Cold nights & early mornings but an otherwise nice weekend. Lows early in the day will dip into the upper 20s to low 30s near & west of Highway 301....near 32 degrees close to I-95...& the mid 30s to around 40 near the intracoastal & beaches. Sat. & Sun. will be sunny with afternoon highs near 60 degrees Sat. & into the 60s Sun. -- enjoy!
Valentine's Day will be nice too with lots of sun & highs close to 70 degrees. A wind shift to the northeast will briefly cool temps. Tue.-Wed. when there could also be a coastal shower but no widespread rain anytime soon.
"Visit Jacksonville" has a new promotional video starring yours truly along with Charlene Shirk -- click here & go to "Jacksonville Is the Place to Meet" in about the middle of the page.
Earth Gauge: Urban Streams
A recent study looked at the impacts of driveways, sidewalks, streets and other hard surfaces on life in streams near urban areas across the country. When just 10 percent of a watershed is covered by pavement, aquatic life declines in streams by as much as 33 percent. Rain water moves rapidly over paved areas into storm drains and streams. This surge of water can change stream flow and water temperature. Pollutants carried by rain water can also degrade water quality. Even small changes in water quality can be detrimental to aquatic insects like mayflies and stoneflies, which are important food sources for fish.
Tip: You can slow the flow of rainwater at home by installing a rain barrel, which will capture rain water from home downspouts before it runs off your property. Water captured in a rain barrel can be used to water plants or wash windows. Plans for building your own rain barrel are available -- click here.
(Source: U.S. Geological Survey. “Effects of Urbanization on Stream Ecosystems.”)
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Climate Number: 2.2 Watts per square meter
Earth’s climatic energy is moving all about us in different forms. Rain falling on us and rushing through rivers back into the ocean is one form. Big ocean currents, like the Gulf Stream, are another form of climatic energy. Energy coming in directly from the sun (shortwave radiation) warms the Earth’s surface and to a lesser extent the atmosphere. Most of the warming of the atmosphere occurs when the surface absorbs shortwave radiation from the sun and reemits it as longwave radiation. This longwave energy is absorbed by the air and some of the energy absorbed by the air makes its way back into outer space, exiting the climate system. Some of the energy absorbed by the atmosphere, however, is sent back to Earth’s surface. This “back radiation,” known as downward longwave radiation (DLR), is the most important component of Earth’s energy budget. Changes in DLR appear to be the dominant driving force behind recent surface temperature increases. Best estimates are that each square meter column of the atmosphere has on average about 350 watts of DLR. As the Earth has warmed since the early 1970s, this value has been increasing by 2.2 watts per square meter per decade.
For Comparison: A clock radio uses about four watts of power. Earth’s surface is about 508,900,000,000,000 square meters.
(Sources: Wang, K and Liang, S. “Global atmospheric downward longwave radiation over land surface under all-sky conditions from 1973 to 2008.” Journal of Geophysical Research: Atmospheres 114 (2009): D19101 and Stephens, GL. “The role of downward long-wave radiation in water vapor feedback and climate change.” The 13th Conference on Cloud Physics/13th Conference on Atmospheric Radiation. Portland, Oregon. 28 June 2010. Accessed Online 6 February 2011.
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Climate in the News: “Rescuing the Earth's Weather History” – New York Times, February 4, 2011.
Climate researchers are using an array of tools to understand past temperature variability.
Check out this beautiful photo from Mark LeSage -- snapped at NAS Jax early Wed.
Hey! I'm looking for weather skypers. If interested, shoot me an email -- weather@actionnewsjax.com.
Have a great & safe weekend!
