Environments

Stunning Aurora Australis: May 2024’s Sky Phenomena Explained

Unveiling the Wonders of the 11-12 May 2024 Night Sky

The formation of auroras, including coronas (see below), is primarily caused by the interaction between charged particles from the solar wind and the Earth’s magnetic field. When these charged particles collide with molecules in the Earth’s atmosphere, they emit light of varying colors, creating the vibrant displays we see as auroras.

The solar wind, composed of charged particles emitted by the Sun, interacts with the Earth’s magnetosphere, which is the region around the Earth dominated by its magnetic field. This interaction causes the charged particles to follow the magnetic field lines towards the Earth’s poles. When these charged particles collide with molecules in the Earth’s atmosphere near the poles, they emit light. The colour dictated by the composition of the molecules encountered, e.g. oxygen:

Green: This is the most common aurora color, occurring at altitudes of around 100-300 kilometers when oxygen atoms are excited and emit light at a wavelength of 557.7 nanometers.
Red: This color can appear at higher altitudes (above 300 kilometers) when oxygen atoms emit light at a wavelength of 630.0 nanometers.

The lower green portion is known as dunes (because presumably they resemble same!)

Around 8-9 pm the display became very dynamic and changed by the minute. This is how it appeared due south.

And then it changed arching from east, to west (as per this image).

And then everything got very surprising! An auroral corona appeared directly overhead.

A corona occurs when the aurora borealis (in the Northern Hemisphere) or aurora australis (in the Southern Hemisphere) appears directly overhead or very close to it. This phenomenon is quite rare and considered the holy grail of aurora photography due to its breathtaking beauty and rarity.

A rare phenomenon called a corona – a convergence that appeared overhead around 8.30 pm.

So, while the solar wind does indeed interact with the Earth’s magnetosphere and follow magnetic field lines towards the poles, the auroras themselves occur at high altitudes above the Earth’s surface, and the converging rays are a result of the observer’s perspective from the ground.

The camera captured some colours (as above and below) that were not obvious to me at the time. I thought I saw more of a black and white display. But I was quite busy realigning camera and tripod.

And like the whole night, changes of colour and form were constant!

Not to be out-done though the solar wind offered another surprise: A STEVE

A STEVE is a type of aurora that has some distinct characteristics compared to traditional auroras.

Key Characteristics of STEVE (Strong Thermal Emission Velocity Enhancement):

Appearance:

Color: STEVE typically appears as a narrow ribbon of light that is often pinkish-purple. It can sometimes have a green component, known as the “picket fence” structure, which appears as a series of vertical green stripes.

Shape: Unlike the diffuse, curtain-like appearance of typical auroras, STEVE manifests as a sharp, narrow arc that can stretch for hundreds of kilometers across the sky.

Formation:

STEVE is formed at lower latitudes than traditional auroras, which are usually found in the auroral zones near the poles.

It is associated with subauroral ion drift (SAID), a phenomenon where fast-moving streams of charged particles move through the Earth’s magnetosphere at subauroral latitudes.

To explain ‘lower latitudes’:
STEVE typically occurs at latitudes farther from the poles and closer to the mid-latitudes. For instance, while traditional auroras (aurora borealis and aurora australis) are most commonly observed at high latitudes (e.g., around 70 degrees north or south), STEVE can be observed at somewhat lower latitudes, closer to the equator than the typical auroral zones.

Cause:

The exact cause of STEVE is still under study, but it is believed to be related to unique interactions between the Earth’s magnetosphere and solar wind, specifically involving high-energy particles and strong electric fields in the subauroral zone.

Discovery and Study:

STEVE has been observed for many years by amateur aurora watchers, but it gained significant scientific attention in recent years, leading to its formal study and categorisation.

Citizen scientists, particularly members of the Alberta Aurora Chasers group, played a crucial role in drawing attention to this phenomenon, leading to increased scientific investigation.

Differentiation from Traditional Auroras:

Altitude: Traditional auroras typically occur at altitudes of about 100-300 km, whereas STEVE can appear at slightly lower altitudes.

