Karst is considered a potential sink for the atmospheric greenhouse gas CH4 because its subsurface drainage networks and solution-enlarged fractures facilitate atmospheric exchange.
Because there are no vascular plants on this landscape and no groundwater input to these streams, atmospheric exchange is the dominant control on δ13C-DIC.
Dissolved oxygen (DO) is one of the most commonly measured parameters in aqueous studies, however its sources and sinks such as atmospheric exchange, photosynthesis or respiration often remain unknown.
Variations in the reservoir age of lakes are furthermore determined by variations of e.g. the ratio between lake surface and lake volume (i.e. water depth), as groundwater DIC can enter the lake from the total underground surrounding the lake, while atmospheric exchange only takes place on the surface [65].
To avoid any potential atmospheric exchange of volatiles that could have interfered with our measurements, each experimental unit was transferred one at a time to a separate room where the 2 external square boxes were opened; all petri dishes were then removed and inspected, while the rest of the unit (including the base and the central cylindrical box) was taken outdoors and opened.
The term 'thermal environment' encompasses both the atmospheric heat exchanges with the body (thermal stress) and the body's physiological response (thermal strain).
This one-dimensional integrated model solves hydrodynamics with mass balance equations to simulate DO dynamics driven by rates of atmospheric oxygen exchange and biochemical processes.
In this species, green plastids of normal function are localized to a ring of cells between the stem pith and cortex that are isolated from atmospheric gas exchange, indicating photosynthesis may occur in this species using recycled respiratory CO2 [ 22] despite an altered xanthophyll cycle in its light-harvesting complex [ 23].
Because no atmospheric gas exchange occurs with chlorophyllous cells in C. reflexa, recycling of respiratory carbon dioxide has been presented as a hypothesis for retention of photosynthesis in that species, and although their source carbohydrates all apparently originate from the host, a net decline in carbon dioxide release is indeed detected in the presence of light [ 22].
It plays a major role in the dynamics of atmospheric circulation, radiation exchange within the atmosphere, and climate variability.
