Monthly Archives: November 2014

A Quiet 2014 Atlantic Hurricane Season Comes to an End

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The 2014 Atlantic Hurricane Season officially ends today.  For a second year in a row, it was relatively quiet.

According to NOAA, there were eight named storms this season. Of these, six developed into hurricanes and only two – Edouard and Gonzalo – were rated category-3 or higher on the Saffir-Simpson Scale. On average, the Atlantic produces twelve named storms and three major hurricanes (category-3 or higher) every year.

Throughout the season, which runs from June 1st to November 30th, only one named storm made landfall in the U.S.  Hurricane Arthur, a category-2 storm, brought powerful winds and storm surge flooding to North Carolina’s Outer Banks for Independence Day in early July. It was the earliest hurricane to strike N.C. in the state’s history.

Other countries, such as Bermuda, were hard hit this hurricane season. In October, two storms – Tropical Storm Fay and Hurricane Gonzalo – slammed the island nation in less than a week.

Experts say broad areas of high pressure and dry air were the main factors that hindered more extensive tropical development in the Atlantic this season.

Hurricanes

Source: NOAA

Warmest October on Record for Planet Earth

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Temperatures across the country and around the world soared last month. In fact, October 2014 was the 4th warmest October on record for the contiguous United States and the warmest ever recorded for the entire planet.

According to the latest global climate report released Thursday by NOAA’s National Climatic Data Center, Earth’s combined average temperature for the month – over both land and sea surfaces – was 58.43°F.  That is 1.33°F above the 20th century average. October 2014 also marked the 38th consecutive October that our global temperature was above its long-term norm and the 5th month this year to break a global temperature record.

Rising ocean temperatures, according to NOAA, helped fuel this record warmth. The global sea surface temperature for October was 1.12°F above the 20th century average of 60.6°F.  That is the highest on record for October and the sixth consecutive month to post a record high global sea surface temperature. Given all this warm water, it is interesting to note that El Niño conditions are not present in the Pacific.

Year to date, the first ten months of 2014 were the warmest of any year on record. Global temperature records date back to 1880.

Credit: NOAA

Credit: NOAA

Lake-Effect Snow

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A relentless snowstorm buried the Buffalo area of western New York State with more than 5 feet of snow this week. Situated on the shore of Lake Erie, the impressive accumulation was the product of a meteorological phenomenon known as “Lake-Effect Snow.”

Lake-effect snowstorms, according to NOAA, develop when cold air blows across the warmer waters of a large unfrozen lake. The bottom layer of the air mass is warmed by the water and allows it to evaporate moisture, which forms clouds. When the air mass reaches the leeward side of the lake its temperature drops again, because the land is cooler than the water. This releases the water vapor as precipitation and enormous amounts of snow can accumulate. The effect is enhanced if the air is lifted upward by local topography.

With the clouds typically forming in bands, the snowfall is highly localized. Some places can see the snow come down at a rate of more than 5 inches per hour, while others will only get a dusting. The shape of the lake and the prevailing wind direction determines the size and orientation of these bands.

Fetch, the distance wind travels over a body of water, also plays a key role. A fetch of more than 60 miles is needed to produce lake effect snow. In general, the larger the fetch, the greater the amount of precipitation, as more moisture can be picked up by the moving air.

The massive surface area of the Great Lakes in the northern United States make them excellent producers of lake-effect snow. With northwesterly winds prevailing in the region, communities along the southeastern shores of the lakes are often referred to as being in the “Snowbelt.”

Credit: NOAA

Credit: NOAA

The Polar Vortex: A Widely Misused Weather Term

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An early season arctic blast has sent temperatures across most of this country plummeting well below average this week and brought last winter’s buzzword, the polar vortex, back into the spotlight. From advertisements for winter coats to social media hashtags for almost anything cold, this technical meteorological term is being widely misused.

