Talking About Art and Environmental Policy at AGU

The 100th Annual Fall Meeting of the American Geophysical Union (AGU) is taking place this week in San Francisco, CA. Marking its centennial, the conference, which is the largest gathering of earth and space scientists in the world, aims to “celebrate the past and inspire the future”.

Thrilled to be a part of it, I will be giving a presentation titled The Power of Perception: Art’s Influence on US Environmental Policy Past and Present. It looks at the role art has played in helping to build the political will behind several landmark environmental policies over the years and how it can help with climate change communication today.

From the Yosemite Land Grant of 1864 to the present, images have helped give the public, and the policymakers they elected, a new way to relate to and understand the issues of their time. In many cases, images mobilized public concern that helped drive legislation. The publication of photos of the Cuyahoga River fire of 1969 in Time Magazine, for example, helped spur the passage of the Clean Water Act and the creation of the EPA in the 1970s.

While environmental concerns have changed over the years, so too has technology and the way we relate to images. As such, this presentation also poses questions about what form of art will reach the most people and motivate them to speak up on climate change today.

Credit: AGU

Gallery Talk: “Weather the Weather” at NY Hall of Science

Art and science have come together at the New York Hall of Science to highlight the fascinating world of weather. In a group exhibition titled Weather the Weather, artworks of various mediums explore the different ways we understand and experience the forces of nature.

Curated by Marnie Benney, this SciArt Initiative exhibition features the work of twenty-one artists from around the world. Honored to be one of them, images from my American Glaciers: Going, Going, Gone and Wildfires series are on display.

If you are in the area, Ms. Benney will lead a gallery tour and talk with several of the artists on Saturday, December 7 from 2 to 3:30 PM. To attend, please register via Eventbrite.

The exhibition will be on view through January 10, 2020 at The New York Hall of Science, 47-01 111th Street, Queens, NY. For hours and directions, visit www.nysci.org

Credit: NYSci/SciArt

First Snowfall of the Season for NYC

New York City saw its first snowfall of the 2019-2020 winter season on Monday.

According to the NWS, 1.5 inches of snow was measured in Central Park. While not a blockbuster event, it was exciting to see the flakes fill the air. With all the holiday lights and decorations on display, the snow also added to the city’s festive atmosphere.

The timing of this first snowfall was about normal for the Big Apple. On average, the first flakes of the season are seen in early to mid-December. Our earliest first snow event on record was on October 21, 1952, and our latest was January 29,1973. New York City typically gets 4.8 inches of snow in December and  25.8 inches for the entire winter season.

Credit: Melissa Fleming

From Snow to Freezing Rain: Why Winter Precipitation Can Take Several Forms

The winter season can produce various types of precipitation – rain, freezing rain, sleet, or snow. The form we see at the surface depends on the temperature profile of the lower atmosphere.

All precipitation starts out as snow up in the clouds.  But, as it falls toward the Earth, it can pass through one or more layers of air with different temperatures.  When the snow passes through a thick layer of warm air – above 32°F – it melts into rain.  If the warm air layer extends all the way to the ground, rain will fall at the surface.  However, if there is a thin layer of cold air – below 32°F – near the ground, the rain becomes supercooled and freezes upon impact with anything that has a temperature at or below 32°F.  This is known as freezing rain.  It is one of the most dangerous types of winter precipitation, as it forms a glaze of ice on almost everything it encounters, including roads, tree branches, and power lines.

Sleet is a frozen type precipitation that takes the form of ice-pellets. Passing through a thick layer of sub-freezing air near the surface, liquid raindrops are given enough time to re-freeze before reaching the ground. Sleet often bounces when it hits a surface, but does not stick to anything.  It can, however, accumulate.

Snow is another type of frozen precipitation.  It takes the shape of six-sided ice crystals, often called flakes.  Snow will fall at the surface when the air temperature is below freezing all the way from the cloud-level down to the ground.  In order for the snow to stick and accumulate, surface temperatures must also be at or below freezing.

When two or more of these precipitation types fall during a single storm, it is called a wintry mix.

