Assessing the Variability of Extreme Weather Events and Its Influence on Marine Accidents along the Northern Coast of Tanzania

The marine accidents are among the main components of the Zanzibar Disaster Management Policy (2011) and the Zanzibar Blue Economy Policy (2020). These policies aimed to institute legal frame works and procedures for reducing both the frequency of marine accidents and their associated fatalities. These fatalities include deaths, permanent disabilities and loss of properties which may result into increased poverty levels as per the sustainable development goal one (SDG1) which stipulates on ending the poverty in all its forms everywhere. Thus, in the way to support these Government efforts, the influence of climate and weather on marine accidents along Zanzibar and Pemba Channels was investigated. The study used the 10 years (2013-2022) records of daily rainfall and hourly wind speed acquired from Tanzania Meteorological Authority (TMA) (for the observation stations of Zanzibar, Pemba, Dares Salaam and Tanga), and the significant wave heights data, which was freely downloaded from Globally Forecasting System (GFS-World model of 13 km resolution). The marine accident records were collected from TASAC and Zanzibar Maritime Authority (ZMA), and the anecdotal information was collected from heads of quay and boat captains in different areas of Zanzibar. The Mann Kendal test, was used to determine the slopes and trends direction of used weather parameters, while the Pearson correlations analysis and t-tests were used to understand the significance of the underlying relationship between the weather and marine accidents. The paired t-test was used to evaluate the extent to which weather parameters affect the marine accidents. Results revealed that the variability of extreme weather events (rainfall, ocean waves and wind speed) was seen to be among the key factors for most of the recorded marine accidents. For instance, in Pemba high rainfall showed an increasing trend of extreme rainfall events, while Zanzibar has shown a decreasing trend of these events. As for extreme wind events, results show that Dar es Salaam and Tanga had an increasing trend, while Zanzibar and Pemba had shown a decreasing trend. As for the monthly variability of frequencies of extreme rainfall events, March to May (MAM) season was shown to have the highest frequencies over all stations with the peaks at Zanzibar and Pemba. On the other hand, high frequency of extreme wind speed was observed from May to September with peaks in June to July, and the highest strength was observed during 09:00 to 15:00 GMT. Moreover, results revealed an increasing trend of marine accidents caused by bad weather except during November. Also, results showed that bad weather conditions contributed to 48 (32%) of all 150 recorded accidents. Further results revealed significant correlation between the extreme wind and marine accidents, with the highest strong correlation of r = 0.71 (at p ≤ 0.007) and r = 0.75 (at p ≤ 0.009) at Tanga and Pemba, indicating the occurrence of more marine accidents at the Pemba channel. Indeed, strong correlation of r = 0.6 between extreme rainfall events and marine accidents was shown in Pemba, while the correlations between extremely significant wave heights and marine accidents were r = 0.41 (at p ≤ 0.006) and r = 0.34 (p ≤ 0.0006) for Pemba and Zanzibar Channel, respectively. In conclusion, the study has shown high influence between marine accidents and bad weather events with more impacts in Pemba and Zanzibar. Thus, the study calls for more work to be undertaken to raise the awareness on marine accidents as a way to alleviate the poverty and enhance the sustainable blue economy.

What determines irrigation efficiency when farmers face extreme weather events? A field survey of the major wheat producing regions in China

Water availability is a major constraint on grain production in China, therefore, improving irrigation efficiency is particularly important when agriculture faces extreme weather events. This paper first calculates irrigation efficiency with a translog stochastic frontier production function and then investigates what happens when extreme weather events occur via a Tobit model. The estimated results reveal several important features of irrigation practices: i) irrigation efficiency is lower when extreme weather events occur; ii) large variations in irrigation efficiency occur across irrigation facilities; iii) the farm plots exhibit an extreme distribution across efficiency levels; and iv) water-saving techniques, technology adoption, and the maintenance of farmers’ economic resilience are major determinants of irrigation efficiency. Based on these results we propose the following recommendations: i) farmers should balance crop yield and water use; undertake relevant training programs and adopt water-saving techniques; ii) local governments and researchers should help farmers to find the optimal level of irrigation water use based on their own circumstances and provide better water-saving techniques and training programs rather than simply encouraging farmers to invest in irrigation facilities in the most extreme weather years; and iii) the income level of farm households should be increased so as to improve their resilience to natural disasters.

