Tropopause height: This is a copy of an e-mail from Masao Kanamitsu to Mark Saunders. -------------------------------------------------------------------------- Date: Thu, 11 Jul 1996 10:17:02 -0400 (EDT) From: 'Masao Kanamitsu' To: Saunders Mark Dear Dr. Saunders, Dr. Chelliah passed your question to me. The tropopause in the reanalysis is computed from temperature analysis on model sigma level fields. This is to avoid unnecessary interpolation from sigma to pressure. The definition of tropopause in our post-processor is as follows: THE TROPOPAUSE IS IDENTIFIED BY THE LOWEST LEVEL ABOVE 450 MB WHERE THE TEMPERATURE LAPSE RATE -DT/DZ BECOMES LESS THAN 2 K/KM. THE TROPOPAUSE IS NOT ALLOWED HIGHER THAN 85 MB. INTERPOLATIONS OF VARIABLES TO TROPOPAUSE ARE DONE LINEARLY IN LOG OF PRESSURE. No one has carefully looked at the product so that you may have to do some verification against Radiosonde observation before using it. I have a feeling that it is a little noisy so that you may have to apply some spatial filtering. Masao Kanamitsu (Kana) e-mail:wd23mk@sun1.wwb.noaa.gov Climate Prediction Center Tel:(301)763-8155 WWB, Rm. 604, W/NP51 Fax:(301)763-8395 5200 Auth Road Camp Springs, MD 20746