#Caroline Ummenhofer

[moko1590m]

ウッズ・ホール海洋研究所の科学者らからなる研究チームが科学誌Current Biologyに発表した論文によると、北大西洋に生息する希少な海鳥であるデゼルタス・ミズナギドリは、他の外洋性海鳥とは対照的に、ハリケーン（熱帯性暴風雨）を避けるのでなく、荒れ狂う自然の脅威をエサの確保に利用しているといいます。体のサイズはハトくらいなのに、大きくて強いハートを持っているようですね。 先行研究では、海鳥はハリケーンの周りを飛ぶか、晴れている穏やかなハリケーンの目の中に逃げ込むとされてきました。ところが、研究チームが追跡したデゼルタス・ミズナギドリの3分の1がどちらの行動もとらず、数日間、何千kmもハリケーンを追いかけ続けたとのこと。 ウッズ・ホール海洋研究所の生物学博士研究員で、論文の筆頭執筆者でもあるFrancesco Ventura氏は、今回の発見について データを見たとき、椅子から転げ落ちそうになりました。こんな行動を観察したのは初めてです。 とプレスリリースで語っています。 デゼルタス・ミズナギドリは、まずハリケーンを追いかけて飛び、追いついてからは追い風に乗って移動しながらエサを捕るといいます。研究に携わった同研究所のCaroline Ummenhofer氏は、この行動について次のようにコメントしています。 海鳥が北大西洋の広範囲にわたる風の状況を移動にうまく使う方法を熟知しているのは驚きでした。平均風速とミズナギドリの採餌行動を重ねると、ほとんど一致しています。 Advertisement デゼルタス・ミズナギドリの驚異的なハリケーン追跡飛行の発見はまだ続きます。Ventura氏は、ハリケーンの強風にあおられてもたたき落とされない飛行テクニックを説明します。 私たちは、最大8mの波や、時速100km（毎秒28m）の強風などの激しさを増すストームの状況と、ミズナギドリの位置を照らし合わせました。すると、彼らは強風にぶつかると、翼が傷つかないように対地速度を落としていたようです。その後、ストームの進路に沿って、追い風の強いルートを飛行しました。驚くべきことに、追跡した海鳥たちは1羽もストームの被害を受けずに巣に帰りました。 エサを求め、嵐を追いかける海鳥 デゼルタス・ミズナギドリは、北アフリカ西岸沖にあるポルトガルのブギオ島に巣を構えます。険しい崖に囲まれた台地が、200組弱のつがいにとって唯一の営巣地です。6カ月におよぶ繁殖期の間、エサを求めて時に数週間、12000kmもの距離を飛び回ります。 彼らが探し求める小魚やイカ、甲殻類は、通常水深180mから900mに生息しています。もちろん、海鳥はそんな深さまで潜れません。穏やかな海では捕まえられないエサが海面付近まで浮上してくる絶好の機会を求めて、嵐を追いかけるんです。 ハリケーンやストームの強風は、海洋の上層部をかき混ぜます。デゼルタス・ミズナギドリは、海水と一緒に海面に浮いてきたエサを捕まえます。ハリケーンハンターは、忍耐強い漁師でもありますね。 ストームは、海洋や沿岸地域の生態系に大きな影響を与えます。今回の研究結果によって、破壊的なストームが、ある種にとってはプラスの機会を生み出す可能性を示しています。 しかし、ストームが遠洋の海洋生物にどんな影響を与えているのかは、まだあまり知られていないそうです。ウッズ・ホール海洋研究所のPhilip Richardson氏は研究の意義について以下のように述べています。 今回の研究では、食物連鎖のトップにいる捕食者を通して、ハリケーンが海洋生態系に与える影響に関する新たな視点が得られました。またこの研究は、極端な気象に対する外洋性海鳥のレジリエンスと採餌行動について貴重な洞察を与えています。 エサを追い求めて何日も何千kmもハリケーンを追いかけ、風もエサもつかまえて、無傷のままエサを待つ家族の元に帰っていくデゼルタス・ミズナギドリ。最高のハンターですね。 Source: Ventura et al. 2024 / Current Biology, Hole Oceanographic Institution

