Fiji Islands
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Suva Chapter 5 Fiji Islands The contributions of Alipate Waqaicelua, Varanisese Vuniyayawa, Ravind Kumar, Arieta Daphne and Bipendra Prakash from the Fiji Meteorological Service are gratefully acknowledged 75 Introduction This chapter provides a brief El Niño-Southern Oscillation) are drought, extreme rainfall, and extreme description of the Fiji Islands, its analysed and discussed. Observed temperature. These projections are past and present climate as well trends and analysis in air temperature, presented along with confidence levels as projections for the future. The rainfall, extreme events including based on expert judgement by Pacific climate observation network and the tropical cyclones, sea-surface Climate Change Science Program availability of atmospheric and oceanic temperature, ocean acidification (PCCSP) scientists. The chapter data records are outlined. The annual and mean and extreme sea level are concludes with a summary table of mean climate, seasonal cycles presented. Projections for air and projections (Table 5.4). Important and the influences of large-scale sea-surface temperature, rainfall, background information, including an climate features such as the South sea level and ocean acidification for explanation of methods and models, is Pacific Convergence Zone and the 21st century are provided, as provided in Chapter 1. For definitions patterns of climate variability (e.g. the are projections for tropical cyclones, of other terms refer to the Glossary. 5.1 Climate Summary 5.1.1 Current Climate • The sea-level rise near Fiji measured • The intensity and frequency of days by satellite altimeters since 1993 is of extreme heat are projected to • Changes in air temperature from about 6 mm per year. increase (very high confidence). season to season are relatively • Tropical cyclones usually affect Fiji • The intensity and frequency of days small and strongly tied to between November and April. Over of extreme rainfall are projected to changes in the surrounding ocean the period 1969–2010, the centre of increase (high confidence). temperature. The country has two 70 tropical cyclones passed within distinct seasons – a warm wet • Little change is projected 400 km of Suva. The high variability season from November to April in the incidence of drought in tropical cyclone numbers makes and a cooler dry season from May (low confidence). it difficult to identify any long-term to October. • Tropical cyclone numbers trends in frequency. • The seasonal cycle is strongly are projected to decline in affected by the South Pacific the south-east Pacific Ocean Convergence Zone, which is most 5.1.2 Future Climate basin (0–40ºS, 170ºE–130ºW) (moderate confidence). intense during the wet season. Over the course of the 21st century: • Ocean acidification is projected to • The El Niño-Southern Oscillation • Surface air temperature and continue (very high confidence). is the most important influence on sea-surface temperature are year-to-year climate variations. projected to continue to increase • Mean sea-level rise is projected to • Annual and seasonal mean air (very high confidence). continue (very high confidence). temperatures at Suva and Nadi • Wet season rainfall is projected to Airport have been increasing, increase (moderate confidence). particularly in the wet season over • Dry season rainfall is projected to the period 1950‑‑2009. decrease (moderate confidence). • Annual and seasonal rainfall • Little change is projected in annual trends for Suva and Nadi Airport mean rainfall (low confidence). for the period 1950–2009 are not statistically significant. 76 Climate Change in the Pacific: Scientific Assessment and New Research Volume| 2: Country Reports 5.2 Country Description Fiji is located in the western South small volcanic islands, low-lying atolls Fiji’s economy is based on sugar Pacific Ocean between 177°E–178°W and elevated reefs (Fiji’s First National and tourism and over recent years and 16°S–20°S. The country has Communication under the UNFCCC, the tourism sector has grown 322 islands and a total land area of 2005; Fiji’s Pacific Adaptation to significantly. Most of the rural and 18 333 km2. The Exclusive Economic Climate Change, 2009). The estimated urban population of Viti Levu live in Zone has an area of 1.3 million km2. population of Fiji in 2010 was 844 420 the coastal zone where the majority of The two largest islands are Viti (Fiji Country Statistics, SOPAC, 2010). services, infrastructure, and economic Levu, 10 429 km2, and Vanua Levu, activities are located (Fiji’s First Viti Levu is the economic centre of 5 556 km2. They take up 87% of the National Communication under the Fiji, with Suva, the capital, located total land area and are mountainous UNFCCC, 2005). on the south coast, and Nadi, the and of volcanic origin with peaks up to tourism centre on the west coast. 