http://bolin.su.se/data/lundevall-zara-2021-asko-methane-1 Maysoon Lundevall-Zara, Erik Lundevall-Zara, Volker Brüchert Bolin Centre Database 2021 Datafile Marine Trace gases Methane Baltic Sea Gas transfer model Floating chamber Shallow inshore areas Coastal habitats Environmental forcing factors Earth science > Atmosphere > Atmospheric chemistry > Carbon and hydrocarbon compounds > Methane Maysoon Lundevall-Zara 2021-08-03T06:22:19+00:00 English 1 This dataset consists of two comma-separated values (csv) files (UTF-8 encoding, the first line contains headers). ##### Sample data File lundevall-zara-2021-asko-methane-1-sample-data.csv consists of 17 columns: 1. Sample name 2. Sampling station name 3. Sample type (air or water sample) 4. latitude for the sampling station location 5. Longitude for the sampling station location 6. Water temperature (°C) 7. Air temperature (°C) - obtained from SMHI 8. Salinity (‰) 9. Wind velocity at 1.5 m height (m/s) - obtained from SMHI 10. Methane concentration (nmol/L) 11. Methane concentration from GC analysis (ppm) 12. Sampling timestamp (date and time) 13. Shimadzu GC analysis date 14. Chamber interval qualifier, for grouping of multiple time series intervals at the same station and sampling month. Only for air samples. 15. Chamber volume (L). Only for air samples 16. Chamber diameter at the water surface (m). Only for air samples 17. Comment field ##### Reference data File lundevall-zara-2021-asko-methane-1-reference-data.csv consists of 7 columns: 1. Sample type (always standard) 2. Area value from Shimadzu GC analysis of the standard sample 3. Standard deviation for all area values for the standard samples from the same analysis session (same date) 4. Mean value for all area values for the standard samples from the same analysis session (same date) 5. Coefficient of variation (%) for all area values for the standard samples from the same analysis session (same date) 6. Shimadzu GC analysis date 7. Comment field The file with reference data refers to the standard methane gas measured during the sample analysis with GC-Shimadzu. This standard data had been used to perform linear regression in order to calculate sample concentrations from GC-area. For each analysis session, we calculated the average of standard areas and used that value to perform the linear regression along with a point in origo. Each analysis session had a different analysis date. The average, standard deviation, and coefficient of variation were calculated for each session and included in this data. See article by Lundevall-Zara et al. (2021) for a description of the area where the data measurements were obtained from, as well as calculation examples for flux based on this data. The principal investigators (Maysoon Lundevall-Zara (see Contact information) and [Volker Brüchert](mailto:volker.bruchert@geo.su.se)) would welcome to receive a notification when the data are used in any publication or derivative work.