Category Archives: meteorology

Eclipse meteorology

“Plan of Observations. -The meteorological observations proposed were especially directed towards the subjects of barometric pressure, air temperature, humidity, solar radiation, and wind velocity. The instruments located on the top of the tower were in charge of Mr. Rotch, and those at its base Mr. Upton.”

―Winslow Upton and A. Lawrence Rotch, Meteorological and other observations made at Willows, California, in connection with the total solar eclipse of January 1, 1889. Annals of the Astronomical Observatory of Harvard College, Vol. XXIX, 1893.

Diagram of the solar eclipse
Drawing of the total solar eclipse of January 1, 1889

The scientific instruments used during a solar eclipse include telescopes with a protective filter to reduce the brightness of the Sun to protect an astronomer’s eyesight. The earliest known image of the Sun taken by a camera was recorded in 1845. But it was still common for scientists to draw sketches with pencil and paper as it has been done for centuries. The above image is based on a number of photos taken with different exposure times. The short exposures record bright features but leave out many of the fainter ones. The longer exposures cause the bright features to be overexposed but reveals subtle details. The sketch above is a composite of these different photographs.

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Nor’easter

On March 2, 2018 a severe storm impacted southeastern New England. The storm was classified as a Nor’easter which is named for the characteristic strong winds from the northeast. During the storm our weather station recorded fifty-five wind gusts greater than 50 miles per hour. The two strongest were 62 mph at 1:48 and again at 1:50 pm.

wind speed graph
Average wind speed and highest wind gusts graph.

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“Aurora” over Providence

Note: this was originally published on March 6. It was updated on March 8 to include new information.

On March 6 we received local reports that the aurora was observed in New England just before sunrise. One of our visitors described seeing it from a rest area on Route 495 near Boston. There was another report from Vermont. Our automated all sky camera was running the entire night and captured the view above Providence. Also visible is the International Space Station (ISS) streaking through the sky about 500 miles from Providence as the planets Mars and Saturn shine brilliantly in the south.

ISS and aurora
A 10 second exposure taken March 6, 2016 at 4:54:18 AM EST. This image has been processed to make it easier to see the stars.

During the night the camera recorded 3,750 images of the sky. North is at right, west at bottom, and the zenith is at center. The field of view is about 140 by 90 degrees, capturing most of the sky above Providence. The images can be processed to produce a time lapse movie that shows 5 minutes of changes in the sky per second of video. Click on the image below to watch an excerpt. A number of artificial satellite can be seen streaking through the sky just before dawn.

Our sky camera has been in operation since the spring of 2008. We’ve never captured images like this before.

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The Weather Bureau in Providence

“In Philadelphia I dragged out a colorless and an unhappy existence till September, 1904, when to my delight I was ordered back to New England, and this time nearer the centre of civilization. (Of course by that I mean Boston, which is the “hub of the universe” the “Athens of America”, the “Centre of Culture”, and last but not least, the home of the humble baked bean and the sacred codfish). I was sent to Providence, R. I., and have remained here ever since and hope to continue my residence here. By a happy combination of circumstances I have lived in the classic halls of Brown University ever since my arrival in Providence. The location and environment are eminently satisfactory.”

―George Francis Field, “Harvard College Class of 1901.” June 1911

University Hall Weather Bureau
An instrument shelter on the roof of University Hall.

In addition to the weather station at Ladd Observatory there was another on the Brown campus. Located on the roof of University Hall it was operated by the U.S. Weather Bureau. The pole behind the chimney at left was likely used to support the anemometer, an instrument to measure wind speed.

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Observing the “rain-bands”

The Leonid meteor shower was approaching and as the astronomers prepared cameras to capture the event they must have wondered: will the skies be clear tonight?

Leonids 1898
Astronomers preparing cameras to capture the Leonid meteor shower, Nov. 14, 1898.

Prof. Winslow Upton taught astronomy at Brown from 1883 until his death in 1914. He also had a keen interest in meteorology. He had been a professor of meteorology at the Weather Bureau of the U.S. Signal Survice from 1881 until 1883. In 1884 he was one of the organizers of the New England Meteorological Society and operated a weather station at Ladd Observatory starting in 1890. We can gain some insight into how he might have forecast the cloudiness of the sky by noting a curious instrument to the left of the cameras in the photo above.

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