Crop Diversification in Coping with Extreme Weather Events in China

Apart from the long-term effects of climate change, the frequency and severity of extreme weather events have been increasing. Given the risks posed by climate change, particularly the changes in extreme weather events, the question of how to adapt to these changes and mitigate their negative impacts has received great attention from policy makers. The overall goals of this study are to examine whether farmers adapt to extreme weather events through crop diversification and which factors influence farmers＇ decisions on crop diversification against extreme weather events in China. To limit the scope of this study, we focus on drought and flood events only. Based on a unique large-scale household survey in nine provinces, this study finds that farmers respond to extreme weather events by increasing crop diversification. Their decision to diversify crops is significantly influenced by their experiences of extreme weather events in the previous year. Such results are understandable because farmers＇ behaviors are normally based on their expectations. Moreover, household characteristics also affect farmers＇ decisions on crop diversification strategy, and their effects differ by farmers＇ age and gender. This paper concludes with several policy implications.

Resilience Building and Collaborative Governance for Climate Change Adaptation in Response to a New State of More Frequent and Intense Extreme Weather Events

The weather conditions of the summer of 2022 were very unusual,particularly in Eastern Asia,Europe,and North America.The devasting impact of climate change has come to our attention,with much hotter and drier conditions,and with more frequent and intense flooding events.Some extreme events have reached a dangerous level,increasingly threatening human lives.The interconnected risks caused by these extreme disaster events are triggering a chain effect,forcing us to respond to these crises through changes in our living environment,which affect the atmosphere,the biosphere,the economy including the availability of energy,our cities,and our global society.Moreover,we have to confront the abnormal consequences of untypical,rapid changes of extreme events and fast switches between extreme states,such as from severe drought to devastating flooding.Recognizing this new situation,it is crucial to improve the adaptation capacity of our societies in order to reduce the risks associated with climate change,and to develop smarter strategies for climate governance.High-quality development must be science-based,balanced,safe,sustainable,and climate-resilient,supported by the collaborative governance of climate mitigation and adaptation.This article provides some recommendations and suggestions for resilience building and collaborative governance with respect to climate adaptation in response to a new planetary state that is characterized by more frequent and severe extreme weather events.

Local Weather Events:Stories of Pedagogical Practice as Possible Cultures of Exploration

Purpose:This article aims to describe and discuss what local weather landscapes mean to children and how weather implies exploring bodily sensations and capabilities.It does so by following the work of a community artist,working as a kindergarten teacher,over 1 year.Design/Approach/Methods:Through a narrative inquiry approach,which also includes studies of archival data and field notes,we analyze how local and personally experienced weather events imply what we call“cultures of exploration”in institutional practices.The epistemologies cross the specter of cultural–historical,pragmatic,and deep ecological philosophy.Findings:Through this study,we exemplify how experiencing weather is intertwined into pedagogical practices like habituating the body to cope with cold and wet weather,learning about danger in a wild natural landscape,and valuing species as a powerful practice.The descriptions exemplify“cultures of exploration”as a pedagogical approach.Originality/Value:In this time of an increasing climate crisis on our planet,the value of our findings is to foreground new insights,awareness,and knowledge relevant to children;to early-childhood education;and to life and societies at large.We can thus develop methods to better care for,protect,and educate children.This article has the potential to show how weather events are intertwined with everyday institutional practices—as well as how children,through exploration,learn to cope with seasonal weather landscapes and local cultural adaptations.

Coastal hypoxia response to the coupling of catastrophic flood,extreme marine heatwave and typhoon:a case study off the Changjiang River Estuary in summer 2020

Massive bodies of low-oxygen bottom waters are found in coastal areas worldwide,which are detrimental to coastal ecosystems.In summer 2020,the response of coastal hypoxia to extreme weather events,including a catastrophic flooding,an extreme marine heatwave,and Typhoon Bavi,is investigated based on multiple satellite,four cruises,and mooring observations.The extensive fan-shaped hypoxia zone presents significant northward extension during July-September 2020,and is estimated as large as 13 000 km^(2) with rather low oxygen minimum(0.42 mg/L) during its peak in 28-30 August.This severe hypoxia is attributed to the persistent strong stratification,which is indicated by flood-induced larger amount of riverine freshwater input and subsequent marine heatwave off the Changjiang River Estuary.Moreover,the Typhoon Bavi has limited effect on the marine heatwave and coastal hypoxia in summer 2020.

