Tag Archives: ocean

Warmest June on Record for Planet Earth

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This past June ranked as the 33rd warmest for the United States. The average temperature for the Earth as a whole, however, soared to a record high for a second straight month.

According to a report released on Monday by NOAA’s National Climatic Data Center, June 2014 was the warmest June ever recorded for the entire planet.  Earth’s combined average temperature for the month – over both land and sea surfaces – was 61.2°F.  That is 1.3°F above the 20th century average. June 2014 also marked the 352nd consecutive month that our global temperature was above its long-term norm.

Rising ocean temperatures, according to NOAA, helped fuel this record warmth. In fact, the June global sea surface temperature was 1.15°F above its long-term average of 61.5°F. That is the highest for any June on record and the highest departure from average for any month. Large parts of both the Pacific and Indian Oceans either hit record-high temperatures or posted readings that were significantly above normal.

The report also noted that, year to date, 2014 is currently tied with 2002 as the Earth’s third warmest year on record. Global temperature records date back to 1880.

Credit: NOAA

Credit: NOAA

Rip Currents

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The dog days of summer have arrived!  As millions of people head to beaches to beat the heat, it is important to remember that the ocean is a dynamic environment that can pose a number of hazards for swimmers.  Chief among these are rip currents.

Rip currents are strong, localized channels of water that move away from the shoreline. They can form on any beach with breaking waves and easily pull swimmers out to sea in a matter of seconds.  According to the U.S. Lifesaving Association, rip currents are responsible for 80% of all surf zone rescues. Nationally, they cause more than one hundred deaths every year.

While rip currents are a serious hazard for all beach goers, they are a natural part of the near-shore ocean circulation.  They develop when wind driven waves break strongly in one area and weakly in another, creating a circulation cell as the water looks for a way back out to sea.  This usually happens at a break in an underwater sandbar or along a jetty or pier. Extending seaward for hundreds of yards, rip currents typically travel at one to two feet per second.  However, they strengthen when onshore wind speeds pick up and wave height and frequency increase.

If caught in a rip current, do not try to swim against it.  Instead, swim parallel to the shoreline until you are out of the current and then make your way back to the beach.

rip-currentImage Credit: NOAA

Record Large Dead Zone is Forecast for the Gulf of Mexico

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Heavy spring rains across the American mid-west have mitigated the region’s extensive drought.  However, they are expected to cause a record large dead zone in the Gulf of Mexico this summer.

According to a recently released forecast from NOAA and its research partners, the University of Michigan and Louisiana State University, the Gulf dead zone this year could grow as large as 8,561 square miles. If it reaches this size, which is roughly equal to the state of New Jersey, it will be the largest dead zone ever recorded in the Gulf.

Dead zones are areas in large bodies of water that do not have enough oxygen to sustain aquatic life.  They are usually caused by nutrient pollution from agricultural run-off.  Specifically, excessive amounts of fertilizers – nitrogen and phosphorus – create massive algae blooms.  When the algae die, they sink to the bottom where they are decomposed by bacteria. This process uses up most, if not all, of the available oxygen in the water.  As a result, fish flee the area and immobile bottom dwelling organisms, like clams, die.

The Midwest is this nation’s agricultural breadbasket and its farmers use fertilizers to help grow an enormous amount of crops.  It is also the watershed of the Mississippi River.  As such, the flooding rains that swept through the area this spring have significantly increased the nutrient load of the water that is flowing into the Gulf of Mexico.

A large dead zone will likely have serious economic ramifications for the Gulf region’s multi-million dollar fishing industry.

Agricultural run-off is the main source of nitrogen and phosphorus that cause the annual Gulf of Mexico dead zone.

Watershed of the Mississippi River runs through America’s agricultural heartland and ultimately drains into the Gulf of Mexico.

Image Credit: Donald Scavia/University of Michigan

A Summer Sea Breeze

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While spending a weekend at the beach recently, I was reminded how pleasant a sea breeze can feel on a hot summer afternoon.

A sea breeze is a localized, daytime wind driven by the temperature difference between land and a large body of water. Since land is able to absorb the sun’s energy more quickly than water, it warms faster. As a result, air over the ground heats and rises, creating an area of low pressure. Cooler air is then drawn from the zone of higher-pressure above the ocean to fill the void, forming an onshore breeze.

These winds typically start flowing around mid-day and last throughout the afternoon.  They are valued for their moderating influence on local temperatures, keeping coastal areas cooler than their inland neighbors during the warmest months of the year.

Image Credit: physicalgeography.net