Impact of the Hunga Tonga volcanic eruption on stratospheric composition.

The explosive eruption of the Hunga Tonga-Hunga Ha'apai (HTHH) volcano on 15 January 2022 injected more water vapor into the stratosphere and to higher altitudes than ever observed in the satellite era. Here, the evolution of the stratospherically injected water vapor is examined as a function of latitude, altitude, and time in the year following the eruption (February to December 2022), and perturbations to stratospheric chemical composition resulting from the increased sulfate aerosols and water vapor are identified and analyzed. The average calculated mass distribution of elevated water vapor between hemispheres is approximately 78% Southern Hemisphere (SH) and 22% Northern Hemisphere in 2022. Significant changes in stratospheric composition following the HTHH eruption are identified using observations from the Aura Microwave Limb Sounder satellite instrument. The dominant features in the monthly mean vertical profiles averaged over 15° latitude ranges are decreases in O3 (-14%) and HCl (-22%) at SH midlatitudes and increases in ClO (>100%) and HNO3 (43%) in the tropics, with peak pressure-level perturbations listed. Anomalies in column ozone from 1.2-100 hPa due to the HTHH eruption include widespread O3 reductions in SH midlatitudes and O3 increases in the tropics, with peak anomalies in 15° latitude-binned, monthly averages of approximately -7% and +5%, respectively, occurring in austral spring. Using a 3-dimensional chemistry-climate-aerosol model and observational tracer correlations, changes in stratospheric composition are found to be due to both dynamical and chemical factors.

Unexpectedly rapid aerosol formation in the Hunga Tonga plume.

The Hunga Tonga-Hunga Ha'apai (HT-HH) volcanic eruptions on January 13 and 15, 2022, produced a plume with the highest signal in stratospheric aerosol optical depth observed since the eruption of Mt. Pinatubo in 1991. Suites of balloon-borne instruments on a series of launches from Réunion Island intercepted the HT-HH plume between 7 and 10 d of the eruptions, yielding observations of the aerosol number and size distribution and sulfur dioxide (SO2) and water vapor (H2O) concentrations. The measurements reveal an unexpected abundance of large particles in the plume, constrain the total sulfur injected to approximately 0.2 Tg, provide information on the altitude of the injection, and indicate that the formation of sulfuric acid aerosol was complete within 3 wk. Large H2O enhancements contributed as much as ~30% to ambient aerosol surface area and likely accelerated SO2 oxidation and aerosol formation rates in the plume to approximately three times faster than under normal stratospheric conditions.

Effects of inappropriate cause-of-death certification on mortality from cardiovascular disease and diabetes mellitus in Tonga.

BACKGROUND: Cardiovascular disease (CVD) and diabetes mellitus are major health issues in Tonga and other Pacific countries, although mortality levels and trends are unclear. We assess the impacts of cause-of-death certification on coding of CVD and diabetes as underlying causes of death (UCoD). METHODS: Tongan records containing cause-of-death data (2001-2018), including medical certificates of cause-of-death (MCCD), had UCoD assigned according to International Classification of Diseases 10th revision (ICD-10) coding rules. Deaths without recorded cause were included to ascertain total mortality. Diabetes and hypertension causes were reallocated from Part 1 of the MCCD (direct cause) to Part 2 (contributory cause) if potentially fatal complications were not recorded, and an alternative UCoD was assigned. Proportional mortality by cause based on the alternative UCoD were applied to total deaths then mortality rates calculated by age and sex using census/intercensal population estimates. CVD and diabetes mortality rates for unaltered and alternative UCoD were compared using Poisson regression. RESULTS: Over 2001-18, in ages 35-59 years, alternative CVD mortality was higher than unaltered CVD mortality in men (p = 0.043) and women (p = 0.15); for 2010-18, alternative versus unaltered measures in men were 3.3/103 (95%CI: 3.0-3.7/103) versus 2.9/103 (95%CI: 2.6-3.2/103), and in women were 1.1/103 (95%CI: 0.9-1.3/103) versus 0.9/103 (95%CI: 0.8-1.1/103). Conversely, alternative diabetes mortality rates were significantly lower than the unaltered rates over 2001-18 in men (p < 0.0001) and women (p = 0.013); for 2010-18, these measures in men were 1.3/103 (95%CI: 1.1-1.5/103) versus 1.9/103 (95%CI: 1.6-2.2/103), and in women were 1.4/103 (95%CI: 1.2-1.7/103) versus 1.7/103 (95%CI: 1.5-2.0/103). Diabetes mortality rates increased significantly over 2001-18 in men (unaltered: p < 0.0001; alternative: p = 0.0007) and increased overall in women (unaltered: p = 0.0015; alternative: p = 0.014). CONCLUSIONS: Diabetes reporting in Part 1 of the MCCD, without potentially fatal diabetes complications, has led to over-estimation of diabetes, and under-estimation of CVD, as UCoD in Tonga. This indicates the importance of controlling various modifiable risks for atherosclerotic CVD (including stroke) including hypertension, tobacco use, and saturated fat intake, besides obesity and diabetes. Accurate certification of diabetes as a direct cause of death (Part 1) or contributory factor (Part 2) is needed to ensure that valid UCoD are assigned. Examination of multiple cause-of-death data can improve understanding of the underlying causes of premature mortality to better inform health planning.

