Doppler radar for upper-air observations in Japan · Doppler radar for upper-air observations in Japan ... 3D radar-echo mapping ... • JMA will start the operation of a Doppler

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 1

Doppler radar for upperDoppler radar for upper--air observations air observations in Japanin Japan

Masahito IshiharaJapan Meteorological Agency

CIMO Expert Team on Remote Sensing Upper-Air Technology and Techniques

14-17 March, 2005Geneva, Switzerland

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 2

IshigakijimaNahaAP

Okinawa

Naze

Tanegashima

Kagoshima AP

Fukuoka AP

Fukuoka

MurotomisakiKansaiAP

HiroshimaMatsue

Osaka AP

Osaka

Fukui

Nagoya

Nagoya AP

Shizuoka

Nagano

Tokyo AP

New-Tokyo AP

Tokyo

SendaiNiigata

Akita

Hakodate

Sapporo

New-ChitoseAPKushiro

40N

30N

140E130E 150E

Weather Radar in JMA●： Conventional Weather Radar (20 sites)◎： Doppler radar for Airport Weather (8 sites)○： Airport Weather Surveillance Radar (1 site)

Weather radar network in JMAWeather radar network in JMA

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 3

Present framework of JMA conventional radars

Conventional radar networkConventional

radar networkRadar-echo composite

Rain gauge network

Rain gauge network

Radar-rain gauge composite Very short-term

precipitation forecast (up to 6 hours)

Mesosocale Model(ever 6 hour)

Mesosocale Model(ever 6 hour)

precipitation nowcast

(up to 1 hour)

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 4

Present framework of JMA Doppler radars

Doppler Radar for Airport

Weather

Doppler Radar for Airport

Weather

Low-level wind shear detection

Wind profiler network

Wind profiler network

Hourly wind analysis

Mesosocale Model(ever 6 hour)

Mesosocale Model(ever 6 hour)

ACARS ACARS

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 5

Plan of JMA radar network

Conventional radars

Conventional radars

3D radar-echo mapping

Numerical weather forecast

with high-resolution

NHM

Doppler radarsreplaced from Conventional

radars

Doppler radarsreplaced from Conventional

radars 3D Doppler velocity data set

3D radar-echo mapping

Monitoring of severe weather

Data quality control& Scan strategy

Data quality control& Scan strategy

4D variationaldata assimilation

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 6

2km

4km

6km

8km

10kmCAPPI Display

- Current Radar Data

H: 2.5km×2.5km V: 2km internal 5layer

3-D Low-Resolution under Low speed communication Network

Originalｌｙ,

Volume Scan Data of Meteorological

Radar is 3-D High-Resolution data.

事例：練馬豪雨

33D highD high--resolution radar data productsresolution radar data products

3D Display- Planning Radar Data

H: 1km×1km V: 1km interval 15layer

3-D High-Resolution under High speed communication Network

19 EL Volume Scanevery 10 min.

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 7

without without

Doppler & GPS water vaporwith with

Doppler & GPS water vapor

Impact of Doppler velocity on NWP Impact of Doppler velocity on NWP

5km NHM Prediction1-hour rainfall at 17JST July 21st, 1999 from 15JST Initial

1-hour rainfall by radar-rain gauge composite

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 8

Strict data quality control with high performance is needed in real-time for operational use of Doppler radars.

Data quality control and scan strategy for operation of Doppler radars

• Ground clutter rejection

• Doppler velocity unfolding

• second-trip echo rejection

• Extension of observation range

Optimal antenna scan strategy is needed accordance with topography around radars and structure and time-evolution of weather targets.

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 9

Extension of Doppler radar coverage

PRF=300Hz

PRF=600Hz PRF=940/752Hz+RP

Muliti-PRF retrieval

m/s

m/s

m/s

m/s

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 10

Ground clutter rejection in Doppler radars

50km

100km

50km

100km

Ref

lect

ivity

(dB

Z)

CIMO ET RS UAT&T, Geneva, 14-17 March 2005 11

Summary

• Doppler radars are being used in the aviation weather services in Japan mainly in order to detect low-level wind shear.

• JMA has examined effectiveness of Doppler radars for numerical weather predection (NWP) and for monitoring severe weathers.

• JMA will start the operation of a Doppler radar mainly for NWP being replacing conventional weather radars to Doppler radars in 2006.

• Data quality control is one of the most important issues to use Doppler radars for weather services effectively.