Extreme Cold Events from East Asia to North America in Winter 2020/21:Comparisons,Causes,and Future Implications

Three striking and impactful extreme cold weather events successively occurred across East Asia and North America during the mid-winter of 2020/21.These events open a new window to detect possible underlying physical processes.The analysis here indicates that the occurrences of the three events resulted from integrated effects of a concurrence of anomalous thermal conditions in three oceans and interactive Arctic-lower latitude atmospheric circulation processes,which were linked and influenced by one major sudden stratospheric warming(SSW).The North Atlantic warm blob initiated an increased poleward transient eddy heat flux,reducing the Barents-Kara seas sea ice over a warmed ocean and disrupting the stratospheric polar vortex(SPV)to induce the major SSW.The Rossby wave trains excited by the North Atlantic warm blob and the tropical Pacific La Nina interacted with the Arctic tropospheric circulation anomalies or the tropospheric polar vortex to provide dynamic settings,steering cold polar air outbreaks.The long memory of the retreated sea ice with the underlying warm ocean and the amplified tropospheric blocking highs from the midlatitudes to the Arctic intermittently fueled the increased transient eddy heat flux to sustain the SSW over a long time period.The displaced or split SPV centers associated with the SSW played crucial roles in substantially intensifying the tropospheric circulation anomalies and moving the jet stream to the far south to cause cold air outbreaks to a rarely observed extreme state.The results have significant implications for increasing prediction skill and improving policy decision making to enhance resilience in“One Health,One Future”.

Characteristics of air pollution events over Hotan Prefecture at the southwestern edge of Taklimakan Desert, China

Hotan Prefecture is located at the southwestern edge of Taklimakan Desert, the world＇s largest shifting sand desert, of China. The desert is one of the main sources for frequent sand-dust weather events which strongly affect the air quality of Hotan Prefecture. Although this region is characterized by the highest annual mean PMlo concentration values that are routinely recorded by environmental monitoring stations across China, both this phenomenon and its underlying causes have not been adequately addressed in previous researches. Reliable pollutant PM_10 data are currently retrieved using a tapered element oscillating microbalance （TEOM） 1400a, a direct real-time monitor, while additional concentration values including for PM_2.5, sulfur dioxide （SO_2）, nitrogen dioxide （NO_2）, carbon monoxide （CO） and ozone （O_3） have been collected in recent years by the Hotan Environmental Monitoring Station. Based on these data, this paper presents a comparison of the influences of different kinds of sand-dust weather events on PM_10 （or PM_2.5） as well as the concentrations of other gaseous pollutants in Hotan Prefecture. It is revealed that the highest monthly average PM_10 concentrations are observed in the spring because of the frequent occurrence of three distinct kinds of sand-dust weather events at this time, including dust storms, blowing dust and floating dust. The floating dust makes the most significant contribution to PM_10 （or PM_2.5） concentration in this region, a result that differs from eastern Chinese cities where the heaviest PM_10 pollution occurs usually in winter and air pollution results from the excess emission of local anthropogenic pollutants. It is also shown that PM_10 concentration varies within wpical dust storms. PM_10 concentrations vary among 20 dust storm events within Hotan Prefecture, and the hourly mean concentrations tend to sharply increase initially then slowly decreasing over time. Data collected from cities in eastern China show the opposite with the hourly mean PM_10 （or PM_2.5） concentration tending to slowly increase then sharply decrease during heavy air pollution due to the excess emission of local anthropogenic pollutants. It is also found that the concentration of gaseous pollutants during sand-dust weather events tends to be lower than those cases under clear sky conditions. This indicates that these dust events effectively remove and rapidly diffuse gaseous pollutants. The analysis also shows that the concentration of SO_2 decreases gradually at the onset of all three kinds of sand-dust weather events because of rapidly increasing wind velocity and the development of favorable atmospheric conditions for diffusion. In contrast, changes in O_3 and NO_2 concentrations conformed to the opposite pattern during all three kinds of sand-dust weather events within this region, implying the inter transformation of these gas species during these events.