Location: STEVE appears in regions further away from the magnetic poles compared to where typical auroras are seen.

Physical Mechanism: While traditional auroras are caused by the collision of solar wind particles with the Earth’s atmosphere, STEVE involves a different mechanism related to ion drifts and thermal emission enhancements.

And then another phenomena…

And in the same time frame of 30 minutes, pulsing started. The analogy was like clouds forming instantaneously then vanishing moments later having apparently moved quite a distance at speeds many times great than our terrestrial based winds. There was no consistency as to direction. Of course they were not clouds, but it’s the only way I can articulate the display. Occasionally I’d have a primal reaction and flinch/duck down.

(I attempted a movie of the pulsing, but sadly my camera could not gather in enough light)

Pulsating auroras, which are a variation of the more common steady auroral displays. They are characterised by rapid fluctuations in the brightness and intensity of the auroral curtains, often resembling pulsating waves of light moving across the sky.

These pulsations indeed can occur over very short time scales, sometimes within seconds, and can give the impression of clouds forming and dissipating rapidly. The movements can be quite dynamic and unpredictable, with changes in intensity and direction occurring suddenly and without a consistent pattern.

The primal reaction I experienced, flinching or ducking down, is apparently not uncommon among observers experiencing pulsating auroras for the first time. The rapid and unpredictable nature of the pulsations can evoke a visceral response, akin to instinctual reactions to sudden changes in the environment.

The exact mechanisms behind pulsating auroras are still not fully understood, but they are thought to be related to variations in the influx of charged particles from the solar wind and fluctuations in the Earth’s magnetosphere. These variations can lead to rapid changes in the energy levels of the auroral particles, resulting in the pulsating behavior observed.

Experiencing such a dynamic and awe-inspiring natural phenomenon is truly a rare and remarkable event. My description I’m told, captures the sense of wonder and primal awe that many people feel when witnessing the beauty and power of the auroras. It’s an experience to cherish and remember for a lifetime!

Southern Lights Aurora

Creator and Sponsor of this Site:

Donald from iCommunicate Wanaka sponsors and maintains this site. Always focusing on a strong alignment with Environmental and Sustainability Values.

Communicating and tech-ing sustainably – because the future is too important to leave to typos and outdated systems

Preserving the Buster Diggings

The Importance of Protecting a Historic and Heritage Landscape in Central Otago, New Zealand

Buster Diggings is a historic gold mining site located near Naseby in Central Otago, New Zealand. The site was active from 1863 to the early 1900s and reached a population of over 700 people at its peak. The Department of Conservation (DOC) now manages the site as an Actively Conserved Historic Place and it is listed several times in the Conservation Management Strategy (CMS), a statutory legal document. Prescriptive in nature. The site is considered to be remarkably intact and of national significance, particularly for its rarity as a high-altitude, alluvial mining landscape. It is comprised of fine cream coloured auriferous-quartz gravels.

Unfortunately, the site is suffering from human impact, primarily from 4wd vehicles and motorbikes, which are driving up the sluice faces for no other reason other than pushing a vehicle to it’s limits. Thus leaving long-term wheel marks or scarring on the surface of the deposits, causing erosion.

Evidence of high risk driving and riding

Using momentum in a four wheel drive to get up a steep slope can be hazardous due to several reasons. One of the biggest hazards is the loss of control if the vehicle fails to make it to the top. In such a scenario, the momentum of the vehicle puts it in a precarious position that makes it difficult or even impossible to control the descent backwards. This can lead to serious accidents, such as a rollover, especially if the slope is steep and the surface is loose or slippery.

Additionally, over-reliance on momentum can put excessive strain on the vehicle’s drivetrain and suspension, potentially leading to mechanical failures. It’s always important to carefully assess the terrain and plan a safe and controlled ascent (or possible descent when traction becomes compromised).

Acknowledgement of the problem

DOC acknowledged this impact many years ago and erected a fence around the main sluice faces at the head of Clarks Gully in 2009. However, stronger protection measures, such as a stronger fence or the use of cameras to identify vehicle users rego (and forward to the Police), could be considered.

