Home | Contact ST  
Follow ST

Environmental Monitoring


March 2013 Issue

NASA to Launch Ocean Wind Monitor to Space Station
Reusing hardware originally built to test parts of NASA's QuikScat satellite, the agency will launch the ISS-RapidScat instrument to the International Space Station in 2014 to measure ocean-surface wind speed and direction.

The ISS-RapidScat instrument will help improve weather forecasts, including hurricane monitoring, and understanding of how ocean-atmosphere interactions influence Earth's climate.

ISS-RapidScat will fill the data gap created when QuikScat, which was designed to last two years but operated for 10, stopped collecting ocean wind data in late 2009. NASA and NOAA have studied next-generation replacements for QuikScat, but a successor will not be available soon. NASA's Jet Propulsion Laboratory and the agency's station program proposed adapting leftover QuikScat hardware in combination with new hardware for use on the space station.

ISS-RapidScat will have measurement accuracy similar to QuikScat's and will survey all regions of Earth accessible from the space station's orbit. The instrument will be launched to the space station aboard a SpaceX Dragon cargo spacecraft. It is expected to operate autonomously aboard the station for two years.

Present scatterometer orbits pass the same point on Earth at approximately the same time every day. Since the space station's orbit intersects the orbits of each of these satellites about once every hour, ISS-RapidScat can serve as a calibration standard and help scientists stitch together the data from multiple sources into a long-term record.

Unique System FZE Installs First Permanent Tidal Station in Dubai
Unique System FZE (Sharjah, United Arab Emirates), along with The Geodesy and Hydrographic Survey Section of Dubai Municipality, established a permanent tidal station at Al Mamzaar. The station will collect precise tide data continuously for 19 years to calculate the mean sea level and annual sea-level rise, provide precise tide and meteorological data, and define and update a precise vertical datum for Dubai Emirate.

There is no such permanent tidal station elsewhere in the Gulf region, and this is first time such a project is being undertaken in the Middle East, Unique System FZE said. As a result of significant dredging and construction in the nearshore and offshore area of Dubai, the sea level has risen. Also, due to global warming, the Geodesy and Hydrographic Survey Section of the Survey Department felt the need for a permanent tide gauge station in the Gulf Sea.

The Survey Department of Dubai Municipality already has a network of five coastal and offshore tide and meteorological stations that have been continuously monitoring and recording data since 2004.

Seafloor Boreholes Illuminate Stress Change in Tohoku Quake
The magnitude-9.0 Tohoku earthquake in March 2011 produced the largest slip ever recorded in an earthquake, more than 50 meters. Such huge fault movement on the shallow portion of the megathrust boundary came as a surprise to seismologists because this portion of the subduction zone was not thought to be accumulating stress prior to the earthquake.

These large slips are the results of a complete stress drop during the earthquake, Integrated Ocean Drilling Program (IODP) reported in a study published in Science, which sheds light on the stress state on the fault that controls the very large slip.

The expedition, mobilized by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) in April 2012, is the first time that 'rapid-response drilling' (within 13 months after the earthquake) has been attempted to measure the temperature across a subduction fault zone.

The team investigated the large displacement by drilling from the ocean floor to the plate boundary, reaching a maximum depth of more than 850 meters below seafloor (mbsf).

Drill sites were located approximately 220 kilometers from the eastern coast of Honshu, Japan, in nearly 7,000 meters of water.

An important finding of the paper is that the present shear stress on the fault is nearly zero, indicating that there was a nearly complete stress change during the earthquake. Usually, earthquakes are thought to release only a portion of the stress on the fault.

The expedition set new milestones in scientific ocean drilling by drilling a borehole to 854.81 mbsf in water depths of 6,897.5 meters. Deep core was obtained and analyzed from this depth. The Japan Trench plate boundary was sampled and a parallel borehole was instrumented with a borehole observatory system.

The expedition is conducting further investigations of core samples and borehole logging data.

Scientists Identify Which El Niño Events Impact US Winters
By examining sharp dips in heat radiating from the tops of deep convective clouds, or outgoing long-wave radiation (OLR), during El Niño, forecasters could more accurately predict the unusual, highly unpredictable weather caused during these events.

This new method, found by scientists from NOAA and the University of Washington, could allow meteorologists to forecast outlooks for the winter season more accurately. The study was published in the February issue of the Journal of Climate.

A network of buoys that spans the Pacific, the TAO-Triton array, observes conditions in the upper ocean and helps forecast El Niño months in advance.

Scientists looked at all El Niño events that were identified by sea surface temperature measurements since 1979. They then examined satellite imagery and found that a subset of the events showed a sharp dip in OLR.

When comparing the El Niño events to historical weather records, they found that the El Niño events with drops in OLR were the ones most likely to play havoc with winter weather.

El Niño events with no corresponding drop in OLR did not produce statistically significant anomalies in weather patterns.

The dip in heat from deep convective clouds usually occurred before winter, so the timing of the signal could help forecasters improve winter seasonal outlooks.


-back to top-

Sea Technology is read worldwide in more than 110 countries by management, engineers, scientists and technical personnel working in industry, government and educational research institutions. Readers are involved with oceanographic research, fisheries management, offshore oil and gas exploration and production, undersea defense including antisubmarine warfare, ocean mining and commercial diving.