From 24ceadb3f2620b0b21d0060c959624984ec92382 Mon Sep 17 00:00:00 2001
From: Zhaoyi Shen <11598433+szy21@users.noreply.github.com>
Date: Mon, 8 Apr 2024 14:11:14 -0700
Subject: [PATCH] limit tke to 0 in pi groups

---
 src/prognostic_equations/edmfx_entr_detr.jl | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/prognostic_equations/edmfx_entr_detr.jl b/src/prognostic_equations/edmfx_entr_detr.jl
index 9a42720944..2da439de5a 100644
--- a/src/prognostic_equations/edmfx_entr_detr.jl
+++ b/src/prognostic_equations/edmfx_entr_detr.jl
@@ -59,7 +59,7 @@ function entrainment(
 
         # non-dimensional pi-groups
         Π₁ = (ᶜz - z_sfc) * (ᶜbuoyʲ - ᶜbuoy⁰) / ((ᶜwʲ - ᶜw⁰)^2 + eps(FT)) / 100
-        Π₂ = ᶜtke⁰ / ((ᶜwʲ - ᶜw⁰)^2 + eps(FT)) / 2
+        Π₂ = max(ᶜtke⁰, 0) / ((ᶜwʲ - ᶜw⁰)^2 + eps(FT)) / 2
         Π₃ = sqrt(ᶜaʲ)
         Π₄ = ᶜRHʲ - ᶜRH⁰
         Π₅ = (ᶜz - z_sfc) / ref_H
@@ -177,7 +177,7 @@ function detrainment(
 
         # non-dimensional pi-groups
         Π₁ = (ᶜz - z_sfc) * (ᶜbuoyʲ - ᶜbuoy⁰) / ((ᶜwʲ - ᶜw⁰)^2 + eps(FT)) / 100
-        Π₂ = ᶜtke⁰ / ((ᶜwʲ - ᶜw⁰)^2 + eps(FT)) / 2
+        Π₂ = max(ᶜtke⁰, 0) / ((ᶜwʲ - ᶜw⁰)^2 + eps(FT)) / 2
         Π₃ = sqrt(ᶜaʲ)
         Π₄ = ᶜRHʲ - ᶜRH⁰
         Π₅ = (ᶜz - z_sfc) / ref_H