海鳥｢なぜハリケーンを追いかけるかって？ そこにエサがいるからさ｣ | ギズモード・ジャパン

[emergencymanagementnews]

WHOI’s Caroline Ummenhofer discusses how interactions between the Pacific and Indian Oceans influenced Pakistan’s monsoon rains

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Spanien und Portugal leiden unter dem trockensten Klima seit 1.200 Jahren

Spanien und Portugal leiden unter dem trockensten Klima seit 1.200 Jahren

In Spanien und Portugal herrscht das trockenste Klima seit mindestens 1.200 Jahren. Dies hat schwerwiegende Folgen für die Lebensmittelproduktion und den Tourismus. Der meiste Regen auf der Iberischen Halbinsel fällt im Winter, wenn feuchte Tiefdruckgebiete vom Atlantik her einströmen. Ein Hochdrucksystem vor der Küste, das Azorenhoch, kann die feuchten Wetterfronten jedoch blockieren. Die…

[sciencespies]

Why more clouds can mean less rain in Australia

https://sciencespies.com/environment/why-more-clouds-can-mean-less-rain-in-australia/

Why more clouds can mean less rain in Australia

A Northwest Cloudband on 12th January 2010, from the MTSAT Satellite. Picture: MTSAT

On any given day in Australia, depending on where you are, you may look up – hoping for those rainclouds to appear in the sky, or wishing them away.

But what you may not realize, is the clouds you’re looking at could be part of a pretty amazing weather phenomena.

The Northwest Cloudband is a huge cloud that stretches from the East Indian Ocean to the southern coast of Australia and can cause widespread rainfall across the country.

It’s thousands of kilometers long, extending from tropical Australia to Tasmania.

Similar systems occur around the world and they go by different names: tropical intrusions, tropical-extratropical cloudbands and tropical plumes. But the names all imply the same idea – the tropics intruding on the higher latitudes and bringing with them a whole lot of water.

Our new study shows that winter extreme rainfall is four times more likely in Victoria during a Northwest Cloudband event and up to twelve times more likely in northwest Australia.

And these events are becoming more common.

Why do cloudbands form?

The eastern Indian Ocean is the Northwest Cloudband nursery.

These giant clouds begin life as water evaporating from the warm surface of the Indian Ocean.

Number of Days with a Northwest Cloudband per year. Graphic: Adapted from Reid et al 2019

This evaporation is enhanced when the sea surface temperatures (SSTs) are warmer in the northeast Indian Ocean and cooler in the southeast Indian Ocean because this temperature difference makes the air above the ocean unstable.

The water vapor rises through the unstable atmosphere and forms clouds. But to get to southeastern Australia, without raining all the water out over the desert, the clouds need to hitch an express ride.

And this is where the extratropics come in.

The extratropics are typically defined as between 30 and 60 degrees latitude, and it’s in this zone that the weather is dominated by high and low-pressure systems.

A land of drought and flooding rains

Southern Australia is prone to these tropical visitors when there are high-pressure systems over southwest Western Australia and Queensland, as this sets up the ideal air flow for Northwest Cloudbands.

The southwestern high pushes cold air from the Southern Ocean towards northwest Australia, while the northeastern high pulls warm and wet air from the Coral Sea towards the center of Australia.

When the warm northeasterly air meets the cold southwesterly air, they clash creating a huge zone of unstable rising air – perfect for cloud formation.

The moist air and cloud that began over the Indian Ocean then traverses our entire continent via this zone of instability.

Conceptual model of Australian Winter Northwest Cloudband. Graphic: Reid et al 2019

How do we know northwest cloudbands are occurring more often?

Scientists were particularly interested in Northwest Cloudbands in the 1980s and 1990s.

