The weekend will be stormy at times. The combination of "Florence" leftovers nearby -- especially Sat. -- & a strong upper level disturbance passing by to the north will lead to midday through afternoon storms with heavy downpours, lots of lightning & gusty winds. There will even be a few morning showers & storms, particularly north & west of Jax. Temps. will still reach 90+ but drop nicely in & near storms.
A couple of First Alert photos. The first one was taken by one of our Action News videographers, David Hickox -- EverBank Field with a towering cumulus cloud seemingly on top of the stadium. The second photo is from late Fri. - Casey Yates, S. Jax Beach.
Earth Gauge: National Water Quality Month
Did you know that you can protect water quality just by limiting your water use? Water conservation puts less stress on our drinking water supplies and diverts less water for municipal use – this helps preserve stream flow and maintain healthy aquatic environments. Efficient outdoor water use also reduces the amounts of pollutants reaching groundwater supplies and running off into storm drains.
Tip: August is National Water Quality Month. Give these tips a try to save water at home and protect water quality:
· Don’t over-water your lawn. Over-watering can increase the flow of fertilizers deep into soils and eventually groundwater supplies, which are an important drinking water source. Walk on your lawn to find out if it is thirsty – if your footprints remain, it is time to water.
· Shorten showers. Shortening your shower by two minutes each day can save five gallons of water – that’s 35 gallons in a week.
· Use rain barrels. Rain barrels are a great way to catch rain water off running off of your roof. You can use the water collected to water plants or wash windows and cars.
(Sources: EPA, “Nutrient Pollution”)
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Climate Trivia: Central American Seaway and the Global Climate
If Earth had a newspaper to chronicle its 4.5 billion year existence, one of the biggest headlines of the last 10 million years would be the joining of North and South America through the closure of the Central American Seaway (CAS). The Central American nations of Panama and Costa Rica are “young” landscapes, formed by volcanism over just the past few million years – a very recent development in the context of geologic time. The period when the CAS closed corresponds to a period of major changes in ocean circulation, ocean temperature distributions and climatic conditions in remote locations throughout the world.
Trivia Question: As the Central American Seaway closed around four million years ago, the Earth’s climate:
a) warmed.
b) cooled.
c) became more sensitive to the influence of orbital cycles.
d) a and c.
e) b and c.
The correct answer is e. The closure of the CAS around four million years ago was followed by a period of brief warming, then steady cooling until the modern 100,000 year glacial-interglacial cycles began around two million years ago. Prior to the closure of the CAS, Earth was between five and 6.5 degrees Fahrenheit warmer than it has been over the past 10,000 years. What would today be considered tropical sea surface temperatures extended all the way into midlatitude waters, with less of a temperature gradient between the tropics and high latitudes. The east-west gradients between warm and cool water patches, such as the gradient that exists in the tropical Pacific particularly during La Niña events, were also reduced. This more diffuse distribution of warm ocean waters meant enhanced evaporation in the tropics and subtropics, which led to more high tropical clouds that work to warm the planet. The closure of the CAS impacted the ocean circulation system that determines sea surface temperature distributions by increasing the salinity contrast between the Pacific and Atlantic Oceans. The closure is the most likely explanation for the retreat of warm tropical waters out of the midlatitudes, the increased strength of La Niña events in the tropical Pacific and gradual cooling of the Earth. This overall cooling and shift in the ocean circulation system made Earth more susceptible to the influence of periodic orbital variations, allowing for growth in ice masses and ice age conditions.
(Source: LaRiviere, JP et al. “Late Miocene decoupling of oceanic warmth and atmospheric carbon dioxide forcing.” Nature 486 (2012): 97-100. )
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Climate in the News: “Giant Moa Had Climate Change Figured Out.” – ScienceDaily, August 3, 2012
New research indicates that New Zealand’s now extinct Moas had stable populations for 40,000 years before humans arrived and that it is unlikely that climate played a significant role in their extinction.
Have a great & safe weekend!
