Source: NIWA – National Institute of Water and Atmospheric Research
2023 is tracking to be one of the top three hottest years on record for Aotearoa New Zealand.
NIWA meteorologist Tristan Meyers says 2022 was our warmest year on record, surpassing the record set the year before in 2021.
“Last month didn’t add to the record books, with it being the 34th-warmest November since NIWA’s seven station temperature series began in 1909 and although the first half of December had mostly average temperatures, a sultry 33C temperature reading in North Canterbury yesterday [Wednesday] marked what would be a hot and humid finish to the year, helping to keep 2023 near the top of the rankings.”
“We’ll be confirming this in our annual climate summary issued early next month.”
In the meantime, Meyers says the Christmas outlook is a mixed bag.
“Showers and areas of rain look to affect the North Island, while a few showers are possible for the Southern Alps and east of the South Island. However, the West Coast looks drier. Parts of the eastern North Island look to also see some temperatures reach the high 20s or low 30s.”
He says while Australian wildfires will also keep raging, the smoke that’s being ferried to New Zealand is nowhere near as bad as the 2019-2020 fires, although he cautions Australians are looking at an above-average bushfire season.
“With the peak of the bushfire season still ahead of us, the recent smoke that’s made its way to New Zealand may be a sign of things to come later in the summer if more large fires break out.”
Source: NIWA – National Institute of Water and Atmospheric Research
A weekly update describing soil moisture patterns across the country to show where dry to extremely dry conditions are occurring or imminent. Regions experiencing significant soil moisture deficits are deemed “hotspots”. Persistent hotspot regions have the potential to develop into drought.
This is the last Hotspot Watch for 2023. Normal service will resume on 11th Jan 2024.
Recent rainfall and current soil moisture conditions:
North Island:
Meagre rainfall totals of 5 mm or less were observed in much of the North Island in the past week.
Pockets of rainfall totals of 10-25 mm were observed in western Waikato and Kapiti Coast, with some larger amounts in higher terrain.
This resulted in significant soil moisture decreases across a majority of the North Island.
The driest soils across the North Island, when compared to normal for this time of the year, are found in interior Waikato, while the wettest soils for this time of the year are found in Cape Reinga and parts of Gisborne and northern Hawke’s Bay.
The previous hotspot in coastal Manawatū-Whanganui and the Kapiti Coast remains in place, while new hotspots have formed in northern Auckland, a small portion of interior Waikato, and coastal eastern Bay of Plenty.
As of 18 December, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Wellington.
South Island:
Rainfall amounts of 30-100 mm were generally observed in the West Coast in the past week.
However, elsewhere in the South Island rainfall amounts were minimal—generally less than 10 mm.
This resulted in significant soil moisture decreases in nearly all of the South Island except for the West Coast, where changes were minimal.
The driest soils across the South Island, when compared to normal for this time of the year, are found in parts of Marlborough, Nelson, eastern Tasman and western Southland, while the wettest soils for this time of the year are found along the immediate western coast.
South Island hotspots are now located in Greater Nelson, Marlborough Sounds, far northern Canterbury, parts of coastal South Canterbury, and western Southland.
As of 18 December, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Tasman, Nelson, Marlborough, North Canterbury, Banks Peninsula, South Canterbury, Otago, coastal Southland, and Stewart Island. Very dry conditions are now located in parts of these same regions as well.
Pictured above: Soil Moisture Anomaly Maps, relative to this time of year. The maps show soil moisture anomalies over the past two weeks.
As of 18 December, the New Zealand Drought Index (NZDI) map below shows thatabnormally dry conditions are currently found in parts of Wellington, Tasman, Nelson, Marlborough, North Canterbury, Banks Peninsula, South Canterbury, Otago, coastal Southland, and Stewart Island. Very dry conditions are now located in parts of these same South Island regions as well. Please note: some hotspots in the text above may not correspond with the NZDI map. This difference exists because the NZDI uses additional dryness indices, including one which integrates the rainfall deficit over the past 60 days. Changes are therefore slower to appear in the NZDI compared to soil moisture anomaly maps that are instantaneously updated.
The week ahead:
North Island:
Thursday through Saturday morning (21-23 December) will be mostly dry, but the chance for showers and periods of rain will increase on Sunday.
Christmas Day and Boxing Day could be unsettled, with periods of at least moderate rainfall across the North Island.
Weekly rainfall totals could reach 30-50 mm across much of the North Island, with pockets of higher amounts likely to occur. Rainfall totals could be slightly lower along the east coast.
Due to the expected rainfall in the next week, small to moderate soil moisture increases are likely in much of the North Island.