A polar vortex, according to NOAA, is a massive and persistent high altitude low-pressure system present over both poles of this planet. Basically a whirlpool-like wind pattern, the northern hemisphere’s polar vortex is anchored above the Arctic. It, as a whole, does not move south over the US.  That said, pieces of it can ocassionally meander southward and influence our weather via the position of the polar jet stream.

When the polar vortex is strong, the jet stream generally flows in a smooth circular pattern from west to east and bottles up the Arctic’s coldest air.  When weak or displaced by an area of high pressure, the shape of the jet stream distorts into a wavy, more north to south pattern.  This allows cold air influenced by the polar vortex to push southward.  When this happens, it is called a polar outbreak.

This week’s unseasonably cold temperatures are the result of a large ridge in the jet stream to our west that was enhanced by former typhoon Nuri in the Pacific.  It, in turn, has caused a sizable trough to develop east of the Rocky Mountains and allowed cold arctic air to flow deep into the US.

In the video below, Dr. Mark Serezze, Director of the National Snow and Ice Data Center, explains exactly what the polar vortex is, how it works, and how climate change may play a role in its future.

Video credit: EarthVisionTrust and YouTube

A Winter Preview in NYC

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The official start of winter is more than a month away, but New York City is experiencing an early preview.

A deep dip in the jet stream has ushered in cold arctic air and sent local temperatures plummeting. After reaching an unseasonably warm high of 65°F on Wednesday, the high in Central Park today was only 42°F. That is a difference of 23°F in just 48 hours. The city’s normal high for this time of year is 54°F.

The cold air also helped produce the city’s first snowflakes of the season. While nothing accumulated on the ground, the National Weather Service reported a trace of snow in Central Park early Friday morning. A trace of snow is defined as less than 0.1 inches.

Unlike earlier cold snaps this season, these current chilly conditions are expected to linger for at least a week.

US and China Reach Climate Change Agreement

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The United States and China have teamed up to tackle the pressing global issue of climate change. President Barack Obama and President Xi Jinping announced their ambitious bi-lateral agreement in a joint press conference on Wednesday in Beijing, where both leaders were attending the Asia Pacific Economic Cooperation (APEC) summit.

Under this historic agreement, the US will reduce its carbon emissions by 26% – 28% below its 2005 levels by 2025. China will cap its growing emissions by 2030, if not earlier, and increase its use of non-fossil fuels by 20% by the same year.

While ambitious, climate scientists say the amount of emission cuts laid out in this bi-lateral agreement alone will not be enough to meet the current global goal of limiting warming to less than 2°C (3.6°F) above pre-industrial levels. That said, it does clear the path for other nations to take similar actions.

China and the US are the world’s two largest economies and two largest carbon polluters. By acting together, President Obama said, “We hope to encourage all major economies to be ambitious – all countries, developing and developed – to work across some of the old divides, so we can conclude a strong global climate agreement next year.”

The first indications of whether this bi-lateral action will spur long stalled global climate negotiations will come this December at the next round of UN climate talks in Lima, Peru. After that, the big test will be the 2015 UN Climate Change Conference in Paris, where the objective is a binding global agreement to reduce greenhouse gas emissions. Any deal reached there will go into effect in 2020.

Art and Climate Change: Sebastião Salgado’s “Genesis”

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Science and photography have joined forces to increase public awareness about the pressing issues of climate change and the environment. Sebastião Salgado’s Genesis, on view at the International Center of Photography in NYC, is a series of 200 black and white photographs that document what society has to lose if actions are not taken to mitigate climate change. They are the product of an eight-year global survey of landscapes, seascapes, wildlife, and indigenous peoples.

Inspired by nature’s ability to restore itself on his family’s former cattle ranch in Brazil, Salgado’s photographs capture the beauty and grandeur of what remains of this planets’s pristine wilderness. In a statement written on a wall of the exhibition, Salgado and his wife/curator, Lélia Wanick Salgado, say, “As well as displaying the beauty of nature, Genesis is also a call to arms. We cannot continue to pollute our soil, water, and air. We must act to preserve unspoiled land and seascapes and protect the natural sanctuaries of ancient peoples and animals. And we have to go further: we can try to reverse the damage we have done.”

