Hawaiian Islands weather details & Aloha paragraphs / April 23-24, 2011

Air Temperatures – The following maximum temperatures were recorded across the state of Hawaii Saturday:

Lihue, Kauai –                    82
Honolulu airport, Oahu –     86
Kaneohe, Oahu –                81
Molokai airport –                 M
Kahului airport, Maui –        86
Kona airport –                    84
Hilo airport, Hawaii –           82

Air Temperatures ranged between these warmest and coolest spots near sea level – and on the highest mountain tops…as of 5pm Saturday evening:

Barking Sands, Kauai – 83
Hilo, Hawaii – 77

Haleakala Crater –     54 (near 10,000 feet on Maui)
Mauna Kea summit – 39 (over 13,500 feet on the Big Island)

Precipitation Totals – The following numbers represent the largest precipitation totals Saturday evening:

0.19    Mount Waialeale, Kauai
0.21    Punaluu Stream, Oahu
0.00    Molokai
0.00    Lanai 
0.00    Kahoolawe
0.11    Oheo Gulch, Maui
0.34    Kawainui Stream, Big Island

Marine Winds – Here’s the latest (automatically updated) weather map showing a 1023 millibar high pressure system to the northeast of the Hawaiian Islands…with a ridge running by to our north. Our trade winds will remain active Sunday and Monday.

Satellite and Radar Images: To view the cloud conditions we have here in Hawaii, please use the following satellite links, starting off with this Infrared Satellite Image of the islands to see all the clouds around during the day and night. This next image is one that gives close images of the islands only during the daytime hours, and is referred to as a Close-up visible image. This next image shows a larger view of the Pacific…giving perspective to the wider ranging cloud patterns in the Pacific Ocean. Finally, here's a Looping IR satellite image, making viewable the clouds around the islands 24 hours a day. To help you keep track of where any showers may be around the islands, here’s the latest animated radar image.

Hawaii’s Mountains – Here’s a link to the live web cam on the summit of near 13,500 foot Mauna Kea on the Big Island of Hawaii. The tallest peak on the island of Maui is the Haleakala Crater, which is near 10,000 feet in elevation. These two web cams are available during the daylight hours here in the islands…and when there’s a big moon rising just after sunset for an hour or two! Plus, during the nights and early mornings you will be able to see stars, and the sunrise too…depending upon weather conditions.

Tropical Cyclone activity in the eastern and central Pacific – Here’s the latest weather information coming out of the National Hurricane Center, covering the eastern north Pacific. You can find the latest tropical cyclone information for the central north Pacific (where Hawaii is located) by clicking on this link to the Central Pacific Hurricane Center. Here’s a tracking map covering both the eastern and central Pacific Ocean. A satellite image, which shows the entire ocean area between Hawaii and the Mexican coast…can be found here. Of course, as we know, our hurricane season ended November 30th here in the central Pacific…and begins again June 1st.

 Aloha Paragraphs

Happy Easter!
 
 
 

Our trade winds will continue to blow, generally on the light side…although locally a bit stronger through Monday.  Glancing at this weather map, we find a high pressure system located to the northeast of the Hawaiian Islands. A ridge of high pressure runs westward from these high pressure cells…to the north of the Hawaiian Islands. The latest forecast continues to suggest that our trade winds will continue through the rest of this holiday weekend into Monday. The computer models show the next increase in our local trade wind speeds beginning again later Tuesday…lasting through the week.  

Our local winds will bring refreshing trade breezes…the following numbers represent the strongest gusts, along with directions Saturday evening:

18 mph       Port Allen, Kauai – SE
21              Honolulu, Oahu – NE 
18              Molokai – NNE    
22              Kahoolawe – E  
21              Lipoa, Maui – E
09              Lanai Airport – SW  
24                South Point, Big Island – NE 

We can use the following links to see what’s going on in our area of the north central Pacific Ocean Saturday evening.  This large University of Washington satellite image shows a large area of high clouds to our south and southeast. Looking at this NOAA satellite picture we see generally clear to partly cloudy skies over the islands, although there are cloudy areas around the mountains locally too. We can use this looping satellite image to see minor cirrus wisps to the southeast…with patchy lower level clouds moving along in the trade wind flow. Checking out this looping radar image shows just a few showers falling over the ocean, with only a couple over the islands themselves.