1 300 m. The other islands consist of 16ºS eef a R Rotuma Se at re G Ahau p 12º42’S u 177º06’E ro G a w Vanua Levu 17ºS a s Bligh Water Taveuni N a o Y r th er Koro n La u G ro Koro Sea up Nadi 18ºS Viti Levu SUVA Ono-i-lau S o ut 20º54’S 19ºS he rn Kadavu La u G 0km 20 40 60km rou South Pacific Ocean p 178º30’W 177ºE 178ºE 179ºE 180º 179ºW Figure 5.1: Fiji Chapter 5: Fiji Islands 77 5.3 Data Availability There are currently 30 climate are located on the south-eastern direct estimates of local vertical land (single observation at 9 am), eight and western sides of Viti Levu motion in future years. Both satellite synoptic (multiple daily observations) respectively. The records from both (from 1993) and in situ sea-level data and 52 rainfall-only operational sites are homogeneous and more than (1950–2009; termed reconstructed meteorological observation stations in 99% complete. sea level; Volume 1, Section 2.2.2.2) Fiji’s meteorological network. Climate are available on a global 1° x 1° grid. Oceanographic records do not records with data available from before cover such a long time period. Long-term locally-monitored 1900 are available for at least six Monthly-averaged sea-level data sea-surface temperature data are stations or multi-station composites. are available from Suva (1972–2009 unavailable for Fiji, so large-scale Climate records for both Suva and 1998–present) and Lautoka gridded sea-surface temperature (the capital) and Nadi Airport (1992– present). A global positioning datasets have been used (HadISST, from 1950–2009 have been used system instrument to estimate vertical HadSST2, ERSST and Kaplan (Figure 5.1). Suva and Nadi Airport land motion was deployed at Lautoka Extended SST V2; Volume 1, in 2001 and will provide valuable Table 2.3). Barometric pressure meter, Fiji Meteorological Service 78 Climate Change in the Pacific: Scientific Assessment and New Research Volume| 2: Country Reports 5.4 Seasonal Cycles Average monthly maximum, mean and The seasonal cycle is strongly affected features have a notable impact on minimum air temperatures are strongly by the South Pacific Convergence Fiji’s climate. Active phases of the tied to changes in the surrounding Zone (SPCZ), which is most intense Madden-Julian Oscillation (MJO; ocean temperature (Figure 5.2). during the wet season. The southern Volume 1, Section 2.4.4) near Fiji can The range in average monthly edge of the SPCZ usually lies near be associated with significant rainfall maximum temperature is about 4ºC Fiji. The effects of large-scale climate for several days in the wet season. for Suva and 3ºC for Nadi Airport. features such as the SPCZ and trade In addition, late afternoon convective In the cooler/drier half of the year winds are modified on some islands thunderstorms contribute significant (May-October) less energy is received due to the influence of mountains. rainfall to the central and western from the sun, south-east trade winds Those regions exposed to the trade parts of Viti Levu. In the dry season, persist and sub-tropical high pressure winds can receive mean annual cold fronts, which are usually weak systems move north bringing cooler, rainfall in excess of 4000 mm, while by the time they reach Fiji’s latitude, drier conditions. About 63% of Suva’s leeward regions receive on average occasionally merge with troughs in rain and 77% of Nadi Airport’s rain less than 2000 mm annually with less the upper atmosphere resulting in falls in the wet season from November than 25% of annual rainfall between widespread rainfall. to April. May and October. Several weather Mean Annual Climate Cycle Maximum temperature Average temperature Minimum temperature Sea-surface temperature 35 35 35 Suva, Fiji 178.45°E, 18.15°S Nadi, Fiji 177.45°E, 17.75°S 400 400 30 30 300 300 e (ºC) e (ºC) 25 25 200 200 emperatur emperatur T T Monthly rainfall (mm) Monthly rainfall (mm) 20 20 100 100 0 0 15 15 Jan Apr Jul Oct Jan Apr Jul Oct Figure 5.2: Mean annual cycle of rainfall (grey bars) and daily maximum, minimum and mean air temperatures at Suva (left) and at Nadi Airport (right), and local sea-surface temperatures derived from the HadISST dataset (Volume 1, Table 2.3). Chapter 5: Fiji Islands 79 5.5 Climate Variability The El Niño-Southern Oscillation the wet season only ENSO has a clear conditions to Nadi Airport, and with (ENSO) is the most important influence and only on temperature, the decreased cloud cover this leads influence on year-to-year climate with warmer nights and cooler days in to warmer daytime temperatures. variations in Fiji. At Suva (Table 5.1), El Niño years. Modoki El Niño events The opposite changes tend to occur dry seasons during El Niño tend to (Volume 1, Section 3.4.1) bring cooler in La Niña years.