Details

Autor(en) / Beteiligte

• Singh, Udisha
• Suresh, K.
• Prabhat, Priyesh
• Rahaman, Waliur
• Kumar, Ashwini

Titel

Geochemical tracing of synoptic scale modern dust transport over the Northeast Arabian Sea during the southwest monsoon

Ist Teil von

• The Science of the total environment, 2023-10, Vol.893, p.164438-164438, Article 164438

Ort / Verlag

Netherlands: Elsevier B.V

Erscheinungsjahr

2023

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• During the Southwest monsoon (SWM), aeolian dust is mainly supplied via wet deposition over the northeast Arabian Sea (NEAS). To understand their impact on the biogeochemistry of the Arabian Sea, it is important to identify their sources and characteristics. In this context, wet deposit particulate (WDP) samples were collected at a coastal station (Goa; 15.4° N, 73.8° E) in the NEAS during the SWM for three years. These samples were used to characterize and identify mineral dust sources using mineralogical, elemental, and isotopic (Sr and Nd) signatures. The WDP samples were classified as Beginning of Monsoon (BM, June samples), Mid Monsoon (MM, July–August samples) and End of Monsoon (EM, September samples). Clay mineralogical composition indicate high palygorskite content during BM, which subsequently found to decrease in MM, and almost negligible in EM. However, smectite is highest during MM, with moderate presence of palygorskite during this period. The considerable variation in the relative percentages of clay minerals suggests significant temporal variability in dust sources which is further corroborated by the radiogenic isotopic composition. A strong seasonality in the isotopic composition is observed with 87Sr/86Sr ratio being relatively less radiogenic during MM than the BM and highly radiogenic at the EM. Whereas ƐNd values show an opposite trend to 87Sr/86Sr ratios throughout the monsoon, with more radiogenic ƐNd in the MM, and less radiogenic at the EM. End member mixing plot indicate dominant contribution of dust from the Arabian Peninsula (ARB) and Northeast African (NEA) sources during BM and MM, while a shift towards the Thar desert and Southwest Asian (SWA) sources at the EM. Trace elements associated with different sources were quantified and suggest high Fe concentration is associated with NEA dust sources, despite ARB being major supplier of aeolian dust to the Arabian Sea. [Display omitted] •Geochemical tracing of dust transport over the Arabian sea during the SW Monsoon•Significant temporal variability in dust characteristics based on 3-year data•Arabian Peninsula and Northeast Africa are major dust sources over the Arabian Sea.•Episodic contribution from Southwest Asia and Thar Desert at the end of SWM•High Fe content found in the NEA sourced dust in contrast to ARB sources dust