The satellite era may have begun in the late 1970s with the launch of the first Geostationary satellites, but they were only just starting to be used to observe the weather – so scientists really only had access to a few years of useful data.

In these early studies, scientists manually identified Northwest Cloudbands by looking at grainy infrared satellite images of clouds over Australia.

But in the 21st Century, interest in the Northwest Cloudband waned.

In 2016, while researching the causes of Victorian changing rainfall with Professor Ian Simmonds and Dr Claire Vincent, we realized part of the puzzle was missing.

We knew Northwest Cloudbands caused rainfall in Victoria, but given we only had northwest cloudband records from the 80s and 90s, we couldn’t tell whether recent changes in Victorian rainfall had any relationship with Northwest Cloudbands.

The simple solution was to create our own updated record with the help of fellow School of Earth Sciences academic Dr Andrew King, the Department of Environment, Land, Water and Planning Victoria and the Australian Research Council Centre of Excellence for Climate Extremes.

The result was an algorithm that identifies Northwest Cloudbands over Australia from satellite observations of clouds.

Instead of manually searching approximately 14,000 images, the algorithm looks at the cloud over Australia from snapshots taken every three hours and tests the shape, location, continuity and size of the cloud to establish whether there is a Northwest Cloudband.

Winter daily rainfall anomalies during Northwest Cloudband days in units of millimetres. Graphic: Reid et al 2019

Our research produced a record of Northwest Cloudbands from 1984 through to 2016; the longest observational record of Australian Northwest Cloudbands. But it doesn’t stop there, as new satellite data becomes available, we are constantly updating the record.

Importantly, this 33-year-old record means we can now observe long-term trends. And we found Northwest Cloudbands are occurring more often over Australia at a rate of about one extra day per year.

In fact, they have nearly doubled in frequency and we don’t really know why.

There’s a raft of possible explanations all needing further research: climate change, the expansion of the tropical circulation system known as the Hadley Cell, aerosols and increased high-pressure systems in Southwest Western Australia.

What’s the impact of more cloudbands?

Given the ongoing concern about the impact of drought in Australia, it would be nice to assume that an increase in the frequency of these cloudbands would bring more rain.

But in fact, the reverse may be true.

We found that while the Northwest Cloudband increases rainfall over northwest, central and southern Australia (blue regions in rainfall map), it’s actually associated with a daily rainfall deficit (brown regions in rainfall map) over eastern and southwestern Australia.

This means that, counterintuitively, more cloudbands could lead to less rainfall in certain parts of Australia.

In fact, we are now trying to understand whether the recent droughts in New South Wales and Queensland have any connection to years with above average Northwest Cloudbands.

We are starting to learn about the impacts of cloudbands, which is especially important for understanding Australia’s rainfall trends in the future climate.

Explore further

NASA IMERG sees Australia’s bicoastal rainfall

More information: Kimberley J. Reid et al. The Australian Northwest Cloudband: Climatology, Mechanisms, and Association with Precipitation, Journal of Climate (2019). DOI: 10.1175/JCLI-D-19-0031.1

Caroline C. Ummenhofer et al. Modulation of Australian Precipitation by Meridional Gradients in East Indian Ocean Sea Surface Temperature, Journal of Climate (2009). DOI: 10.1175/2009JCLI3021.1

Sarah M. Kang et al. Expansion of the Hadley Cell under Global Warming: Winter versus Summer, Journal of Climate (2012). DOI: 10.1175/JCLI-D-12-00323.1

Raktima Dey et al. Investigating observed northwest Australian rainfall trends in Coupled Model Intercomparison Project phase 5 detection and attribution experiments, International Journal of Climatology (2018). DOI: 10.1002/joc.5788

Michael R. Grose et al. Severe Frosts in Western Australia in September 2016, Bulletin of the American Meteorological Society (2018). DOI: 10.1175/BAMS-D-17-0088.1

Provided by University of Melbourne

Citation: Why more clouds can mean less rain in Australia (2019, December 2) retrieved 2 December 2019 from https://phys.org/news/2019-12-clouds-australia.html

This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.

