  Estimates of greenhouse gas emissions from Arctic estuarine environments are
dominated by in situ summer-time ice-free dissolved gas measurements due to the
logistical ease of performing field observations in these conditions. Recent
evidence in coastal Arctic environments, however, has demonstrated that
dissolved methane (CH4) and carbon dioxide (CO2) are strongly seasonally
variable, and at least one significant gas ventilation event occurs during the
spring freshet. Whether the Arctic serves as a source or sink of greenhouse
emissions has significant implications on modeling climate change and its
feedback mechanisms. To enable higher resolution spatiotemporal measurements of
dissolved gases in typically undersampled conditions, remotely operated
vehicles (ROVs) can be used to extract near continuous water samples below ice
before and during the spring freshet. Here, we present a size, weight, and
power-constrained (SWAP) underwater vehicle (UV) and novel geochemical sampling
system suitable for taking under-ice geochemical observations and demonstrate
the proposed system in a field-analog setting for Arctic estuarine studies.
