Impact of a High Pressure Weather System - Summer Anticyclone

European Summer Heatwave 2003

Introduction

It is estimated that around 20,000 people died as a result of the heatwave in August 2003, which is said to have been the hottest in Europe for perhaps 500 years. The UK experienced its highest temperature on record. An area of high pressure sat over most of western Europe. Air moving around the high in a clockwise direction, brought a hot, dry tropical continental air mass to the UK at this time.

This pattern occurred for much of the rest of the month. High pressure areas usually bring little cloud and warm conditions in summer. Rainfall over much of Europe was below what is normally expected during the months of June, July and August. The long-lasting high pressure system tended to reduce the amount of rainfall that fell.

Physical impacts

Low river flows and lake levels

The River Danube in Serbia fell to its lowest level in 100 years. This allowed World War 2 bombs and tanks to be revealed for the first time. These caused a danger to people swimming in the rivers.

Reservoirs and rivers used for public water supply and hydroelectric schemes either dried up or ran very low.

Forest fires

The lack of rainfall meant that very dry conditions occurred over much of Europe during the Summer of 2003. Forest fires broke out in many countries in Europe.

In Portugal 215,000 hectares area of forest were destroyed. This is an area the same size as Luxembourg.

It is estimated that millions of tonnes of topsoil were eroded in the year after the fires as the protection of the forest cover was removed. This has made river water quality poor when the ash and soil washed into rivers.

Human impacts

Human health

About 11,000 people died due to the heat in France, which led to a shortage of space to store dead bodies in mortuaries. Temporary mortuaries were set up in refrigeration lorries.

There were also heat-related deaths in the UK (900), Spain (100), Portugal (1,300), Italy (2,000), Holland (1,500) and Germany (300). Elderly people are especially likely to suffer from the effects of heat.

Heat strokes
Normally we sweat, and this keeps us cool on hot days. On very hot days our bodies can sweating. This can lead to headaches, dizziness and even death.

Dehydration
This is the loss of water from a body. It can cause tiredness and problems with breathing and heart rates.

Sunburn
Damage to the skin which can be painful and may increase the risks of getting skin cancer.

Water supplies
Drinking water supplies were affected in some parts of the UK and hosepipe bans introduced.

Effects on tourism in the UK

Many parts of the UK reported increased levels of tourism. UK residents decided to holiday in the UK where the weather was unusually dry and hot, rather than travelling abroad.

People died while swimming in rivers and lakes trying to cool off from the hot weather.

The London Eye closed on one day as it became too hot in the cabins.

Effects on agriculture

Many chickens, pigs and cows died during the heat in Europe and crops failed in the dry conditions. This led to higher prices for food in the year after the hot weather. It is thought to have cost European farming 13.1 billions euros (£7 billion).

Effects on transport

Trains
Some railway tracks buckled in the heat in the UK and thousands of people faced delays. Some trains broke down and conditions became unbearable inside, particularly on the London Underground. Speed restrictions were imposed on some routes to prevent trains from derailing.

Roads
In some places road surfaces melted, which caused traffic problems, and some roads had to be resurfaced.

Shipping
Large boats were prevented from sailing on some rivers in eastern Europe as river levels were so low.

River levels were low enough to allow people to illegally cross some rivers which form natural borders between neighbouring countries.

Reduced power consumption

Rising river water temperatures and lack of water caused two nuclear power plants to close down in Germany. These rely on water for cooling in the power generation process.

Responses

• In the UK, a joint Met Office/Department of Health project called the Heat-Health Watch now gives advanced warning of UK hot weather. It operates every summer from 1 June to 15 September.
• The French government plans to improve its prevention, surveillance and alert system for people such as the elderly living alone. Extra funding will be made available.
• France requested aid from the European Union to deal with the effects of the heatwave.
• Public water supply shortages occurred in several countries, including the UK and Croatia, which led to the banning of use of hose pipes.
• TV news, internet and newspapers informed the public on how to cope with the heat - drinking plenty of water, wearing cool clothing, staying in the shade in the middle of the day.
• Network Rail in the UK imposed speed restrictions for trains when the temperature was above 30 °C. This was to help avoid trains derailing when railway lines might have buckled.
• Workers around Europe altered their working hours. Some dustmen started earlier to pick up rapidly decomposing rubbish from the streets.
• Summers as hot as 2003 could happen every other year by the year 2050 as a result of climate change due to human activities.

D.Drake 2008

Source - Met Office