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Thailand drought leaves lasting effects, even as rainy season begins

By Harland Dahl

While some areas of Thailand currently face heavy monsoon rains, others suffer from the effects of a drought that began in November of 2014. This was the worst drought experienced by Thailand in over a decade.

Water reserves run low in Thailand's Lamtakong Dam.

Water reserves run low in Thailand’s Lamtakong Dam.

The drought has had lasting negative effects on Thailand’s agricultural sector and has led to difficulties in rice farming, a crucial crop for Thai farmers and families. Thailand is the world’s largest rice exporter, with rice farming taking up 40% of Thai agricultural land and representing a significant portion of Thailand’s labor force and economy.

A farmer walks through his dry rice field.

A farmer walks through his dry rice field.

Other crops have been affected, as well, threatening the livelihood of many Thai citizens. Over half of Thailand’s working age population is supported by the agricultural sector.

In response to water shortages caused by the drought, the Thai government has asked farmers to delay rice production. Thai Minister of Agriculture and Cooperatives Petipong Pungbun Na Ayudhya explained, “The agriculture ministry and irrigation department have requested that farmers delay rice planting in the Chao Phraya area because the Chao Phraya area is a large rice growing area… and we need to organize the water that is being used.”

By delaying rice production, the government hopes to reduce nonessential water usage until monsoon rains bring relief from the drought. Thailand’s rainy season usually lasts from May to October, bringing an average of 2.4 meters of rain to Thailand’s southern regions, and 1.4 meters to the northern and central parts of the country.

p.90day.figb

Although Thailand’s rainy season had already begun, as of July 6th, 22 of the country’s 76 provinces were still facing drought conditions. The Thai Meteorological Department anticipates that this year’s rainy season will deliver mostly “near normal” rains. A report published by the department on June 26th predicts that the southwest monsoon will begin to travel north in July, bringing heavy to very heavy rains to Upper Thailand. Then, as is typical in the seasonal cycle, the rainfall maximum of the South Asian monsoon will shift southward in October towards Southern Thailand.

The Thai government is struggling to simultaneously provide relief from the drought, implement a water management plan to safeguard against future droughts, and prepare for threats presented by monsoon rains.

In response to the drought, the Thai government has implemented a system of daily water delivery to the most drought-affected areas using water trucks. Unfortunately, these efforts have often been insufficient to fulfill many communities’ water needs. The government has also used cloud seeding technology to create artificial rain to aid Thai farmers who depend on rice farming for their livelihood and keep rice production levels up.

Thai soldiers oversee the construction of new groundwater wells.

Thai workers build new groundwater wells.

Thailand has also announced a plan to invest $7.5 billion in water management projects in the coming years. These include a 10-year water management plan, a replacement for the less successful management plan of a previous regime.

The start of the rainy season has already led to flooding and mudslides in Bangkok, as well as in Thailand’s Central Plans. To prepare for future rains, the government has begun to dig waterways to contain rainwater and use social media to warn citizens of flooding risks.

Scientists Predict Strong El Nino for 2015

Government research centers and universities around the world are predicting that 2015 will bring a strong El Nino event. On NOAA’s ENSO blog, Emily Becker from the National Weather Service Climate Prediction Center, writes, “forecasters currently favor a ‘strong’ event for the fall/early winter”. The UK Met Office has also indicated that their models “suggest that this El Nino could strengthen from September onwards”. Some scientists are even warning that current conditions are reminiscent of the 1997 El Nino – the most severe on record. A report released by the Australian Bureau of Meteorology notes the abnormally warm sea-surface temperature observed in the Pacific Ocean over the last 2 weeks: “It is unusual to have such a broad extent of warmth across the tropical Pacific; this has not been seen since the El Niño event of 1997-98.”

Source: U.S. National Oceanic and Atmospheric Administration (NOAA). Warmer than normal sea surface temperatures in the Pacific Ocean during the 1997 El Nino event, the strongest on record.

Source: U.S. National Oceanic and Atmospheric Administration (NOAA). Warmer than normal sea surface temperatures in the Pacific Ocean during the 1997 El Nino event, the strongest on record.

