Does solar activity affect regional climate?

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A composite image assembled from NASA satellite images shows the UK covered with snow during a spell of cold winter weather in January 2010.

Yes, but effects are small compared to changes driven by greenhouse gases

By Summit Voice

FRISCO — After carefully studying cycles of solar activities and matching them against seafloor sediments that offer clues about ocean temperatures, Cardiff University scientists say low sunspot activity may be linked with phases of cold weather in Europe.

The study found that changes in the Sun’s activity can have a considerable impact on the ocean-atmospheric dynamics in the North Atlantic, with potential effects on regional climate.

While the effects of variations in solar energy are small compared to the impacts of increasing greenhouse gas concentrations, the effects of solar output on the ocean and atmosphere should be taken into account when making future climate projections, the researchers said. Continue reading

Climate: New effort launched to monitor ocean currents

Researchers eye global warming impacts to North Atlantic region

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Ocean currents help shape global climate, and understanding how global warming may change those currents will inform more accurate climate projections.

By Summit Voice

FRISCO — Some of the biggest potential global warming impacts could occur if major ocean currents change in strength or direction — a shift in the Gulf Stream, for example, would have major implications for parts of northwestern Europe, kept temperate by the transport of subtropical water.

Some research has suggested that increasing amounts of cold, fresh water in the North Atlantic could have a big impact on the Gulf Stream and other important currents, but there’s not a lot of detailed historic or baseline data against which to measure changes. But that could change in the next few years, as science agencies in the U.S. and the U.K. team up on a $70 million project to study North Atlantic currents. Continue reading

Climate: ‘Today’s flood is tomorrow’s high tide … ‘

‘The ocean is rising and it’s going to keep rising for quite some time’

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A NOAA aerial photo shows damage caused by superstorm Sandy along the New Jersey shoreline. Click on the photo to see before and after images on the NASA EO website.

By Bob Berwyn

FRISCO — What until recently was a mostly academic discussion about sea level rise is starting to hit home — literally —as Americans watch devastating storms like Katrina, Irene and Sandy engulf cities and fundamentally alter the shape of coastal areas.

“What is very clear is, the ocean is rising and it’s going to keep rising for quite some time. The difference from last time is, now, there are a lot of people living on the coast,” said Margaret Davidson, acting director of NOAA’s Office of Ocean and Coastal Resource Management. Davidson’s powerpoint presentation is online here, and a video of her presentation should also be posted at the same place soon.

The consequences of rising sea level are likely to be enormous, given that the majority of the country’s population lives along coastlines, and those coastal cities generate a huge percentage of the country’s economic wealth.

“How do we begin to think about that? We’ve never had to think about relocating large populations,” Davidson said, addressing an audience of broadcast meteorologists and climate scientists during the annual Glen Gerberg Weather and Climate Summit in Breckenridge. Continue reading

Study helps pinpoint East Coast sea level rise

Location of tide stations on the Atlantic coast of North America. Sea-level data for U.S. tide stations are collected and distributed by NOAA’s National Ocean Service.

Rate of increase is highest along the northeast coast

By Summit Voice

SUMMIT COUNTY — Calculating sea level rise has been vexing for climate and ocean scientists. Melting ice and thermal expansion both contribute, but the water doesn’t just go up evenly like a bathtub that’s filling up.

Pinpointing the rate and location of sea level rise is critical for planners tasked with adapting their communities to coastal flooding, said John Boon, emeritus professsor at the Virginia Institute of Marine Science.

“Localized projections of sea-level rise are needed to guide the regional planning and adaptation measures that are being pursued with increasing urgency in many coastal localities,” said Boon, who recently completed a new study showing that the rate of sea level rise is increasing at tidal stations along the Atlantic coast of North America, including those in Norfolk, Baltimore, New York, and Boston. Continue reading

Climate: Current warming in Arctic unprecedented

Is Svalbard ground zero for global warming?

August 2012 global temperatures anomalies.

Svalbard might be ground zero for global warming, with some research suggesting it may warm faster than any other spot on Earth. Photo courtesy, NASA.

By Summit Voice

SUMMIT COUNTY — A group of researchers led by a Columbia University climate scientist William D’Andrea took direct aim at misleading information about historic climate records this week, releasing a study showing that temperatures in some parts of the Arctic are higher than they’ve been at any time during the past 1,800 years.Global warming deniers have used evidence of warmer temperatures during the so-called Medieval Warm Period to undermine the reality that heat-trapping greenhouse gases are inexorably warming the planet.

