Chambered Nautilus Threatened

The link below will take you to an excellent article in this week's NY Science Times on the chambered nautilus.  It's ancestors go about 500 million years back in the fossil record.

NY Science Times Article

Green Sea Turtles

All sea turtles are at least threatened.  Check out these short but interesting articles on green turtles.
NOAA Green Sea Turtles Article

NatGeo Green Sea Turtles Article

Wikipedia Green Sea Turtle Article

Coral Reef Health

You can't judge a book by its cover.

Changes in Rainfall Patterns Are Projected for Next 30 Years On Hawaii's Oahu

ScienceDaily (Oct. 10, 2011) — Scientists at University of Hawaii - Manoa have projected an increased frequency of heavy rainfall events but a decrease in rainfall intensity during the next 30 years (2011-2040) for the southern shoreline of Oahu, according to a recent study published in the Journal of Geophysical Research.

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See Also:

Earth & Climate

• Weather
• Water
• Climate
• Environmental Issues
• Volcanoes
• Global Warming

Reference

• Infiltration (hydrology)
• Consensus of scientists regarding global warming
• Precipitation (meteorology)
• Monsoon

Chase Norton, a Meteorology Research Assistant at the School of Ocean and Earth Science and Technology (SOEST) at UH -- Manoa, and colleagues (Professors Pao-Shin Chu and Thomas Schroeder) used a statistical model; rainfall data from rainfall gauges on Oahu, Hawaii; and a suite of General Circulation Models (GCMs) from the Intergovernmental Panel on Climate Change (IPCC) to project future patterns of heavy rainfall events on Oahu. GCMs play a pivotal role in the understanding of climate change and associated local changes in weather.

Heavy rainfall and flash floods are common in the Hawaiian Islands due to their steep terrain, rain‐producing weather systems, and abundant moisture supply. They have caused multimillion dollars damage to homes, properties, roads, agriculture, and other sectors. Environmentally, heavy rainfall and runoff events in Hawaii, which are likely to cause slope and coastal erosion, pollutant discharges to the near shore marine environment, coral reef degradation, among others, are expected to change as Earth undergoes an unprecedented warming. Given the socioeconomic repercussions resulting from past storm events, it is of considerable interest to investigate changes in the frequency and intensity of heavy rainfall events in Hawaii, particularly for Oahu, as it is the most populous island in Hawaii.

"The results presented in this study may benefit many agencies who are concerned with floods and relevant policy-making in the face of climate change," says Chu, UH - Manoa Meteorology Professor, Hawaii State Climate Office Director, and co-author of the study. "For instance, changes in rainstorm intensity may be a serious consideration in aquifer management - as precipitation is the primary water source for streams and groundwater supply."

Norton, Chu, and Schroeder would like to use the IPCC GCM simulations and extend the rainfall model to project future events in other locations. They also plan to use a high resolution regional climate model to project future changes in water resources in the Hawaiian Islands.

