# Converting Langley to Watts

I'm reading a really old paper which looks at estimating the surface energy fluxes for The Great Lakes. They show all of their values as Langleys per day. Can this be converted to Watts per meter squared? Also, what is a Langley?

$$1\frac{\rm ly}{\rm min}=697.3\,\frac{\rm W}{\rm m^2}$$
So you'll have to do some more unit conversions to get the ly/day to W/m$^2$ conversion.