The current hotspots in the North Island may weaken at least somewhat in the next week, although they may not dissipate entirely. There is a small chance that a new hotspot could form in southern Hawke’s Bay.
South Island:
A few showers will be possible each day through Saturday (21-23 December), although rainfall amounts will generally be light.
Moderate to heavy rain may affect the West Coast on Sunday (24 December), with showers farther east.
A few showers will again be possible during early-to-mid next week.
Weekly rainfall totals of 50-100 mm are possible in the West Coast, with 20-40 mm in the lower South Island. However, amounts less than 20 mm are likely along the east coast.
Due to the expected rainfall in the next week, additional soil moisture decreases will be possible in Marlborough and Canterbury, with slight increases possible in Otago and Southland.
The current hotspots in the upper South Island and Southland may weaken somewhat in the next week, while the hotspots in Canterbury could strengthen.
Long-term outlook (through mid-January):
The drier (25th percentile) and middle (50th percentile) rainfall scenarios both favour drier or much drier than normal conditions in the upper and eastern North Island and lower South Island through late January.
However, in the wetter (75th percentile) scenario, above normal rainfall could occur in large parts of the North Island and upper South Island.
Very dry soil conditions could affect parts of both islands in the drier rainfall scenario.
Pictured above: 35-day forecast rainfall anomaly scenarios (Top), and 35-day forecast dryness and drought scenarios (Bottom). These maps are updated daily at https://niwa.co.nz/climate/seasonal-climate-outlook
Background:
Hotspot Watch: a weekly advisory service for New Zealand media. It provides soil moisture and precipitation measurements around the country to help assess whether extremely dry conditions are imminent.
Soil moisture deficit: the amount of water needed to bring the soil moisture content back to field capacity, which is the maximum amount of water the soil can hold.
Soil moisture anomaly: the difference between the historical normal soil moisture deficit (or surplus) for a given time of year and actual soil moisture deficits.
Hotspot: A hotspot is declared if soils are “severely drier than normal” which occurs when Soil Moisture Deficit (SMD) is less than -110 mm AND the Soil Moisture Anomaly is less than -20 mm.
Source: NIWA – National Institute of Water and Atmospheric Research
NIWA gathers information about fishing practices and the catch of an estimated 600,000 people who participate in recreational fishing every year. Interviewers will be at boat ramps along the north-eastern coast of the North Island, as well as parts of the west coast and some areas of the South Island.
The project, led by NIWA Fisheries Scientist, Dr Jade Maggs, recruits interviewers who are often passionate fishers or members of local fishing clubs.
“We would just like to know a little about what you caught, and how you caught it. All information collected is kept private. The interviewers are not there to enforce the law, but only to collect scientific information. It’s completely voluntary and we don’t share people’s secret fishing spots.”
Interviewers will approach people returning from a day’s fishing, enquiring about how many and what kind of fish they’ve caught, where they’ve been, the bait they’ve been using and how long they’ve been out.
NIWA Chief Scientist Richard O’Driscoll says it is really important that we know how many fish are being taken out of the ocean.
“This includes the recreational catch, which in some areas is as high or higher than the commercial take for species like snapper and blue cod. Our interviews, with the help of recreational fishers, provide the information needed for effective management of inshore fish stocks.”
These surveys are a vital part of NIWA’s research on recreational fisheries for Fisheries New Zealand.
Fisheries New Zealand Principal Scientist Ian Tuck says that this research provides an important source of information about recreational fishing.
“We’ve had boat ramp surveys since the early 1990s – it’s one of the ways we get data on recreational fishing activity. This complements other research like the National Panel Survey, which is our largest recreational fishing survey, and area-specific surveys where more detailed information is needed, such as sampling of catch during the recent recreational pāua season in Kaikōura. The interviewers will be asking fishers about their catch, and this information will go towards stock assessments and informing fisheries management settings, such as catch and size limits.”
This year, NIWA are also collecting data on the number of snapper being caught and released in the recreational fishery. This follows on from an experiment last year, which looked at the survival rates of recreationally caught snapper that are released back to the sea. The new data collection initiative will involve volunteer fishers taking measuring mats and information sheets out on their fishing trips to record the size and numbers of snapper caught, as well as information about how deep they are caught and how they are hooked.
Everything we do at ESR is driven by our mission to detect, connect and protect – so we can deliver cutting-edge science that benefits all Aotearoa New Zealand, from our bustling urban centres to most isolated rural environments. I’m delighted to reflect on the difference our science has made for New Zealand over the past year, and to share some highlights with you.