But the climate reconstruction from Svalbard casts new doubt on the reach of the Medieval Warm Period, and undercuts skeptics who argue that current warming is also natural. Since 1987, summers on Svalbard have been 2 degrees to 2.5 degrees Celsius (3.6 to 4.5 degrees fahrenheit) hotter than they were there during warmest parts of the Medieval Warm Period, according to the new study. Continue reading

Climate: Record ocean temps reported off New England

Fish populations continue to shift northward

A June 2011 photo taken from the International Space Station shows Cape Cod and other sections of the New England coast, down to the northern end of Long Island. Photo courtesy NASA. Click on the image for more information.

By Summit Voice

SUMMIT COUNTY — Federal ocean scientists said this year’s sea surface temperatures along the northeast coast of the U.S. set all-time records, with as-yet unknown consequences for marine ecosystems.

Above-average temperatures were found in all parts of the ecosystem, from the ocean bottom to the sea surface and across the region, and the above average temperatures extended beyond the shelf break front to the Gulf Stream, according to an ecosystem advisory issued by NOAA’s Northeast Fisheries Science Center.

The warm waters led to the earliest, most intense and longest-lasting plankton bloom on record, with  implications for marine life, from the smallest creatures to the largest marine mammals like whales. Atlantic cod continued to shift northeastward from its historic distribution center. Continue reading

Climate: Tropical plankton invades the Arctic

A plankton bloom in the Arctic waters of the Barents Sea. Photo courtesy NASA.

Research suggests shift in ocean currents my be linked with global warming

By Summit Voice

SUMMIT COUNTY — A pulse of warm Atlantic water has carried tropical and subtropical species of marine protozoa north of the Arctic Circle for the first time ever, and while researchers said their find was not directly linked with overall global warming, it may foreshadow expected changes in ocean currents and the distribution of species.

Arctic waters are warming rapidly, and such pulses are predicted to grow as global climate change causes shifts in long-distance currents, and the recent research hints at potential  climate-induced changes already overtaking the oceans. Continue reading

Tropical system strengthens near Carolinas

Beryl named as subtropical storm

Subtropical Storm Beryl is spinning off the southeastern coast of the U.S.

Beryl may make landfall as s tropical storm somewhere near the Florida-Georgia border.

By Summit Voice

SUMMIT COUNTY — Although the official start of the Atlantic hurricane season is just a few days away, Beryl, the second named storm of the season, has formed off the coast of the Carolinas.

Tropical storm watches and warnings have been issued for parts of the southeastern coast from Florida up to South Carolina, where a storm surge and heavy rains are expected Sunday. According to the National Hurricane Center forecast, the storm is likely to peak with winds of 50 mph. Continue reading

South Atlantic current a big player in global climate

Warm, salty water from the south could balance impacts of melting polar ice cap

Agulhas Current system and its "leakage" into the Atlantic Ocean, affecting climate. Credit: Erik van Sebille, RSMAS.

By Summit Voice

SUMMIT COUNTY — Leakage from an ocean current running along the east coast of Africa could ameliorate some anticipated global warming impacts in the northern hemisphere, according to University of Miami researchers, who recently published a study in the journal nature suggesting that the Agulhas Current could be a significant player in global climate variability.

The Agulhas Current transports warm and salty waters from the tropical Indian Ocean to the southern tip of Africa. There most of the water loops around to remain in the Indian Ocean (the Agulhas Retroflection), while some water leaks into the fresher Atlantic Ocean via giant Agulhas rings.

Once in the Atlantic, the salty Agulhas leakage waters eventually flow into the Northern Hemisphere and act to strengthen the Atlantic overturning circulation by enhancing deep-water formation. Recent research points to an increase in Agulhas leakage over the last few decades, caused primarily by human-induced climate change. Continue reading

Ocean currents sensitive to saline balance

Global warming could result in reversal of deep water circulation

New research confirms that major ocean circulations are very sensitive to shifts in salinity. GRAPHIC COURTESY NASA.

By Summit Voice

SUMMIT COUNTY — By tracing the age of isotopes in seafloor sediments, researchers say they’ve been able to pinpoint times when ocean circulations were dramatically different than today, including a period about 20,000 years ago. when the flow of deep waters in the Atlantic was reversed.

The findings, published in the journal NATURE, may offer some clues as to what might happen in the oceans as global temperatures heat up in the coming decades. The reversal happened when the climate of the North Atlantic region was substantially colder and deep convection weakened. At that time the balance of seawater density between the North and South Atlantic was shifted in such a way that deep water convection was stronger in the South Polar Ocean. Continue reading

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