Behavior of Typhoon observed by NIMBUS -7 TOMS data

Behavior of Typhoon observed by NIMBUS -7 TOMS data

Manabu Matsuda,Fumihiko Hiruma,Kiyoshi Tsuchiya
Remote Sensing and Image Research Centre Chiba Univ.
1-33 Yayoi - Cho Chiba 260 Japan

Makoto Suzuki, Nobuo Takeuchi
The National Institute For Environmental Studies
16-2 Onogawa,Tsukuba Ibaragi 305 Japan

Abstract
The pattern of total ozone (total column density of ozone) in NIMBUS-7 TOMS (total ozone mapping spectrometer) data was found to reflect the typhoon behavior in the West Pacific. Some patterns of total ozone are found to be influenced by typhoon and are similar to the for of typhoon. In synoptic scale the area that the total ozone concentration changes in middle or mid high latitude corresponds to the part of the behind or front of the 300 mb trough line movement .it is that the pattern of total ozone is closely related to the atmospheric motion.

Introduction
Since the Antarctic ozone (O₃) hole was observed there have been many reports that ozone layer in stratosphere would be broken by CFM (chlorofluoro methane) the behavior on ozone is still under in intensive investigation .The behavior of ozone concentration is closely related to meteorological change in stratosphere it is important to know about the movement of ozone in the atmosphere and the mechanism of exchange between stratosphere and troposphere. The occurrence of the high concentration of ozone at the surface is mostly caused by ozone failing stratosphere troposphere (WMO 1985) Harthon et al (1976) proposed a mechanism of ozone falling the explained this mechanism as follows: ozone rich stratospheric air flows down in to developing frontal layer then ozone moves down within the frontal layer and around to a position near the trailing edge and as the trailing edge dissipates ozone is transported to the surface .

It is considered that violent atmosphere disturbance such as a typhoon may effect ozone distribution however as far the report on this problem is very few .An attempt is made to clarify the relationship between ozone distribution and typhoon together with contour pattern at 300 mb level.

Case Study for typical data
The pattern of ozone accompanied by typhoon is categorized in to three groups (1) which have high concentration swirls into the center of typhoon (2) The center of typhoon shows thicker concentration than the surroundings (3) A slight relationship between the two . I this study two typical case are selected for intensive study . the first case is that of August 24 1986 which belongs to the type of ozone swirling in to the typhoon . The second case is that September 26 1986 which belongs to the type thicker concentration of ozone in the center of typhoon.

Case Study : august 24, 1986
1. The relationship between total ozone and the surface pressure pattern.
  
  In Fig. 1 shown the surface weather map at 00 GMT August 24 1986 in which two typhoons VERA (typhoon) 8613) and WAYNE (typhoon 8614) in the Pacific Ocean. The central pressure of the former is 945 mb while 985 mb for the latter. The total ozone distribution pattern corresponding to the time of the surface weather map is shown in Fig.2, which shows that the high concentration of ozone (from 280 to 290 Dobson unit) swirls into an area at the left side. The high concentration of ozone extends toward southwest from the middle-upper part in TOMS image . The white parts. Of the map means no data.
2. The relationship between daily ozone distribution and synoptic atmosphere condition
  
  Fig. 3 is 300 mb chart at 00 GMT on August 24, 1986 in which jet stream axis is indicated with a heavy broken line while trough lines are indicated with heavy solid lines. The difference image of TOMS data between Aug 23 and Aug 24 (24th-23th), 1986 is shown in Fig. 4. It can be seen that total ozone has increased more than 15 DU to the west of the 300 mb trough line
  
  or near of the trough line Movement. This is the area where divergence prevails resulting in large scale descending motion. The area where ozone amount decreases more than 15 Dobson unit corresponds to the east of the trough where upward motion prevails. Fig. 5 shows the vertical profile of E-W component of the wind speed on the longitude 130 E with positive for west component on the latitude 1300E. The easterly wind blows between the equator and the latitude 200N. The westerly wind blows on the north of the latitude 300N. The easterly wind in low latitude seems to move ozone toward west. Then Ozone swirls into the typhoon (typhoon of 8614).
Case study : September 26 1986
1. The relationship between total ozone and the surface pressure pattern
  
  In Fig. 1 is shown the surface weather map at 00 GMT August 24, 1986 in which tow typhoons There is a large typhoon named Ben (typhoon 8617) pacific ocean which is shown in the surface weather map ay 00GMT on September 26 1986 in reference with (total ozone distribution ) it can be seen that the amount of total ozone is large than the surrounding area with 260 270 DU over the center of typhoon while 250 260 in the surrounding area.
2. The relationship between total ozone and vertical profile of potential temperature
  
  The vertical profile of potential temperature on the longitude 1400E is shown in fig 8 The arrow in the figure indicates the position of the typhoon it is found the lower height of 360 K potential temperature correspond to higher total ozone.

Conclusions
Based on results by the present analysis it can be concluded as follows ; there is a tendency that total ozone increases in the typhoon area , There is closely relationship between trough line movement at 300 mb in middle or mid high latitude and charge of total ozone The study will give a clue of the transportation mechanism of ozone using satellite data.

Acknowledgement
The authors are grateful to Tokyo International Airport Meteorological Observatory for providing upper atmosphere weather map and ozone Layer Analysis section meteorological agency for TOMS data and thanks to Kajiwara H.Kuki for their advises and supports.

Reference

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hawthorn and H.m Walker (19760 ; A "Texas sizes " ozone tracked to its source . Int Conf on Photochemical Oxidant Pollution and its Control EPA Report No EPA-600/3-77-001a.
(19850 : Atmospheric Ozone , WMO Report NO 16.