Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical Islands
In order to establish data to be used for comparison with future evolution related to climate change, physical, chemical and biological characteristics of dew and rainwater as collected during the 2005 dry season (plus a few data during the 2004 dry season) are reported. They have been collected in...
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| Format: | Article |
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MDPI AG
2021-01-01
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| Series: | Atmosphere |
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| Online Access: | https://www.mdpi.com/2073-4433/12/1/69 |
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| author | Marc Muselli Owen Clus Pascal Ortega Iryna Milimouk Daniel Beysens |
| author_facet | Marc Muselli Owen Clus Pascal Ortega Iryna Milimouk Daniel Beysens |
| author_sort | Marc Muselli |
| collection | DOAJ |
| description | In order to establish data to be used for comparison with future evolution related to climate change, physical, chemical and biological characteristics of dew and rainwater as collected during the 2005 dry season (plus a few data during the 2004 dry season) are reported. They have been collected in two characteristic tropical islands of French Polynesia, Tikehau (TKH), a low-lying coral atoll in the Tuamotu Archipelago, and the mountainous Tahiti island at the University of French Polynesia (TAH). Trade winds dominate the trajectory of air masses, ensuring constant temperature and humidity to the lower layers of the atmosphere where dew forms. In addition to the comparison of dew yields with a physical model using simple meteorological data (air and dew point temperatures, windspeed, cloud cover), the following parameters were studied: pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness, suspended matter, ion concentration with major cations (Ca<sup>2+</sup>, K<sup>+</sup>, Na<sup>+</sup>, Mg<sup>2+</sup>, NH<sub>4</sub><sup>+</sup>) and major anions (Cl<sup>−</sup>, SO<sub>4</sub><sup>2−</sup>, NO<sub>3</sub><sup>−</sup>), reviviscible aerobe microorganisms and compared to two Polynesian spring waters (“Eau Royale” and “Vaimato”). Dew, with a chemical composition mainly consisting of Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Cl<sup>−</sup> and SO<sub>4</sub><sup>2−</sup>, exhibits much higher ion concentration than rain and compares well with the composition of local spring waters. The values of pH, EC and TDS are larger in dew than in rainwater. At TAH, the volume weighted mean (VWM) pH values of dew were 6.05 in 2004 and 5.23 in 2005, larger than the pH of rain (4.69). The VWM dew EC (at TAH, 203 μS·cm<sup>−1</sup> in 2004 and 237 μS·cm<sup>−1</sup> in 2005; 321 μS·cm<sup>−1</sup> at TKH in 2005) and dew TDS (152 mg·L<sup>−1</sup> at TAH and 225 mg·L<sup>−1</sup> at TKH) were higher than the corresponding quantities in rain. Mean total hardness (TH) values of dew water are much higher than in rainwater (2.8 for dew versus 0.5 for rain at TAH and 5.7 for dew versus 0.5 for rain at TKH). Ions Na<sup>+</sup>, Mg<sup>2+</sup> and Cl<sup>−</sup> are clearly of sea origin while the presence of Ca<sup>2+</sup> is due to coral particles. From their chemical characteristics, dew and rainwater could be used as an alternative source of water in dry season but, due to the presence of reviviscible aerobe microorganisms at 22 °C and 36 °C (>300 CFU·mL<sup>−1</sup>), water must be disinfected to be potable. |
| first_indexed | 2024-03-10T13:28:14Z |
| format | Article |
| id | doaj.art-9dc7fe54a89c45979f9a157b61cbbd64 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-10T13:28:14Z |
