The Science Behind the Summer Solstice

Today is the June Solstice, the first day of summer in the northern hemisphere. The new season officially begins at 15:54 UTC, which is 11:54 AM Eastern Daylight Time.

Our astronomical seasons are a product of the tilt of the Earth’s axis – a 23.5° angle – and the movement of the planet around the sun. During the summer months, the northern half of the Earth is tilted toward the sun. This position allows the northern hemisphere to receive the sun’s energy at a more direct angle and produces our warmest temperatures of the year.

Since the winter solstice in December, the arc of the sun’s daily passage across the sky has been getting higher and daylight hours have been increasing. Today, the sun will be directly overhead at the Tropic of Cancer (23.5°N latitude), its northernmost position, marking the “longest day” of the year. This observable stop in the sun’s apparent annual journey is where today’s event takes its name. Solstice is a word derived from Latin and means “the sun stands still”.

While today brings us the greatest number of daylight hours (15 hours and 5 minutes in NYC), it is not the warmest day of the year.  The hottest part of summer typically lags the solstice by a few weeks. This is because the oceans and continents need time to absorb the sun’s energy and warm up – a phenomenon known as seasonal temperature lag.

Earth’s solstices and equinoxes. Image Credit: NASA

Earth Posts 4th Warmest May and 2nd Warmest March-May Season on Record

Our global temperature continued its upward trend last month. May 2019 marked not only Earth’s fourth warmest May but also closed out the planet’s second warmest March-May season on record.

According to the State of the Climate report by NOAA’s National Centers for Environmental Information, Earth’s combined average temperature for May – over both land and sea surfaces – was 60.13°F, which is 1.53°F above the 20th-century average. This May also marked the 413th 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.

The three-month period of March, April, and May – meteorological spring in the northern hemisphere – was also unusually warm. NOAA reports that Earth’s average temperature for the season was 1.73°F above the 20th century average of 56.7°F. That makes it the second warmest such period on record. It is also important to note that the five warmest March-May periods have all occurred since 2015.

While heat dominated most of the planet this season, some places were particularly warm, including Alaska and western Canada. For the contiguous US as a whole, this spring was close to average and ranked in the middle third of the national record.

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 five months of 2019 were the third warmest such period of any year on record. Global temperature records date back to 1880.

Credit: NOAA

Climate Communication: Art Helps Build Political Will for Change

The Conference on Communication and Environment (COCE) is taking place this week in Vancouver, Canada. Organized by the International Environmental Communication Association, the theme of this year’s event is “Waterlines: Confluence and Hope through Environmental Communication.”

Thrilled to be a part of it, I will be giving a presentation titled “The Power of Perception: Art, Climate, and the History of US Environmental Policy”. 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 policy makers 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 issues have changed over the years, so 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: IECA

Weather and Health: Hot Cars Can Be Dangerous for Kids

Warm weather can pose a number of health and safety concerns, from poor air quality to being hit by lightning. One of the more deadly risks for children, however, is heatstroke when they are left in a hot car.

Since 1998, according to kidsandcars.org, there has been an average of 38 hot car deaths in the US every year. That is one every nine days. This year, there have already been 11 deaths reported and the official start of summer is still more than a week away.

Credit: USA Today

On a sunny day, the interior temperature of a parked car can increase 19°F in just ten minutes. That means if the outside air temperature is a seemingly comfortable 70°F, the inside of the car can heat up to near 90°F in a very short period. The situation is even worse when the outside temperature is higher and the car sits in the sun longer.

According to the Mayo Clinic, if the human body reaches 104°F, organ damage and death become a real risk. Children are even more vulnerable because their smaller bodies can heat up between three to five times faster than that of an adult. Most hot car victims are under the age of three.

These dangerous situations develop in a number of different ways. Children can sometimes find their own way into a car while playing outside or a guardian leaves them alone in a vehicle for what seems like a quick errand. However, the majority of hot car deaths occur when a parent or caregiver gets distracted or has a change in their daily routine and simply forgets that a child is in the back seat when they park their car.

To avoid a heartbreaking tragedy, remember to Look Before You Lock!

806 children have died in hot cars since 1998 in the US. Year to date for 2019, there have been 11. Credit: NoHeatStroke.org

Weather Lingo: A 500-Year Flood

Flooding rain events are becoming more common in many parts of the United States. But, the terms used to describe some of them, such as “100-year flood” or “500-year flood”, can be misleading.

While these phrases can make it sound like the flooding is cyclical, only happening once every 100 or 500 years, it is not. Storms are not on a schedule. Rather, these terms refer to statistical probabilities. For example, the “100-year flood” means there is a 1% chance of a flood of that magnitude happening in any given year in a given location. For the 500-year flood, the probability is 0.2%.

Given the right conditions, it is possible to see multiple 100-year or 500-year flood events in a relatively short period of time. Ellicott City, MD, for example, recently saw two 1000-year flood events only two years apart. For more information, watch the video below from the NWS.