More than once the lock on this gate, will I daresay, have succumbed to a bullet many times.

However…

Education plays a crucial role in the success of any management program.

By educating the public, individuals are empowered to make informed decisions and take ownership of their role in achieving the desired outcome.
This approach is more effective in the long term as it creates a sense of shared responsibility and fosters a culture of sustainability.
Furthermore, educating the public also helps to build trust in the management program and its goals, as individuals are better equipped to understand the reasoning behind specific policies and actions.
Ultimately, an educational approach leads to a more engaged and invested community, resulting in greater buy-in and higher rates of success for the management program.
DOC (Department of Conservation) Interpretation Boards are an effective tool for public education as they provide information and context to the public about the local environment, conservation efforts, and the cultural and historical significance of an area. The boards can also help foster appreciation and respect for the environment, which can lead to greater support for conservation efforts.

In Conclusion

Buster Diggings is a historically significant and rare site in Central Otago, New Zealand, that is currently suffering from human impact. DOC has a responsibility to protect the site and mitigate the risks posed by 4wd vehicles and motorbikes. Stronger protection measures should be considered to preserve the site for future generations to enjoy and appreciate.

CONSERVATION MANAGEMENT STRATEGY Otago 2016

Page 51-57 on pdf: The history of the Place is protected and brought to life at the Ngāi Tahu site of Manuhaea Conservation Area at The Neck and at the Buster Diggings actively conserved historic site.

The historic Buster Diggings has to be a protected and actively managed accessible visitor site.

References:

Heritage assessment by DOC

ODT Feb 2019

Sustainability & NZ Farming

Why preserving Natural Beauty and Biodiversity is Important

Join me on a journey through the stunning Waikouaiti River catchment, starting in the Nenthorn area and ending at the coast at the town Waikouaiti.

For a small population someone went to a lot of trouble!

Located within the precincts of the beautiful city of Dunedin, New Zealand,. The Waikouaiti River “Mauri” offers a glimpse from the rolling high country to near the mouth of the river.

The small town of Karitane, just 35 kilometers north of the city centre, serves as a popular holiday destination for residents of Dunedin. Come discover the beauty of the Waikouaiti River and its surrounding areas for yourself.

The Journey Begins

Macreas is now well known for it’s vast gold mining operation. Middlemarch is very much a hub for rural farming communities.

Clearing of Native and Snow Tussock Grasses

High country lands in New Zealand have long been treasured for their unique and diverse ecosystems, which include native and snow tussock grasses. However, the conversion of these lands for agricultural purposes has resulted in the widespread clearing of these grasses. This not only destroys the habitats of native species but also destabilizes the soil, leading to soil erosion and loss of fertility.

Snow tussock grasses on the Nenthorn Conservation Area. The remains of the building probably a remnant of historic gold mining operations.

Replacement with Exotic Non-Native Tree Species

In an effort to increase productivity and profitability, many farmers have replaced native grasses with exotic non-native tree species. This has further impacted the ecosystem by reducing the biodiversity and altering the natural balance of the land.

A few minutes drive from the last photo! Wilding pines spreading to the right

Wilding Pines: A Threat to New Zealand’s High Country

Wilding pines, also known as feral pines, are a major problem in New Zealand’s high country. They quickly take over the landscape, replacing native species and reducing biodiversity. The trees form dense stands that can cover vast areas of land, shading out native vegetation and altering the natural balance of the ecosystem. In addition, their extensive root systems can make it difficult for other plants to grow and compete for resources.

The clumped nature of wilding pines also makes it difficult for people or livestock to enter areas, further reducing the potential for land use and impacting the livelihoods of those who depend on these lands. As a result, the rapid spread of wilding pines is a significant threat to the sustainability and viability of New Zealand’s high country lands. Effective management and control of wilding pines is essential to protect these unique and valuable ecosystems.

