Measured performances, from the validation activities, cover both Top-Of-Atmosphere (TOA) and Bottom-Of-Atmosphere (BOA) products. Results
more » ... d in this paper show the good quality of the mission products both in terms of radiometry and geometry and provide an overview on next mission steps related to data quality aspects. between minimizing cloud cover and ensuring suitable sun illumination. An overview of the MSI imaging payload is provided in the following section. The Sentinel-2 satellites will systematically acquire observations over land and coastal areas from −56 ° to 84 ° latitude including islands larger 100 km 2 , EU islands, all other islands less than 20 km from the coastline, the whole Mediterranean Sea, all inland water bodies and all closed seas. Over specific calibration sites, for example DOME-C in Antarctica, additional observations will be made. The two satellite units will work on opposite sides of the orbit. Sentinel-2A launch took place in June 2015 and Sentinel-2B is foreseen beginning 2017. Therefore, this paper focuses only on the performances achieved by Sentinel-2A. The availability of products with good data quality performances (both in terms of radiometry and geometry accuracies) has a paramount importance for many applications. This is indeed a key enabling factor for an easier exploitation of time-series, inter-comparison of measurements from different sensors or detection of changes in the landscape. Calibration and validation (Cal/Val) corresponds to the process of updating and validating on-board and on-ground configuration parameters and algorithms to ensure that the product data quality requirements are met. This paper provides a description of the calibration activities and the current status, one year after Sentinel-2A launch, of the mission products validation activities. Measured performances, derived from the validation activities, have been estimated for both Top-Of-Atmosphere (TOA) and Bottom-Of-Atmosphere (BOA) products (referred respectively as Level-1 and Level-2A and further described later in this paper). . Multi-Spectral Instrument Overview This section provides a brief overview of Sentinel-2 Multi-Spectral Instrument (MSI). It aims at giving to the reader the basis required to fully understand the measured performances and the Calibration and Validation (Cal/Val) approach. MSI Design The MSI instrument design has been driven by the large swath requirement together with the demanding geometrical and spectral performances of the measurements. It is based on a push-broom concept, featuring a Three-Mirror Anastigmatic (TMA) telescope feeding two focal planes spectrally separated by a dichroic filter, as shown on Figure 1 . One focal plane includes the Visible and Near-Infrared (VNIR) bands and the other one the Short-Wave Infrared (SWIR) bands. Figure 1. MSI internal configuration. On the left, full instrument view and optical path construction to the SWIR/VNIR (see §2.2) splitter and focal planes. Spectral Bands and Resolution Preprints ( | NOT PEER-REVIEWED | Posted: Overlapping area = 98 pixels @ 20m 10 bands B/H cross-detector B/H cross-band Nb pixels / detector module: 2592 (10m) or 1296 (20m -60m) Satellite track YLOS XLOS ZLOS ψX ψY Viewing direction Preprints ( | NOT PEER-REVIEWED | Posted:
doi:10.3390/rs9060584 fatcat:fglsduu6g5bjpd6nmxpspa2hfy

The response of Mediterranean thermohaline circulation to climate change: a minimal model

P. Th. Meijer, H. A. Dijkstra
2009 Climate of the Past  
We thank Bahjat Alhammoud and Pasha Karami for stimulating discussions and Bernd Haupt and an anonymous referee for providing constructive reviews.  ... 
doi:10.5194/cp-5-713-2009 fatcat:dogzgybijjhj5nwxakxrdi4pty

Observations and Recommendations for the Calibration of Landsat 8 OLI and Sentinel 2 MSI for Improved Data Interoperability

Dennis Helder, Brian Markham, Ron Morfitt, Jim Storey, Julia Barsi, Ferran Gascon, Sebastien Clerc, Bruno LaFrance, Jeff Masek, David Roy, Adam Lewis, Nima Pahlevan
2018 Remote Sensing  
Authors 5, 6 and 7 thank Bahjat Alhammoud (ARGANS) and Marion Neveu Van Malle (Thales Alenia Space) for providing the results for Sentinel-2 radiometric and geometric validation respectively.  ... 
doi:10.3390/rs10091340 fatcat:xudyr6znp5hypgznqw22rltu5a