 

An El Nino event entails warmer than usual sea-surface temperatures in the Pacific Ocean, which in turn impact weather systems around the world — triggering high temperatures, poor monsoons, and drought in Asia and east Africa, while causing heavy rains and floods in South America. Prof. Adam Scaife, of the UK Met Office’s Hadley Centre, said “With the current event, things like the Indian monsoon, tropical West Africa, the maritime continent [Indonesia], and Australian impacts are all appearing in current forecasts – all of those regions are at increased risk of drought.”

Image Source: International Research Institute (IRI) for Climate and Society, Columbia University. Models compiled by IRI predict a strong El Nino event by Fall 2015. The model average is marked by the bold yellow line.

 

El Nino events occur approximately every 2 to 7 years as part of a natural ocean-atmospheric cycle, though some research suggests that extreme El Nino events will become more frequent under climate change. Additionally, this year’s El Nino event could prompt record-breaking global temperatures, as the first four months of 2015 have already been the warmest on record according to the NOAA and NASA.

Image Source: Miami Univeristy, Ohio. Effect of El Nino events during the summer growing season.

 

A strong El Nino will be extremely hazardous for countries whose economies are highly dependent on agriculture, with crop failure and rising food prices creating food insecurity. The arrival of El Nino is most significant in regions where the main cropping season has just begun, such as in South Asia and West Africa; rain-fed rice production in South and Southeast Asia will be affected by the suppressed monsoon rains. In 2009, El Nino caused the worst drought in 40 years in India. In an interview with Reuters, K.K. Singh, the Head of the Agricultural Meteorology Division of the Indian Weather Office noted, “Crops like soybean and cotton are under El Nino watch for being sown mainly in rainfed conditions. El Nino looms large over soybean areas of the central parts and cotton belts of the western and the northern regions.”

Image Source: Inter Press Service News Agency. Woman stands in front of drought-affected rice paddy in Sri Lanka.

 

A strong El Nino year is likely to disrupt food markets and elevate prices of staple food crops such as rice, coffee, sugar and cocoa. Some reports estimate that an El Nino event can cause tens of billions of dollars of economic damage to the Asia-Pacific region. In a country like Indonesia, where the agriculture, forestry, and fisheries sectors account for 18% of the GDP, historically, El Nino events have caused a percentage drop in the GDP and spiked inflation.

 

 

 

Monsoon affects economy, health in India

By Harland Dahl 

India’s monsoon hit the Southern Indian state of Kerala on Friday, June 5th, four days later than expected. With monsoon rains comes relief from India’s stifling heat wave, which began in May.

The Indian Institute of Tropical Meteorology predicts that the monsoon will spread across most of India by the end of June. Rains are expected to reach the country’s West coast by June 17th and central India by June 25th. The India Meteorological Department predicts that the monsoon will be weaker than usual, bringing less than 90% of typical monsoon rainfall.

It is estimated that crop planting in India has gone down by 9% since last year. This is due to weak monsoon rains, which not only lead to low crop production, but to high food prices. The crops most affected are grains and cotton.

In response, the Indian government has taken several steps to boost agricultural production. The India Meteorological Department has begun to send mobile weather alerts to farmers, and public officials have been promoting the cultivation of more drought-resistant crops.

Minister of Agriculture Eknath Khadse explained, “Growing vegetables and fruits would be our priority. This will give farmers something for daily survival, without too much investment, along with the main crops ahead of the kharif season.”

The agricultural sector employs more Indian citizens than any other sector of the economy. This means that a below-average monsoon could have a significant effect on the Indian economy, as a whole. The ICICI Bank of India estimates that weak rains will cause a drop in India’s GDP growth for this fiscal year, from the originally estimated growth rate of 7.8% to 7.3%.

But even during a relatively dry year, monsoon rains have the potential to negatively impact other sectors of the Indian economy, as well. Heavy rains put crucial infrastructure at risk throughout India, and are particularly threatening to burgeoning industrial cities such as Bangalore, home to 30% of India’s startup companies.

A busy street in Bangalore, India.

 

With heavy rains come blackouts and losses in internet connectivity. While larger corporations can afford more reliable internet connections, smaller companies often depend on unreliable nationwide internet service providers or local cable networks.

Weakened infrastructure has also lead to sanitation problems in many parts of India, particularly in poorer parts of the country’s largest cities. Although overall water contamination levels have gone down in the past decade, contamination usually rises significantly during monsoon season.