#Environment

[shirlleycoyle]

Centuries-Old Sea Captain Diaries Are Confirming Modern Climate Science

When 19th century whalers jotted down weather and temperature measurements at sea, few might have imagined that their logbooks would become records of a warming planet more than 150 years later.

But that’s exactly the kind of value that climate scientists such as Caroline Ummenhofer of the Woods Hole Oceanographic Institution see in whaling logbooks. Packed with daily local observations, they can be used to corroborate climate change trends revealed in standardized temperature readings and geological records.

“We’ve observed a lot of changes over recent decades, including warming oceans, melting ice sheets on Greenland, shifts in weather patterns, and more frequent, intense droughts and floods,” said Ummenhofer in a statement.

“However, in many remote areas, such as the Arctic, we lack long datasets that can put recent observations into a long-term context,” she added. “This has limited our ability to understand how shifting weather and climate patterns may affect human society and ecosystems.”

The notes taken by whaling captains and first mates can help to fill in some of the gaps left in the record of mean global temperatures, which only extends back to 1880. American whaler diaries, in contrast, have been kept since the late 1700s, adding more than a century of supplementary observations to the climate record.

The logbooks also contain information about remote ocean locations rarely visited by other types of vessels, at that time, such as war and merchant ships, which tended to stick to established sea routes. Whalers deviated from these shipping lanes to find far-flung areas known for an abundance of marine mammals.

In particular, regions where climate change is wreaking the most havoc, such as the Arctic and the Indian Ocean, can be contextualized by whalers’ accounts of monsoons, ice cover, and other local weather phenomena.

For instance, whalers and many other mariners depended on the windy conditions in the so-called Roaring Forties band of latitude to propel them across the Indian Ocean. In recent decades, however, the winds have been shifting south into latitudes known as the Furious Fifties. Whaling logbooks may contain clues about how and when this trend began.

Read More: Cleopatra’s Downfall Was Partly Sparked by Climate Change and Volcanoes

Ummenhofer has partnered with Timothy Walker, a historian at the University of Massachusetts Dartmouth, to collect, examine, and digitize the logbooks preserved in many institutions around New England, which was the epicenter of America’s whaling industry.

“By bringing together a team of oceanographers, climatologists, and historians, we’re in a position to extract the climate data we need to make better sense of the past,” she said, “while showcasing how this aspect of our local history here in New England still has relevance today.”

Centuries-Old Sea Captain Diaries Are Confirming Modern Climate Science syndicated from https://triviaqaweb.wordpress.com/feed/

[capecoddaily]

Deck: Rate of melting might be temporarily increased or decreased by two existing climate patternsTowns: Woods HoleTopic: NewsHub Category: OutdoorsAuthor: CapeCodToday StaffTeaser: Rate of melting might be temporarily increased or decreased by two existing climate patternsMain Image: Main Image Credit: Caroline Ummenhofer, climate modeler at the Woods Hole Oceanographic Institution (Photo by Thomas Kleindinst, Woods Hole Oceanographic…

[sciencespies]

Scientists Are Mining Ship Logs From 19th-Century Whaling Vessels For Climate Data

https://sciencespies.com/news/scientists-are-mining-ship-logs-from-19th-century-whaling-vessels-for-climate-data/

Scientists Are Mining Ship Logs From 19th-Century Whaling Vessels For Climate Data

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says Dr. Caroline Ummenhofer, a climate researcher at Woods Hole Oceanographic Institution.

The daily logs from a fleet of over 30 whaling ships are helping fill climate data gaps by providing perspective on changes in the marine environment. Similar records from trade and military vessels have also been useful, but their observations are largely confined to specific routes. In contrast, whalers often took several detours in an effort to chase down their prey.