We saw our mission in action throughout 2023, with the ongoingdetection and measuring of COVID-19(external link)in our communities. As self-reporting has decreased, ESR’s wastewater testing, alongside our genomics surveillance, has proved vital for establishing levels of the virus, to support health providers and the public with their decision making.
To further support decision making, this year our public health surveillance information shifted to live in one place as part of a new lookNgā Kete Intelligence Hub(external link). Having all our public health intelligence in a centralised hub is a huge step forward for making this information accessible. Stay tuned for more updates to our website in the new year, as we continue to improve how we present our research and services, to have an even greater impact for our communities.
On the influenza front, 2023 markedfive years since the WellKiwis programme launched(external link). The programme is playing a key role in helping ESR experts better understand immunity and how more effective vaccines could be developed for influenza and other viruses.
ESR continues to lead the way when it comes to embracing new technologies. ESR’s experts turned their attention to how artificial intelligence could further enhance research, while ensuring AI’s power is harnessed in an ethical, productive way. To help guide use of AI, we’re proud to have signed-up to theAlgorithm Charter for AotearoaNew Zealand(external link), which commits to ensuring New Zealanders have confidence in how government agencies use data and algorithms.
We were also excited to host theESR Symposium on Precision Health, bringing together people from a range of sectors to help understand the opportunities for New Zealand in this rapidly advancing field of data-informed healthcare.
We’re extremely proud of the work undertaken with our co-host, the University of Otago, and key Māori partners, to grow and embedTe Niwha, a holistic approach to reduce inequities in infectious diseases and health responses(external link). With a commitment to the principles of Vision Mātauranga,Te Niwha provides a comprehensive approach to infectious disease research and response in Aotearoa New Zealand, focusing on partnership and collaboration with Māori and our most vulnerable communities.
ESR has championed increased CRI collaboration throughpan-Crown research institution initiativessuch as improving Māori data sovereignty practices and developing a Pacific environmental exposure assessment to investigate and assess potential climate change risks.
As an example of ESR collaboration, we’re leading a New Zealand Government Jobs for Nature project gathering freshwater data to model potential health risks from swimming. Nine councils are involved in collecting samples from 40 water bodies to create a new model that will supportNew Zealand’s freshwater recreational guidelines(external link). ESR scientists also worked alongside GNS and Environment Canterbury on an online tool formicrobial risk assessment of land use on drinking water supplies(external link). The tool is designed to give guidance to councils and others seeking to protect the safety of their drinking water sources.
We continue to push the boundaries in science excellence, including building on the commercial successes of ESR’s ground-breaking andaward-winning products Lumi™ and STRmix™(external link). Lumi is now being used as a frontline policing tool by the New Zealand Police for drug detection. Lumi’s success in being awarded the Excellence in Forensic Science Award at the World Police Summit in 2023, is testament to the innovation of ESR’s scientists working in collaboration with the New Zealand Police.
This really is just a snapshot of the important science undertaken by ESR this year. These achievements have only been made possible through the dedicated work of our incredible colleagues and partners. I am so proud of the dedication, spirit and professionalism of all our people, who continue to deliver outstanding contributions to the health and wellbeing of our communities. The ESR team looks forward to our continued collaborations throughout 2024.
Source: NIWA – National Institute of Water and Atmospheric Research
A weekly update describing soil moisture patterns across the country to show where dry to extremely dry conditions are occurring or imminent. Regions experiencing significant soil moisture deficits are deemed “hotspots”. Persistent hotspot regions have the potential to develop into drought.
Recent rainfall and current soil moisture conditions:
North Island:
Meagre rainfall totals of less than 10 mm were observed in much of the North Island in the past week.
Pockets of rainfall totals of 10-20 mm were observed in the eastern and lower North Island.
This resulted in moderate soil moisture decreases in a majority of the North Island, although some western regions observed large soil moisture decreases.
The driest soils across the North Island, when compared to normal for this time of the year, are found in southern Waikato and western Wellington, while the wettest soils for this time of the year are found in Cape Reinga and parts of Gisborne and northern Hawke’s Bay.
A hotspot is now in place in coastal Manawatū-Whanganui and the Kapiti Coast.
As of 12 December, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Wellington.
South Island:
Rainfall amounts of 30-70 mm were generally observed in the West Coast in the past week, with 100 mm or more in Fiordland.
Much of northern Canterbury and Southland observed amounts of 15-30 mm, but meagre rainfall was observed in the upper South Island along with interior and South Canterbury.
