1. Overview of IHOP-FRA activities including LEANDRE 2 analyses
IHOP_2002 Spring Science Workshop
24-26 March 2003
NCAR, Foothills Laboratory, Boulder, CO

2. Overview of IHOP-FRA activities
Teams and objectives of IHOP
LEANDRE 2 contribution
IHOP-FRA priority days
Activities envolving LEANDRE 2
20 June ELLJ/Bore case
CI-related activities
BLE-related activities
BLH-related activities (poster by J. Tarniewicz)
Intercomparison exercise (oral by Behrendt)
Other activities
GPS (oral by J. van Baelen)
Modelling (poster by F. Couvreux)

3. Teams and objectives of IHOP-FRA

4. Teams and objectifs of IHOP-FRA
3 TEAMS (CNRS/METEO-FRANCE):
LEANDRE 2: L2 operation during IHOP, L2 data processing and
analysis
GPS: operation of 7 GPS receivers, processing and analysis
Modelling: Meso-NH and MM5 simulations (LES, CRM)
3 TRANSVERSE RESEARCH THEMATICS :
Theme 1 : ABL processes; secondary circulations in the ABL;
WV heterogeneities in the ABL and its connections with surface
heterogeneities
Theme 2 : Morphology of drylines and breeze-like circulations
Theme 3 : Convective initiation; moisture transport into MCSs;
Diurnal cycle of convection

5. LEANDRE 2 contribution to IHOP_2002

6. DIAL H2O LEANDRE 2 Standard processing: 100 shots (10 sec.)
800 m horizontal resolution
300 m vertical resolution
Precision:
g kg-1 at 3.5 km
g kg-1 near surface
Bias RMS / RSD:
0.15 g kg-1

7. LEANDRE 2 in the NRL P-3 Sideway pointing in the ABL
Vertical pointing (nadir or zenith)
coupling with ELDORA clear air measurements
Radom ELDORA
L2 mirror fairing

8. LEANDRE 2 operations during IHOP
142 h scientific flights
Boundary-Layer Heterogeneity*: 7 missions / 35h28
Boundary-Layer Evolution**: 3 missions / 21h16
Convective Initiation**: 12 missions / 73h18
Evening Low-Level Jet*: 2 missions / 11h19
*nadir pointing
**horizontal pointing

9. Collaborations (ongoing/anticipated)
LEANDRE 2 golden days
Quality LEANDRE data / high scientific interest (12/24):
BLH: 27 May; 29 May; 07 June
BLE: 14 June; 21 June; 25 June IHOP-FRA priorities
ELLJ: June; 20 June
CI: 10 June; 12 June; 15 June; 19 June
Collaborations (ongoing/anticipated)
CI:
Tammy W., Dave K., Hanne M., and Roger W. : 10, 12, and 19 June cases,
Wen-Chau and Huaqing: 9 and 11 June cases.
Bore: Steve K. and the “Bore science Team”: 20 June case
BLE: Tammy W.: 14 June case
BLH: Ken D. and Ken C.: all cases

10. LEANDRE 2 processing 2 3 1 terrain 4 LEANDRE 2 scientists:
C. Flamant, K. Lhomme (PhD), and T. Weckwerth
with support from:
P. Genau (CNRS) and C. Pettet (NCAR) 2 3
CNRS:
Horizontal data processing: K. Lhomme and C. Flamant
(Analyses are conducted by Karen as part of her PhD)
Nadir data processing: C. Flamant 1
terrain 4

11. Analyses envolving LEANDRE 2

12. ELLJ/Bore related activities 20 June 2002 case

13. ELLJ/Bore-related activities
Objectives:
Study the life cycle of a bore event,
Compare observations with hydraulic theory,
Understand the role of bores in nocturnal convection
maintenance,
Water vapor budget,
Validatation for high-resolution numerical simulations.
Means/instruments:
WSR-88D radars (triggering mechanisms),
L2+S-POL (temporal evolution),
Profiling in Homestead (break-down),
Dropsondes
MANDOP-type 3DVAR analyses –including ELDORA, S-POL,
DDC radar and L2 (MCS dynamics, budgets). 2 3 1
terrain 4

14. ELLJ mission 20 June 2002 2 3 1
terrain 4

15. ELLJ mission 20 June 2002 2 3 1
terrain 4

19. 0329 UTC
LEANDRE 2
Temporal evolution
0408 UTC
0555 UTC

20. S-POL

21. LEANDRE 2
Dropsonde
WV profiles south of
the MCS

22. WV profiles close the MCS
LEANDRE 2
Dropsonde
WV profiles close the MCS

23. BLE- related activities 14 and 21 June 2002

24. BLE-related activities
Objectives:
Analyze water vapor variability evolution with time,
in connection with the entrainment process,
Investigate relationships between water vapor
distribution dynamical structures in the ABL (rolls, cells),
Provide some sort of validation for LES and high-
Resolution “real case” simulations,
Means/instruments:
Large Eddy Simulations
Idealized 3-D simulations
Real case simulations
IHOP data (including S-POL, ELDORA, DIALs)
MANDOP-type 3DVAR analyses 2 3 1
terrain 4

25. BLE mission 14 June 2002 2 3 1
terrain 4

26. BLE mission 14 June 2002 LEANDRE 2: sideway pointing in the ABL
Blind zone

27. BLE mission 14 June 2002 Also see Fleur’s Poster!!
Present the existing diagnostic tools for water vapor
variability analyses using the mesoscale model Meso-NH
Verify wether Meso-NH can simulate the observed water
vapor variability,
Use the diagnostic tools to identify the origin of water
vapor variability.

28. BLH- related activities 29 June 2002

29. BLH-related activities
Objectives:
Analyze east-west water vapor variability, in connection
with the entrainment process and soil moisture,
Analyze the impact of small scale water vapor
variability on GPS IWV retrievals
Means/instruments:
Real case simulations
IHOP data (including S-POL, ELDORA, DIALs, GPS)
MANDOP-type 3DVAR analyses 2 3 1
terrain
Also see Jerome’s Poster!! 4

30. CI- related activities 10, 12, 15 and 19 June 2002

31. CI-related activities
Objectives:
better understand CI in connection with ABL processes,
surface heterogeneity, dryline morphology and
breeze-like circulations,
analyze the role of « lateral entrainment » process,
explore the role of moisture “pockets” resulting from Cu
dissipation on CI,
assess whether dry air intrusion mechanisms inhibit CI
as they do in the Tropics
analyze the transition between shallow and deep
convection and the role of the moisture field above the ABL
Means:
Large Eddy Simulations
Idealized 3-D simulations (front, triple point)
Real case simulations
IHOP data (L2, AERI, MAPR, RDS, FM-CW, S-POL)

32. CI mission 19 June 2002 2 3 1
terrain 4

33. CI mission 19 June 2002 P-3 flying at 1500 m LEANDRE 2: sideway
Blind zone
LEANDRE 2: sideway
pointing in the ABL through
a « dry-line »

34. Intercomparison exercise 8 June 2002

35. CI-related activities
Activities conducted in the framework of the
ESA project coordinated by V. Wulfmeyer
Objective: Intercomparison of DLR, NASA and
CNRS DIAL measurements
I would like to propose that we do not just compare
profiles and performance, but have the different
groups PROCESS the data from other groups (there
is a lot to learn in this process).
Assessement of the algorithms performances, not just
instruments performances