The Negative Impact of Slash from Plantation Forestry Operations on Marine Ecosystems

A major contributor to marine sediment is the harvesting activities undertaken by plantation forestry operations. In particular, the period after clear-felling, known as the “window of vulnerability,” which typically lasts around 7 years, poses a significant risk of erosion and sedimentation.

With the increasing frequency of high rainfall events caused by the global climate crisis, steep land that has recently been harvested is more susceptible to landslides and erosion. The resulting sediment runoff can have devastating effects on the marine environment, smothering aquatic life and altering the delicate balance of the ecosystem.

In the Marlborough Sounds, this pollution is leading to significant adverse impacts on marine flora and fauna. The accumulation of slash, or the branches left to rot after harvesting, is a prime example of the short-sighted practices that are causing harm to the environment. The slash acts as a source of sediment during high rainfall events, contributing to the degradation of marine habitats and the decline of marine species.
It is crucial that we take steps to mitigate the negative impact of slash from plantation forestry operations on marine ecosystems. This includes proper management of harvesting activities, implementation of best practices to reduce sediment runoff, and investment in research and development to find sustainable solutions.

Loss of the Blotting Paper Effect

Native grasses severely degraded from waist high/several centuries old. With a backdrop of rural European style development. Nenthorn Conservation Area behind the photographer (myself).

The conversion of high country lands for agriculture has reduced their ability to absorb and retain water, causing soil loss and sedimentation in rivers. With increasing conversion at altitude, native vegetation regeneration is virtually non-existent.

Even more contrasts. Bare ground, cattle, cropping and sheep. With native tussocks on the road side.

If the terrain is at the limit of what a tractor can traverse, then in terms of rain water run off, it’s too steep. There will be severe downstream effects during floods.

Introduction of Cattle and Sheep Grazing

The introduction of cattle and sheep grazing has also had a significant impact on the high country lands. These animals consume large amounts of vegetation, causing soil erosion and degradation of the land. They also trample the soil and compact it, reducing its ability to retain water and nutrients.

Snow tussock area being cleared just a little east of the Nenthorn Conservation Area. Fertiliser trucks spreading… Presumably for planned pasture for stock.

Detrimental Effect on Marine Species

The soil erosion and sedimentation of rivers have had a detrimental effect on marine species near the coastline, including penguin populations. The sediment clouds the water, reducing the amount of light that reaches the ocean floor and impacting the health of marine plants and animals. Additionally, the increased nutrients from fertilisers can lead to harmful algal blooms, which can have toxic effects on marine life.

The Waikouaiti River flooding 2022. The access bridge to Karitane to the right. Taken very close to the fine weather photo above of a fishing boat. Photo courtesy the Internet.

Driving through the town of Waikouaiti 2018. Sediment is evident. From nearby creeks, and is typical of what washes down all the way from Nenthorn. Water supply tests in 2020 revealed concerning levels of lead in the town’s water supply (now fixed). Problems abound and compound on all fronts!

In conclusion

The conversion of New Zealand’s high country lands for agricultural purposes has had numerous negative effects on the ecosystem. From the clearing of native grasses and introduction of exotic non-native tree species, to the loss of the blotting paper effect and the impact on marine species, it is clear that the sustainability of these lands should be a top priority.

Honouring the native and indigenous status quo is a much better outcome for all concerned!

Update on inland Otago bio diversity

kea; aspiring; hut

Tena koutou katoa

I’ve had it in mind for a wee while to do a sort of good news newsletter, so here it is.

The new year of 2012 has progressed into feelings of autumn in the air. Things were pretty hectic for me at the end of last year. Family and close friends stuff – mostly health issues (now resolved) and a couple of deaths.

So here is my news garnered from a few sources – people at the coal face doing the work. Two of which are retired DOC people. With a lifetime of experience in many responsible roles:

Ten years ago 25 Sth Island robin were bought back into the West Matukituki Valley and released near Aspiring Hut. Now they total an estimated 300 and have spread up valley and down to into the Rob Roy valley and the East branch of the Matukituki.

The initial instigator of this was my good friend Stu. He and Heather are still tracking the birds and are now close to saying the project is closed.

