Remote sensing of phytoplankton distribution in the Red Sea and Gulf of Aden

Analysis of high-resolution 4 km sea surface temperature, Chlorophyll a （Chl a）, and wind datasets provides a detailed description of the spatio-temporal seasonal succession of phytoplankton biomass in the Red Sea and Gulf of Aden. Based on Moderate Resolution Imaging Spectroradiometer on-board aqua platform （MO- DIS Aqua） data andsynoptic observations in the Red Sea, Chl a varies from north to south, with the northern part appearing to be oligotrophic. This is likely due to the absence of strong mixing and low nutrient intru- sion in comparison to the southern part during winter. In the Gulf of Aden, the emergence of upwelling cell is clearly evident along the coast of Yemen, and is only distinct from the summer-autumn seasons. Most notable is the pulsating nature of the upwelling, with warm and cold events clearly distinguished with phytoplankton response to this physical forcing also evident. The phytoplankton biomass distribution varies considerably between the two regions of study. In both study areas, water temperature and prevailing winds control nutrient concentrations.

A three-dimensional Moho depth model beneath the Yemeni highlands and rifted volcanic margins of the Red Sea and Gulf of Aden, Southwest Arabia

Knowing Moho discontinuity undulation is fundamental to understanding mechanisms of lithosphereasthenosphere interaction, extensional tectonism and crustal deformation in volcanic passive margins such as the study area, which is located in the southwestern corner of the Arabian Peninsula bounded by the Red Sea and the Gulf of Aden. In this work, a 3D Moho depth model of the study area is constructed for the first time by inverting gravity data from the Earth Gravitational Model(EGM2008) using the ParkerOldenburg algorithm. This model indicates the shallow zone is situated at depths of 20 km to 24 km beneath coastal plains, whereas the deep zone is located below the plateau at depths of 30 km to 35 km and its deepest part coincides mainly with the Dhamar-Rada ’a Quaternary volcanic field. The results also indicate two channels of hot magmatic materials joining both the Sana’a-Amran Quaternary volcanic field and the Late Miocene Jabal An Nar volcanic area with the Dhamar-Rada’a volcanic field. This conclusion is supported by the widespread geothermal activity(of mantle origin) distributed along these channels,isotopic data, and the upper mantle low velocity zones indicated by earlier studies.

Conflict in Yemen and its impacts on China’s interests in the region

The conflict in Yemen,which has been going on for 8 years,has great repercussions for Yemen and the entire region.Yemen’s strategic position has made it a key player in a crucial area that influences energy supplies,and international shipping routes,as well as a point of contact between Asia,Africa,and Europe.China,the area’s greatest economic partner and largest importer of oil,was one of those affected,particularly with the announcement of the Chinese BRI and its massive projects in the region.The pro-longed conflict in Yemen has hampered Chinese investments and the construction of several key and strategic BRI projects in Yemen,as well as jeopardising many of its mega projects in the region.It also posed a new threat to the Red Sea and the Gulf of Aden’s sea routes,as well as the establishment of new military bases in strategic areas capable of controlling international trade routes and intensifying military rivalry in the region.