Numerical Simulation and Analysis of Storm Surges Under Different Extreme Weather Event and Typhoon Experiments in the South Yellow Sea

In this study,a coupled tide-surge-wave model was developed and applied to the South Yellow Sea.The coupled model simulated the evolution of storm surges and waves caused by extreme weather events,such as tropical cyclones,cold waves,extratropical cyclones coupled with a cold wave,and tropical cyclones coupled with a cold wave.The modeled surge level and significant wave height matched the measured data well.Simulation results of the typhoon with different intensities revealed that the radius to the maximum wind speed of a typhoon with 1.5 times wind speed decreased,and its influence range was farther away from the Jiangsu coastal region;moreover,the impact on surge levels was weakened.Thereafter,eight hypothetical typhoons based on Typhoon Chan-hom were designed to investigate the effects of varying typhoon tracks on the extreme value and spatial distribution of storm surges in the offshore area of Jiangsu Province.The typhoon along path 2 mainly affected the Rudong coast,and the topography of the Rudong coast was conducive to the increase in surge level.Therefore,the typhoon along path 2 induced the largest surge level,which reached up to 2.91 m in the radial sand ridge area.The maximum surge levels in the Haizhou Bay area and the middle straight coastline area reached up to 2.37 and 2.08 m,respectively.In terms of typhoons active in offshore areas,the radial sand ridge area was most likely to be threatened by typhoon-induced storm surges.

MULTIMODEL CONSENSUS FORECASTING OF LOW TEMPERATURE AND ICY WEATHER OVER CENTRAL AND SOUTHERN CHINA IN EARLY 2008

Based on the daily mean temperature and 24-h accumulated total precipitation over central and southern China, the features and the possible causes of the extreme weather events with low temperature and icing conditions,which occurred in the southern part of China during early 2008, are investigated in this study. In addition, multimodel consensus forecasting experiments are conducted by using the ensemble forecasts of ECMWF, JMA, NCEP and CMA taken from the TIGGE archives. Results show that more than a third of the stations in the southern part of China were covered by the extremely abundant precipitation with a 50-a return period, and extremely low temperature with a 50-a return period occurred in the Guizhou and western Hunan province as well. For the 24- to 216-h surface temperature forecasts, the bias-removed multimodel ensemble mean with running training period(R-BREM) has the highest forecast skill of all individual models and multimodel consensus techniques. Taking the RMSEs of the ECMWF 96-h forecasts as the criterion, the forecast time of the surface temperature may be prolonged to 192 h over the southeastern coast of China by using the R-BREM technique. For the sprinkle forecasts over central and southern China, the R-BREM technique has the best performance in terms of threat scores(TS) for the 24- to 192-h forecasts except for the 72-h forecasts among all individual models and multimodel consensus techniques. For the moderate rain, the forecast skill of the R-BREM technique is superior to those of individual models and multimodel ensemble mean.

Impacts on Bats by a Supertyphoon vs.Ordinary Typhoons along a Habitat Urbanization Gradient

Two major human-caused threats to ecosystems are habitat modification and the increasing frequency and intensity of extreme weather events.To study the combined effect of these threats,the authors used acoustic monitoring of bats along a habitat modification gradient on the island of Okinawa,Japan.During the observation period,the island experienced numerous typhoons and one supertyphoon.Native bat species remained active even at high wind speeds(up to 30 m/s in some cases).Milder typhoons had no observable effect on bat populations,with activity levels fully recovering within a few hours or days.The super typhoon also did not seem to affect bats in fully or partially forested habitats but caused their local disappearance at the urban site,which they have not re-colonized three years after the event.Notably,bats that disappeared at the urban site were species roosting in well-protected places such as caves and concrete structures.In all cases,the biomass of small flying insects and the acoustic activity of insects recovered within days after extreme weather events.Thus,the striking difference between habitats in supertyphoon effects on bats cannot be explained by the super typhoon directly killing bats,destroying their roosting sites,or decreasing the abundance of their prey.The results underscore the importance of preserving natural habitats in areas particularly affected by changing climate and show that the survival of species and ecosystems during the numerous episodes of climate change in the Earth’s history does not necessarily mean their ability to survive the accelerating climate change of our time.

