Minimum conc:     <xarray.DataArray 'WD_spec001' ()>
array(-0.00052358, dtype=float32)
Minimum conc:     <xarray.DataArray 'WD_spec002' ()>
array(-2.4094741e-05, dtype=float32)
Minimum conc:     <xarray.DataArray 'DD_spec001' ()>
array(-0.00128655, dtype=float32)
Minimum conc:     <xarray.DataArray 'DD_spec002' ()>
array(-0.00093488, dtype=float32)