This resulted in small soil moisture decreases in much of the South Island in the past week, although small increases were observed in northern Canterbury and Banks Peninsula.
The driest soils across the South Island, when compared to normal for this time of the year, are found in parts of Marlborough Sounds and western Southland, while the wettest soils for this time of the year are found in the upper West Coast and northern Canterbury.
In the past week, the previous hotspot located in Banks Peninsula dissipated, the hotspots in Marlborough Sounds and Nelson remained in place, while conditions remained near hotspot criteria in South Canterbury, parts of Otago, and Southland.
As of 12 December, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Wellington, Tasman, Nelson, Marlborough, North Canterbury, Banks Peninsula, South Canterbury, Otago, coastal Southland, and Stewart Island. Very dry conditions are now located in southeast Otago.
Pictured above: Soil Moisture Anomaly Maps, relative to this time of year. The maps show soil moisture anomalies over the past two weeks.
As of 12 December, the New Zealand Drought Index (NZDI) map below shows thatabnormally dry conditions are currently found in parts of Wellington, Tasman, Nelson, Marlborough, North Canterbury, Banks Peninsula, South Canterbury, Otago, coastal Southland, and Stewart Island. Very dry conditions are now located in southeast Otago. Please note: some hotspots in the text above may not correspond with the NZDI map. This difference exists because the NZDI uses additional dryness indices, including one which integrates the rainfall deficit over the past 60 days. Changes are therefore slower to appear in the NZDI compared to soil moisture anomaly maps that are instantaneously updated.
The week ahead:
North Island:
This weekend (16-17 December) will be mostly dry, although some showers will affect Wellington and the western North Island.
Monday and Tuesday will have a better chance for showers and isolated thunderstorms, particularly in the central North Island.
High pressure will then bring generally dry weather late next week.
Weekly rainfall totals will again be meagre in many regions, especially in the upper North Island and east coast where amounts may be less than 10 mm. Pockets of 10-20 mm are possible from Taranaki to Wellington.
Due to the expected rainfall in the next week, moderate soil moisture decreases are again likely in the upper and eastern North Island, with minor decreases possible in western regions.
The current hotspot in coastal Manawatū-Whanganui and the Kapiti Coast may not change substantially in the next week, while a new hotspot may form in parts of Auckland.
South Island:
The upper South Island will see some rain on Saturday, with additional heavy rain for much of the West Coast on Sunday (17 December).
High pressure will then provide generally dry weather from Monday to Wednesday (18-20 December).
Another front may bring moderate rain to the western and lower South Island late next week.
Weekly rainfall totals of 70-100 mm are possible in the West Coast, but much lighter amounts of 20 mm or less are expected east of the Alps.
Due to the expected rainfall in the next week, soil moisture decreases will be likely east of the Alps, with smaller changes likely in the upper South Island.
The current hotspots in Marlborough Sounds and Nelson may strengthen slightly in the next week, while new hotspots may form in parts of the lower South Island.
Long-term outlook (through mid-January):
The drier (25th percentile) and middle (50th percentile) rainfall scenarios both favour widespread drier or much drier than normal conditions across both islands through mid-January.
Even in the wetter (75th percentile) scenario, below normal rainfall is still favoured in the upper and eastern North Island, although western New Zealand shows a chance for above normal rainfall in the wetter scenario.
Very dry soil conditions could affect large swaths of both islands in the drier rainfall scenario.
Pictured above: 35-day forecast rainfall anomaly scenarios (Top), and 35-day forecast dryness and drought scenarios (Bottom). These maps are updated daily at https://niwa.co.nz/climate/seasonal-climate-outlook
Background:
Hotspot Watch: a weekly advisory service for New Zealand media. It provides soil moisture and precipitation measurements around the country to help assess whether extremely dry conditions are imminent.
Soil moisture deficit: the amount of water needed to bring the soil moisture content back to field capacity, which is the maximum amount of water the soil can hold.
Soil moisture anomaly: the difference between the historical normal soil moisture deficit (or surplus) for a given time of year and actual soil moisture deficits.
Hotspot: A hotspot is declared if soils are “severely drier than normal” which occurs when Soil Moisture Deficit (SMD) is less than -110 mm AND the Soil Moisture Anomaly is less than -20 mm.
Source: NIWA – National Institute of Water and Atmospheric Research
A weekly update describing soil moisture patterns across the country to show where dry to extremely dry conditions are occurring or imminent. Regions experiencing significant soil moisture deficits are deemed “hotspots”. Persistent hotspot regions have the potential to develop into drought.
Recent rainfall and current soil moisture conditions:
North Island:
Rainfall totals of 25-60 mm were observed in much of the upper half of the North Island in the past week.