Sunset Commentary: Here in Kula, Maui at around 510pm Saturday evening, the air temperature was 67.8F degrees. Skies were partly cloudy here on the slopes of the Haleakala Crater. There was still sunshine beaming down along our coasts. When I was down in Paia this afternoon doing my food shopping, the air temperature was a warm 86 degrees. As I drove back up the mountain to Kula, the temperature had dropped to 71 degrees by the time I got home…during those 25 minutes or so. As I had lunch after getting home, the clouds became darker and thickened, leading to a very short period of the lightest showers. My weather deck barely got dampened, although I needed to take in my laundry off the line…fortunately they had dried during the day. I'll be having a nice dinner of fresh Mahi mahi and Ono this evening, plated along side some organic fingerling potatoes. I saw a poster in Paia for some dancing in Makawao tonight, and am strongly considering going down there around 10pm. I haven't been dancing in quite some time, and it seems like a good opportunity. If I do end up going down there, I'm sure I'll be going to bed late. Since tomorrow is Easter, I'll likely try and sleep in later than usual. I will however be back with your next new weather Sunday morning. I hope you have a great Saturday night until then. Please allow me to wish you an early Happy Easter! Aloha for now…Glenn.

Interesting: Coastal residents and oil-rig workers may soon have longer warning when a storm headed in their direction is becoming a hurricane, thanks to a University of Illinois study demonstrating how to use existing satellites to monitor tropical storm dynamics and predict sudden surges in strength. Meteorologists have seen large advances in forecasting technology to track the potential path of tropical storms and hurricanes, but they've had little success in predicting storm intensity.

One of the biggest forecast problems facing the tropical meteorology community is determining rapid intensification, when storms suddenly transform into much stronger cyclones or hurricanes. Hurricane damage comes not only from wind, but also from rain, tornadoes, floods, and the effects of very low air pressure. So a system that would rank hurricanes by wind force alone would not tell the whole tale.

In the 1970s the Saffir-Simpson hurricane intensity category system was developed to characterize the destructive potential of hurricanes. In addition to maximum sustained wind speed and central pressure, the Saffir-Simpson hurricane categorization includes storm-surge height and coastal destruction potential.

On average, there are about 10 named tropical storms off the east coast of the United States each year. Of these, 6 are likely to develop into hurricanes, but only 2 to 3 are likely to reach Saffir-Simpson category 3 or greater intensity.

"Rapid intensification means a moderate-strength tropical storm, something that may affect a region but not have a severe impact, blowing up in less than 24 hours to a category 2 or 3 hurricane," Harnos said. "This big, strong storm appears that wasn't anticipated, and the effects are going to be very negative.

If you don't have the evacuations in place, people can't prepare for something of the magnitude that's going to come ashore." For example, Hurricane Charlie, which hit southern Florida in 2004, was initially forecast as a category 1 storm. However, when it made landfall less than 24 hours later, it had strengthened to a category 4, causing major damage.

Rapid intensification is so hard to predict in part because it's driven by internal processes within the storm system, rather than the better-predicted, large-scale winds that determine the direction of the storms. The satellite imagery most commonly used for meteorology only looks at the clouds at the top of the storms, giving little insight as to what's going on inside the system.

Harnos and Nesbitt focused their study on passive microwave satellite imagery. Such satellites are used commonly for estimating precipitation, surface temperature and other data. The Illinois researchers were the first to use them systematically to observe hurricane structure and intensity changes. "What makes it ideal for what we are doing is that it's transparent to clouds.

It senses the amount of ice within the clouds, which tells us the strength of convection or the overturn of the atmosphere within the hurricane," Nesbitt said. "It's somewhat like trying to diagnose somebody with a broken arm by taking a picture of the arm, versus being able to X-ray it." The researchers scoured data from passive microwave satellites from 1987 to 2008 to see how hurricanes behaved in the 24 hours before a storm underwent rapid intensification.

Such a big-picture approach, in contrast to the case studies atmospheric scientists often perform, revealed clear patterns in storm dynamics. They found that, consistently, low-shear storm systems formed a symmetrical ring of thunderstorms around the center of the system about six hours before intensification began.

As the system strengthened into a hurricane, the thunderstorms deepened and the ring became even more well-defined. The study also looked at high-shear storms, a less common phenomenon involving atmospheric winds hanging with height. Such storms showed a different structure when intensifying: They form a large, bull's-eye thunderstorm in the center of the system, rather than a ring around the center.

