# Presentation: 376176

## ENSO and Convective Activities in Southeast Asia and Western Pacific

- Satoru YOSHIDA
- _Takeshi MORIMOTO_*
- Tomoo USHIO
- Zen-Ichiro KAWASAKI
- (Lightning Research Group of Osaka University)

## Monthly LTG Variation around Indonesia

- _Monthly LTG Variation around Indonesia_

## Lightning Distributions 

- _Lightning Distributions _

- March 1998 (El Niño)

- March 1999 (La Niña)

*much lightning flashes with less rainfall ??*

## Lightning and Storm Height Distributions 

- _Lightning and Storm Height Distributions _

- Lightning Flashes

- Storm Height

## Storm Height Frequency 

*We have much active convection in El Niño period.*

## Monthly Variation of SOI and LTG Flash Rate

-       _Index of correlation_
- 6 years	       : -0.43
- El Niña & La Niña   : -0.61

- _Monthly Variation of SOI and LTG Flash Rate_

**East/South-East Asia**
** ****(90********-130******** ****E****,****10******** ****S-40******** ****N)**

## Monthly Variation of SOI and LTG Flash Rate

-       _Index of correlation_
- 6 years	       : -0.43
- El Niña & La Niña   : -0.61
- Jan. '98 – May '00  : -0.73

**East/South-East Asia**
** ****(90********-130******** E****,****40******** N-10******** S)**

- El Nino

- La Nina

- _Monthly Variation of SOI and LTG Flash Rate_

## Areal Distributions of LTG Flash Rate

- El Niño

- La Niña

- ■>+30%>■>+5%>■>-5%>■>-30%>■

**Western Pacific**
** ****(100********-160******** ****E****,****40******** ****N-40******** ****S)**

## Definition of El Niño/La Niña Annual Anomaly

- El Niño

- La Niña

*Annual averages are compared with 6 years average.*

## Areal Distributions of LTG Flash Rate

- El Niño

- La Niña

- ■>+30%>■>+5%>■>-5%>■>-30%>■

## Areal Distributions of LTG Flash Rate

- Flash Rate during El Niño is much higher than that during La Niña.

- El Niño

- La Niña

- _Areal Distributions of LTG Flash Rate_

## Areal Distributions of Rain Count

- _Areal Distributions of Rain Count_

- El Niño

- La Niña

- ※Rain Count: number of detections precipitation at 2 km altitude.

- ■>+30%>■>+5%>■>-5%>■>-30%>■

## Areal Distributions of Rain Count

- La Niña

- Rain Count has clear difference.
- The regions w/ high Flash Rate and Rain Count are not the same.

- _Areal Distributions of Rain Count_

## Areal Distributions of Rainfall Intensity

- _Areal Distributions of Rainfall Intensity_

- El Niño

- La Niña

- ■>+30%>■>+5%>■>-5%>■>-30%>■

## Areal Distributions of Rainfall Intensity

- _Areal Distributions of Rainfall Intensity_

- El Niño

- La Niña

- Rainfall intensity during El Niño increases at the areas w/ high Flash Rate.

## Areal Distributions of Sea Level Pressure

-       -1.5               0           +1.5 [mb]

- _Areal Distributions of Sea Level Pressure_

- El Niño

- La Niña

- From : NCEP/NCAR Reanalysis Project.

## Areal Distributions of Sea Level Pressure

- _Areal Distributions of Sea Level Pressure_

- El Niño

- La Niña

- Sea level pressure is much higher during El Niño than that during La Niña.
- The variation is higher over the ocean than that in land.

## Areal Distributions of Sea Level Pressure

- _Areal Distributions of Sea Level Pressure_

## Areal Distributions of Wind Vector

- _Areal Distributions of Wind Vector_

- El Niño

- La Niña

- From : NCEP/NCAR Reanalysis Project.

## Areal Distributions of Wind Vector

- _Areal Distributions of Wind Vector_

## Areal Distributions of Wind Vector

- _Areal Distributions of Wind Vector_

- El Niño

- La Niña

- Wind Vector spreads from the area where Sea Level Pressure is high to the low pressure area over the land.
- Flash Rate increases at the areas where Wind Vector reaches land from ocean.

## Summary

- There is a clear inverse correlation between lightning flash rate and SOI in the East Asia region.
- During El Niño, Sea Level Pressure is higher than that of 6 years average, especially over the ocean.
-  decrease up-drafts
-  curb Rain Count
- In the regions where Sea Level Pressure anomalies are higher over the ocean than that over land, Wind Vector from the ocean to the land are remarkable.
-  moist air from the ocean is warmed over the land
-  strong updrafts
-  well-developed cumulonimbus w/ much active lightning

## Thank you.

- Monthly variations of global lightning activities by TRMM/LIS.

## What we have leaned by 

- _TRMM LIS/PR observations?_

- 1. Lightning Activity around Japan
- 2. Parameterization of Thunderclouds
- 3. Impacts of El Niño Event for
-        Lightning Activity in Western Pacific

## Lightning Distribution on Japan and the Pacific

- _Lightning Distribution on Japan and the Pacific_

**Winter 98**

**Winter 99**

**Summer 98**

**Summer 99**

## Parameterization of Lightning Flash Rate

- _Parameterization of Lightning Flash Rate_

- Inland area

- Coastal area

- Oceanic area

- Snow Depth

- Storm Height

*Global fifth power law !!*

## Carnegie Curve via LIS

- The most active lightning area is Africa.
- Americas has active areas in both hemispheres.

- _Carnegie Curve via LIS_

## Carnegie Curve

***カーネギー曲線(赤色):世界標準時の夕方静電場が最大を示す***

- Sergey V. Anisiov, “Global electric circuit and lower atmospheric electricity”, ICAE2003.

- _Carnegie Curve_

- Electrostatic field is maximum in the evening (UT).