| publishDate | 2021-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-9dc7fe54a89c45979f9a157b61cbbd642023-11-21T08:37:04ZengMDPI AGAtmosphere2073-44332021-01-011216910.3390/atmos12010069Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical IslandsMarc Muselli0Owen Clus1Pascal Ortega2Iryna Milimouk3Daniel Beysens4Campus Grimaldi, Université de Corse Pasquale Paoli, Avenue du 9 Septembre, BP 52, 20250 Corte, FranceCampus Grimaldi, Université de Corse Pasquale Paoli, Avenue du 9 Septembre, BP 52, 20250 Corte, FranceUniversité de la Polynésie Française, BP 6570, 98702 Faa’a, French PolynesiaOPUR, 2 rue Verderet, 75016 Paris, FranceOPUR, 2 rue Verderet, 75016 Paris, FranceIn order to establish data to be used for comparison with future evolution related to climate change, physical, chemical and biological characteristics of dew and rainwater as collected during the 2005 dry season (plus a few data during the 2004 dry season) are reported. They have been collected in two characteristic tropical islands of French Polynesia, Tikehau (TKH), a low-lying coral atoll in the Tuamotu Archipelago, and the mountainous Tahiti island at the University of French Polynesia (TAH). Trade winds dominate the trajectory of air masses, ensuring constant temperature and humidity to the lower layers of the atmosphere where dew forms. In addition to the comparison of dew yields with a physical model using simple meteorological data (air and dew point temperatures, windspeed, cloud cover), the following parameters were studied: pH, electrical conductivity (EC), total dissolved solids (TDS), total hardness, suspended matter, ion concentration with major cations (Ca<sup>2+</sup>, K<sup>+</sup>, Na<sup>+</sup>, Mg<sup>2+</sup>, NH<sub>4</sub><sup>+</sup>) and major anions (Cl<sup>−</sup>, SO<sub>4</sub><sup>2−</sup>, NO<sub>3</sub><sup>−</sup>), reviviscible aerobe microorganisms and compared to two Polynesian spring waters (“Eau Royale” and “Vaimato”). Dew, with a chemical composition mainly consisting of Na<sup>+</sup>, Ca<sup>2+</sup>, Mg<sup>2+</sup>, Cl<sup>−</sup> and SO<sub>4</sub><sup>2−</sup>, exhibits much higher ion concentration than rain and compares well with the composition of local spring waters. The values of pH, EC and TDS are larger in dew than in rainwater. At TAH, the volume weighted mean (VWM) pH values of dew were 6.05 in 2004 and 5.23 in 2005, larger than the pH of rain (4.69). The VWM dew EC (at TAH, 203 μS·cm<sup>−1</sup> in 2004 and 237 μS·cm<sup>−1</sup> in 2005; 321 μS·cm<sup>−1</sup> at TKH in 2005) and dew TDS (152 mg·L<sup>−1</sup> at TAH and 225 mg·L<sup>−1</sup> at TKH) were higher than the corresponding quantities in rain. Mean total hardness (TH) values of dew water are much higher than in rainwater (2.8 for dew versus 0.5 for rain at TAH and 5.7 for dew versus 0.5 for rain at TKH). Ions Na<sup>+</sup>, Mg<sup>2+</sup> and Cl<sup>−</sup> are clearly of sea origin while the presence of Ca<sup>2+</sup> is due to coral particles. From their chemical characteristics, dew and rainwater could be used as an alternative source of water in dry season but, due to the presence of reviviscible aerobe microorganisms at 22 °C and 36 °C (>300 CFU·mL<sup>−1</sup>), water must be disinfected to be potable.https://www.mdpi.com/2073-4433/12/1/69atmospheric depositiondew waterrainwaterchemical and biological analysistropical conditions |
| spellingShingle | Marc Muselli Owen Clus Pascal Ortega Iryna Milimouk Daniel Beysens Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical Islands Atmosphere atmospheric deposition dew water rainwater chemical and biological analysis tropical conditions |
| title | Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical Islands |
| title_full | Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical Islands |
| title_fullStr | Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical Islands |
| title_full_unstemmed | Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical Islands |
| title_short | Physical, Chemical and Biological Characteristics of Dew and Rainwater during the Dry Season of Tropical Islands |
| title_sort | physical chemical and biological characteristics of dew and rainwater during the dry season of tropical islands |
| topic | atmospheric deposition dew water rainwater chemical and biological analysis tropical conditions |
| url | https://www.mdpi.com/2073-4433/12/1/69 |
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