Rising underground water levels during the monsoon season affect outdated underground sewages systems and leaking pipes, leading to abnormally high levels of E Coli and other bacteria. These bacteria cause diarrheal disease and various water-borne illnesses.

Vector-borne diseases such as malaria and dengue are also particularly prominent during monsoon season. To avoid exposure to contaminants, Indians are encouraged by health officials to take precautionary measures such as boiling all drinking water and only eating foods stored inside.

A municipal worker fumigates a residential area during an anti-malaria fumigation drive in Mumbai.

 

Fumigation efforts are also ramped up during monsoon season, which is also breeding season for mosquitos. Those most affected by both vector and water-borne diseases include children and the elderly, often due to time spent outside or an inability to fend off infection.

 

India awaits monsoon after deadly heat wave

By Harland Dahl

India faces a heat wave annually, but this year temperatures have been higher than normal. As of June 2, the heat wave’s death toll reached over 2,300. This makes the 2015 Indian heat wave the fifth deadliest heat wave in world history, and the second deadliest heat wave in Indian history.

Temperatures in India are high enough to melt asphalt

Temperatures in India are high enough to melt asphalt

The states most affected by the heat wave were Andhra Pradesh and Telangana in southeast India, with 1,490 and 489 deaths, respectively. Other deaths occurred in the states of Uttar Pradesh, Punjab, Odisha, and Bihar.

The poor, who must continue to work to support themselves despite soaring temperatures, have suffered the most casualties. These include construction workers, many working as day laborers in the nation’s capital. Elderly Indians have also been disproportionately affected by the heat wave. These casualties are often the result of heat stroke or dehydration.

The heat wave lasted for weeks, bringing temperatures up to about 120 degrees Fahrenheit. The abnormally high temperatures are likely related to the infrequent pre-monsoon season rains. These rains brought less water to India than they have in the past, leaving Indian cities hot and dry.

Anomalies.figb

 

The approaching monsoon season has already begun to bring relief for Indian citizens suffering from these high temperatures. Unfortunately, the monsoon, which was expected to arrive between May 29th and 31st, has been delayed. Light to moderate rainfall occurring before the onset of the continental-scale monsoon has cooled some regions, and most regions have cooled somewhat in the past few days.

Meteorologists have delivered conflicting predictions as to when the monsoon will arrive, but many agree that it will be around June 4th or 5th. When the monsoon arrives, its rainfall generally expands northward across India.

2015 Monsoon

This means continued danger for already at-risk Indian citizens. In order to combat this threat, the Indian government has taken several precautionary measures. These include the distribution of oral rehydration kits and administration of intravenous fluids in public places such as bus stops and train stations.

Indians, many of whom have been suffering from headache and dizziness, have tried various methods to stay cool. In some cities, the demand for air conditioning in response to the heat wave has led to power outages. In other areas, Indians have been spending the warmest part of the day in rivers or streams to cool off. The government has also advised citizens to remain indoors or in the shade as much as possible.

Indians seek refuge from the heat wave.

When the monsoon does arrive, it is possible that it will bring less rainfall than usual. The summer monsoon, which typically lasts from June to September, is predicted by the India Meteorological Department to bring levels of rain that are “below normal” — only 90% of normal according to their just-issued seasonal forecast. Last year this was also true, with the 2014 monsoon resulting in a 12% rainfall deficit. This year the monsoon could be inhibited by the current El Niño event that is predicted to strengthen during summer.

Hotter temperatures are generally expected to result from climate change. India’s National Disaster Management Authority states that climate change has caused more frequent and severe Indian heat waves in recent years.

The Intergovernmental Panel on Climate Change agrees, reporting that “higher daily peak temperatures and longer, more intense heat waves are becoming increasingly frequent in South Asia as a result of climate change.”

Limited rains like these could mean a lasting drought and limited agricultural production for India. As the monsoon brings four-fifths of India’s annual rainfall, it is crucial for millions of Indian farmers.

Two earthquakes bring health risks to Nepal

By Harland Dahl

A 7.3 magnitude earthquake hit Nepal last Tuesday, only two weeks after a devastating 7.8 earthquake shook the country on April 25th. These earthquakes killed over 8,000 people and displaced close to 3 million others.