However, much of the lower North Island received lighter amounts of 20 mm or less.
Particularly meagre rainfall was observed in Wairarapa.
This resulted in small to moderate soil moisture increases in the upper North Island, while decreases were observed in the lower North Island.
The driest soils across the North Island, when compared to normal for this time of the year, are found in western Wellington, while the wettest soils for this time of the year are found in the Far North and parts of Gisborne and Hawke’s Bay.
While no hotspots currently exist in the North Island, a new hotspot is close to emerging along the Kapiti Coast.
As of 5 December, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Wellington.
South Island:
Rainfall amounts of 50-100 mm were generally observed in the West Coast, Tasman, and parts of Marlborough Sounds in the past week, with pockets up to 150 mm in higher terrain.
Elsewhere in the South Island, light rainfall amounts of 15 mm or less were generally observed.
This resulted in at least minor soil moisture increases in the West Coast, Tasman, and Marlborough Sounds, while minor decreases were generally observed elsewhere.
The driest soils across the South Island, when compared to normal for this time of the year, are found in parts of Marlborough Sounds and western Southland, while the wettest soils for this time of the year are found in Tasman and Fiordland.
In the past week, the hotspot located in Marlborough Sounds remained in place, while new, small hotspots emerged in Nelson and Banks Peninsula. Conditions are also approaching hotspot criteria in South Canterbury and parts of Otago and Southland.
As of 5 December, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Nelson, Marlborough, North Canterbury, Banks Peninsula, South Canterbury, and interior Otago.
Pictured above: Soil Moisture Anomaly Maps, relative to this time of year. The maps show soil moisture anomalies over the past two weeks.
As of 5 December, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Wellington, Nelson, Marlborough, North Canterbury, Banks Peninsula, South Canterbury, and interior Otago. Please note: some hotspots in the text above may not correspond with the NZDI map. This difference exists because the NZDI uses additional dryness indices, including one which integrates the rainfall deficit over the past 60 days. Changes are therefore slower to appear in the NZDI compared to soil moisture anomaly maps that are instantaneously updated.
The week ahead:
North Island:
After a generally dry Saturday, a weakening front will bring showers to the island on Sunday afternoon and Sunday night (10 December), followed by isolated showers on Monday.
Additional showers will be possible on Tuesday and Wednesday (12-13 December), but then dry weather returns late next week.
Weekly rainfall totals of 15-30 mm are possible in the lower and eastern North Island, but meagre accumulations of 10 mm or less are expected elsewhere.
Due to the expected rainfall in the next week, moderate soil moisture decreases may occur in the upper North Island, with minor decreases possible in the east and west.
There is a small chance that a new hotspot may form in western Wellington in the next week.
South Island:
A strong cold front will bring heavy rain to the West Coast from Saturday afternoon through Sunday morning (9-10 December), with moderate rain potentially affecting Canterbury.
After a mostly dry Monday (11 December), scattered showers will be possible on Tuesday, with more widespread showers possible on Wednesday.
Generally dry weather is likely on Thursday, but another front may bring more rain to the West Coast on Friday (15 December).
Weekly rainfall totals of 100-250 mm are possible in the West Coast, with 30-50 mm possible in interior Canterbury and Southland.
However, lighter amounts of 25 mm or less are forecast in the upper South Island, coastal Canterbury, and Otago.
Due to the expected rainfall in the next week, soil moisture decreases may occur in Nelson, Marlborough Sounds, coastal Canterbury, and Otago, with minor to moderate increases possible elsewhere.
The current hotspots in Marlborough Sounds and Nelson may strengthen in the next week, while the hotspot in Banks Peninsula may not change substantially.
Long-term outlook (through early January):
The drier (25th percentile) and middle (50th percentile) rainfall scenarios both favour widespread drier or much drier than normal conditions across both islands through early January.
Even in the wetter (75th percentile) scenario, below normal rainfall is still favoured in large parts of both islands.
Very dry soil conditions could begin to affect large swaths of both islands in the drier rainfall scenario.
Pictured above: 35-day forecast rainfall anomaly scenarios (Top), and 35-day forecast dryness and drought scenarios (Bottom). These maps are updated daily at https://niwa.co.nz/climate/seasonal-climate-outlook
Background:
Hotspot Watch: a weekly advisory service for New Zealand media. It provides soil moisture and precipitation measurements around the country to help assess whether extremely dry conditions are imminent.
Soil moisture deficit: the amount of water needed to bring the soil moisture content back to field capacity, which is the maximum amount of water the soil can hold.
