Radium concentration in water samples from the Northeast Atlantic

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Auteurs principaux: Kromer, Bernd, Roether, Wolfgang
Format: Dataset Open Access
Langue:en
Publié: PANGAEA 1983
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author Kromer, Bernd
Roether, Wolfgang
author_facet Kromer, Bernd
Roether, Wolfgang
collection Datos científicos de ciencias marinas y ambientales
contents We present field measurements of air-sea gas exchange by the radon deficit method that were carried out during JASIN 1978 (NE Atlantic) and FGGE 1979 (Equatorial Atlantic). Both experiments comprised repeated deficit measurements at fixed position over periods of days or longer, using a previously descibed precise and fast-acquiaition, automatic radon measuring system. The deficit time series exhibit variations that only partly reflect the expected changes in gas transfer. By evaluating averages over each time series we deduce the following gas transfer velocities (average wind velocity and water temperature in parentheses): JASIN phase 1: 1.6 ± 0.8 m/d (at ~6 m/s, 13°C) JASIN phase 2: 4.3 ± 1.2 m/d (at ~8 m/s, 13°C) FGGE: 1.2 ± 0.4 m/d (at ~5 m/s, 28°C) 0.9 ± 0.4 m/d (at ~7 m/s, 28°C) 1.5 ± 0.4 m/d (at ~7 m/s, 28°C) The large difference betwen the JASIN phase 2 and FGGE values despite quite similare average wind velocity becomes even larger when the values are, however, fully compatible with the range of gas transfer velocities observed in laboratory experiments and the conclusion is suggested that their difference is caused by the highly different wind variability in JASIN and FGGE. We conclude that in gas exchange parameterization it is not sufficinent to consider wind velocity only. A comparison of our observations with laboratory results outlines the range of variations of air-sea gas transfer velocities with wind velocity and sea state. We also reformulate the radon deficit method, in the light of our observed deficit variations, to account explicitely for non-stationary and horizontal inhomogeneity in previous radon work introduces considerable uncertainty in deduced gas transfere velocity. We furthermore discuss the observational rewuirements that have to be met for an adequate exploitation of the radon deficit method, of which an observation area of minimum horizontal inhomogeneity and monitoring of the remaining inhomogeneities are thought to be the most stringent ones.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_604844
institution PANGAEA
language en
publishDate 1983
publisher PANGAEA
record_format pangaea
spellingShingle Radium concentration in water samples from the Northeast Atlantic
Kromer, Bernd
Roether, Wolfgang
Atlantic Ocean; CTD/Rosette; CTD-RO; FGGE-Equator 79 - First GARP Global Experiment; JASIN 1978; M49; M49_001; M49_002; M49_005; M49_011; M51; M51_286-6; M57; M57_001; M57_002; M57_003; M57_004; M57_005; M57_006; Meteor (1964); North Atlantic Ocean; North East Atlantic; North Sea; PO_08_1978_1501; Water sample; WS
We present field measurements of air-sea gas exchange by the radon deficit method that were carried out during JASIN 1978 (NE Atlantic) and FGGE 1979 (Equatorial Atlantic). Both experiments comprised repeated deficit measurements at fixed position over periods of days or longer, using a previously descibed precise and fast-acquiaition, automatic radon measuring system. The deficit time series exhibit variations that only partly reflect the expected changes in gas transfer. By evaluating averages over each time series we deduce the following gas transfer velocities (average wind velocity and water temperature in parentheses): JASIN phase 1: 1.6 ± 0.8 m/d (at ~6 m/s, 13°C) JASIN phase 2: 4.3 ± 1.2 m/d (at ~8 m/s, 13°C) FGGE: 1.2 ± 0.4 m/d (at ~5 m/s, 28°C) 0.9 ± 0.4 m/d (at ~7 m/s, 28°C) 1.5 ± 0.4 m/d (at ~7 m/s, 28°C) The large difference betwen the JASIN phase 2 and FGGE values despite quite similare average wind velocity becomes even larger when the values are, however, fully compatible with the range of gas transfer velocities observed in laboratory experiments and the conclusion is suggested that their difference is caused by the highly different wind variability in JASIN and FGGE. We conclude that in gas exchange parameterization it is not sufficinent to consider wind velocity only. A comparison of our observations with laboratory results outlines the range of variations of air-sea gas transfer velocities with wind velocity and sea state. We also reformulate the radon deficit method, in the light of our observed deficit variations, to account explicitely for non-stationary and horizontal inhomogeneity in previous radon work introduces considerable uncertainty in deduced gas transfere velocity. We furthermore discuss the observational rewuirements that have to be met for an adequate exploitation of the radon deficit method, of which an observation area of minimum horizontal inhomogeneity and monitoring of the remaining inhomogeneities are thought to be the most stringent ones.
title Radium concentration in water samples from the Northeast Atlantic
topic Atlantic Ocean; CTD/Rosette; CTD-RO; FGGE-Equator 79 - First GARP Global Experiment; JASIN 1978; M49; M49_001; M49_002; M49_005; M49_011; M51; M51_286-6; M57; M57_001; M57_002; M57_003; M57_004; M57_005; M57_006; Meteor (1964); North Atlantic Ocean; North East Atlantic; North Sea; PO_08_1978_1501; Water sample; WS
url https://doi.org/10.1594/PANGAEA.604844