Prior to 3 poison drops since 2014 and the subsequent installation of nearly a thousand traps by the Matukituki Trust in partnership with DOC, the survival rate has gone up from 1 fledgling out of 4 surviving to 4 out of 4, estimated.

The buff weka project – another relocation by Stu. At least 30 years ago he bought a bunch of birds back from the Chatham Islands and established an aviary on Stevenson Island on Lake Wanaka. So each hatching had the best chance of success. Then they were re-estabished on other islands in the immediate area around Wanaka and Queenstown.

One way or another I’ve taken an interest in this project too, after doing work on the island long ago. I will soon be mooting for getting some up-to-data data on numbers and well being. And likewise I’m taking quite an interest in braided river species/locals. Over a decade I’ve helped on many of the surveys. Based on what we’ve learnt I think how they are done needs a reexamination. Work in progress – best done before next spring!

One of the locals – tūturiwhatu / banded dotterel strutting his/her stuff

Another old friend Paul has gone from advancing the Matukituki Trust plans to coordinating several trusts and organisations trapping between Wanaka and the upper West Matukituki and lower East Matukituki.

Here is a now out-of-date map showing the gaps to filled up the valley. Glendhu Bay being on the left. Last I heard over 1600 traps.

The Matukituki Trust has just installed a new trap line up to the top of Cascade Saddle at 1800 mts

And another up an old track to the right here of Shovel Flat. Again up into the subalpine. The track being a rough line, up to Glengyle, put in by our old friend Geoff who ran Mountain Recreation climbing instruction courses for years out of Shovel Flat.

While looking at the above photo note that is French Ridge in the shade above the trampers. There is another line up there also, to away above the winter snow line. And in the valley to the right of the ridge we have Gloomy Gorge. Home of a rock wren population and bunch of stoats. So there is another line in there as well.
All this is in extremely steep and rugged terrain. A lot of the trappings is done with helicopter support. Groups being dropped off at the top, just like farmers now do mustering.

Also up to 14 have been hanging about French Ridge – probably the same birds. And other good news has been 27 spotted on Cascade Saddle by a ski touring friend. On the weekend before Labour weekend last year.
Not in our area, but also an unprecedented 13 of, are now frequenting the Red Tarns track at Mt Cook village

———-

Back in 2014 – 17 there were only two kaka in the valley. And then I found one dead near a trappinator [‘possum trap]. After much forensic work we decided both it and a stoat had taken an interest in a dead possum and the stoat pounced on the kaka.

Now it’s a similar story to the robins: there are several down valley and up the East Branch

On closing Wanaka/Matukituki news: other species are back in abundance, which means the dawn chorus is back – no more sleeping in at Aspiring Hut!

Also the potential hut rebuild decision-making with the Alpine Club and DOC is still fraught with tough calls. Geo technical in nature. Nothing will be a happening this season.

I’ve not mentioned the vast Makarora catchment. Good things are happening there also >>

And Forest and Bird, the old timers in the area, are still doing the work of unsung heroes. Trapping, trapping and trapping. Also trialing electronic means for traps to send info via satellite as to their status.

Ngā mihi
Donald

PS If you haven’t seen it already and have 4 minutes to kill then check out this attached link to the video taken by Crux on the Matukituki Charitable Trust a couple of weeks ago.

And on Radio NZ over the weekend – some very useful good thoughts during 27 mins. of:
Lonely Planet founder Tony Wheeler.

Braided River Bird Monitoring – how it works

Braided rivers are a common in Alaska, Canada, New Zealand’s South Island, and the Himalayas, which all contain young, rapidly eroding mountains. They are a unique environment inhabited by equally unique birds.

They simply cannot contain a river in a straight line. In floods especially they carry sediment, and in places where the flow slows down this settles on the bottom, thus raising it. And the water flows off to the side of least resistance. This will happen constantly during floods.

The technique for gathering bird numbers on these sort of rivers is quite simple: a team of four people spread out, in radio contact with each other, walk downstream counting every bird they see in front of them. On the ground or airborne.