Nepal Earthquake Map

Today, Nepal’s government and organizations are struggling to rebuild critical infrastructure and provide those affected with food and shelter.

Many factors have made relief efforts challenging, including Nepal’s mountainous terrain, the high proportion of Nepalese people living in rural areas, and limited funding. These efforts are further complicated by the impending monsoon season.

Nepal’s monsoon season is expected to begin in June, giving aid workers between three and five weeks to prepare for heavy rains. The monsoon season usually lasts from June to September, bringing Nepal 80 percent of its precipitation for the year. Nepal’s average annual rainfall is 1.6 meters (about 5 feet), with some regional variation across Nepal.

With monsoon season comes many risks for Nepalese people. Heavy rains lead to water-borne diseases, sanitation problems, the contamination of drinking sources, and worsened living conditions. The impending monsoon will also present challenges for the Nepalese government and international organizations attempting to deliver aid. To combat these threats, the government and aid organizations are focused on improving infrastructure and sanitation before the monsoon hits.

The earthquakes destroyed or damaged much of Nepal’s sanitation and water infrastructure, including water pipes and latrines. In response, the Nepalese government has announced a plan to construct temporary pit latrines in the weeks before the monsoon hits. They hope to build one latrine for every 50 Nepalese males and every 30 Nepalese females.

Relief workers build toilets in an effort to improve sanitation before the start of monsoon season.

Relief workers build toilets in an effort to improve sanitation before the start of monsoon season.

Aid organizations such as the UN and OCHA have focused on providing temporary shelter for families whose homes were rendered uninhabitable by the two earthquakes. It is imperative that these temporary shelters be provided prior to the start of the monsoon season in order to give earthquake victims protection from health risks brought by heavy rains.

While some displaced people use “Shelter Kits” provided by agencies such as the UK’s Department for International Development, others use vegetation and materials found in rubble to build shelter for their families. Buildings that survived the earthquakes are also being used as emergency shelters, including schools and some governmental buildings.

The monsoon will also cause logistical problems for the Nepalese government and aid organizations. Rainstorms will make travel and the transport of food and supplies to remote communities especially difficult. Relief operations will not only encounter flooding and mountainous terrain when attempting to deliver aid, but an increased risk of landslides, a result of earthquakes worsened by the start of monsoon season. Helicopters, which are often used to deliver aid to hard-to-reach regions, will be grounded by the heavy rains, as well.

Relief workers are attempting to combat these logistical barriers by changing the methods they use to reach affected populations. In lieu of vehicles, some aid workers have begun to carry supplies to rural communities by foot. Other workers have been using mules, donkeys, and paid porters to deliver supplies to remote locations. The Nepalese government has also taken advantage of social media as a way of warning citizens of impending rainstorms and informing citizens of where and how to acquire supplies and relief.

Aid for Nepal

With funding low, many relief organizations are having difficulties implementing relief operations before the start of the monsoon season. The United Nations, for example, has announced that it has only raised 20 percent of the estimated $432 million necessary to carry out its planned relief operations.

Forthcoming Monsoon Rains May Complicate Disaster Relief Efforts in Nepal

by Nina Horstmann

On April 25, a 7.9 magnitude earthquake struck Nepal. While reports about the extent of damage in rural areas are still trickling in, the UN currently estimates that over 8 million people have been affected by the quake and the Nepali government has accounted for over 7,000 fatalities. Since the quake, persistent aftershocks have triggered further avalanches and landslides, compounding the destruction. In addition to the capital city of Kathmandu, remote mountainous areas of Nepal have been particularly impacted, yet the ability of relief efforts to reach these areas has been impeded by the devastation.

The South Asian monsoon circulation brings rainfall to Nepal from June to September; during these 3 months the southwest monsoon brings more than 75% of the annual rainfall. The monsoon is critical for agricultural production in Nepal, which relies on monsoon rains for irrigation. According to the Nepali Department of Agriculture, the agriculture sector employs 2/3 of the population and makes up nearly 35% of the GDP.

Nepali farmers take shelter from rain in the countryside (Image from FAO.org)

Impending monsoon rains may frustrate relief efforts. Sienna Craig, a professor of Anthropology at Dartmouth University who has worked in Nepal for over 20 years, notes that monsoon rains will bring further challenges to the region, complicating access to clean water and triggering landslides that may frustrate reconstruction efforts. Pre-monsoon rains have already curtailed humanitarian aid in the region.