Since passive microwave satellites orbit every three to six hours, meteorologists can use them to track tropical storms and watch for the telltale rings to give forecasters about a 30-hour window before a storm hits its maximum strength. "The satellite gives up as snapshot of what's taking place," Harnos said. "We know what's going on, but not how those changes are occurring to end up in the pattern that we're seeing. So what we're working on now is some computer modeling of hurricanes."

Interesting2: The level of the Amazonas River in Peru in the last few weeks has increased from its normal level of 110.42 meters above sea to 117 meters and are threatening to flood the southern Iquitos region, Peru's Regional National Defense Office said on Wednesday. Iquitos regional defense chief Robert Falcon said the level is expected to reach 117.46 meters this week, surpassing the river's critical level of 117 meters registered last week and prompting authorities to issue an alert for the risk of flooding.

Flooding has already been reported in the San Juan, Belen and Punchana municipalities where many houses are affected, Falcon said, while the government of the Maynas province has declared a state of emergency for the town of Iquitos. This will allow prioritizing aid for the affected people in their temporary settlements. In the Maynas municipality, the floods have affected more than 5,264 people, 10 roads and 270 houses, while 130 families had to be evacuated.

Interesting3: Five fires in three different municipalities of Quintana Roo state on Mexico's Yucatan peninsula have destroyed more than 2,500 hectares, the Environment and Natural Resources Ministry said on Wednesday. The worst affected municipalities are Felipe Carrillo Puerto in the Sian Ka An biosphere where 400 hectares have been affected; Benito Juarez in San Pedro where 600 hectares have been affected; the Lazaro Cardenas area in the Costa Rica Lagoon where 1,000 hectares were hit, and in Santa Julia where 450 hectares were destroyed.

Some 500 fire agents of community brigades, 140 agents from the National Forest Commission and six agents from other states are helping to fight the fires, which broke out on April 14. During a recent visit to the affected zone, Environment and Natural Resources Minister Rafael Quesada said high temperatures, fuel storage and difficult access to the affected areas have complicated the firefighting.

Interesting4: Earth may be able to recover from rising carbon dioxide emissions faster than previously thought, according to evidence from a prehistoric event analyzed by a Purdue University-led team. When faced with high levels of atmospheric carbon dioxide and rising temperatures 56 million years ago, Earth increased its ability to pull carbon from the air. This led to a recovery that was quicker than anticipated by many models of the carbon cycle — though still on the order of tens of thousands of years, said Gabriel Bowen, the associate professor of earth and atmospheric sciences who led the study.

"We found that more than half of the added carbon dioxide was pulled from the atmosphere within 30,000 to 40,000 years, which is one-third of the time span previously thought," said Bowen, who also is a member of the Purdue Climate Change Research Center. "We still don't know exactly where this carbon went, but the evidence suggests it was a much more dynamic response than traditional models represent."

Bowen worked with James Zachos, a professor of earth and planetary sciences at the University of California, Santa Cruz, to study the end of the Palaeocene-Eocene Thermal Maximum, an approximately 170,000-year-long period of global warming that has many features in common with the world's current situation, he said.

"During this prehistoric event billions of tons of carbon was released into the ocean, atmosphere and biosphere, causing warming of about 5 degrees Celsius," Bowen said. "This is a good analog for the carbon being released from fossil fuels today."

Scientists have known of this prehistoric event for 20 years, but how the system recovered and returned to normal atmospheric levels has remained a mystery. Bowen and Zachos examined samples of marine and terrestrial sediments deposited throughout the event. The team measured the levels of two different types of carbon atoms, the isotopes carbon-12 and carbon-13.

The ratio of these isotopes changes as carbon dioxide is drawn from or added to the atmosphere during the growth or decay of organic matter. Plants prefer carbon-12 during photosynthesis, and when they accelerate their uptake of carbon dioxide it shifts the carbon isotope ratio in the atmosphere. This shift is then reflected in the carbon isotopes present in rock minerals formed by reactions involving atmospheric carbon dioxide, Bowen said.

"The rate of the carbon isotope change in rock minerals tells us how rapidly the carbon dioxide was pulled from the atmosphere," he said. "We can see the fluxes of carbon dioxide in to and out of the atmosphere. At the beginning of the event we see a shift indicating that a lot of organic-derived carbon dioxide had been added to the atmosphere, and at the end of the event we see a shift indicating that a lot of carbon dioxide was taken up as organic carbon and thus removed from the atmosphere."