Soil moisture anomaly: the difference between the historical normal soil moisture deficit (or surplus) for a given time of year and actual soil moisture deficits.
Hotspot: A hotspot is declared if soils are “severely drier than normal” which occurs when Soil Moisture Deficit (SMD) is less than -110 mm AND the Soil Moisture Anomaly is less than -20 mm.
‘The team was the key ingredient that made Lumi™ happen’ – Dion Sheppard, Lumi™ Drug Scan Team Awardee
Trust and confidence at the frontline stems from reliable and consistent decision making. Lumi™ Drug Scan, developed by a team of ESR forensic experts working with police, is a revolutionary approach to drug investigations, making forensic science accessible to frontline responders. Lumi™ enables police to safely detect illicit drugs within seconds, while providing rich data and insights about drug use in Aotearoa.
“Lumi™ can currently detect methamphetamine, cocaine, and MDMA, which are the three highest priority targets for New Zealand Police. They’re the drugs that represent the highest harm. It started in conversations with Police about what they were wanting to do.
“The team was really the key ingredient that made Lumi™ happen – we were lucky enough to have a really good diversity of expertise to draw on,” says Dion Sheppard, Lumi™ Drug Scan Manager.
This Kiwi technology delivers science at the point of need, empowering rapid detection of illicit substances by analysing packaged samples on a palm-sized scanning device that harnesses infrared to determine if cocaine, ecstasy, or methamphetamine are present. The device is paired via Bluetooth with the Lumi™ App on the officer’s smartphone, powered by sophisticated machine learning algorithms in the cloud developed from over 600,000 scans from drug samples curated by ESR scientists. Lumi™ is a game-changing innovation supporting better policing and drug harm reduction in communities.
“A key enabler of the Lumi™ project was that relationship with New Zealand Police,” Dion says.
“Congratulations for winning the Team Award. It’s a fantastic recognition of all the hard work and collaboration between New Zealand Police and ESR,” says Inspector Simon Welsh, Manager Implementation & Evaluation, Evidence Based Policing Centre.
“Lumi has certainly got an amazing response from our frontline staff. It makes it easier to identify drugs on the side of the road, and it’s more efficient.”
Source: NIWA – National Institute of Water and Atmospheric Research
A new study has comprehensively mapped the immediate after effects of the January 2022 eruption of Hunga Tonga – Hunga Ha’apai, highlighting the risks of similar events.
The study, published in Nature Communications, is part of the joint international project, the NIWA-Nippon Foundation Tonga Eruption Seabed Mapping Project (TESMaP), which includes 13 partners from Tonga, New Zealand, Australia, Germany, USA, and the UK.
The eruption was the biggest atmospheric explosion recorded on Earth in more than 100 years, displacing almost 10km3 of seafloor, and generating a tsunami that sent shockwaves around the world.
Following the eruption, scientists from New Zealand’s National Institute of Water and Atmospheric Research (NIWA) set sail on RV Tangaroa for a month-long voyage to collect geological data, video footage, seabed imagery and water column samples. Using this information, they were able to show the far-reaching ocean impacts of such a large eruption, including the widespread loss of seafloor life.
NIWA biogeochemist and lead author of the study Dr Sarah Seabrook says the initial voyage has led to discoveries never before seen, reshaping our understanding of the impacts of volcanic eruptions on ocean ecosystems.
“Just one example is the role of underwater mountains (seamounts) providing a sheltering effect from the powerful seafloor density currents that smothered much of the seafloor around the volcano, wiping out seafloor life in the area, but left the seamounts relatively unscathed,” Dr Seabrook says.
“Such refugia have been reported on land, where vegetation and people have been sheltered, but not in the ocean. But survival after the initial event is only the first hurdle. The eruption causes dramatic changes to nutrient and oxygen levels in the water which could have feedbacks that we are yet to understand.
“We do not know the timescale over which the seafloor communities in the Hunga Volcano may recover, but we think it may be aided by re-colonisation of the life which survived near these seamounts. The only way to see if it has survived, and to what extent, is to revisit the area.”
She says that most eruptions of submarine volcanoes go undetected or underreported with little data before or after eruptions.
Dr Seabrook says that there is still much to be learned about the 22 mapped volcanoes in the Kingdom of Tonga, along with hundreds more along the Tonga-Tofua-Kermadec Arc, and numerous others worldwide.“Future monitoring, of both the volcanic edifice itself and the surrounding seafloor and habitats, is necessary to robustly determine the resilience and recovery of both human and natural systems to major submarine eruptions. It will also help more broadly assess the risks posed by the many similar submerged volcanoes that exist worldwide.”