Precipitation type depends on the temperature profile of the atmosphere. Credit: NOAA

November 2019: Unusually Cold and Dry in NYC

November felt like a wild ride of weather in New York City. Highs ranged from an unseasonably warm 71°F to a chilly 34°F. But, with 20 out of 30 days posting below-average readings, the cold won out in the end. The month also produced our first freeze of the season and two record cold overnight lows. Overall, the city’s mean temperature for November was 43.9°F, which is 3.8°F below average.

On the precipitation side of things, the month was unusually dry. Only nine days delivered measurable rainfall, which added up to a paltry 1.95 inches in Central Park. New York City, on average, gets 4.02 inches for the month.

Active 2019 Atlantic Hurricane Season Comes to a Close

The 2019 Atlantic Hurricane Season officially ended on Saturday.  It marked the fourth year in a row with above-average activity.

According to NOAA, there were eighteen named storms this season. Of these, six developed into hurricanes and three were major hurricanes with ratings of category 3 or higher on the Saffir-Simpson Scale. It also posted an Accumulated Cyclone Energy (ACE) index of 129.8 An average season produces twelve named storms, six hurricanes, three major hurricanes, and an ACE of 106.

Officially running from June 1 to November 30, the season got off to an early start with Subtropical Storm Andrea forming in May. This was the fifth consecutive year to see a pre-season storm develop. The biggest names of the season, however, were Dorian and Lorenzo.

In September, Hurricane Dorian made landfall in the Bahamas as a category-5 storm with winds measured up to 185mph and a minimum pressure of 910 millibars.  It was the strongest storm on record to hit the island nation, claiming the lives of at least 60 people and leaving several billion dollars worth of damage in its wake.

Dorian also marked 2019 as the fourth year in a row to see a category-5 storm develop in the Atlantic basin, a new record.

Out at sea, Hurricane Lorenzo became the second category-5 storm of the season. It was also the easternmost Category-5 storm in the Atlantic on record. As for a possible connection to climate change, it is interesting to note that twenty-eight category-5 storms have developed in the Atlantic since 1950 with fourteen of them occurring since 2003.

For the contiguous United States this season, Tropical Storm Imelda caused the most damage. Moving slowly across Texas and Louisiana, it dumped between 30 and 44 inches of rain on the area over the course of three days. It unleashed catastrophic flooding throughout the region and became the fifth wettest tropical cyclone on record in the continental US.

This active hurricane season, according to NOAA, was largely the result of above-average sea surface temperatures in the Atlantic, a stronger than normal West African monsoon, and ENSO neutral conditions in the Pacific. In other words, the combination of warm water to fuel storms and reduced wind shear across the Gulf of Mexico allowed for unhindered tropical development in the Atlantic basin.

Credit: NOAA

Windy Conditions Expected for the Thanksgiving Day Parade in NYC

The Macy’s Thanksgiving Day Parade is a long-standing holiday tradition in New York City.  For 93 years, it has marched rain or shine. Nevertheless, the weather has affected the event several times over the years.

Famous for its giant character balloons, high winds are the main weather challenge for the parade. According to city guidelines, the multi-story balloons cannot fly if there are sustained winds in excess of 23 mph or gusts higher than 34 mph. These regulations were put in place following a 1997 incident where gusty winds sent the “Cat in the Hat” balloon careening into a light post, which caused debris to fall on and injure spectators.

The only time the balloons were grounded for the entire parade was in 1971, when torrential rain swept across the city. In 1989, a snowstorm brought the Big Apple a white Thanksgiving and the “Snoopy” and “Bugs Bunny” balloons had to be pulled from the parade because of damage from high winds.

This year, the wind could potentially be a problem again. Gusts are forecast to be between 30 and 40 mph during the parade hours. City officials say they will wait to see what conditions are actually like on the day before they make any decisions about grounding or limiting the balloons.

Marching from West 77th Street to West 34th Street in Manhattan, the 93rd Annual Macy’s Thanksgiving Day Parade is scheduled to begin at 9 AM on Thursday morning.