Woman amid destruction in  Bhaktapur, on the outskirts of Kathmandu

Woman amid destruction in Bhaktapur, on the outskirts of Kathmandu (Image from Wall Street Journal)

The seasonal monsoon brings heavy daily rains, as well as the threat of floods or landslides. Last year, torrential monsoon rains in Nepal caused multiple landslides and flooding; a particularly fatal landslide demolished an entire village east of Kathmandu, killing 156 people. Landslides may cause further fatalities, destroy makeshift shelters, and wipe out roads. Efforts by relief teams to reach remote regions may be hampered by rains that make it difficult for helicopters to fly and by landslides that bury roads in rubble.

A landslide in the Sindhupalchowk district wipes out hillside (Image from NBCNews.com)

Rownak Khan, the UNICEF deputy representative in Nepal, has stated that the forthcoming monsoon season is a concern, as deadly disease outbreaks could be triggered by the wet and muddy conditions. “Hospitals are overflowing, water is scarce, bodies are still buried under the rubble and people are still sleeping in the open. This is a perfect breeding ground for diseases,” said Khan. Another UNICEF spokesperson, Chris Tidey, warned that the prevalence of diarrheal diseases, respiratory illnesses, measles and cholera will soar during the monsoon season if people are living in the open during heavy rains. Thirteen UK humanitarian organizations that are involved in relief efforts in the country cautioned that the hundreds of thousands living outdoors will be vulnerable to the coming monsoon. Many are currently living in the open, camping outdoors or in makeshift shelters, because 130,000 homes have been flattened by the quake.

Makeshift shelter in Kathmandu (Image from Wall Street Journal)

As medical expert Dr. Nikhil Joshi forewarns, “We often look at things in terms of death toll from a disaster. But that really only tells a fraction of the story.” Humanitarian relief to Nepal will be an ongoing trial, especially given the logistical difficulties of providing appropriate goods and services in a mountainous region that will soon be subject to the hydrological extremes of the monsoon season.  People who are considering donating to the relief efforts might consider the particular efforts that have been recommended by the Yale Himalaya Initiative.

 

First Forecasts of the Season Released for Indian Monsoon

by Walter Hsiang

With the anticipated arrival of monsoon season in Asia at the start of May, people have a right to be anxious. The annual summer monsoon is the major source of rain in India and much of South Asia, so it has a huge impact on environmental, social, and economic factors in those regions. For example, an overly strong or weak Indian summer monsoon can result in flooding or crop failures. Therefore, accurate monsoon predictions are important for everyone from farmers to politicians so that they may prepare accordingly.

IMD’s annual report on the monsoon season is widely anticipated and affects decisions from the farming to policy-making level (image from Live Mint)

IMD’s annual report on the monsoon season is widely anticipated and affects decisions from the farming to policy-making level (image from Live Mint)

India has an age-old relationship with the monsoon, and very few climate-related events around the globe can compare with the monsoon’s scale and its impact on the economy. The monsoon is estimated to influence 15% of India’s GDP, and the agriculture and energy sectors are most heavily affected. But beyond the economy, the monsoon greatly affects the livelihood of people who live in rural India. These people don’t have access to robust infrastructure and depend on farming for sustenance.

Because the monsoon season bears so much weight, the release of the India Meteorological Department’s long-range forecast (released this past week) has become an annual financial and political event. Private forecasting companies like Skymet have tried to capitalize on this anticipation by releasing their own forecast reports ahead of time.

This year, Skymet has predicted normal monsoon rainfall (102% of the long-term average), while the India Meteorological Department has forecast below-normal rainfall (only 93% of the long-term average). Skymet’s forecast had brought hope to the region, particularly after last year’s deficit monsoon which brought very little rainfall. But if the Meteorological Department is right, the region is in for another dry year — although their forecast of 93% of normal rainfall may not seem that bad, widespread drought characterized the 2012 monsoon which had a total rainfall very near that exact value. And it is good to remember that rainfall can vary regionally within India and temporally throughout the year;  unseasonal rains this past February damaged over 27 million acres of farmland in six regions of India.