Dr Isobel Yeo is a volcanologist, and lead scientist of the UK part of this international programme, based at the National Oceanography Centre (NOC).
“This work has highlighted the potential of offshore volcanoes to produce immense eruptions that pose a serious threat to coastal communities and subsea infrastructure, and highlights the urgent need for more research on and monitoring of these volcanic systems, not just in Tonga, but globally,” she says.
Dr James Hunt of the UK’s National Oceanography Centre says international partnerships were key to the success of the research. “This complex project required mobilisation of a vessel immediately after the eruption and brought together a truly multidisciplinary science team. This could only be achieved through international collaborations, underlining a need to work across borders to understand volcanic hazards.”
Source: NIWA – National Institute of Water and Atmospheric Research
A new study has comprehensively mapped the immediate after effects of the January 2022 eruption of Hunga Tonga – Hunga Ha’apai, highlighting the risks of similar events.
The study, published in Nature Communications, is part of the joint international project, the NIWA-Nippon Foundation Tonga Eruption Seabed Mapping Project (TESMaP), which includes 13 partners from Tonga, New Zealand, Australia, Germany, USA, and the UK.
The eruption was the biggest atmospheric explosion recorded on Earth in more than 100 years, displacing almost 10km3 of seafloor, and generating a tsunami that sent shockwaves around the world.
Following the eruption, scientists from New Zealand’s National Institute of Water and Atmospheric Research (NIWA) set sail on RV Tangaroa for a month-long voyage to collect geological data, video footage, seabed imagery and water column samples. Using this information, they were able to show the far-reaching ocean impacts of such a large eruption, including the widespread loss of seafloor life.
NIWA biogeochemist and lead author of the study Dr Sarah Seabrook says the initial voyage has led to discoveries never before seen, reshaping our understanding of the impacts of volcanic eruptions on ocean ecosystems.
“Just one example is the role of underwater mountains (seamounts) providing a sheltering effect from the powerful seafloor density currents that smothered much of the seafloor around the volcano, wiping out seafloor life in the area, but left the seamounts relatively unscathed,” Dr Seabrook says.
“Such refugia have been reported on land, where vegetation and people have been sheltered, but not in the ocean. But survival after the initial event is only the first hurdle. The eruption causes dramatic changes to nutrient and oxygen levels in the water which could have feedbacks that we are yet to understand.
“We do not know the timescale over which the seafloor communities in the Hunga Volcano may recover, but we think it may be aided by re-colonisation of the life which survived near these seamounts. The only way to see if it has survived, and to what extent, is to revisit the area.”
She says that most eruptions of submarine volcanoes go undetected or underreported with little data before or after eruptions.
Dr Seabrook says that there is still much to be learned about the 22 mapped volcanoes in the Kingdom of Tonga, along with hundreds more along the Tonga-Tofua-Kermadec Arc, and numerous others worldwide.“Future monitoring, of both the volcanic edifice itself and the surrounding seafloor and habitats, is necessary to robustly determine the resilience and recovery of both human and natural systems to major submarine eruptions. It will also help more broadly assess the risks posed by the many similar submerged volcanoes that exist worldwide.”
Dr Isobel Yeo is a volcanologist, and lead scientist of the UK part of this international programme, based at the National Oceanography Centre (NOC).
“This work has highlighted the potential of offshore volcanoes to produce immense eruptions that pose a serious threat to coastal communities and subsea infrastructure, and highlights the urgent need for more research on and monitoring of these volcanic systems, not just in Tonga, but globally,” she says.
Dr James Hunt of the UK’s National Oceanography Centre says international partnerships were key to the success of the research. “This complex project required mobilisation of a vessel immediately after the eruption and brought together a truly multidisciplinary science team. This could only be achieved through international collaborations, underlining a need to work across borders to understand volcanic hazards.”
Source: NIWA – National Institute of Water and Atmospheric Research
A weekly update describing soil moisture patterns across the country to show where dry to extremely dry conditions are occurring or imminent. Regions experiencing significant soil moisture deficits are deemed “hotspots”. Persistent hotspot regions have the potential to develop into drought.
Recent rainfall and current soil moisture conditions:
North Island:
Substantial rainfall of 60-100 mm was observed across Gisborne and northern Hawke’s Bay in the past week.
However, much less rainfall occurred elsewhere across the North Island, where totals were generally less than 25 mm.
Particularly meagre rainfall was observed in Northland, Auckland, and northern Waikato.
