Based on long-term trends of water chemistry parameters of photochemical significance from four lakes located in the Alps (Iseo, Garda, Piburgersee, Geneva), we calculated the corresponding steady-state concentrations of photoinduced transient species with an ad-hoc photochemical model. Such transients were the hydroxyl ((•)OH) and carbonate (CO3(-•)) radicals, singlet oxygen ((1)O2), and the triplet states of chromophoric dissolved organic matter ((3)CDOM*). Among the investigated lakes, Lake Iseo, for example, showed a long-term near-stability in chemical parameters that resulted in a photochemical stability. By contrast, Piburgersee underwent important chemical modifications, but the interplay of compensation (parallel increase of both inorganic and organic carbon) and near-saturation effects (organic matter as main (•)OH source and sink) prevented the modelled photochemistry to undergo significant shifts over time. This result suggests the occurrence of a sort of "photochemical buffering" in some lake ecosystems, which would dampen modifications of the steady-state concentration of the photochemically-formed reactive transients, even in the case of significant changes in water chemistry. Finally, in lakes Garda and Geneva, long-term changes in water chemistry had an effect on photochemistry. While in Lake Garda the small increase in DOM was associated to a small increase in (1)O2 and (3)CDOM*, in Lake Geneva, the increases in pH and bicarbonate and the decrease in nitrite resulted in an (•)OH decrease. Overall, our results predict very different lake photochemistry patterns in relation to alterations in water chemistry parameters caused by climate change, such as changes in water alkalinity and dissolved organic carbon concentration.

Minella, M.; Leoni, B.; Salmaso, N.; Savoye, L.; Sommaruga, R.; Vione, D. (2016). Long-term trends of chemical and modelled photochemical parameters in four Alpine lakes. SCIENCE OF THE TOTAL ENVIRONMENT, 541: 247-256. doi: 10.1016/j.scitotenv.2015.08.149 handle: http://hdl.handle.net/10449/27238

Long-term trends of chemical and modelled photochemical parameters in four Alpine lakes

Salmaso, Nico;
2016-01-01

Abstract

Based on long-term trends of water chemistry parameters of photochemical significance from four lakes located in the Alps (Iseo, Garda, Piburgersee, Geneva), we calculated the corresponding steady-state concentrations of photoinduced transient species with an ad-hoc photochemical model. Such transients were the hydroxyl ((•)OH) and carbonate (CO3(-•)) radicals, singlet oxygen ((1)O2), and the triplet states of chromophoric dissolved organic matter ((3)CDOM*). Among the investigated lakes, Lake Iseo, for example, showed a long-term near-stability in chemical parameters that resulted in a photochemical stability. By contrast, Piburgersee underwent important chemical modifications, but the interplay of compensation (parallel increase of both inorganic and organic carbon) and near-saturation effects (organic matter as main (•)OH source and sink) prevented the modelled photochemistry to undergo significant shifts over time. This result suggests the occurrence of a sort of "photochemical buffering" in some lake ecosystems, which would dampen modifications of the steady-state concentration of the photochemically-formed reactive transients, even in the case of significant changes in water chemistry. Finally, in lakes Garda and Geneva, long-term changes in water chemistry had an effect on photochemistry. While in Lake Garda the small increase in DOM was associated to a small increase in (1)O2 and (3)CDOM*, in Lake Geneva, the increases in pH and bicarbonate and the decrease in nitrite resulted in an (•)OH decrease. Overall, our results predict very different lake photochemistry patterns in relation to alterations in water chemistry parameters caused by climate change, such as changes in water alkalinity and dissolved organic carbon concentration.
Climate change
Environmental photochemistry
Indirect photochemistry
Long-term trends
Seasonal trends
Settore BIO/07 - ECOLOGIA
2016
Minella, M.; Leoni, B.; Salmaso, N.; Savoye, L.; Sommaruga, R.; Vione, D. (2016). Long-term trends of chemical and modelled photochemical parameters in four Alpine lakes. SCIENCE OF THE TOTAL ENVIRONMENT, 541: 247-256. doi: 10.1016/j.scitotenv.2015.08.149 handle: http://hdl.handle.net/10449/27238
File in questo prodotto:
File Dimensione Formato  
Minella_etal_2016_ Long-term trends of chemical and modelled photochemical parameters in four Alpine lakes.pdf

solo utenti autorizzati

Licenza: Tutti i diritti riservati (All rights reserved)
Dimensione 2.45 MB
Formato Adobe PDF
2.45 MB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10449/27238
Citazioni
  • ???jsp.display-item.citation.pmc??? 4
  • Scopus 21
  • ???jsp.display-item.citation.isi??? 19
social impact