And at that point the simplicity vanishes! Very finely tuned river crossing skills are needed, as well as “an eye” for the line that will give the best results. Plus physical stamina.

The tools of the trade are: a radio each, walking pole to aid crossings, binoculars, sun-cream, sun hat, good boots and gaiters [to stop gravels getting in the socks], GPS each, and a pen/paper/clipboard. Plus lunch, warm clothing, a camera etc. Warm dry socks also help at the end of the day.

A view upstream of the Hunter River that feeds Lake Hawea in Otago, New Zealand

Preparation. In this case to get into the very remote Hunter Valley. In the Wanaka area two other rivers, the Matukituki and Makarora are also done, and they don’t require a helicopter drop in. There is 25 years now of history – each river being monitored every third year.

The three year cycle is sometimes hard to maintain. The work has to be done in the spring when the birds are breeding, and this is when there is a high frequency of floods, with high levels due to snow melt.

After a short but steep climb in the helicopter from Makarora town-ship, on popping over the ridge the large and rugged Mckerrow Range come into full panoramic view [actually named after a close friend’s grandfather who did lots of surveying and exploring.

Dropping the over-night gear off by a hut, before flying further up the valley to begin the survey.

On the left [note the silt in the grass!] where we only go to avoid a complex river crossing; and where we do – the gravel on the right.

One species of many that we’re looking for. The ‎nationally vulnerable banded dotterel / tūturiwhatu, is the most common small plover of New Zealand seashores, estuaries and riverbeds.

This one is feigning a broken wing to lead the surveyor/photographer away from a nest.

After breeding, they either remain at the nesting area or move relatively short distances to nearby estuaries.

Typical nesting surface, and one of the team striding it out. Being very careful to not stand on eggs!

On the wing. A black fronted tern. Not in the Hunter though, but the Tasman River near Mt Cook. The blue colouring of the very cold water is caused by rock ground up by glaciers.

There are about six species that are primarily dependent on the braided river habitat: wrybill, banded dotterel, south island pied oyster-catcher, black-fronted tern, black-billed gull, black stilt) as well as the caspian tern and the pied stilt. The villain of the piece though is the black-back gull, as they predate on the eggs of the others.

Teaming up – linking arms for mutual support. Lots of concentration is required so it’s harder to observe what maybe in the air ahead. However the most experienced person leading the crossing, which is nearly done, has in this instance time to look. River crossing is best done by not looking down, which upsets balance, and with great care – there is no Plan B if people get swept away.

When not to cross at all – just too big and not braided into smaller channels.

What we don’t want to see, but if we do, weeds are recorded as Way Points on a GPS, so that DOC staff can return later to deal to them. The most often encountered on the above mentioned rivers is this area, is often broom.

We don’t encounter many lupins in the above mentioned rivers. This photo is in the nearby Ahuriri. Lupins, which the birds don’t like, offer cover to predators. Foolishly seeds were spread many decades ago by well meaning people wanting to add some colour to the grey landscape. And the seeds can remain for years until uncovered by a flood as they’re coated with a protective oil.

A sad aspect of some surveys is that we know that after a bank-to-bank spring flood hundreds of these young birds are washed away. These are a few surviving gulls after such an event in the Matukituki a few years back.

Knock off time – a classic old-time hut.

Evening and time for sleep. Tomorrow morning the survey will resume tidying up the riverbed to the right.

The long and sometimes bumpy drive home beside Lake Hawea

Obviously the results of such monitoring give a good guide as to the health of the environments concerned.

However the data as regards where breeding colonies are located, can be used for the most efficient locations for a new trapping lines. There is an attrition of traps though – during floods despite them being anchored by a chain to a long steel stake hammered in, they get washed away. Often the best compromise often considered, is for them to be near a bank that exhibits a history of stability, and place them with a shorter distance apart than the 200 mt standard in the bush, so as to create a fence of sorts.

Category: Environments

Stunning Aurora Australis: May 2024’s Sky Phenomena Explained

Unveiling the Wonders of the 11-12 May 2024 Night Sky

And then everything got very surprising! An auroral corona appeared directly overhead.