Data Surfer

Sites you need to see

Cooler temperatures this spring have delayed the inevitable bad air typical of Sacramento's warmer days. But soon we'll see the return of air pollution that affects everyone, but particularly those with certain respiratory ailments.

You can see how Sacramento's air quality compares to other metropolitan areas in the 2010 State of the Air report, recently published by the American Lung Association. The greater Sacramento region, according to the study, is among the most polluted areas in the country. It ranks fifth in ozone pollution and sixth in short-term (24-hour) particle pollution. (Los Angeles and Bakersfield are first, respectively.)

The full text of the report (available free online) contains county-level statistics on pollution levels and at-risk groups. Sacramento County (p. 53) gets a grade "F" for both the number of high ozone and high particle pollution days. The county is also home to a sizable population of people suffering from chronic health problems (diabetes, lung and cardio-vascular dieseases) that make them especially vunerable to airborne pollutants (p. 54).


Iceland's Eyjafjallajokull volcano certainly has gotten a lot media attention, what with the havoc it's caused in the European airline industry. But compared to other eruptions in history, this current one is pretty puny.

So how do scientists determine the overall ferocity of a volcanic event? They use a measurement akin to the earthquake Richter Scale. The Volcanic Explosivity Index is a 1 to 8 scale in which each number is ten times as intense as the preceding one. The VEP takes into account a variety of factors, including volume of material ejected, height, flow and duration. Mount St. Helens in 1980 measured a VEI of 5. Pinatubo in 1991 measured between 5 and 6. The massive eruption that formed Yellowstone 600,000 years ago is estimated at the top VEI of 8. In contrast, the current Icelandic event is coming in at 2 to 3.

Incidentally, the BBC web site has a simple, but elegant animated guide explaining the origin and development of volcanoes around the world. It's a good 5-minute introduction to the science.

rain2.JPGThe Bee's data reporter Phillip Reese has come up with another nifty interactive database. This one produces Sacramento weather conditions for any day between Jan. 1, 1911 and Feb. 28, 2010. Just enter a date and you'll easily see the high and low temperatures, plus any precipitation (in inches) for that day. Normally this sort of research requires one to browse through reels of Bee micorfilm at the public library, so the online database is a real time-saver.

If you need weather data more current than February, see the Sacramento history page on the Weather Underground site. (Weather Underground is the source of The Bee's weather page information.) Here you'll be able to retrieve city climate data from 1941 through the present. And if you're looking for historic weather records covering temperature, rainfall, wind, storms, etc., NOAA has collected these in a free online document: Climate of Sacramento, California (revised in June 2005).

The climate change summit in Copenhagen appears to be deadlocked with developed and developing countries arguing over targets, verification and aid to poorer nations. China and the United States, in particular, are debating just how much each should reduce their carbon emissions. That begs the question, just how much carbon do these and other nations spew into the atmosphere?

The British Guardian newspaper has posted a terrific data visualization that vividly shows the total carbon produced by each country since the Kyoto conference (1997-2007). The graphic is color-coded with larger circles corresponding to the bigger emitters. Over the ten-year period, the United States produced the most carbon (64,166 million tonnes), followed by China (45,301 million tonnes). But China surpassed the U.S. in CO2 emissions during the latest year measured (2007) and the former appears to be increasing its carbon releases at a faster rate. Those figures are available in a Google spreadsheet tracking world emissions by country from 1980 through 2007. A second table ranks countries by per-capita CO2.

Last night's low temperatures remind us that sub-freezing conditions are not unusual in the Sacramento region. Such cold weather can last even several days, according to historic records. NOAA's climate memorandum for Sacramento (p. 43) says the longest span of consecutive days with minimum temperatures 32 degrees or below was 13 (Dec. 20, 1990 thru Jan. 1, 1991). As for non-consectutive periods, Jan. 1949 wins with 24 days of sub-freezing temps in one month.

The California Energy Commission today approved the nation's first energy-efficiency standards for televisions. The Commission estimates that TVs now account for 10 percent of household power consumption. And the new standards would save consumers $50-250 in electricity bills for the life of each set.

