８. Helmholtz Decomposition is wrong (Chapter 8-1)

８. Helmholtz Decomposition is wrong (Chapter 8)

Chapter 8-1 Meteorological disturbance

Generally, a meteorological disturbance consists of a front area and a back area.

Fig8.1 The framework of the meteorological disturbance

In the front area, cumulonimbuses are developing up, and the airs which are tossed off in

the upper layer are starting to ageostrophic motin.

And in the back area, the airs have come to the end of the ageostrophic motion of the western

neighbor trough.

Fig8.2 shows a meteorological disturbance from 8th to 9th of Octorber 2010.

Fig8.2 An example of a meteorological disturbance

A developing low pressure system was passing through Japan on 9th of Octorber 2010. In the

front part of that system, we can see the flows which have considerable ageostrophic

components faceing to the left hand side of the direction of analyzed wind. They force the
airs to accelerate, and tend to make divergent area in upper layer as I have said in
Chapter 7.
There, we can see developing clouds(white area on the water vapor image).

And on the way to the area of downstream, their ageostrophic components turn around
clockwise, and come to the end of ageostrophic motion. Their ageostrophic component come to

face to the right hand side of the analyzed wind, and tend to decelerate the speed, and make
a convergent area. It is shown as black area on the water vapor image.

As I have just described, a ageostrophic component can explain a divergent area and
convergent area with a meteorological disturbance in the westerlies zone.

Violent heat in August 2010
These meteorological disturbance usually disappear on the monthly weather map. But, if that
disturbance stays or moves very slowly, sometimes it appears even on monthly weather map.
We had violent heat in summer in 2010. It was for the first time in decades.
Fig8.3 shows the changes of monthly mean temperature in August from year to year in West
Japsn.

Fig8.3 The changes of monthly mean temperature in August from year to year in West Japsn

Fig8.4 shows the mean height and the distribution of ageostrophic component of 200hPa.

Fig8.4 The ageostrophic components seen on the monthly mean weather map(August 2010)

We can see the statianally trough at around 115 degrees east longitude.
And there was an area where the ageostrophic components was facing to the left hand sides of

analyzed winds(that is in first or forth quadrant shown in Chapter 7) on the east of the
trough. So, the flows would have come to diverge. It happened around Korea Peninsula.

The downstream of that flows were deflected clockwise, and at the east of Japan ageostrophic

component came to face to the right hand sides of analyzed wind (that is in second or third
quadrant).So, the flows would have come to converge.It happened near Japan.

Fig8.5 shows the analyzed wind and the distribution of divergence on the

OLR distribution map in August 2010.

Fig8.5 Thedistribution of divergence and OLR in August 2010

In comparison between Fig8.4 and Fig8.5, the area where the ageostrophic component belonged

to the first or forth quadrant conformed to the divergent area around Korea Peninsula.

OLR value is small in these area. And the area where the ageostrophic component belonged to

the second or third quadrant conformed to the convergent area near Japan.

So, we can say that
= the cause of violent heat in summer 2010 is the statinally trough at around 115degrees east
longitude. =

Meanwhile, let us see if we can find the cause of violent heat in summer 2010 by using the
velocity potential and divergent wind.

Fig8.6 The distribution of velocity potential and divergent wind( blue arrows) in August 2010

Fig8.6 shows that there is a center of divergence near Philippines islands, and some
divergent winds go out northward, and converge at the east of, or near Japan.
So, we can find that the cause of violent heat in summer 2010 comes from the center of
velocity potential near the Pilippines islands.

Actually, which is right? Is the cause of violent heat stationary trough at 115degrees east

longitude, or from the center of velocity potential near Philippines islands?

We need to do more research of another summers.(to be continued