IMD’s report on predicted monsoon rainfall (dark blue) and actual rainfall (light blue) (Image from IMD)

 

The Indian economy is really a gamble on the monsoon. Seventy percent of India’s annual rainfall, which irrigates the country’s farmland, comes from the monsoon. The associated weather patterns affect productivity, industrial and agricultural output, health, and energy consumption. When monsoon season does not strike the delicate balance between not-too-much and not-too-little rainfall, it can increase food prices and reduce energy output, which worsens inflation.

Yet India’s reliance in recent years on the monsoon forecasting by the India Meteorological Department (IMD) has also been a gamble. Between 1988 and 2002, the IMD used a 16-parameter statistical prediction model that was claimed to be successful until it crumbled in a 2002 drought. Monsoons have been less predictable since then. The IMD has been working hard on new models that combine statistical and dynamic forecasts, but the average prediction error has only come down by 2% in the last decade. Just last year, the IMD’s prediction of monsoon rainfall was off by nearly 10%.  The current forecasts use both a 5-parameter statistical model and an experimental atmosphere-ocean dynamical model.

Despite Skymet’s and IMD’s monsoon prognosis, huge uncertainty remains. It calls into question India’s continued reliance on the monsoon rains, especially with the country’s fast development and modernization. Above all, it outlines a need to develop solutions that reduce India’s vulnerability to unexpected changes in the monsoon.

First Forecasts of the Season Released for Indian Monsoon

by Walter Hsiang

With the anticipated arrival of monsoon season in Asia at the start of May, people have a right to be anxious. The annual summer monsoon is the major source of rain in India and much of South Asia, so it has a huge impact on environmental, social, and economic factors in those regions. For example, an overly strong or weak Indian summer monsoon can result in flooding or crop failures. Therefore, accurate monsoon predictions are important for everyone from farmers to politicians so that they may prepare accordingly.

 

IMD’s annual report on the monsoon season is widely anticipated and affects decisions from the farming to policy-making level (image from Live Mint)

IMD’s annual report on the monsoon season is widely anticipated and affects decisions from the farming to policy-making level (image from Live Mint)

India has an age-old relationship with the monsoon, and very few climate-related events around the globe can compare with the monsoon’s scale and its impact on the economy. The monsoon is estimated to influence 15% of India’s GDP, and the agriculture and energy sectors are most heavily affected. But beyond the economy, the monsoon greatly affects the livelihood of people who live in rural India. These people don’t have access to robust infrastructure and depend on farming for sustenance.

Because the monsoon season bears so much weight, the release of the India Meteorological Department’s long-range forecast (released this past week) has become an annual financial and political event. Private forecasting companies like Skymet have tried to capitalize on this anticipation by releasing their own forecast reports ahead of time.

This year, Skymet has predicted normal monsoon rainfall (102% of the long-term average), while the India Meteorological Department has forecast below-normal rainfall (only 93% of the long-term average). Skymet’s forecast had brought hope to the region, particularly after last year’s deficit monsoon which brought very little rainfall. But if the Meteorological Department is right, the region is in for another dry year — although their forecast of 93% of normal rainfall may not seem that bad, widespread drought characterized the 2012 monsoon which had a total rainfall very near that exact value. And it is good to remember that rainfall can vary regionally within India and temporally throughout the year;  unseasonal rains this past February damaged over 27 million acres of farmland in six regions of India.

IMD’s report on predicted monsoon rainfall (dark blue) and actual rainfall (light blue) (Image from IMD)

IMD’s report on predicted monsoon rainfall (dark blue) and actual rainfall (light blue) (Image from IMD)

The Indian economy is really a gamble on the monsoon. Seventy percent of India’s annual rainfall, which irrigates the country’s farmland, comes from the monsoon. The associated weather patterns affect productivity, industrial and agricultural output, health, and energy consumption. When monsoon season does not strike the delicate balance between not-too-much and not-too-little rainfall, it can increase food prices and reduce energy output, which worsens inflation.