The power limit on TVs won't kick in until Jan. 2011, but consumers can choose to buy an efficient model before then. About 1,000 types of televisions in the market already comply with the California mandate. Here's a helpful chart showing the brand, model, screen type, size and energy drain of each one. The list is arranged alphabetically, but with some spreadsheet magic one can sort the models by size, then efficiency. See the attached Excel file.  

I don't know about you, but daylight savings time seems to be ending very late this year. Actually it does end later than most of us remember as kids. (A federal law changed the end date from the last Sunday in October to the first Sunday in November starting in 2007.) This year the end of DST falls on Nov. 1. That's the earliest it can be (though it still seems really late this year.) But just wait until next fall: you'll have to wait til Nov. 7 to get relief from the morning darkness.

Here's a handy chart showing dates for the start and end of daylight savings time for years 1990 through 2015. It's compiled by the California Energy Commission which also provides an interesting article on the history and rationale for the time change.

rain.JPGFor me it's always a bit of a surprise to experience the first rain in Sacramento after months of no precipitation. And yesterday's storm certainly started the wet season with a bang. About 3.04 inches fell on downtown Sacramento in 24 hours -- from 4 a.m. Tuesday to Wednesday morning. But that was hardly a record. According to the National Weather Service's Climate of Sacramento record book, the most rain that ever fell on the city in a 24-hour period was 7.24 inches (April 19-20, 1880). That document also contains a chart showing "excessive storms" since 1903. (An "excessive storm" is one that produces 2.5 or more inches of precipitation in a 48-hour period.)  You can see the dates and amounts for record rainfall in 48-hour, 24-hour, 2-hour and 1-hour periods.

[UC Davis students on First Street near the campus, Oct. 13, 2009. Sacramento Bee / Manny Crisostomo.]

Yesterday The Bee published its package of stories and illustrations commemorating the 20th anniversary of the Loma Prieta Earthquake. The lead story was written by Marjie Lundstrom (who incidentally wrote the Bee's first-day lead story on the quake in 1989). This current package includes the best YouTube videos, important external links and historic photos, as well as a look at the science of earthquake prediction and illustrations on the seismic and liquefaction hazards in the Bay Area. Bee data guy Phillip Reese contributed a statewide interactive map displaying the 2,190 bridges retrofitted since 1989.

Quake history junkies should also check out the 20th anniversary remembrance published by the San Francisco Chronicle.

Britain's Guardian newspaper has posted impressive online graphics on greenhouse gas emissions. One is an interactive chart showing carbon dioxide output by country. The latest (2006) data shows China surpassing the United States in total CO2 emission, 6017.69 to 5902.75 million metric tons. But consider that the per capita CO2 emission in the United States dwarfs China's, 19.78 to 4.58 metric tons.

The other provides a quick, but comprehensive overview of all the industries and human activities that contribute to the three main greenhouse gasses: carbon dioxide, methane and nitrous oxide. The largest contributor is the electricity production-heating sector. But the activity that emits the most gases (on a percentage basis) is transportation -- with road vehicles spewing the bulk of them.


(A lightning bolt hits the ground near the 15 and 215 freeways in San Bernardino, Calif. Wednesday afternoon. AP Photo/ Mike Meadows)

Two people were killed and seven others injured in lightning strikes that accompanied storms around the state last night. Locally, a woman carrying an umbrella was struck by lightning in Plumas County.

Ironically, National Lightning Safety Week is two weeks off (June 22-28). The event is sponsored by the National Weather Service, which also collects statistics on lightning fatalities and injuries. To date, six people have been killed by strikes in 2009. 28 have died and hundreds were permanently injured in 2008. You can get a summary of each death (including name, age, location and activity) that occurred from 2006 to the present.

Historically, there were 3,885 lightning deaths in the United States between 1959 and 2008. Florida led the way with 455 fatalities. Washington had the least with five. California had 28.

It's easy for some to be cynical about Earth Day. We set aside one day to focus on the environment, the critics mutter, but how about the rest of the year? Fair point.

So what can we do to help the planet every day? One good source of practical advice for easing our environmental impact is, the federal government's portal to events and information available on U.S. agency web sites. Here you'll find tips for saving energy and water, recycling and disposing of toxics at home and at work. There are also links to volunteer opportunities in your community. Teachers will find a good collection of links on environmental topics, learning activities, classroom games, etc. Kids have their own Earth Day page.