A paper detailing the team's National Science Foundation-funded work was published in Nature Geoscience. It had been thought that a slow and fairly constant recovery began soon after excess carbon entered the atmosphere and that the weathering of rocks, called silicate weathering, dictated the timing of the response.

Atmospheric carbon dioxide that reacts with silicon-based minerals in rocks is pulled from the air and captured in the end product of the reaction. This mechanism has a fairly direct correlation with the amount of carbon dioxide in the atmosphere and occurs relatively slowly, Bowen said. The changes Bowen and Zachos found during the Palaeocene-Eocene Thermal Maximum went beyond the effects expected from silicate weathering, he said.

"It seems there was actually a long period of higher levels of atmospheric carbon dioxide followed by a short and rapid recovery to normal levels," he said. "During the recovery, the rate at which carbon was pulled from the atmosphere was an order of magnitude greater than the slow drawdown of carbon expected from silicate weathering alone."

A rapid growth of the biosphere, with a spread of forests, plants and carbon-rich soils to take in the excess carbon dioxide, could explain the quick recovery, Bowen said. "Expansion of the biosphere is one plausible mechanism for the rapid recovery, but in order to take up this much carbon in forests and soils there must have first been a massive depletion of these carbon stocks," he said.

"We don't currently know where all the carbon that caused this event came from, and our results suggest the troubling possibility that widespread decay or burning of large parts of the continental biosphere may have been involved." Release from a different source, such as volcanoes or sea floor sediments, may have started the event, he said.

"The release of carbon from the biosphere may have occurred as a positive feedback to the warming," Bowen said. "The forests may have dried out, which can lead to die off and forest fires. If we take the Earth's future climate to a place where that feedback starts to happen we could see accelerated rates of climate change."

The team continues to work on new models of the carbon cycle and is also investigating changes in the water cycle during the Palaeocene-Eocene Thermal Maximum. "We need to figure out where the carbon went all those years ago to know where it could go in the future," he said. "These findings show that the Earth's response is much more dynamic than we thought and highlight the importance of feedback loops in the carbon cycle."

Interesting5: In a study to be published in the April 21st issue of Science, researchers at Columbia University's School of Engineering and Applied Science report their findings that the ozone hole, which is located over the South Pole, has affected the entire circulation of the Southern Hemisphere all the way to the equator. While previous work has shown that the ozone hole is changing the atmospheric flow in the high latitudes, the new Columbia Engineering paper demonstrates that the ozone hole is able to influence the tropical circulation and increase rainfall at low latitudes in the Southern Hemisphere.

This is the first time that ozone depletion, an upper atmospheric phenomenon confined to the polar regions, has been linked to climate change from the Pole to the equator. "The ozone hole is not even mentioned in the summary for policymakers issued with the last IPCC report," noted Lorenzo M. Polvani, Professor of Applied Mathematics and of Earth & Environmental Sciences, Senior Research Scientist at the Lamont-Doherty Earth Observatory, and co-author of the paper.

"We show in this study that it has large and far-reaching impacts. The ozone hole is a big player in the climate system!" "It's really amazing that the ozone hole, located so high up in the atmosphere over Antarctica, can have an impact all the way to the tropics and affect rainfall there — it's just like a domino effect," said Sarah Kang, Postdoctoral Research Scientist in Columbia Engineering's Department of Applied Physics and Applied Mathematics and lead author of the paper.

The ozone hole is now widely believed to have been the dominant agent of atmospheric circulation changes in the Southern Hemisphere in the last half century. This means, according to Polvani and Kang, that international agreements about mitigating climate change cannot be confined to dealing with carbon alone — ozone needs to be considered, too.

"This could be a real game-changer," Polvani added. Located in Earth's stratosphere, just above the troposphere (which begins on Earth's surface), the ozone layer absorbs most of the Sun's harmful ultraviolet rays. Over the last half-century, widespread use of humanmade compounds, especially household and commercial aerosols containing chlorofluorocarbons (CFCs), has significantly and rapidly broken down the ozone layer, to a point where a hole in the Antarctic ozone layer was discovered in the mid 1980s.

Thanks to the 1989 Montreal Protocol, now signed by 196 countries, global CFC production has been phased out. As a result, scientists have observed over the past decade that ozone depletion has largely halted and they now expect it to fully reverse, and the ozone hole to close by midcentury. But, as Polvani has said, "While the ozone hole has been considered as a solved problem, we're now finding it has caused a great deal of the climate change that's been observed."

