A new maximum angle method has been developed to determine surface mixed-layer (a general name for isothermal/constant-density layer) depth from profile data. It has three steps: (1) fitting the profile data with a first vector (pointing downward) from an upper level to a depth and a second vector (pointing downward) from that depth to a deeper level; (2) identifying the angle (varying with dep...

We present results from a new global atmospheric mercury model coupled with a mixed layer slab ocean. The ocean model describes the interactions of the mixed layer with the atmosphere and deep ocean, as well as conversion between elemental, divalent, and non-reactive mercury species. Our global mean aqueous concentrations of 0.07 pM elemental, 0.80 pM reactive, and 1.51 pM total mercury agree w...

[1] Formaldehyde (HCHO) measurements in snow and shallow firn at three Antarctic sites gave concentrations around 6 ppbw in surface snow and 1 ppbw and lower below 1–2 m depth. The variable concentration patterns in shallow snow and firn result from temperature-dependent uptake and release of HCHO in response to annual temperature cycles. Deeper concentrations are constant with depth, and appar...

The onset of phytoplankton blooms in late winter, early spring has been traditionally associated with the shoaling of the mixed layer above a critical depth. Here we show that the onset of a bloom can also be triggered by a reduction in air-sea fluxes at the end of winter. When net cooling subsides at the end of winter, turbulent mixing becomes weak, thereby increasing the residence time of phy...