The Environmental Protection Agency also celebrates Earth Day with event information, photos, video, podcasts, consumer tips, historical documents and an environmental timeline. 

Thumbnail image for DD45.jpgAssociated Press reported today (too late for praying) that on Monday an asteroid came within 48,000 miles of hitting Earth. The asteroid (dubbed DD45) is as big as the space rock that clobbered Siberia in 1908. Apparently scientists had been tracking it since late February and considered it no threat to our planet.

NASA's Near Earth Object Program tracks comets and asteroids whose orbits take them close to the Earth. The program's website provides a readable introduction to NEOs, as well as specific information about space junk that have hit the earth, came close in the past or are expected to come close in the future. It also has interactive 3-D graphics showing the trajectory of these things as they pass through the solar system. Take a look at the data and graphic on our recent guest, DD45

  drought2.jpgWith California experiencing a third season of abnormally low precipitation, water experts are fearing the state is entering into its worst drought in modern history. A new Bee graphic shows that much of California is currnetly affected by severe drought conditions.

Drought Monitor, a University of Nebraska service, is a good source of maps that track dry conditions across the United States. The maps are color-coded for five levels of severity, ranging from "D0" (abnormally dry) to D4 (exceptional drought). As of Jan. 27 much of the western part of the country was in a drought, including sections of northern California and south-central Texas that suffer with at least D3 dryness. In addition to the current static map, there are 6-week and 12-week animations illustrating change over time. 

Drought Monitor also allows you to call up drought statistics by region and state. These figures tell you what percentage of land area is experiencing various levels of drought. An historic table for California contains weekly readings of the extent of drought back to January 2000. The data indicates that at least 50 percent of the state's land area has suffered from dry conditions for more than three years.

Yesterday the weather at Sacramento Executive Airport burst through the daily record with a high temperature of 74 degrees. The previous January 12th high was 67 degrees in 1980.

Where do you go to find daily high and low temperature records? The Bee's official source for climate data is Weather Underground. WU provides a useful calendar which displays the day's recorded temperatures and precipitation. Click on a specific day and you see daily records, median and year-to-date data on temperatures, precipitation, moisture and wind.

For other historical information the National Weather Service offers The Climate of Sacramento, California (1877-2005), a 91-page online report filled with daily, monthly and seasonal records of all types. Some of my favorites:

*Greatest number of consecutive days with maximum temperatures of 105 degrees or higher: Aug. 5-11, 1990.

*Greatest number of consecutive days with minimum temperatures of 32 degrees or lower: Dec. 20, 1990-Jan. 1, 1991.

*Wettest and driest water years: 1982-83 (37.49 inches of rain) and 1975-76 (7.25 inches). 

Today the Bee reported that a federal agency will investigate Wednesday's natural gas explosion which killed a man, leveled a home and damaged two other residences in Rancho Cordova. The Office of Railroad, Pipeline and Hazardous Materials of the National Transportation Safety Board is the body that oversees the transmission and distribution of natural gas.

The NTSB website complies statistics on significant pipeline incidents, which resulted in deaths or injuries and/or sizeable property damage. A year-by-year table summarizes natural gas pipeline events occuring from 1988 to the present. It includes the total number of fatalities, injuries and the total property damage cost for the year. In the past 20 years there have been 1,818 natural gas distribution incidents that killed 321 people, injured 1,325 and cost nearly $1 billion in property damage.

The NTSB also provides a series of narratives describing the most serious pipeline accidents. These cover pipeline transport of crude oil, gasoline and other hazardous materials -- as well as natural gas.

About Data Surfer

It's all about information -- statistics, documents and data of all types that help us understand the world, make informed decisions and monitor government. It's about empowering citizens with tools and sources so they can conduct their own investigative research. This blog is a place to discuss information that's available on the Internet. What's relevant, useful, valid and accurate -- and what's not.

We know the Sacramento region is home to knowledgeable people who use online information in their respective fields. We want to hear from you. Please tell us what you think of the data we use in stories and post on The Bee's website. And share tips about online resources you think are valuable to this blog's readers. Post comments on this blog or contact Pete Basofin directly at

June 2010

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