More Foliage

The Science of Color in Autumn Leaves

As the days get cooler and frost is in the air, deciduous trees and shrubs put on an autumn show in all shades of red, yellow, purple, and brown. The splendor of crisp fall days and vibrant leaves brings to mind memories for nearly everyone who lives in an area wheredeciduous forests are the dominant vegetation. In many parts of the country, autumn leaves are an important factor in tourism. Many think that cool weather or frost cause the leaves to change color. While temperature may dictate the color and its intensity, it is only one of many environmental factors that play a part in painting deciduous woodlands in glorious fall colors. To understand the whole process, it is important to understand the growth cycle of deciduous trees and shrubs. Most have a relatively short period of annual growth. New stems begin to grow from overwintering buds when the days become long enough and the weather is warm enough to support growth. For most trees, growth is usually completed by late June in the Northern Hemisphere. Next year's leaf buds are set at this time and will not open until they experience the chill and short days of winter followed by the warmth and longer days of spring. Once the leaves are fully expanded and the buds are set, the work of manufacturing and storing carbohydrates to support next year’s growth goes full speed ahead. These carbohydrates are stored in the branches, roots, and buds throughout the growing season to support next year's growth. The process that starts the cascade of events that result in fall color is actually a growth process. In late summer or early autumn, the days begin to get shorter, and nights are longer. Like most plants, deciduous trees and shrubs are rather sensitive to length of the dark period each day. When nights reach a threshold value and are long enough, the cells near the juncture of the leaf and the stem divide rapidly, but they do not expand. This abscission layer is a corky layer of cells that slowly begins to block transport of materials such as carbohydrates from the leaf to the branch. It also blocks the flow of minerals from the roots into the leaves. Because the starting time of the whole process is dependent on night length, fall colors appear at about the same time each year in a given location, whether temperatures are cooler or warmer than normal. During the growing season, chlorophyll is replaced constantly in the leaves. Chlorophyll breaks down with exposure to light in the same way that colored paper fades in sunlight. The leaves must manufacture new chlorophyll to replace chlorophyll that is lost in this way. In autumn, when the connection between the leaf and the rest of the plant begins to be blocked off, the production of chlorophyll slows and then stops. In a relatively short time period, the chlorophyll disappears completely. This is when autumn colors are revealed. Chlorophyll normally masks the yellow pigments known as xanthophylls and the orange pigments called carotenoids — both then become visible when the green chlorophyll is gone. These colors are present in the leaf throughout the growing season. Red and purple pigments come from anthocyanins. In the fall anthocyanins are manufactured from the sugars that are trapped in the leaf. In most plants anthocyanins are typically not present during the growing season. As autumn progresses, the cells in the abscission layer become more dry and corky. The connections between cells become weakened, and the leaves break off with time. Many trees and shrubs lose their leaves when they are still very colorful. Some plants retain a great deal of their foliage through much of the winter, but the leaves do not retain their color for long. Like chlorophyll, the other pigments eventually break down in light or when they are frozen. The only pigments that remain are tannins, which are brown. Temperature, sunlight, and soil moisture greatly influence the quality of the fall foliage display. Abundant sunlight and low temperatures after the time the abscission layer forms cause the chlorophyll to be destroyed more rapidly. Cool temperatures, particularly at night, combined with abundant sunlight, promote the formation of more anthocyanins. Freezing conditions destroy the machinery responsible for manufacturing anthocyanins, so early frost means an early end to colorful foliage. Drought stress during the growing season can sometimes trigger the early formation of the abscission layer, and leaves may drop before they have a chance to develop fall coloration. A growing season with ample moisture that is followed by a rather dry, cool, sunny autumn that is marked by warm days and cool but frostless nights provides the best weather conditions for development of the brightest fall colors. Lack of wind and rain in the autumn prolongs the display; wind or heavy rain may cause the leaves to be lost before they develop their full color potential. The character of autumn color is different in different parts of the world. In New England and the northeast sections of Asia, a few species dominate the deciduous forests. The display there tends to be short but intense because the change is rapid and rather uniform. In the southern Appalachians, the change is often gradual and the fall foliage season may last for more than a month because of the greater diversity of plant species found in the forest there. Mixed forests that have both evergreen conifers such as spruce and deciduous trees such as aspen or larch are found in the far north or at high elevations. Here, the dominant color is yellow and the change is rapid, with trees often going from green through brilliant yellow to bare over a period of two weeks. Tropical forests often have many deciduous trees that lose their leaves in response to drought; typically the leaves do not change color before they drop. In areas that are often cloudy for much of the autumn, with rather warm temperatures, fall colors are dull at best. This is often the case in much of Europe. While the whole process of fall color is fairly well understood, the reason for it is less clear. Scientists have long known that xanthophylls and carotenoids play an important part in photosynthesis by helping to capture light energy, but the benefit of anthocyanins is not well understood.  It might seem more logical for plants to remove all the carbohydrates they possibly can from the leaf before making it fall off. If this were the case, we wouldn’t have the red and purple pigments that we see in sugar maple, black gum, burning bush, or sweet gum. Carbohydrates are needed to manufacture these pigments. Some entomologists believe that the evolutionary reason that plants expend energy to produce fall color is to warn pests. A plant that is healthy is able to produce lots of carbohydrates, and therefore more anthocyanin. This may cause certain insect pests laying eggs in the fall to seek another host plant for their offspring that is weaker and drab by comparison. Some scientists believe that anthocyanins may act as a sunscreen to inhibit the destruction of the chlorophyll, help to prevent frost injury to leaf tissues, or limit water loss during dry spells in autumn. As far as the fall foliage watcher is concerned, their purpose is simple—they signal a last hurrah for the growing season and delight the optic nerve.

