Updating Townsends snow model references (#2384)

* Updating  Townsends snow model references

* Applying reviews

* Adding a note to the whatsnew file for v0.11.3

* Applying review

* Add myself as contributor and apply reviews

* Fix the line length issue

* Adding actual title of the poster

* correct doi syntax

Author: ayushjariyal

docs/sphinx/source/whatsnew/v0.11.3.rst

@@ -17,6 +17,7 @@ Documentation
 ~~~~~~~~~~~~~
 * Fix Procedural and Object Oriented simulation examples having slightly different results, in :ref:`introtutorial`. (:issue:`2366`, :pull:`2367`)
 * Restructure the user guide with subsections (:issue:`2302`, :pull:`2310`)
+* Add references for :py:func:`pvlib.snow.loss_townsend`. (:issue:`2383`, :pull:`2384`)
 
 Testing
 ~~~~~~~
@@ -40,3 +41,4 @@ Contributors
 * Mark Campanelli (:ghuser:`markcampanelli`)
 * Jason Lun Leung (:ghuser:`jason-rpkt`)
 * Manoj K S (:ghuser:`manojks1999`)
+* Ayush jariyal (:ghuser:`ayushjariyal`)

pvlib/snow.py

@@ -278,16 +278,23 @@ def loss_townsend(snow_total, snow_events, surface_tilt, relative_humidity,
     axis to the module edge.
 
     The parameter `string_factor` is an enhancement added to the model after
-    publication of [1]_ per private communication with the model's author. The
-    definition for snow events documented above is also based on private
-    communication with the model's author.
+    publication of [1]_, as described in [2]_.
+    The definition for snow events documented above is based on [3]_.
 
     References
     ----------
     .. [1] Townsend, Tim & Powers, Loren. (2011). Photovoltaics and snow: An
        update from two winters of measurements in the SIERRA. 37th IEEE
        Photovoltaic Specialists Conference, Seattle, WA, USA.
        :doi:`10.1109/PVSC.2011.6186627`
+    .. [2] Townsend, T. and Previtali, J. (2023). A Fresh Dusting: Current
+        Uses of the Townsend Snow Model. In "Photovoltaic Reliability
+        Workshop (PVRW) 2023 Proceedings: Posters.", ed. Silverman,
+        T. J. Dec. 2023. NREL/CP-5900-87918.
+        Available at: https://www.nrel.gov/docs/fy25osti/90585.pdf
+    .. [3] Townsend, T. (2013). Predicting PV Energy Loss Caused by Snow.
+        Solar Power International, Chicago IL.
+        :doi:`10.13140/RG.2.2.14299.68647`
     '''
 
     # unit conversions from cm and m to in, from C to K, and from % to fraction