This resulted in small to moderate soil moisture decreases across a majority of the North Island, although little change was observed in Gisborne and Hawke’s Bay.
The driest soils across the North Island, when compared to normal for this time of the year, are found in Kapiti Coast, while the wettest soils for this time of the year are found in parts of Gisborne and Hawke’s Bay.
No hotspots currently exist in the North Island.
As of 27 November, the New Zealand Drought Index (NZDI) map below shows that no unusually dry conditions are currently found across the North Island.
South Island:
Rainfall amounts of 30-50 mm were observed in much of the West Coast and Fiordland, along with portions of northern and central Canterbury.
Elsewhere in the South Island, rainfall amounts of 25 mm or less were generally observed.
This resulted in at least minor soil moisture decreases across much of the South Island, although minor increases were observed in central Canterbury.
The driest soils across the South Island, when compared to normal for this time of the year, are found in Marlborough Sounds and coastal Southland, while the wettest soils for this time of the year are found in western Tasman.
In the past week, the hotspot located in coastal Banks Peninsula and Selwyn District dissipated, while a new hotspot formed in Marlborough Sounds.
As of 27 November, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Nelson, Marlborough, North Canterbury, and Banks Peninsula.
Pictured above: Soil Moisture Anomaly Maps, relative to this time of year. The maps show soil moisture anomalies over the past two weeks.
As of 27 November, the New Zealand Drought Index (NZDI) map below shows that abnormally dry conditions are currently found in parts of Nelson, Marlborough, North Canterbury, and Banks Peninsula. Please note: some hotspots in the text above may not correspond with the NZDI map. This difference exists because the NZDI uses additional dryness indices, including one which integrates the rainfall deficit over the past 60 days. Changes are therefore slower to appear in the NZDI compared to soil moisture anomaly maps that are instantaneously updated.
The week ahead:
North Island:
Scattered showers will be possible on Friday and Saturday (1-2 December), but many parts of the North Island will remain dry.
Moderate to heavy rain may overspread much of the island on Sunday and Sunday night.
There is currently some uncertainty regarding the timing and amount of rainfall expected next week, but periods of at least moderate rain are possible from Tuesday (5 December).
Weekly rainfall totals of 25-50 mm are forecast across a majority of the North Island, but localised higher amounts may occur.
Due to the expected rainfall in the next week, a majority of the North Island is likely to see little change to soil moisture levels, or small increases.
No hotspots are expected to form in the North Island in the next week.
South Island:
Other than isolated showers, mostly dry weather is expected through Saturday morning (2 December), followed by rain for many regions through Sunday. Heavy rain will affect the West Coast during this time.
After showers on Monday (4 December), mostly dry weather is expected through Wednesday morning.
During the middle of next week, another front could bring lighter rain to the West Coast.
Weekly rainfall totals of 100-200 mm are generally expected in the West Coast, with 30-50 mm possible in interior areas.
However, lighter amounts of 25 mm or less are forecast along the east coast, Otago, and Southland.
Due to the expected rainfall in the next week, soil moisture decreases may occur in the lower South Island, with minor increases possible in the West Coast.
The current hotspot in Marlborough Sounds may not change significantly in the next week, while coastal Southland could approach hotspot criteria.
Long-term outlook (through late December):
The drier (25th percentile) and middle (50th percentile) rainfall scenarios both favour drier or much drier than normal conditions in the upper and eastern North Island and eastern South Island.
Even in the wetter (75th percentile) scenario, below normal rainfall is still favoured in the lower South Island.
Near normal to above normal rainfall is favoured for the North Island in the wetter scenario.
Very dry or meteorological drought conditions are unlikely to develop in the next 35 days, but cannot be ruled out under the driest-case scenario for parts of the South Island.
Pictured above: 35-day forecast rainfall anomaly scenarios (Top), and 35-day forecast dryness and drought scenarios (Bottom). These maps are updated daily at https://niwa.co.nz/climate/seasonal-climate-outlook
Background:
Hotspot Watch: a weekly advisory service for New Zealand media. It provides soil moisture and precipitation measurements around the country to help assess whether extremely dry conditions are imminent.
Soil moisture deficit: the amount of water needed to bring the soil moisture content back to field capacity, which is the maximum amount of water the soil can hold.
Soil moisture anomaly: the difference between the historical normal soil moisture deficit (or surplus) for a given time of year and actual soil moisture deficits.
Hotspot: A hotspot is declared if soils are “severely drier than normal” which occurs when Soil Moisture Deficit (SMD) is less than -110 mm AND the Soil Moisture Anomaly is less than -20 mm.