Amazonia's Physiographical Characteristics and Rainfall Relationships Studied by Remote Sensing
Case: January 20, 1999
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Between 1400 and 1600 local time, a convective system passed through Ji-Parana, Rondonia. During this period, there is a noticeable decrease in air temperature. The incoming shortwave radiation decreases as well, due to the increased cloud cover. There is also a significant increase in the wind speed where it peaks at approximately 32 m/s. |
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There appears to be two areas of precipitation which is related to the reflectivity. The strongest occurrence is between 1800 and 2000 UTC, which correlates with the tower microclimate data results above. |
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The two systems are evident also from the Doppler velocity data. The system that passes through between 1800 and 2000 UTC has areas of updrafts that extend up to 10 km above sea level. Also impressive is the strong and relatively constant downdraft activity during this period. |
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On this day, the wind was mainly from the southwest. Between 1400 and 1600 LST, a shift occurs with a northeasterly component. After this period, the wind returns to southwesterly, indicating the passage of a system. |