Table 4: Tropopause Structure


IOP Trop fold on PV=1.5 PVU?

PV=2 PV on 500mb Surface
MIN Ht (km)* Time of MIN Position of MIN at this time MAX Value (PVU)* Time of MAX value
1 No 6 9Z 10/1 45N, 25W 1.2 9Z 10/1
2 No (Lear flight) 5 15Z 12/1 52N, 27W 2.0 15Z 12/1
4 No6 (No clear min time) - 1.2 9Z 17/1
5 No 6.4 12Z 22/1 46N, 22W 1.2 12Z 22/01
6 Yes 3 21Z 23/1 57N, 20W 3.5 21Z 23/1
7 Yes (G-IV flight)5.5 18Z 25/1 56N, 30W 1.8 21Z 25/1
9 No? 7.0 12Z 2/2 55N, 38W 1.5 12z 2/2
10 No 6.5 12Z 4/2 55N, 10W 1.0 9Z-12Z 4/2
11 No 5 21Z 5/2 40N, 35W 2.4 21Z 5/2
11a No 7 12Z 08/2 53N, 25W 1.0 12Z 08/2
12 Yes 4.6 15Z 9/2 52N, 37W 2.6 15Z 09/2
15 No 4.1 00Z 15/2 50N, 33W 3.2 00Z 15/2
16 Yes (Lear flight) 5.5 11Z 17/2 54N, 29W 1.7 9Z 17/2
17 Yes (Lear flight) 4.1 09Z 18/2 37N, 53W 3.1 (along G-IV track) 18Z 18/2
18 Yes 2.7 00Z 22/2 53N, 62W 4.0 00z 22/2
19 Yes (not within flights) 4.1 03Z 27/2 57N, 30W 1.7 15Z 27/2
IOP Trop fold on PV=1.5 PVU?

PV=2 height PV on 500mb Surface
MIN Ht (km)* Time of MIN Position of MIN at this time MAX Value (PVU)* Time of MAX value

* Before end of MSA observations

** range of highest to lowest value of minimum height attained during the IOP


Humphrey W Lean | | hwlean@meto.gov.uk