Rain monitoring by satellites

Rain over Amazonas (PR)

Date : 97/12/19
Time : 4:57~5:02(UT)
Orbit No. : 336
Resolution : 4.3km
Swath width : 215km

	This figure shows a horizontal cross section of rain over Amazonas at an altitude of 2.0km from 04:57 to 05:02 on Dec. 19, 1997 (UT) together with image an infrared image taken from the American geostational meteorological satellite (GOES). The rain fell on the upper stream of the Amazon river where is about 500km northwest of Porto Velho near the border of Brazil and Bolivia.
	This figure shows a three-dimensional image which depicts the structure of the convective rainfall on the lowland of the Amazonas. The cross section of rainfall shows the vertical distribution of rain intensity along the line AB, and the white below about 1km were excluded because of strong influence from the surface reflection. In both figures, the altitude was indicated by green to brown colors. The lowland indicated by green from east to west like lines is the area along tributaries of the Amazon river.

There were both rainy and rainless areas where same white was observed by the meteorological satellite from Fig. 2. Existence of high rain up to about 16km shows the heavy convective activity in the tropical rain forest region.

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Rain over Argentina (PR)

Date : 97/12/21
Time : 10:40 - 10:48(UT)
Orbit No. 372

These images are simultaneous images of rain over northern Argentina and Uruguay from Precipitation Radar (PR) from 10:40 to 10:48 on Dec. 21, 1997 (UT).

Figure 1 shows the horizontal cross section of rain at 2.0km height.
Figure 2 shows the vertical cross section of rain along the line AB of Fig. 1.

It is clear in Fig. 2 that the heavy rain developed in the layers above the heavy rain which was in the lower layers. Generally, there were ice crystals over the rain which developed at high altitudes.

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Heavy snow in the Kanto area of Japan

Date : 98/1/15
Time : 3:10~3:15(JST)
Orbit No. : 756
Resolution : 4.3km, Swath width : 215km

These figures show the horizontal cross section at a height of 2.5km (Fig. 1) and three-dimensional image (Fig. 2) acquired by the TRMM Precipitation Radar (PR) which passed over Japan from 03:10 to 03:15 (JST) on Jan. 15,1998.

The PR observed a wide area of the three-dimensional precipitation structure which extends approximately 1500km to the east and west over Japan. The red or yellow horizontal layer indicated by over Chugoku and Kyushu areas is a melting layer where snow melts into rain and much stronger radar reflectivity is observed than from real rain. Another melting layer near the surface reflects to the fact that sleet or watery snow fell over the Kanto-Koushin area.

After that, the heavy snow that disrupted traffic in the metropolitan area fell after the movement of a extratropical cyclone from off Shikoku to the south coast of Kanto. Though many cyclones which bring heavy snow pass over Japan in early spring in a normal year, several pressure patterns identical to these could be seen in January this year because the winter pressure pattern could not be sustained due to the El Nino effect.

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Horizontal Slice Images of Super Typhoon PAKA (PR)

Date : 97/12/19
Time : 4:16~4:20(UT), Orbit No. : 326
Resolution : 4.3km, Swath width: 215km

These images are the horizontal cross sections of rainfall every 750m in altitude in the Super Typhoon PAKA observed with the Precipitation Radar (PR) on Dec. 19, 1997. This typhoon did great damage to the Guam islands in Dec. 1997. The cloud image shown at the uppermost layer was the typhoon image from the meteorological satellite (GMS). The eye of typhoon can be seen up to about 10km and heavy rain was observed in the lower layers. The rainfall was not symmetric, but existed only in the east of the typhoon, even though the clouds form almost concentric circles. The heavy rainfall indicated in red was observed around the eye of the typhoon. Another rain band was observed in the upper six layers that could not seen in the lower layers. The Philippine Islands are on the left of the map, and Guam on the right.

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Courtesy of NASDA (Sept.4,1998 by Yukio HARUYAMA), NASA and CRL (Communications Research Laboratory).