Detailed Patterns of Methane Distribution in the German Bight

Although methane is a widely studied greenhouse gas, uncertainties remain with respect to the factors controlling its distribution and diffusive flux into atmosphere, especially in highly dynamic coastal waters. In southern North Sea, Elbe Weser rivers are two major tributaries contributing overall budget of German Bight. June 2019, we continuously measured basic hydrographic parameters at high temporal spatial resolution (one measurement per minute every 200–300 m) on transect between Cuxhaven Helgoland. These measurements revealed that driver dilution riverine methane-rich water methane-poor marine water. For both Weser, determined an input concentration 40–50 nmol/L compared only 5 area. Accordingly, observed comparatively steady pattern toward realm. Moreover, small-scale anomalous patterns unexpectedly higher dissolved concentrations were discovered certain sites times. associated significant correlations oxygen or turbidity. However, these local anomalies not consistent over time (days, months). The calculated from atmosphere values approximately 3.5 times than background (median 36 128 μmol m –2 d –1 ). We evaluate this occurred because combination increasing wind speed those locations. Hence, our results demonstrate improved can provide more accurate estimation and, consequently, functional understanding dynamics flux.