BIBLIOS

Tipo
Artigos em Revista

Tipo de Documento
Artigo Completo

Título
Bromine soil/sediment enrichment in tidal salt marshes as a potential indicator of climate changes driven by solar activity: New insights from W coast Portuguese estuaries

Participantes na publicação
J. Moreno (Author)
IDL
F. Fatela (Author)
Dep. Geologia
IDL
E. Leorri (Author)
F. Moreno (Author)
M.C. Freitas (Author)
Dep. Geologia
IDL
T. Valente (Author)
M.F. Araújo (Author)
J.J. Gómez-Navarro (Author)
L. Guise (Author)
W.H. Blake (Author)

Resumo
This paper aims at providing insight about bromine (Br) cycle in four Portuguese estuaries: Minho,\\nLima (in the NW coast) and Sado, Mira (in the SW coast). The focus is on their tidal marsh environments, quite\\ndistinct with regard to key biophysicochemical attributes. Regardless of the primary bromide (Br−) common\\nnatural source, i.e., seawater, the NW marshes present relatively higher surface soil/sediment Br\\nconcentrations than the ones from SW coast. This happens in close connection with organic matter (OM)\\ncontent, and is controlled by their main climatic contexts. Yet, the anthropogenic impact on Br concentrations\\ncannot be discarded. Regarding [Br] spatial patterns across the marshes, the results show a general increase\\nfrom tidal flat toward high marsh. Maxima [Br] occur in the upper drift line zone, at transition from highest low\\nmarsh to high marsh, recognized as a privileged setting for OM accumulation. Based on the discovery of OM\\nubiquitous bromination in marine and transitional environments, it is assumed that this Br occurs mainly as\\norganobromine. Analysis of two dated sediment cores indicates that, despite having the same age (AD ~1300),\\nthe Caminha salt marsh (Minho estuary) evidences higher Br enrichment than the Casa Branca salt marsh\\n(Mira estuary). This is related to a greater Br storage ability, which is linked to OM build-up and rate dynamics\\nunder different climate scenarios. Both cores evidence a fairly similar temporal Br enrichment pattern, and may\\nbe interpreted in light of the sun–climate coupling. Thereby, most of the well-known Grand Solar Minima during\\nthe Little Ice Age appear to have left an imprint on these marshes, supported by higher [Br] in soils/sediments.\\nBesides climate changes driven by solar activity and impacting marsh Br biogeodynamics, those Br enrichment\\npeaks might also reflect inputs of enhanced volcanic activity covarying with Grand Solar Minima.


Instituição
FACULDADE DE CIÊNCIAS DA UNIVERSIDADE DE LISBOA

Suporte
Science of The Total Environment

Identificadores da Publicação
ISSN - 0048-9697

Editora
Elsevier BV



Identificadores do Documento
DOI - https://doi.org/10.1016/j.scitotenv.2016.11.130
URL - http://dx.doi.org/10.1016/j.scitotenv.2016.11.130

Identificadores de Qualidade
SCOPUS Q1 (2017) - 1.546 - Environmental Chemistry
Web Of Science Q1 (2017) - 4.61 - ENVIRONMENTAL SCIENCES - SCIE
SCOPUS Q1 (2017) - 1.546 - Environmental Engineering
SCIMAGO Q1 (2017) - 1.546 - Environmental Chemistry

Keywords
Salt marshes; Br cycle; OM storage; Grand Solar Minima; Climate modelling; Climate variability