structures of multiple fronts observed in the baiu frontal zone over the east china sea: aircraft...
TRANSCRIPT
Structures of multiple fronts observed in the Baiu frontal zone over the East China Sea:
Aircraft observation on 27 June 2004
Institute of Observational Research for Global Change (IORGC),Japan Agency for Marine-Earth Science and Technology
Qoosaku MOTEKICoauthors are T. Shinoda, S. Shimizu, S. Maeda, H. Minda, K. Tsuboki, H. Uyeda: HyARC, Nagoya Univ.T. Kato: Meteorological Research Institute
CHINA
KOREA
KYUSHU
Multiple fronts in the Baiu frontal zoneover the East China Sea
(Moteki et al., 2004, JMSJ)
Aircraft observation on 27 June 2004
CHINA
KOREA
KYUSHU
In situ measurement: p, T, Td, u, v, w at 500 m MSL,0852-0950 JST
Drop sondes: dropped from 12 km MSL at 6 points,1023-1209 JST
NAHA
CHEJU
Objectives of this study
To show observational evidence for the fact that multiple fronts exist inside the Baiu frontal zone.
To quantitatively show their features (horizontal gradients of PT, Qv, etc.)
Case overview (09 JST 26 - 03 JST 27 JUNE 2004)
Aircraft observation on 27 June 2004In situ measurement: p, T, Td, u, v, w at 500 m MSL,
0852-0950 JSTDrop sondes: dropped from 12 km MSL at 6 points,
1023-1209 JST
Definitions on the basis of cloud image at 10 JST
CHINA
KOREA
KYUSHU
Baiu frontal zone: the zone with a north-south width of about 500 km including 3 cloud zones.
NAHA
CHEJU
Definitions on the basis of cloud image at 10 JST
CHINA
KOREA
KYUSHU
Frontal zone 1 (FZ1): the zone on the southern side of BFZ.
NAHA
CHEJU
Frontal zone 2 (FZ2): the zone in the middle of BFZ.
Frontal zone 3 (FZ3): the zone on the northern side of BFZ.
Flight level data at 500 m from 0852-0950 JST
S N
FZ1 FZ2 FZ3
ΔPT
(K/100km) 6.4 3.0
ΔQv
(g/kg/100km) 1.7 3.0 3.2
Vertical cross section based on dropsonde data
S
PT
Qv
S N
Vertical cross section based on dropsonde data
S N
( )v
F confluencey y
0, 0v
y y
Vertical cross section based on dropsonde data
S N
RH
Melting level
Schematic illustration of the multiple frontal structures
S N
ConclusionsThe multiple frontal structures that formed in different time and had different features were observed on 27 June 2004 over the East China Sea.
FZ1: small ΔPT, ΔQv=1.7(g/kg/100km), no rainfall.
FZ2: ΔPT=6.4(K/100km), ΔQv=3.0(g/kg/100km), strong rainfall.
FZ3: ΔPT=3.0(K/100km), ΔQv=3.2(g/kg/100km), moderate rainfall.
Hypothesis
Although the Baiu front analyzed on the surface weather map seems to have stagnated, it is replaced with the new front from the old front in a few hours.
The old frontThe old front
The new frontThe new front
FZ0
FZ1
FZ2
FZ3
FZ4
L
Synoptic low(passed at 18Z
on 24)
The position of stationary front
Time-Lat. Sec. of TBB(09JST23-09JST28)
Case overview (04 JST 27 - 10 JST 27 JUNE 2004)
Vertical cross section based on dropsonde data
S N
PT
Qv
Vertical cross section based on dropsonde data
S N
PT
V
Confluence term of FGF with RANAL
FZ1
FZ2
FZ3
Confluence term of FGF with RANAL
FZ1
FZ2
FZ3
Shear term of FGF with RANAL
FZ1
FZ2
FZ3
Heating term of FGF with RANAL
FZ1
FZ2
FZ3
FGF with RANAL
FZ1
FZ2
FZ3
Convergence with RANAL (09JST27)
FZ1
FZ2
FZ3
Convergence with RANAL (21JST26)
FZ1
FZ2
Convergence with RANAL (03JST26)
FZ1