Overview of China Polar Climate Change Annual Report(2022)

The China Meteorological Administration recently released China Polar Climate Change Annual Report(2022)in Chinese,with the following main conclusions.Using the China Reanalysis-40 dataset(CRA-40),rapid warming has been observed in the Antarctic Peninsula and West Antarctica since 1979,with some parts of East Antarctica also experiencing warming.In 2022,the regional average temperature in Antarctica based on observational data was close to the long-term average(1991-2020).The Arctic,on the other hand,has experienced a warming trend at a rate of 0.63℃per decade from 1979 to 2022 based on CRA-40,which is 3.7 times the global mean during the same period(0.17℃per decade).In 2022,the overall temperature in the Arctic,using station data,was 1.10℃above the long-term average(1991-2020).In recent years,both the Antarctic and Arctic regions have witnessed an increase in the frequency and intensity of extreme weather events.In 2022,based on the sea ice extent from National Snow and Ice Data Center,USA,Antarctic sea ice reached its lowest extent on record since 1979,and on 18 March,the most rapid surface warming event ever recorded on Earth occurred in the Antarctic,with a temperature increase of 49℃within 3 d.This report has been integrated into China's National Climate Change Bulletin system,to contribute to raising public awareness of polar climate change and providing valuable scientific references to address climate change.

Climate change characteristics of Amur River

Unusually severe weather is occurring more frequently due to global climate change. Heat waves, rainstorms, snowstorms, and droughts are becoming increasingly common all over the world, threatening human lives and property. Both temperature and precipitation are representative variables usually used to directly reflect and forecast the influences of climate change. In this study, daily data （from 1953 to 1995） and monthly data （from 1950 to 2010） of temperature and precipitation in five regions of the Amur River were examined. The significance of changes in temperature and precipitation was tested using the Mann-Kendall test method. The amplitudes were computed using the linear least-squares regression model, and the extreme temperature and precipitation were analyzed using hydrological statistical methods. The results show the following： the mean annual temperature increased significantly from 1950 to 2010 in the five regions, mainly due to the warming in spring and winter; the annual precipitation changed significantly from 1950 to 2010 only in the lower mainstream of the Amur River; the frequency of extremely low temperature events decreased from 1953 to 1995 in the mainstream of the Amur River; the frequency of high temperature events increased from 1953 to 1995 in the mainstream of the Amur River; and the frequency of extreme precipitation events did not change significantly from 1953 to 1995 in the mainstream of the Amur River. This study provides a valuable theoretical basis for settling disputes between China and Russia on sustainable development and utilization of water resources of the Amur River.

A New Method to Identify the Maximum Time Interval between Individual Events in Compound Rainstorm and Heatwave Events

Growing evidence indicates that extreme heat and rain may occur in succession within short time periods and cause greater impacts than individual events separated in time and space.Therefore,many studies have examined the impacts of compound hazard events on the social-ecological system at various scales.The definition of compound events is fundamental for such research.However,there are no existing studies that support the determination of time interval between individual events of a compound rainstorm and heatwave(CRH)event,which consists of two or more potentially qualifying component heatwave and rainstorm events.To address the deficiency in defining what individual events can constitute a CRH event,this study proposed a novel method to determine the maximum time interval for CRH events through the change in CRH event frequency with increasing time interval between individual events,using southern China as a case study.The results show that the threshold identified by the proposed method is reasonable.For more than 90%of the meteorological stations,the frequency of CRH events has reached a maximum when the time interval is less than or equal to the threshold.This study can aid in time interval selection,which is an important step for subsequent study of CRH events.

State of China’s climate in 2021

This report is a summary of China’s climate,as well as major weather and climate events,during 2021.In 2021,the mean temperature in China was 10.5°C,which was 1.0°C above normal(1981–2010 average)and broke the highest record since 1951.The annual rainfall in China was 672.1 mm,which was 6.7%above normal.Also,the annual rainfall in northern China was 40.2%above normal,which ranked second highest since 1961.The rainstorm intensity in the rainy season was strong and featured significant extremes,and disasters caused by rainstorms and flooding were more serious than the average in the past decade.In particular,the extremely strong rainstorm in Henan during July and autumn caused flooding in the middle and lower reaches of the Yellow River with severe consequences.Heatwaves occurred more frequently than normal,and their durations in southern China were longer than normal in summer and autumn.Phased drought was obvious,and caused serious impacts in South China.The number of generated and landfalling typhoons was lower than normal;however,Typhoon In-fa broke the record for the longest overland duration,held since 1949,and affected a wide area.Severe convective weather and extreme windy weather occurred frequently,causing serious impacts.The number of cold waves was more than normal,which caused wide-ranging extremely low temperatures in many places.Sandstorms appeared earlier than normal in 2021,and the number of strong dust storm processes was more than normal.

