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Hi NCL-Talk,
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<div class="">I was checking out the pot_temp_equiv function in NCL. Unfortunately, I believe I found an error. <a href="https://www.ncl.ucar.edu/Document/Functions/Contributed/pot_temp_equiv.shtml" class="">https://www.ncl.ucar.edu/Document/Functions/Contributed/pot_temp_equiv.shtml</a> </div>
<div class="">The descriptions page states it uses Davies-Jones (2009) for the calculation. However, looking at the contributed file, the code uses Stull 1988 §13.1 p. 546, which does not use the lifting condensation temperature. </div>
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<div class="">I use Bolton 1980 equation 22 for lifting condensation temperature and equation 39 for equivalent potential temperature. </div>
<div class="">Using typical warm pool values, T = 27°C-31°C, and an average humidity 75% at 1000mb:</div>
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<div class="">NCL: pot_temp_equiv <span class="Apple-tab-span" style="white-space:pre">
</span>= 69.1°C, 72.7°C, 76.4°C, 80.3°C, 84.3°C</div>
<div class="">Bolton Eqn 39 <span class="Apple-tab-span" style="white-space:pre">
</span>= 77.8°C, 82.2°C, 86.9°C, 91.8°C, 97.0°C</div>
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<div class="">These are substantially different values for the warm pool. This is important for researchers analyzing buoyancy differences for tropical disturbances. </div>
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<div class="">-Jonathan R. Buzan</div>
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