Happy Thanksgiving!

The Paddington Bear balloon floats down 6th Ave in Macy’s Thanksgiving Day Parade.           Credit: Macy’s

Why the Sky Looks Bluer in Autumn

Autumn is well known as the time of year when leaves change color. Not as well known, however, is the fact that the sky also changes shades with the season.

In general, we see the sky as blue because of Rayleigh scattering. This is a phenomenon where the molecules of nitrogen and oxygen that make up most of Earth’s atmosphere scatter the incoming light radiation from the sun. More to the point, they are most effective at scattering light with short wavelengths, such as those on the blue end of the visual spectrum. This allows blue light to reach our eyes from all directions and dictates the color we understand the sky to be.

The arc height of the sun’s apparent daily passage across our sky, which varies with the seasons, determines how much of the atmosphere the incoming light must pass through. This, in turn, affects how much scattering takes place. Simply put, the more Rayleigh scattering, the bluer the sky appears.

That said, humidity levels also play a role. Water vapor and water droplets are significantly larger than nitrogen and oxygen molecules and therefore scatter light differently. Instead of sending light in all directions, they project it forward. This is known as Mie scattering and tends to create a milky white or hazy appearance in the sky.

During the summer months, when the sun is higher in the sky, light does not have to travel as far through the atmosphere to reach our eyes. Consequently, there is less Rayleigh scattering. The warm temperatures of summer also mean the air can hold more moisture, increasing the effect of Mie scattering. As a result, the summer sky tends to be relatively muted or pale blue.

In autumn, the sun sits lower on the horizon, increasing the amount of Rayleigh scattering. The season’s cooler temperatures also decrease the amount of moisture the air can hold, diminishing the degree of Mie scattering. Taken together, these two factors produce deep blue skies.

When this azure hue is contrasted with the reds and yellows of the season’s famous foliage, all of the colors look even more vibrant.

Photo credit: Azure-Lorica Foundation

October 2019: Earth’s Second Warmest October on Record

Our global temperature continued its upward trend last month with October 2019 marking the second warmest October ever recorded on this planet. Only October 2015 was warmer.

According to NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for the month – over both land and sea surfaces – was 58.86°F. That is 1.76°F above the 20th-century average. October also marked the 418th consecutive month with a global temperature above its long-term norm. That means the last time any month posted a below-average reading was December 1984.

Furthermore, the ten warmest Octobers have all occurred since 2003, with the last five Octobers being the five warmest on record.

While heat dominated most of the planet this October, some places were particularly warm, including Alaska, northern Canada, eastern Europe, northern Russia, the Middle East, and western Australia. These soaring temperatures are largely attributed to the long-term trend of human-caused climate change.

For many people in the northern and central parts of the contiguous US, however, this October was unusually cold. To put this disparity into context, consider that the United States constitutes less than 2% of the total surface of the Earth. This detail also highlights the fact that climate change is a complex global phenomenon that involves much more than the short-term weather conditions that are happening in any one part of the world.

Year to date, the first ten months of 2019 were the second warmest such period of any year on record. At this point, it is very likely that 2019 will finish among the top five warmest years on record. Global temperature records date back to 1880.

Credit: NOAA

Arctic Blast Brings Record Cold Temperatures to NYC

The calendar says November, but it felt more like January in New York City on Wednesday as a blast of frigid arctic air plunged into the region.

In Central Park, the temperature dropped to 25°F late Tuesday night and hit 23°F early Wednesday morning, setting new record lows for both dates. According to the NWS, the previous records of 26°F for November 12 and 24°F for November 13 were set in 1926 and 1986, respectively.

The high temperature on Wednesday only reached 34°F, which is 8°F colder than the normal low for this time of year. The average high for the city in mid-November is 55°F.

Produced by a deep dip in the jet stream, these unusually cold conditions are expected to hang around for a while. Temperatures are forecast to moderate slightly but still remain below average as we move into next week. Keep those hats and gloves handy!

Credit: The Weather Gamut