Yet India’s reliance in recent years on the monsoon forecasting by the India Meteorological Department (IMD) has also been a gamble. Between 1988 and 2002, the IMD used a 16-parameter statistical prediction model that was claimed to be successful until it crumbled in a 2002 drought. Monsoons have been less predictable since then. The IMD has been working hard on new models that combine statistical and dynamic forecasts, but the average prediction error has only come down by 2% in the last decade. Just last year, the IMD’s prediction of monsoon rainfall was off by nearly 10%.  The current forecasts use both a 5-parameter statistical model and an experimental atmosphere-ocean dynamical model.

Despite Skymet’s and IMD’s monsoon prognosis, huge uncertainty remains. It calls into question India’s continued reliance on the monsoon rains, especially with the country’s fast development and modernization. Above all, it outlines a need to develop solutions that reduce India’s vulnerability to unexpected changes in the monsoon.

Deforestation at high latitudes could impact monsoons

By Julia Rothchild

Russians don’t usually worry about monsoons. But a new study says maybe they should. Research suggests that deforestation in the far north could significantly impact South Asian monsoon rainfall.

The study, published last month in the Proceedings of the National Academy of Sciences, used an idealized climate model to show how cutting down trees at high latitudes might change monsoon circulations.

The researchers found that heavy deforestation would shift what is called the Intertropical Convergence Zone (ITCZ) towards the south. The ITCZ is a band of clouds and precipitation circling the globe where the northeast and southeast trade winds converge and rise. It hovers near the equator, but migrates hundreds to thousands of miles north and south of the equator during the course of the seasonal cycle. The ITCZ’s movement determines where and when monsoons occur.

The ITCZ lies north of the equator during June, July, August, and September, when the northern hemisphere’s summer occurs and the warm, rising air lies in the northern hemisphere. During that time, monsoons occur north of the equator. In December, January, February, and March, the ITCZ moves south, and showers the southern hemisphere with monsoon rain during its summer.

Deforestation would push the ITCZ south by providing a remote forcing. Cutting down dark green forests exposes land, and bare land reflects more sunlight than the original forests. In other words, deforestation increases the albedo of the Earth’s surface. The result is less solar absorption, and an energy deficit in the northern hemisphere’s high latitude systems. This causes the ITCZ to shift away from the imposed energy sink.

The ITCZ's normal movement north and south of the equator. (Image from Wikipedia.)

The ITCZ’s normal movement north and south of the equator. (Image from Wikipedia.)

The idea that the ITCZ might move to the north or south in response to a high-latitude heat source or sink is not new. Numerous studies have shown that an expansion of reflective ice cover in the northern hemisphere would shift the ITCZ southward. It is thought that the decades-long drought in Africa’s Sahel resulted from a southward shift in Africa’s monsoon precipitation, which was caused by temperature changes in the Atlantic Ocean – cooling north of the equator, and warming south of it. These and other studies relating shifts in tropical precipitation to cross-equatorial gradients in energy sources were reviewed here.

A southward shift of the ITCZ would mean that many places in the northern hemisphere that rely on monsoon rains would receive less precipitation. These places include North America, North Africa, and South Asia. In the study’s ideal climate model, northern deforestation causes the rainfall over India in particular to decline by 18%. Correspondingly, the southern hemisphere monsoon regions – South Africa, South America, and Australia – would experience a precipitation increase. It should be noted that the model assumed drastic, major deforestation, in which all trees north of 50 degrees latitude were eliminated and replaced by grasses. But in places that rely on monsoons for life, even a precipitation change of less than 18% would have major impacts on livelihood: droughts and floods plague India when the summer rainfall is only ten percent weaker or stronger than usual.

The study found that far-away deforestation actually has more of an impact on the South Asian monsoon region than does local land surface changes in South Asia. In other words, land changes in India might have less effect on Indian monsoons than deforestation in Russia. We focus on Russia because that particular country has the most forested area of any state on Earth. About 20,000 square kilometers in Russia alone are deforested every year.

A Google Earth map of eastern Russia shows areas of deforestation in red. (Image from The Guardian.)

A Google Earth map of eastern Russia shows areas of deforestation in red. (Image from The Guardian.)

The upshot is that people living in India might have less environmental control over the monsoons than people in Russia. This seems not only unintuitive, but politically inconvenient: the people who may be most affected by northern latitude deforestation – Indians, for example – have little say in its occurrence.