Investigating the health status of primary school children in Tonga: Lessons learnt and reflections on field work in the Pacific Islands.

Globally, the child health focus has been on reducing under-5-year mortality, with large populations in low-resource regions prioritised. Children in older age groups, particularly in less populated regions such as the Pacific, have received limited attention. Child health research in the Pacific region has been lacking, and research approaches for the region have historically been from Western biomedical paradigms. We completed the study of primary school children's health over a period of 5 years. Firstly, we conducted a literature review, then we completed an audit of hospital admissions of primary school children, then we completed a two-round Delphi process and finally, we piloted the survey in three primary schools. Our results found there were high levels of oral health problems, ear health, obesity and exposure to violence and poverty impacting on the quality of health of primary school-age children. Identifying these indicators was made possible by the partnerships and trust established by the study team and provides specific and measurable targets for future work to improve the quality of child health outcomes. This paper describes key field work lessons learnt for research in the Pacific region. It must: (i) be on the platform of relationship, cultural safety and local ownership; (ii) include consideration of holistic Pacific paradigms of health; (iii) be adaptive to the context and environment; and (iv) be committed to long-term partnership and work.

Quantized Information in Spectral Cyberspace.

The constant-Q Gabor atom is developed for spectral power, information, and uncertainty quantification from time-frequency representations. Stable multiresolution spectral entropy algorithms are constructed with continuous wavelet and Stockwell transforms. The recommended processing and scaling method will depend on the signature of interest, the desired information, and the acceptable levels of uncertainty of signal and noise features. Selected Lamb wave signatures and information spectra from the 2022 Tonga eruption are presented as representative case studies. Resilient transformations from physical to information metrics are provided for sensor-agnostic signal processing, pattern recognition, and machine learning applications.

Tracking the 2022 Hunga Tonga-Hunga Ha'apai Aerosol Cloud in the Upper and Middle Stratosphere Using Space-Based Observations.

On 15 January 2022, the submarine Hunga Tonga volcanic eruption lofted materials high into the upper stratosphere, reaching a record-breaking altitude of ∼58 km, unprecedented in the satellite observations era. Within two weeks, the bulk of the injected material circulated the globe between 20-30 km altitude, as observed by satellite instruments. We estimate that the stratospheric aerosol optical depth (sAOD) is the largest since the Pinatubo eruption and is at least twice as great as the sAOD after the 2015 Calbubo eruption despite the similar SO2 injection from that eruption. We use space-based observations to monitor the Hunga-Tonga volcanic plume evolution and transport at different altitudes as it circulates the globe. While the main aerosol layer remains trapped in the tropical pipe, small parts have already made it to both the northern and southern hemisphere poles by April, which is almost certain to influence this year's ozone hole.

Surviving versus thriving: The wellbeing of primary school aged children in Tonga.

AIM: To enable improvements in global child health, the focus must move beyond child survival to child wellbeing. In the Pacific Islands, the wellbeing of children has received little attention. This study aimed to investigate the wellbeing of children from three primary schools in Tonga. METHODS: A cross-sectional survey was completed in three primary schools in Nuku'alofa with children aged 5-15 years. The study participants (256 children, 143 caregivers) completed the Child Health and Illness Profile - Child Edition, CHIP-CE (Version 1.0). RESULTS: On average, >70% of children and caregivers described home and school environments as positive. From the children's reports, boys had significantly lower scores for risk avoidance than girls (3.40 vs. 3.73, P < 0.001). Children aged 5-7 versus 8-15 years had significantly lower scores for satisfaction (3.63 vs. 3.92, P = 0.002), resilience (3.34 vs. 3.56, P = 0.016) and achievement (3.25 vs. 3.62, P = 0.002). From the caregivers' report, girls had significantly lower scores for academic performance than boys (3.60 vs. 3.81, P = 0.04). Boys had significantly lower scores for individual risk association compared to girls (3.93 vs. 4.29, P = 0.01). Overall CHIP-CE scores were lower than those of comparable populations in the West, while at the same time protective factors were documented. CONCLUSIONS: Understanding child wellbeing in the Pacific is critical for strengthening protective factors known to mitigate poor child health outcomes. Continuing to base global child health success on child survival alone misses opportunities for improving the wellbeing of nations.