Climate Communication: Using Art to Get Beyond the Numbers

Climate change is a complex scientific subject with a plethora of data-rich reports that detail its causation and diverse impacts. However, as important as all that information is, not everyone responds to facts and figures or charts and graphs. That is why art, which taps into human emotion and tells visual stories, can help create new pathways to understanding this global issue.

Marking World Environment Day on June 5, I will be discussing this idea in a presentation titled “Climate Communication: Using Art to Get Beyond the Numbers” at the UN Committee of New Canaan in New Canaan, CT. Blending the qualitative and quantitative, this talk reviews the results of a recent poll that measured the influence climate-art has on people’s opinions and highlights specific artworks that speak to the assorted impacts of this critical issue and its possible solutions.

As the famous scientist, Lord Kelvin, said, “When you can measure what you are speaking about, and express it in numbers, you know something about it.” If that is true, then art has an important role to play in helping to broaden the public conversation on climate change.

Credit: Melissa Fleming/The Weather Gamut

May 2019: A Soggy Month for NYC

May was another month of wild temperature swings in New York City. Producing several cases of weather whiplash, highs ranged from a chilly 48°F to an unseasonably balmy 86°F. In the end, however, these extremes balanced each other out. The city’s mean temperature for the month was 62.2°F, which is only 0.2°F below average.

On the precipitation side of things, May was unusually wet. The month brought the city a relatively rare spring nor’easter and several impressive thunderstorms. One of which produced golf ball sized hail on Staten Island, one the city’s five boroughs. Overall, 19 out 31 days posted measureable rainfall that added up to 6.82 inches for the month. While that is a soggy statistic, it was not the wettest May the city has seen. That dubious honor belongs to May 1989 when 10.24 inches of rain was measured in Central Park. The city, on average, gets 4.19 inches for the month.

Credit: The Weather Gamut

Names for the 2019 Atlantic Hurricane Season

Today is the first day of the 2019 Atlantic Hurricane Season. Although one named storm, Andrea, already formed, the season officially runs from June 1 to November 30.

Since 1950, each tropical storm or hurricane to form in the Atlantic has been given a unique name. They come from a set of six rotating lists produced by the World Meteorological Organization. A name is retired only when a storm was particularly noteworthy – causing a large number of fatalities or an extraordinary amount of damage.

Some notable retired names include:  Harvey, Irma, Katrina, Maria, Michael, and Sandy. The names for this year’s storms are listed below.

Credit: NOAA

Strong Storm Pelts NYC Borough with Large Hail

A powerful thunderstorm moved through New York City on Tuesday night. Generating strong winds and heavy rain across area, it also brought hail to Staten Island, one of the city’s outer boroughs.

According to reports, hailstones measuring 1.8 inches in diameter came down in the Bull’s Head neighborhood. Roughly the size of golf balls, it was the largest hail reported in the city since 2011.

The storm was strong enough to warrant a tornado warning for the area, but luckily no twisters touched down in the five boroughs. Nonetheless, the large hail is a testament to the storm’s intensity. Simply put, the stronger the updraft of a storm, the longer hailstones remain suspended, allowing them to grow larger.

The largest hailstone ever recorded in the US was found in Vivian, South Dakota on June 23, 2010. It measured 7.9 inches in diameter and weighed 1.94 pounds.

Large hail fell from an intense thunderstorm over Staten Island, NYC on May 28, 2019. Image Credit: Staten Island Advance/ J Yates

The 2019 Atlantic Hurricane Season Outlook

The number of hurricanes that develop in the Atlantic basin varies from year to year. For 2019, NOAA’s Climate Prediction Center is forecasting a near average season.

Tropical cyclones, known as hurricanes in the United States, develop around the globe at different times of the year. In this country, we are most impacted by the Atlantic hurricane season, which affects the North Atlantic Ocean, Caribbean Sea, and the Gulf of Mexico. It runs from June 1 through November 30.

Overall, NOAA predicts a 70% likelihood of nine to fifteen named storms forming this season, of which four to eight could become hurricanes, including two to four major hurricanes. An average season produces twelve named storms, including six hurricanes and three that become major hurricanes.

A major hurricane is one that is rated category 3 or higher on the Saffir-Simpson scale.

This year’s outlook, according to NOAA, reflects several competing factors. On one side, there are above average sea surface temperatures in the tropical Atlantic to fuel any storms that develop. Additionally, there is an enhanced west African monsoon in place that can initiate disturbances that turn into storms over the Atlantic. On the other hand, there is an ongoing El Niño event. El Niño conditions in the Pacific tend to cause increased wind shear in the Atlantic, which suppresses tropical development in that basin.

Last year, 2018, saw a very destructive hurricane season in the Atlantic. It produced fifteen named storms, including, Florence and Michael.

Regardless of the number of storms that actually form this year, it is important to remember that it only takes one land-falling system to make it an impactful season.