The idea that land surface albedo changes might affect monsoons is not new, and it is unclear whether realistic amounts of deforestation would have an appreciable effect on monsoons. Still, this study emphasizes the truly global nature of climate change issues. Maintaining a climate that is healthy for human populations cannot be accomplished by one country alone.

Monsoon rains induce flooding in Jakarta, Indonesia

by Nina Horstmann

In early February, persistent rains triggered massive flooding in Jakarta, the capital of Indonesia, with floodwaters reaching up to 100 cm. Seasonal monsoon rains and the poor drainage of the low-lying capital city make flooding from late January to mid February an annual event. Other parts of Indonesia, such as the islands of Sumatra and Sulawesi, also experience seasonal flooding and mudslides, but these events are typically most severe in the capital. Around 240 square kilometers of central Jakarta lie below sea level, and flooding can become acute when heavy rain and high tides coincide.

Women wade through floodwaters (Image from Telegraph.co.uk)

Indonesia experiences extreme variations in rainfall between its wet and dry seasons because of the seasonal shifts in winds that constitute monsoons. Jakarta lies about six degrees of latitude south of the equator, and so receives the most rain in January, when the warmest, wettest air rises just south of the equator in the summer hemisphere.  In fact, the island of Java, which is home to Jakarta, is right in the center of the Indian Ocean’s intertropical convergence zone – the near-equatorial band of precipitation that stretches around the planet.

Average January Rainfall 1998-2001. The fuchsia circle indicates the location of Jakarta. (Image from NASA)

The annual nature of the monsoon and related flooding in Jakarta complicates disaster response. In contrast to abrupt events such as a typhoon or tsunami, annual flooding is anticipated and gradual. Because of its expectedness, annual flooding enters the realm of the ordinary and does not prompt swift action or response. However, the Indonesian government still has not created a comprehensive system for addressing massive flooding, which annually brings the city of Jakarta to a standstill. Yayat Supriatna, a public infrastructure analyst, commented in The Jakarta Post that, “The city administration has to run faster by repairing the poor drainage system to allow a smooth flow of rainwater to all rivers; and also the pump houses, so that floodwater can be pumped out to the sea rapidly.” Because of the dense population of the Jakarta metropolitan area (according to the Central Bureau of Statistics, approx. 28 million in 2010), these annual flooding events affect millions of citizens.

Flooded motorways in the center of Jakarta (Image from Telegraph.co.uk)

Yearly, flooding disrupts transit and business activity, displaces thousands of residents, creates economic damage, and results in dozens of fatalities. Importantly, because the imbalance between precipitation and surface evaporation is expected to increase as climate warms, flooding might worsen in future decades. In 2013, Jakarta experienced an extreme year; a river burst its banks and flooding engulfed the Central Business District, resulting in hundreds of millions of dollars in property damage. In 2007, the human impacts of annual flooding were particularly dire, when 80 people were killed and an additional 200,000 were displaced due to severe flooding.

Flooding disrupts business operations in Jakarta shopping centers (Image from Telegraph.co.uk)

In order to prepare citizens and inform them of the extent of seasonal flooding, the Indonesian government is turning to the Internet and social media to disseminate forecast information. On its website, the Indonesian Agency for Meteorology, Climatology, and Geophysics (BMKG) provides a daily weather forecast as well as a map displaying the flood potential for different parts of the city. Additionally, the Natural Disaster Mitigation Agency (BPBD) and the Traffic Management Center of the Jakarta Police Department are using Twitter to release regular information of flood conditions in the city. A new website, PetaJakarta.org, also draws on the Twitter platform, using crowdsourcing to aggregate and map flood-related tweets.

Real-time map of flooding in Jakarta on January 18 (Image from PetaJakarta.org)

PetaJakarta is an initiative run by BPBD and the SMART Infrastructure Facility at the University of Wollongong in Australia. The project reported that on February 9, a day which experienced massive flooding, their map pulled in around 800 flood-related tweets per hour and more than 12,000 users logged onto their site that day. The PetaJakarta mapping initiative allows BPBD to receive real-time reports, expediting their response to emergencies, and enables citizens to monitor flooding and traffic levels in their neighborhoods. Social media and Internet resources offer exciting new opportunities to disseminate advance forecasts and real-time weather and traffic conditions. This model could perhaps be extrapolated to other megacities in the tropics that are affected by monsoons and flooding.