Tsunami Effects on the Coast of Mexico by the Hunga Tonga-Hunga Ha'apai Volcano Eruption, Tonga.

The massive explosion by the January 15, 2022 Hunga Tonga-Hunga Ha'apai volcano in Tonga triggered a trans-oceanic tsunami generated by coupled ocean and atmospheric shock waves during the explosion. The tsunami reached first the coast of Tonga, and later many coasts around the world. The shock wave went around the globe, causing sea perturbations as far as the Caribbean and the Mediterranean seas. We present the effects of the January 15, 2022 Tonga tsunami on the Mexican Pacific Coast, Gulf of Mexico, and Mexican Caribbean coast, and discuss the underrated hazard caused by great volcanic explosions, and the role of early tsunami warning systems, in particular in Mexico. The shock wave took about 7.5 h to reach the coast of Mexico, located about 9000 km away from the volcano, and the signal lasted several hours, about 133 h (5.13 days). The shock wave was the only cause for sea alterations on the Gulf of Mexico and Caribbean Sea, while at the Mexican Pacific coast both shock wave and the triggered tsunami by the volcano eruption and collapse affected this coast. The first tsunami waves recorded on the Mexican Pacific coast arrived around 12:35 on January 15, at the Lázaro Cárdenas, Michoacán tide gauge station. The maximum tsunami height exceeded 2 m at the Ensenada, Baja California, and Manzanillo, Colima, tide gauge stations. Most tsunami warning advisories, with two exceptions, reached communities via social media (Twitter and Facebook), but did not clearly state that people must stay away from the shore. We suggest that, although no casualties were reported in Mexico, tsunami warning advisories of far-field tsunamis and those triggered non-seismic sources, such as landslides and volcanic eruptions, should be included and improved to reach coastal communities timely, explaining the associated hazards on the coast. Supplementary Information: The online version contains supplementary material available at 10.1007/s00024-022-03017-9.

Preliminary Observations and Impact in Japan of the Tsunami Caused by the Tonga Volcanic Eruption on January 15, 2022.

The tsunami caused by the Tonga submarine volcanic eruption that occurred at 13:15 Japan Time (JST) on January 15, 2022, exposed a blind spot in Japan's tsunami monitoring and warning system, which was established in 1952 for local tsunamis and expanded to distant tsunamis after the 1960 Chile tsunami. This paper summarizes how the warning system responded to the unprecedented tsunami, the actual evacuation process, and the damage it caused in Japan. Initially, the tsunami from the volcanic eruption was expected to arrive at approximately midnight with amplitudes of less than 20 cm. However, a series of short waves arrived at approximately 21:00, a few hours earlier than expected. The early arrival of these sea waves coincided with a rapid increase in atmospheric pressure; then, the short-period component was predominant, and the wave height was amplified while forming wave groups. After a 1.2 m tsunami was observed in Amami City in southern Japan at 23:55 JST, the Japan Meteorological Agency issued a tsunami warning/advisory. The tsunami continued, and all advisories were cleared at 14:00 JST on January 16. Information about this tsunami and the response to it are summarized here, including the characteristics and issues of the actual tsunami evacuation situation in each region. There were no casualties, but the issues that emerged included difficulty evacuating on a winter night and traffic congestion due to evacuation by car and under the conditions of the COVID-19 pandemic. In the coastal area, damage to fishing boats and aquaculture facilities was reported due to the flow of the tsunami. In addition, damage to aquaculture facilities, including those producing oysters, scallops, seaweed and other marine products, decreased the supply of marine products, and the economic impact is likely to increase in the future.

Barriers and facilitators to the introduction of import duties designed to prevent noncommunicable disease in Tonga: a case study.

BACKGROUND: In Tonga, import duties were lowered on tinned fish and seafood in 2013 and raised on soft drinks, dripping and other animal fats. Additional import duties were applied to soft drinks and dripping and other fats in 2016 and duties were also applied to high fat meats, mutton flaps and turkey tails. The objective of this study was to describe barriers to and facilitators of these import duties from a policy-maker perspective. METHODS: A case study was conducted to analyse implementation of policies originally modelled by the Pacific Obesity Prevention in Communities project to reduce mortality in the Kingdom of Tonga. Policymakers (n = 15) from the Ministries of Revenue, Health, Finance and Labour and Commerce involved in the development and implementation of Tonga's food-related policies participated in key-informant interviews. RESULTS: The main facilitator of import duties were strong leadership and management, cross-sector collaboration, awareness raising and advocacy, nature of the policy, and the effective use of data to model policy impacts and inform the general public. The absence of clear lines of responsibility and a decline in collaboration over time were identified as barriers to implementation of the import duties. CONCLUSION: In a small Island state implementing import duties to prevent non-communicable disease can be straight forward providing policymakers and the community have a shared understanding of the health and economic costs of NCDs.