2018 Annual Report Summary
Read a recap of AsRA's work and accomplishments in 2018.
Connectivity for Stream Health
How do we ensure the health of wild streams?Restoring connectivity by replacing or retrofitting undersized, collapsing, or deteriorated road crossings is one essential step. The 4-sided concrete structure in the "before" photo below is slightly...
What causes parallel lines of bubbles to form on lakes?
Langmuir circulation, or Langmuir spirals, causes horizontal lines of bubbles or foam to form on the surface of lakes. Under the right wind conditions, the combination of wave action and shear stress causes spiraling horizontal currents to form near the lake surface. Adjacent cells rotate counter to one another, creating alternating areas of upwelling and downwelling. Air bubbles and other debris get caught in the downwelling areas, forming long lines that run parallel to the direction of the prevailing winds.