Fabulous Autumnal Colors on the Way?

I know this isn't really oceanography, but I couldn't resist.  Autumn in all its splendor is just so beautiful.

Cool Autumn Weather Reveals Nature’s True Hues

High resolution (Credit: NOAA)

A favorite American pastime in fall is to pack a picnic basket and set off with loved ones on a Sunday drive along one of the nation’s many scenic byways. It’s a time of year when people enjoy crisp cool weather and marvel at the transforming landscape as tree leaves turn from lush green to gorgeous shades of yellow, orange, red, purple and brown.

While we relish the opportunity to frolic in a big pile of freshly raked leaves, we don’t often think about the science behind why leaves change color and eventually fall from their branches. The answer may surprise you!

Recipe for Fabulous Foliage: Cool Nights and Sunny Days

Weather factors such as temperature, sunlight, precipitation and soil moisture influence fall color arrival, duration and vibrancy. According to United States National Arboretum, a wet growing season followed by a dry autumn filled with sunny days and cool, frostless nights results in the brightest palette of fall colors. Changes in weather can speed up, slow down or change the arrival time of fall’s colorful foliage. For example:

High resolution (Credit: NOAA)

• Drought conditions during late summer and early fall can trigger an early “shutdown” of trees as they prepare for winter. This causes leaves to fall early from trees without reaching their full color potential.
• Freezing temperatures and hard frosts can kill the processes within a leaf and lead to poor fall color and an early separation from a tree.

How can you find the best place and time to see fall foliage in your area? NOAA’s National Weather Serviceregional forecast offices can provide you with a 7-day forecast of weather conditions, including the arrival times of different air masses, to help you determine the best location in your area for vibrant fall color.

True Colors Come From Inside 

Trees actually begin to show their true colors in autumn, and here’s why. 

The four primary pigments that produce color within a leaf are: chlorophyll (green); xanthophylls (yellow); carotenoids (orange); and anthocyanins (reds and purples). During the warmer growing seasons, leaves produce chlorophyll to help plants create energy from light. The green pigment becomes dominant and masks the other pigments. 

High resolution (Credit: NOAA)

Trees must replenish the chlorophyll because sunlight causes it to fade over time. As days get shorter and nights become longer, trees prepare for winter and the next growing season by blocking off flow to and from a leaf’s stem. This process stops green chlorophyll from being replenished and causes the leaf’s green color to fade.

The fading green allows a leaf’s true colors to emerge, producing the dazzling array of orange, yellow, red and purple pigments we refer to as fall foliage.

Following the Feast of Fall Colors

Fall’s color “parade” varies from region to region and year to year, depending on weather conditions. For areas under calm and dry high pressure, cool nights and sunny days can lengthen fall color displays. Cold or warm fronts can produce strong winds and heavy rain that cause leaves to fall off trees more rapidly.

High resolution (Credit: NOAA)

If you’re planning a trip to see fall foliage, first check out the current and near-term weather conditions in your area from NOAA’s National Weather Service.

The Web links below offer a variety of fall foliage resources, including popular scenic drives and peak viewing times. NOAA’s Climate Prediction Center offers a range of forecast information related to seasonal temperature, precipitation, soil moisture and drought conditions.

Other Resources:

National Tree Cover Atlas:
Offers digital maps of forest cover for 25 different tree types, helping travelers seeking the right locations for specific fall colors.

United States National Arboretum
Learn more about the pigmentation processes that occur within leaves.