Swap sign of flux divergence

docs/whats-new.rst

@@ -8,7 +8,8 @@ v1.6.x (not released)
 
 Enhancements
 ~~~~~~~~~~~~
-
+- Resolved inverted sign of flowline diagnostics flux divergence (:pull:`1815`).
+  By `Brandon Tober <https://github.com/btobers>`_
 - Added ``tasks.compute_fl_diagnostics_quantiles``, this task is designed to
   calculate quantiles from multiple fl_diagnostic files. It enables users to
   compute metrics such as the median flowline across various GCM projections

oggm/core/flowline.py

@@ -1347,7 +1347,7 @@ def run_until_and_store(self, y1,
                             surface_h_previous[fl_id] = fl.surface_h
                         if 'flux_divergence' in ovars_fl and (yr > self.y0):
                             # calculated after the formula dhdt = mb + flux_div
-                            val = ds['dhdt'].data[i, :] - ds['climatic_mb'].data[i, :]
+                            val = ds['climatic_mb'].data[i, :] - ds['dhdt'].data[i, :]
                             # special treatment for retreating: If the glacier
                             # terminus is getting ice free it means the
                             # climatic mass balance is more negative than the