The Daily Parker

Politics, Weather, Photography, and the Dog

Historical population data, visualized

Citylab's Map of the Day today comes from Northeastern University history professor Benjamin Schmidt. It visualizes population data from three data sets, one of which came from a single Wikipedia editor:

This is a narrative description of the city populations dataset I’ve assembled for the Creating Data project. The headline here is: Wikipedia editors have created a much more comprehensive database of American city and town populations than historians have had to this point.

I’m writing it up separately and releasing it before any other components of the project for two reasons. First, the data is useful: there are a wide variety of fields where a more comprehensive, long-term database of city sizes is useful, and I’ve already spoken to a few people for whom it might be useful. (If you wish to download the data, you can do it from the github site for this dataset.)

Second, I wanted to use it to try a beta launch for some of the narrative display elements of this project. I’m trying something here that’s a central part of the full project: finding ways to explore through historical data that allow both narrative and exploratory data analysis.

It's one of the most interesting geographic data visualizations I've seen in a while. You don't have to be a geography nerd to enjoy it.

Yes, it's getting hotter

We have lovely weather in Chicago today—24°C and sunny—but summer has been pretty warm so far. It's been worse in other places. The Times demonstrates today that this is a worldwide trend:

During the base period, 1951 to 1980, about a third of summers across the Northern Hemisphere were in what they called a “near average” or normal range. A third were considered cold; a third were hot.

Since then, summer temperatures have shifted drastically, the researchers found. Between 2005 and 2015, two-thirds of summers were in the hot category, while nearly 15 percent were in a new category: extremely hot.

Practically, that means most summers today are either hot or extremely hot compared to the mid-20th century.

The Climate Prediction Center calls for above-average chances (+33% to +50%) for above-normal temperatures throughout the U.S. through August, except for parts of the Southwest that are normally too hot for humans. The forecast for August through October calls for 40%+ probabilities of above-normal temperatures throughout all the U.S., particularly along the Gulf, Atlantic, and Bering coasts. The MET predicts the same for most of the world.

 

Google Earth Engine

Google now has a tool that will show you a time-lapse of any part of the world from 1984 to present:

In 2013, we released Google Earth Timelapse, our most comprehensive picture of the Earth's changing surface. This interactive experience enabled people to explore these changes like never before—to watch the sprouting of Dubai’s artificial Palm Islands, the retreat of Alaska’s Columbia Glacier, and the impressive urban expansion of Las Vegas, Nevada. Today, we're making our largest update to Timelapse yet, with four additional years of imagery, petabytes of new data, and a sharper view of the Earth from 1984 to 2016. We’ve even teamed up again with our friends at TIME to give you an updated take on compelling locations.

The examples on the demo page are striking. I would also suggest a few more to check out: Las Vegas (the city quadrupled in size in 22 years); North Suburban Illinois (watch the Glenview Naval Air Station disappear like a leaf in winter); Dubai; Mount St. Helens (watch the forest grow back and logging operations resume). Very cool stuff.

Millions of blue bikes

Software developer Todd Schneider has analyzed 22 million CitiBikes trips (the New York equivalent of Chicago's Divvy). He's even got some cool animations:

If you stare at the animation for a bit, you start to see some trends. My personal favorite spots to watch are the bridges that connect Brooklyn to Lower Manhattan. In the morning, beginning around 8 AM, you see a steady volume of bikes crossing from Brooklyn into Manhattan over the Brooklyn, Manhattan, and Williamsburg bridges. In the middle of the day, the bridges are generally less busy, then starting around 5:30 PM, we see the blue dots streaming from Manhattan back into Brooklyn, as riders leave their Manhattan offices to head back to their Brooklyn homes.

Sure enough, in the mornings there are more rides from Brooklyn to Manhattan than vice versa, while in the evenings there are more people riding from Manhattan to Brooklyn. For what it’s worth, most Citi Bike trips start and end in Manhattan. The overall breakdown since the program’s expansion in August 2015:

  • 88% of trips start and end in Manhattan
  • 8% of trips start and end in an outer borough
  • 4% of trips travel between Manhattan and an outer borough

There are other distinct commuting patterns in the animation: the stretch of 1st Avenue heading north from 59th Street has very little Citi Bike traffic in the morning, but starting around 5 PM the volume picks up as people presumably head home from their Midtown offices to the Upper East Side.

Schneider previously analyzed 1.1 billion New York taxi trips.