Whalers kept meticulous notes as they pursued whales, documenting changes in wind speed and air temperature, ship maintenance procedures, and life on the water. Combined, this information can provide insight into how rapidly climate change has altered portions of the oceans where some recent and virtually no historical climate data exists.

For example, in 1871, several whaling ships were approaching a wall of ice that towered above the ship. Without any wind to help the ship detour, over one thousand people fled to nearby rescue boats. Amidst the harrowing details of this incident were descriptions of the damage done to the ship’s exterior by the ice. Now, almost 150 years later, it is safe to say that contemporary whalers would likely never find themselves in such a predicament due to the rapid decline of Arctic ice as the planet has warmed.

"[These] logbook-derived data will not only help push the instrumental climate record back to the late 1700s, but they can give us a much broader geographical distribution of weather data than is currently available," says Dr. Timothy Walker, a history professor at the University of Massachusetts Dartmouth (UMassD), "This can lead to a better understanding of modern climate records and help predict future changes."

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Whalers in action. Historical view from the 19th century. Wood engraving after a paintig (The Flurry, c. 1848) by William Charles Duke (Irish-Australian painter, 1814 – 1853) in Allport Library and Museum of Fine Arts (Hobart, Tosmania, Australia),

Getty

Climate scientists are relying on the records of 19th-century whalers to understand how climate change has affected some of the more remote regions of the ocean, including the Indian Ocean – where changes in monsoon patterns threaten nearly one billion people – and the Arctic.

“We’ve observed a lot of changes over recent decades, including warming oceans, melting ice sheets on Greenland, shifts in weather patterns, and more frequent, intense droughts and floods,” says Dr. Caroline Ummenhofer, a climate researcher at Woods Hole Oceanographic Institution.

The daily logs from a fleet of over 30 whaling ships are helping fill climate data gaps by providing perspective on changes in the marine environment. Similar records from trade and military vessels have also been useful, but their observations are largely confined to specific routes. In contrast, whalers often took several detours in an effort to chase down their prey.

Whalers kept meticulous notes as they pursued whales, documenting changes in wind speed and air temperature, ship maintenance procedures, and life on the water. Combined, this information can provide insight into how rapidly climate change has altered portions of the oceans where some recent and virtually no historical climate data exists.

For example, in 1871, several whaling ships were approaching a wall of ice that towered above the ship. Without any wind to help the ship detour, over one thousand people fled to nearby rescue boats. Amidst the harrowing details of this incident were descriptions of the damage done to the ship’s exterior by the ice. Now, almost 150 years later, it is safe to say that contemporary whalers would likely never find themselves in such a predicament due to the rapid decline of Arctic ice as the planet has warmed.

“[These] logbook-derived data will not only help push the instrumental climate record back to the late 1700s, but they can give us a much broader geographical distribution of weather data than is currently available,” says Dr. Timothy Walker, a history professor at the University of Massachusetts Dartmouth (UMassD), “This can lead to a better understanding of modern climate records and help predict future changes.”

#News

[shirlleycoyle]

Centuries-Old Sea Captain Diaries Are Confirming Modern Climate Science

When 19th century whalers jotted down weather and temperature measurements at sea, few might have imagined that their logbooks would become records of a warming planet more than 150 years later.

But that’s exactly the kind of value that climate scientists such as Caroline Ummenhofer of the Woods Hole Oceanographic Institution see in whaling logbooks. Packed with daily local observations, they can be used to corroborate climate change trends revealed in standardized temperature readings and geological records.

“We’ve observed a lot of changes over recent decades, including warming oceans, melting ice sheets on Greenland, shifts in weather patterns, and more frequent, intense droughts and floods,” said Ummenhofer in a statement.

“However, in many remote areas, such as the Arctic, we lack long datasets that can put recent observations into a long-term context,” she added. “This has limited our ability to understand how shifting weather and climate patterns may affect human society and ecosystems.”

The notes taken by whaling captains and first mates can help to fill in some of the gaps left in the record of mean global temperatures, which only extends back to 1880. American whaler diaries, in contrast, have been kept since the late 1700s, adding more than a century of supplementary observations to the climate record.