Using the images as a springboard for discussion, the ICP has arranged a number of events to accompany the exhibition. These include a series of lectures and panel discussions as well as a schedule of gallery walks where climate scientists from Columbia University explain the environmental issues facing the particular regions represented in Salgado’s photographs.

The exhibition runs through January 11, 2015.  For the full schedule of events, visit: http://www.icp.org/museum/exhibitions/icp-talks

Salgado_Genesis

The eastern part of the Brooks Range, The Arctic National Wildlife Refuge, Alaska, USA, 2009. © Sebastião Salgado.  Credit: Sebastião Salgado/ICP

IPCC Fifth Assessment Synthesis Report

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The UN’s Intergovernmental Panel on Climate Change (IPCC) released the final installment of its massive fifth assessment report on Sunday.  It synthesizes the reports from each of its three working groups – physical science, impacts and vulnerabilities, and mitigation.

Here are some the key findings:

  • “Warming of the climate system is unequivocal, and since the 1950s, many of the observed changes are unprecedented over decades to millennia. The atmosphere and ocean have warmed, the amounts of snow and ice have diminished, and sea level has risen.”
  • “Human influence on the climate system is clear, and recent anthropogenic emissions of greenhouse gases are the highest in history. Recent climate changes have had widespread impacts on human and natural systems.”
  • “Ocean warming dominates the increase in energy stored in the climate system, accounting for more than 90% of the energy accumulated between 1971 and 2010 (high confidence) with only about 1% stored in the atmosphere.”
  • “Over the period 1901–2010, global mean sea level rose by 0.19 [0.17 to 0.21] m.  The rate of sea-level rise since the mid-19th century has been larger than the mean rate during the previous two millennia (high confidence).”
  • “Surface temperature is projected to rise over the 21st century under all assessed emission scenarios. It is very likely that heat waves will occur more often and last longer, and that extreme precipitation events will become more intense and frequent in many regions. The ocean will continue to warm and acidify, and global mean sea level to rise.”
  • “Increasing magnitudes of warming increase the likelihood of severe, pervasive, and irreversible impacts for people, species and ecosystems. Continued high emissions would lead to mostly negative impacts for biodiversity, ecosystem services, and economic development and amplify risks for livelihoods and for food and human security.”
  • “Adaptation can reduce the risks of climate change impacts, but there are limits to its effectiveness, especially with greater magnitudes and rates of climate change.”
  • “Without additional mitigation efforts beyond those in place today, and even with adaptation, warming by the end of the 21st century will lead to high to very high risk of severe, widespread, and irreversible impacts globally (high confidence).”
  • “There are multiple mitigation pathways that are likely to limit warming to below 2°C relative to pre- industrial levels. These pathways would require substantial emissions reductions over the next few decades, and near zero emissions of CO2 and other long-lived GHGs by the end of the century.”
  • “Effective adaptation and mitigation responses will depend on policies and measures across multiple scales: international, regional, national and sub-national.”

This synthesis report will be used as a guide for the policy makers attending the UN Global Climate Summit scheduled for December 2015 in Paris. Any treaty agreed to there will take effect in 2020.

NYC Monthly Summary: October 2014

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October was a bit of weather roller coaster in New York City this year. We had highs ranging from a chilly 53°F to a balmy 77°F. In the end though, with 19 out of 31 days posting warmer than average readings, the warmth won out. All together, the city’s mean temperature for the month was 59.6°F. That is 2.6°F above average.

In terms of precipitation, the city was fairly soggy this October. Central Park measured 5.77 inches of rain, which is 1.37 inches above normal. Most of this came down during three significant rain events that each produced more than an inch of rain in a 24-hour period.  Nonetheless, following a parched August and September, NYC and its surrounding area is still listed as “abnormally dry” on the latest report from US Drought Monitor.

Oct2014_temp

Credit: The Weather Gamut

Oct2014_Rain

Credit: The Weather Gamut