So, even though CFCs are no longer being added to the atmosphere, and the ozone layer will recover in the coming decades, the closing of the ozone hole will have a considerable impact on climate. This shows that through international treaties such as the Montreal Protocol, which has been called the single most successful international agreement to date, human beings are able to make changes to the climate system.

Together with colleagues at the Canadian Centre for Climate Modelling and Analysis in Victoria, BC, Kang and Polvani used two different state-of-the-art climate models to show the ozone hole effect. They first calculated the atmospheric changes in the models produced by creating an ozone hole. They then compared these changes with the ones that have been observed in the last few decades: the close agreement between the models and the observations shows that ozone has likely been responsible for the observed changes in Southern Hemisphere.

This important new finding was made possible by the international collaboration of the Columbia University scientists with Canadian colleagues. Model results pertaining to rainfall are notoriously difficult to calculate with climate models, and a single model is usually not sufficient to establish credible results. By joining hands and comparing results from two independent models, the scientists obtained solid results. Kang and Polvani plan next to study extreme precipitation events, which are associated with major floods, mudslides, etc. "We really want to know," said Kang, "if and how the closing of the ozone hole will affect these."

Interesting6: Deforestation in parts of the Peruvian Amazon has increased six-fold in recent years as small-scale miners, driven by record gold prices, blast and clear more of the lowland rainforest, according to a new Duke University-led study. The study, published April 19 in the online journal PLoS ONE, combined NASA satellite imagery spanning six years with economic analyses of gold prices and mercury imports to document the forces responsible for deforestation in Peru's biologically diverse Madre de Dios region.

Roughly 7,000 hectares, or about 15,200 acres, of pristine forest and wetlands were cleared at two large mining sites between 2003 and 2009, with a dramatic increase in deforestation occurring in the last three years. "In addition to these two large sites, there are many scattered, small but expanding areas of mining activity across Madre de Dios that are more difficult to monitor but could develop rapidly like the sites we've tracked over time," says Jennifer Swenson, assistant professor of the practice of geospatial analysis at Duke's Nicholas School of the Environment.

Much of the deforestation visible in the satellite images has been caused by unregulated, artisanal mining by miners who are often among the poorest and most marginalized members of their society. "These are small-time miners; there is no big 'Goliath' mining company to blame," Swenson says. The miners often lack modern technology, have limited knowledge of mining's environmental or human health effects and rarely have safeguards to limit the release of the mercury they use to process their gold into the air, soil or water.

Artisanal mining has occurred in the region since the time of the Incas, but the recent record-setting rise in gold prices, which now exceed $1,400 an ounce, has shifted its pace into hyperdrive, she says. The mining "is now plainly visible from space," Swenson says. "At the two sites we studied, Guacamayo and Colorado-Puquiri, nearly 5,000 acres were cleared in just three years, between 2006 and 2009, largely outpacing nearby deforestation caused by human settlement."

Land cleared for mining has a different spectral signature on satellite images, allowing Swenson and her team to differentiate it from deforestation caused by farming, road-building or other settlement-related activities. Most of the gold mined artisanally in Madre de Dios comes from alluvial deposits in the channels and floodplains of Amazon tributaries. Miners blast away river banks and clear floodplain forests to expose potential gold-yielding gravel deposits and use mercury to process the gold ore.

The mercury contaminates local water and soil, and ravages the nervous system of miners and their families, but the risks extend far beyond the local area, Swenson says. Small-scale gold mining is the second-largest source of mercury pollution in the world, behind only the burning of fossil fuels. Mercury from artisanal mines can travel hundreds of miles in the atmosphere or in surface waters — eventually settling in sediments and moving up the food chain into fish, fish-eating wildlife and humans.

"Virtually all mercury imported to Peru is used for artisanal gold mining and imports have risen exponentially since 2003, mirroring the rise in gold prices," Swenson says. "Given the rate of recent increases, we project mercury imports will more than double by the end of 2011, to about 500 tons a year." It's been difficult for Peru's government to monitor and control all artisanal mining within its borders, she says, but another approach, worth considering, may be to be start limiting mercury imports.

It will take at least 10 years to eradicate the H5N1 bird flu virus, which has killed scores of humans, from poultry in the six countries where it is endemic, a UN agency said today. The strain of the avian influenza virus was reported in 60 countries at its peak in 2006, but most had managed to stamp it out, the Food and Agriculture Organization said in a report.