The logbooks also contain information about remote ocean locations rarely visited by other types of vessels, at that time, such as war and merchant ships, which tended to stick to established sea routes. Whalers deviated from these shipping lanes to find far-flung areas known for an abundance of marine mammals.

In particular, regions where climate change is wreaking the most havoc, such as the Arctic and the Indian Ocean, can be contextualized by whalers’ accounts of monsoons, ice cover, and other local weather phenomena.

For instance, whalers and many other mariners depended on the windy conditions in the so-called Roaring Forties band of latitude to propel them across the Indian Ocean. In recent decades, however, the winds have been shifting south into latitudes known as the Furious Fifties. Whaling logbooks may contain clues about how and when this trend began.

Read More: Cleopatra’s Downfall Was Partly Sparked by Climate Change and Volcanoes

Ummenhofer has partnered with Timothy Walker, a historian at the University of Massachusetts Dartmouth, to collect, examine, and digitize the logbooks preserved in many institutions around New England, which was the epicenter of America’s whaling industry.

“By bringing together a team of oceanographers, climatologists, and historians, we’re in a position to extract the climate data we need to make better sense of the past,” she said, “while showcasing how this aspect of our local history here in New England still has relevance today.”

Centuries-Old Sea Captain Diaries Are Confirming Modern Climate Science syndicated from https://triviaqaweb.wordpress.com/feed/

[shirlleycoyle]

Centuries-Old Sea Captain Diaries Are Confirming Modern Climate Science

When 19th century whalers jotted down weather and temperature measurements at sea, few might have imagined that their logbooks would become records of a warming planet more than 150 years later.

But that’s exactly the kind of value that climate scientists such as Caroline Ummenhofer of the Woods Hole Oceanographic Institution see in whaling logbooks. Packed with daily local observations, they can be used to corroborate climate change trends revealed in standardized temperature readings and geological records.

“We’ve observed a lot of changes over recent decades, including warming oceans, melting ice sheets on Greenland, shifts in weather patterns, and more frequent, intense droughts and floods,” said Ummenhofer in a statement.

“However, in many remote areas, such as the Arctic, we lack long datasets that can put recent observations into a long-term context,” she added. “This has limited our ability to understand how shifting weather and climate patterns may affect human society and ecosystems.”

The notes taken by whaling captains and first mates can help to fill in some of the gaps left in the record of mean global temperatures, which only extends back to 1880. American whaler diaries, in contrast, have been kept since the late 1700s, adding more than a century of supplementary observations to the climate record.

The logbooks also contain information about remote ocean locations rarely visited by other types of vessels, at that time, such as war and merchant ships, which tended to stick to established sea routes. Whalers deviated from these shipping lanes to find far-flung areas known for an abundance of marine mammals.

In particular, regions where climate change is wreaking the most havoc, such as the Arctic and the Indian Ocean, can be contextualized by whalers’ accounts of monsoons, ice cover, and other local weather phenomena.

For instance, whalers and many other mariners depended on the windy conditions in the so-called Roaring Forties band of latitude to propel them across the Indian Ocean. In recent decades, however, the winds have been shifting south into latitudes known as the Furious Fifties. Whaling logbooks may contain clues about how and when this trend began.

Read More: Cleopatra’s Downfall Was Partly Sparked by Climate Change and Volcanoes

Ummenhofer has partnered with Timothy Walker, a historian at the University of Massachusetts Dartmouth, to collect, examine, and digitize the logbooks preserved in many institutions around New England, which was the epicenter of America’s whaling industry.

“By bringing together a team of oceanographers, climatologists, and historians, we’re in a position to extract the climate data we need to make better sense of the past,” she said, “while showcasing how this aspect of our local history here in New England still has relevance today.”

Centuries-Old Sea Captain Diaries Are Confirming Modern Climate Science syndicated from https://triviaqaweb.wordpress.com/feed/