Market opportunities do not explain the ability of herders to meet livelihood objectives over winter on the Mongolian Plateau

Drylands under pastoral land use are considered one of the most vulnerable social-ecological systems to global climate change,but the herders'abilities to adapt to the different extreme weather events have received little attention in the drylands.Herders on the Mongolian Plateau(MP;including Inner Mongolia Autonomous Region of China and Mongolia),have had a long history of adapting climatic variability and extreme weather events.However,it is unclear how changes such as increased levels of infrastructure and market integration affect the ability of herders to achieve the key livelihood objectives:the minimisation of the death and abortion rates of livestock in the winter.Here,we used remotely sensed and household survey data to map,model and explore the climate exposure and sensitivity of herders in the settled area(Inner Mongolia of China)and nomadic area(Mongolia)in the winter of 2012–2013.We aimed to quantify the multi-scaled characteristics of both climate exposure and sensitivity through the lens of key adaptive strategies utilized by herders.Our results showed that the higher levels of infrastructure and market integration,and the lower levels of remoteness on the MP did not increase the herders'ability to achieve the key livelihood objectives.Our results also suggested that exposure to the snow that is comparatively greater than the long-term average(cumulative exposure)may be more important in determining the social-ecological vulnerability than absolute exposure.We suggested that neither the risk management strategies available to these herders,nor the demographic variables,could compensate for the mode of production governing the pastoral systems.Our study could provide further evidence for the complex and scaled nature of climate exposure and sensitivity,and the results imply that any analysis of the relationship among exposure,sensitivity and vulnerability of pastoral households to climate change in the drylands will require a multi-scaled and interdisciplinary approach.

Climate Change and Food Price: A Systematic Review and Meta-Analysis of Observational Studies, 1990-2021

Climate extreme events have threatened food security and the second Sustainable development goals (SDGs) “zero hunger” both directly via agricultural food loss and indirectly through rising food prices. We systematically searched and used a combination of results from various models, which play a crucial role in predicting the potential impact of climate change on agricultural production and food price. Therefore, we searched online databases including EMBASE, Web of Science, Scopus, Google Scholar, and grey literature. Then observational studies were included from January 1990 to August 2021, which reported food price proportion under climate disturbances. Results showed that 22 out of 26 studies from 615 articles, identified in the meta-analysis predicted the food price ratio would be fluctuated up to 28% before 2020, while the ratio will be marked up at 31% from 2020 to 2049 and then will scale down during 2050-2100. The compiled ratio was estimated at 26% in the long period between 2000 until 2100 under climatic weather events. Drought was a significant weather disturbance with a 32% increase in food prices. Consequently, the Food price increase will significantly affect food accessibility in lower-income countries, primarily until 2050. Policymakers should prioritize and act through redesigning food security policies according to climatic extremes in their settings.

Community-Based Coral Reef Rehabilitation in a Changing Climate:Lessons Learned from Hurricanes,Extreme Rainfall,and Changing Land Use Impacts

