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Posts tagged Mozambique Channel

Mayotte and Sediments from Sofia and Betsiboka Rivers Off Coast of Madagascar – September 21st, 2012

14.7S 46.8E

September 21st, 2012 Category: Image of the day, Rivers

Madagascar – September 16th, 2012

Rivers along the coast of Madagascar release rusty red sediments into the Mozambique Channel. Here, sediments can be seen spilling forth from the Sofia River (center, right) and the Betsiboka River (center, left). The sediments’ distinct red color is due to the red lateritic soils in Madagascar’s central highlands.

Visible by the top edge of the image is Mayotte, an overseas department and region of France consisting of a main island, Grande-Terre (or Mahoré), a smaller island, Petite-Terre (or Pamanzi), and several islets around these two. The archipelago is located in the northern Mozambique Channel in the Indian Ocean, namely between northwestern Madagascar and northeastern Mozambique. Mayotte’s area is 374 square kilometres (144 sq mi) and, with its estimated 194,000 people, is very densely populated (520 /km2 or 1,300 /sq mi).

Madagascar, from Rainforest to Highlands to Coastal Sediments

19.9S 46.6E

June 13th, 2012 Category: Sediments

Madagascar - May 31st, 2012

Along the length of the eastern coast of Madagascar runs a narrow and steep escarpment containing much of the island’s remaining tropical rain forest, easily observable by the bright green strip of land along the coast. To the west of this ridge lies a plateau region in the center of the island ranging in altitude from 750 to 1,500 m (2,460 to 4,920 ft) above sea level.

These central highlands are the most densely populated part of the island and are characterized by terraced, rice-growing valleys lying between grassy, deforested hills. To the west of the highlands, the increasingly arid terrain gradually slopes down to the Mozambique Channel. Deforestation leading to erosion means that over the years more and more sediment from the highlands has run down the slope and into the channel.

Green Lake Ihotry Near Mouth of Mangoky River, Madagascar

21.7S 43.3E

May 4th, 2012 Category: Lakes, Rivers

Madagascar - April 28th, 2012

Rivers along the western coast of Madagascar carry tan sediments from the country’s central highlands to the Mozambique Channel. The river releasing the most sediments, visible in the lower part of the image, is the Mangoky River. With a length of 564 kilometers (350 mi), the river enters the Mozambique Channel north of the city of Morombe.

Visible south of the rivermouth and slightly further inland is Lake Ihotry, appearing bright green here. It is a closed saline lake in semi-arid southwestern part of Madagascar with an area that varies seasonally, from 96 km² to 112 km².

Tropical Cyclone Irina (14S) Still Moving Westward – March 9th, 2012

28.3S 37.2E

March 9th, 2012 Category: Image of the day, Tropical Storms

Tropical Cyclone Irina (14S) - March 8th, 2012

Enhanced image

Track of TS 14S - March 8th, 2012 © Univ. of Wisconsin

Track of TS 14S

Tropical Cyclone Irina (14S), is located approximately 415 nm east-southeast of Maputo, Mozambique. The system has tracked west-northwestward at 04 knots over the past six hours.

The intensity is estimated at 40 knots. Maximum significant wave height is 14 feet. TC 14S continues to track generally westward along the periphery of a low-level subtropical steering ridge to the south. This motion is expected to continue through the forecast period.

Animated infrared satellite imagery shows convection becoming shallower over a still tightly-wrapped low-level circulation center. Upper level outflow has decreased significantly over the past 12 hours. Mminimal outflow and passage over a cool sea surface will lead to dissipation of the system by TAU 24.

Tropical Cyclone Irina Expected to Move Towards Mozambique

27.6S 29.5E

March 4th, 2012 Category: Tropical Storms

Tropical Cyclone Irina (14S) - March 3rd, 2012

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Track of TS 14S - March 4th, 2012 © Univ. of Wisconsin

Track of TS 14S

Tropical Cyclone Irina (14S), located approximately 90 nm east-southeast of Maputo, Mozambique, has tracked southwestward at 06 knots over the past six hours. Maximum significant wave height is 18 feet. Animated infrared satellite imagery shows that TC 14S is regenerating deep convection and turning back into the Mozambique Channel.

Despite the recent movement away from land, rainbands in the outer periphery are generating downpours along the coast, especially between Maputo and Inhambane, Mozambique. The other concentration of heavy convection associated with the storm is displaced to the distant southwest, a product of convergence within the belt of easterlies feeding into the system.

An ASCAT image depicts an expansive area of persistent gales over the southeastern quadrant. An SSMIS image shows the improved organization in the convective banding, and the 37 ghz image reveals a developing microwave eye. PGTW upper level streamline analysis depicts a cyclone just north of Inhambane, and its associated subsidence is stifling convection over the northeastern quadrant of the storm.

The cyclone has been retrograding slowly southwest and neither filling nor deepening. Total precipitable water loops confirm a general lack of deep moisture over the northern semicircle. Sscatterometry data also confirm the lop-sided nature of the system, with expansive areas of gale force winds over the poleward semicircle and a very narrow area of gales on the equatorial side. Animated water vapor imagery indicates that the system has lost the superb equatorial outflow channel that existed 24 hours ago, but vigorous poleward outflow persists, and there is adequate outflow over the western quadrant.

The upper level cyclone is severely impinging on outflow over the northern semicircle. Water vapor animation also shows a deep mid-latitude trough tracking over South Africa that will exert an increasing steering influence on the storm during the next 24 hours, along with a boost to poleward outflow. The upper levels of the storm and the northwesterlies ahead of the trough are going to begin linkage during the next 12 hours.

Currently, Irina is being kept over the western Mozambique Channel by a low- to mid-level anticyclone directly south of Madagascar, which is part of the subtropical ridge. The anticyclone is beginning to give way and reorient eastward, allowing the system to drift back towards the center of the channel. The retreating anticyclone coupled with the southeastward draw from the approaching trough will cause a net southward movement of the storm over the next 24 hours. The majority of model guidance indicates the trough will be a near miss and not couple with the storm, passing over the system between TAU 24 and 48. Following the passage of the trough, the subtropical ridge will rebuild south of Madagascar and Irina will resume movement towards southern Mozambique, where it will maintain intensity at low tropical storm strength in the moderately favorable environment of the Mozambique Channel. Thus, the forecast continues to call for a slow reversal back towards landfall over southern Mozambique after TAU 24 and a relatively flat intensity trend through landfall.