From 0cfe42ea08e39f8ce5119bdf5f6a62d72e040947 Mon Sep 17 00:00:00 2001
From: "J. Michelle Hu" <43484205+jmichellehu@users.noreply.github.com>
Date: Thu, 1 Oct 2026 17:51:31 -0600
Subject: [PATCH] Distribute - Albedo - set vis and ir albedo to None when sun
 is down

 - Zero-fill of vis and ir from PR #27 overrides broadband albedo branch in SolarHRRR.calculate_net_solar
 - Results in net_solar radiation being made equivalent to incoming solar
 - Explicit None definition ensures broadband albedo branch kicks in correctly
---
 smrf/distribute/albedo.py                |  4 +--
 smrf/tests/distribute/test_albedo.py     | 26 ++++++++++++++++
 smrf/tests/distribute/test_solar_hrrr.py | 38 +++++++++++++++++++++++-
 3 files changed, 65 insertions(+), 3 deletions(-)

diff --git a/smrf/distribute/albedo.py b/smrf/distribute/albedo.py
index 2f81ef7b..cfa3f3e5 100755
--- a/smrf/distribute/albedo.py
+++ b/smrf/distribute/albedo.py
@@ -194,8 +194,8 @@ def distribute(
                 self.albedo_ir = utils.set_min_max(alb_ir, self.min, self.max)
 
         else:
-            self.albedo_vis = np.zeros(storm_day.shape)
-            self.albedo_ir = np.zeros(storm_day.shape)
+            self.albedo_vis = None
+            self.albedo_ir = None
 
     def date_method(
         self,
diff --git a/smrf/tests/distribute/test_albedo.py b/smrf/tests/distribute/test_albedo.py
index 9d67ad0c..a241d32b 100644
--- a/smrf/tests/distribute/test_albedo.py
+++ b/smrf/tests/distribute/test_albedo.py
@@ -98,6 +98,32 @@ def test_distribute_file_broadband(self, mock_read_netcdf):
         npt.assert_equal(subject.albedo, values)
         mock_source.load.assert_called_with("albedo", TIMESTEP)
 
+    @patch("smrf.distribute.variable_base.ReadNetCDF")
+    def test_distribute_file_broadband_after_sun_down(self, mock_read_netcdf):
+        # A night step must not set vis/ir values, as these take priority over the
+        # broadband albedo in the net solar calculation
+        values = np.array([0.9, 0.5])
+        mock_source = MagicMock()
+        mock_source.variables = ["albedo"]
+        mock_source.load.return_value = values
+        mock_read_netcdf.return_value = mock_source
+
+        config = self._copy_config(CONFIG)
+        config["albedo"]["source_files"] = "path/to/files"
+        subject = Albedo(config, topo_mock())
+        subject.initialize(pd.DataFrame())
+
+        # Sun is down
+        subject.distribute(TIMESTEP, None, STORM_DAYS)
+        self.assertIsNone(subject.albedo_vis)
+        self.assertIsNone(subject.albedo_ir)
+
+        # Sun is up
+        subject.distribute(TIMESTEP, COS_Z, STORM_DAYS)
+        npt.assert_equal(subject.albedo, values)
+        self.assertIsNone(subject.albedo_vis)
+        self.assertIsNone(subject.albedo_ir)
+
     @patch("smrf.distribute.variable_base.ReadNetCDF")
     def test_distribute_file_vis_ir(self, mock_read_netcdf):
         values_vis = np.array([0.8, 0.7])
diff --git a/smrf/tests/distribute/test_solar_hrrr.py b/smrf/tests/distribute/test_solar_hrrr.py
index a64bd4b0..37c8c91d 100644
--- a/smrf/tests/distribute/test_solar_hrrr.py
+++ b/smrf/tests/distribute/test_solar_hrrr.py
@@ -1,5 +1,5 @@
 import unittest
-from unittest.mock import patch
+from unittest.mock import MagicMock, patch
 
 import numpy as np
 import numpy.testing as npt
@@ -114,6 +114,42 @@ def test_distribute_with_vegetation(self, vegetation_mock):
             diffuse, self.subject.veg_tau
         )
 
+    @patch("smrf.distribute.variable_base.ReadNetCDF")
+    @patch("smrf.distribute.solar_hrrr.mask_for_shade")
+    def test_net_solar_broadband_albedo_after_sun_down(
+        self, shade_mock, mock_read_netcdf
+    ):
+        shade_mock.return_value = ILLUMINATION_MOCK, np.array([1, 1])
+
+        broadband = np.array([[0.8, 0.5]], dtype=np.float32)
+        mock_source = MagicMock()
+        mock_source.variables = ["albedo"]
+        mock_source.load.return_value = broadband
+        mock_read_netcdf.return_value = mock_source
+
+        config = {
+            "time": {"start_date": "2025-10-01 00:00", "time_zone": "utc"},
+            "albedo": {"decay_method": None, "source_files": "path/to/files"},
+            "solar": {"correct_veg": False},
+        }
+        albedo = Albedo(config=config, topo=topo_mock())
+        albedo.initialize(pd.DataFrame())
+
+        # A night step precedes the first daylight step, like at the start of a run
+        storm_days = np.zeros_like(ILLUMINATION_MOCK)
+        albedo.distribute(DATETIME, None, storm_days)
+        albedo.distribute(DATETIME, COS_Z, storm_days)
+
+        self.subject.distribute(
+            DATETIME, DATA_MOCK, COS_Z, AZIMUTH, ILLUMINATION_MOCK, albedo
+        )
+
+        # Net solar is reduced by the broadband albedo and not passed through
+        npt.assert_allclose(
+            self.subject.net_solar, self.subject.hrrr_solar * (1 - broadband)
+        )
+        self.assertTrue(np.all(self.subject.net_solar < self.subject.hrrr_solar))
+
     def test_distribute_sun_is_down(self):
         self.subject.distribute(
             DATETIME,