Coral reefs have largely declined across multiple spatial scales due to a combination of local-scale anthropogenic impacts, and due to regional-global climate change. This has resulted in a significant loss of entire coral functional groups, including western Atlantic Staghorn coral (Acropora cervicornis) biotopes, and in a net decline of coral reef ecosystem resilience, ecological functions, services and benefits. Low-tech coral farming has become one of the most important tools to help restore depleted coral reefs across the Wider Caribbean Region. We tested a community-based, low-tech coral farming approach in Culebra Island, Puerto Rico, aimed at adapting to climate change-related impacts through a two-year project to propagate A. cervicornis under two contrasting fishing management conditions, in coastal areas experimenting significant land use changes. Extreme rainfall events and recurrent tropical storms and hurricanes had major site-and method-specific impacts on project outcome, particularly in areas adjacent to deforested lands and subjected to recurrent impacts from land-based source pollution (LBSP) and runoff. Overall, coral survival rate in “A frame” units improved from 73% during 2011-2012 to 81% during 2012-2013. Coral survival rate improved to 97% in horizontal line nurseries (HLN) incorporated during 2012-2013. Percent tissue cover ranged from 86% to 91% in “A frames”, but reached 98% in HLN. Mean coral skeletal extension was 27 cm/y in “A frames” and 40 cm/y in HLN. These growth rates were up to 545% to 857% faster than previous reports from coral farms from other parts of the Caribbean, and up to 438% faster than wild colonies. Branch production and branchiness index (no. harvestable branches > 6 cm) increased by several orders of magnitude in comparison to the original colonies at the beginning of the project. Coral mortality was associated to hurricane physical impacts and sediment-laden runoff impacts associated to extreme rainfall and deforestation of adjacent lands. This raises a challenging question regarding the impact of chronic high sea surface temperature (SST), in combination with recurrent high nutrient pulses, in fostering increased coral growth at the expense of coral physiological conditions which may compromise corals resistance to disturbance. Achieving successful local management of reefs and adjacent lands is vital to maintain the sustained net production in coral farms and of reef structure, and the provision of the important ecosystem services that they provide. These measures are vital for buying time for reefs while global action on climate change is implemented. Adaptive community-based strategies are critical to strengthen institutional management efforts. But government agencies need to transparently build local trust, empower local stakeholders, and foster co-management to be fully successful. Failing to achieve that could make community-based coral reef rehabilitation more challenging, and could potentially drive rapidly declining, transient coral reefs into the slippery slope to slime.

The 2020 Summer Floods and 2020/21 Winter Extreme Cold Surges in China and the 2020 Typhoon Season in the Western North Pacific

China experienced significant flooding in the summer of 2020 and multiple extreme cold surges during the winter of 2020/21.Additionally,the 2020 typhoon season had below average activity with especially quiet activity during the first half of the season in the western North Pacific(WNP).Sea surface temperature changes in the Pacific,Indian,and Atlantic Oceans all contributed to the heavy rainfall in China,but the Atlantic and Indian Oceans seem to have played dominant roles.Enhancement and movement of the Siberian High caused a wavier pattern in the jet stream that allowed cold polar air to reach southward,inducing cold surges in China.Large vertical wind shear and low humidity in the WNP were responsible for fewer typhoons in the first half of the typhoon season.Although it is known that global warming can increase the frequency of extreme weather and climate events,its influences on individual events still need to be quantified.Additionally,the extreme cold surge during 16–18 February 2021 in the United States shares similar mechanisms with the winter 2020/21 extreme cold surges in China.

A Study of Soil-dynamics Based on a Simulated Drought in an Alpine Meadow on the Tibetan Plateau

Extreme weather events have played an important role in driving the ecosystem dynamics in high altitude areas, but the underlying mechanism remains unclear. To understand if and how the soil processes of an ecosystem react to extreme drought, we manipulated a once-in-a-century meteorological extreme drought in an alpine meadow on the Tibetan Plateau, which is also known as the ＂forerunner of global weather changes＂. The extremity was determined by statistical extreme weather events with respect to a historical reference period from April to September during 1962 - 2004, where the local historical precipitation data was calculated and intensified to loo-year recurrent drought event with Gumbel I distribution. The indicators we measured included soil microbial biomass C/N/P and soil enzymatic activities of phosphatase （AP） disbounding organic phosphate, cellobiohydrolase （CBH）, β- glucocidase （BG）, N-releasing enzyme N-acetyl- glucosaminidase （NAG） as well as soil respirations, during and after the treatments. It was found that the manipulated event induced a rapid shift in microbial biomass and activities, indicating a lower resistance of the underground process. However, the microbial and biochemical parameters saw rapid recovery after the event, which meant the soil processes enjoyed high resilience. The high responsiveness and lag-time effects of the soil indicators rendered new horizons for us to evaluate the interaction between the extremes and the ecosystem stability. Our study indicated that the once-in-a-century extreme drought induced very short term response in the soil biotic process, and the soil processes worked to buffer against such events under the observation period.