First Stage of FOCRAII 2012

In order to make better preparation of FOCRAII 2012, BCC has made analysis on recent climate. Please review the following analysis by BCC, and return your comments, if any, to FOCRAII Secretariat at your earliest convenience. 1. Major weather and climate events in Asia in 2011 2. Monitoring of key factors in the 2011/12 boreal winter 3. ENSO outlook 4. Summer climate prediction for Asia in 2012 1、Major weather and climate events in Asia in 2011

The year 2011 in Asia was characterized by rainstorm/flood, cold wave, snowstorm, heat wave, drought and tropical storm events (Fig 1), especially the rainstorm/flood events in Thailand, , Pakistan and central and southern , as well as tropical storm in . These events caused important infrastructure damages, human life loss and economic losses in many countries. Unusual cold wave and snowstorm events affected most parts of Asia at the beginning of the year. On the mid-January, the cold wave hit Korean peninsula, India and Bangladesh, causing at least 129 deaths in India and 12 deaths in Bangladesh. At the same time, southern China suffered freezing temperatures and winter precipitation, causing nearly six thousand people evacuated. In mid-February, snowstorms attacked , South and North Korea with great economic losses. In the second half of December, a cold wave killed at least 128 people in northern India. Various episodes of heavy rainfall occurred in Asia from March to November. In the end of March, heavy rains brought severe flooding and to southern Thailand, causing at least 40 deaths. During April to mid-July, heavy rains raided Bangladesh, western Kazakhstan, northeastern Syria, central and southern China, Nepal, northeastern India, South Korea, northwest Iran, causing floods and with at least 512 deaths and dozens of missing and homeless. From the end of July to mid-November, the worst flooding since 1942 hit Thailand with at least 602 deaths, 2.9 million people were impacted by the floods and as well as at least 350 people lost their lives in Vietnam and Cambodia. From mid-August to the end of September, heavy monsoon rains triggered floods hit southern Pakistan, causing at least 369 deaths, more than 8.2 million people were impacted. There are also severe heat wave and drought events from spring to fall in Asia. From July to September, severe drought persisted in Southwest China, which is the most serious drought in recent 60 years. Extreme daily maximum temperature exceeds 40°C in the central Henan, southwestern Chongqing, eastern Sichuan, eastern and northwestern Xinjiang. Continuous drought resulted in a more serious impact on the regions of Southwest China in industry, agriculture, forestry, water resources, hydropower, ecological environment and people's lives, especially in Guizhou province. From July to August, consecutive high temperature hit Japan and South Korea, causing 50 deaths in Japan and 3 deaths in South Korea. In 2011, 15 storms hit Asia and killed lots of people. During April 4-5th, northwestern Bangladesh suffered severe storm with at least 17 deaths and more than 150 people injured. On May 18th, northern India suffered severe storm with at least 50 deaths. During May 7-9th, tropical storm “Aere” hit eastern Philippines, causing at least 31 death. In the end of July, tropical storm “Nock-Ten” hit Philippines, causing at least 66 deaths and 17 more missing. On August 23rd, super “Nanmadol” attacked the northern Philippines, and Province of China, totally with at least 29 deaths and 12 missing. In early September, typhoon “Talas” attacked western Japan, causing at least 59 deaths and 50 missing. During September 20-22th, typhoon “Locke” attacked Japan with 12 deaths. From the end of September to early October, typhoon “Nesat” and “Nalgae” hit Philippines respectively, totally with 101 deaths. On December 16th, tropical storm “Washi” made landfall the southern Philippine island of , causing at least 1257 deaths and thousands of people were injured. On April 13th, a strong dust storm moved across the Middle East, including Kuwait and Iraq. The visibility dropped to 50 meters in Iraq. At the same time, the visibility was less than 200 meters in Kuwait, which is the fourth dry winter in a row for the country. A strong dust storm process during April 28-30 affected 11 provinces (autonomous regions and municipalities), which was the one with the widest extent in China in 2011, and had an adversely impact on agriculture, transportation, and air quality. In a word, the notable events in Asia including flood, snowstorm, tropical storm, drought and cold wave, which caused a lot of losses in most countries of Asia in 2011. So it is necessary to build an effective monitoring, prediction and early warning system to reduce the losses of disasters. Fig 1 Major weather and climate events in Asia in 2011

2. Monitoring of key factors in the 2011/12 boreal winter

(1) Abnormally stronger than normal East Asian winter monsoon

The monitoring of daily Arctic Oscillation Index exhibited strong intra-seasonal variations in the boreal winter (Dec. 2011 – Feb. 2012), with positive phase during the period from Dec. 2011 to middle Jan. 2012, and second half of Feb. 2012, and keeping negative phase from later Jan. 2012 to first half of Feb. 2012 (Fig.2). In this winter, the East Asian winter monsoon (EAWM) intensity index was 2.6, indicating the strongest EAWM together with the 1967/68 boreal winter (Fig. 3). During this period, the Siberian cold high was abnormally stronger than normal, with a peak in the mid- winter (Fig. 4). Seasonal mean surface air temperature anomaly field showed that most negative anomalies were observed in most of the middle-high latitudes of Eurasia and East Asia, with minimum values in the East European Plain and the West Siberian Plain (Fig. 5). Fig.2 Variations of the daily Arctic Oscillation Index during the 2011/12 boreal winter

Fig.3 Variations of the East Asian winter monsoon (EAWM) intensity index

Fig. 4 Variations of the Siberian cold high Index Fig. 5 Global seasonal mean temperature anomalies(unit: ℃). Dec. 2011 – Feb. 2012

(2) La Nina reaching its peak in the winter

In September 2011, negative SST anomalies below -0.5℃ appeared in most of the central and eastern equatorial Pacific and NINO Z (NINO 1+2+3+4) index decreased to -0.6 ℃, indicating that La Niña conditions came into being (Fig.5). Negative SST anomalies enhanced in most of the eastern and central equatorial Pacific from October to November 2011, and NINO Z index was -0.7℃ and -0. 8℃, respectively. La Nina conditions peaked in December 2011 with NINO Z index being 1.0℃ and maintained in January 2012. During February 2012, La Niña conditions decayed, and negative SST anomalies weakened in the equatorial eastern Pacific and NINO Z index was -0.5℃. From September to December, Southern Oscillation Index (SOI) correspondingly was positive and reached its peak with 2.1 in December 2011. In February 2012, SOI dropped rapidly from 1.0 in January 2011 to 0.3 (Fig.6). 3 2.5 SOI NINO Z NINO 3.4 2 1.5 1 0.5 0 -0.5 -1 -1.5 -2 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 2010 2011 2012

Fig.6 Variations of Niño Z, Niño 3.4 SSTa indices (unit: ℃) and SOI

(3) Main features of sea ice and snow cover

Snow Cover in the Northern Hemisphere: During the boreal winter (Dec. 2011 – Feb. 2012), the total area of snow cover was larger than normal in Eurasia and in the Tibetan Plateau, with the 3rd and 4th largest values respectively (Fig. 7).

Fig. 7 Variations of snow cover area anomalies in Eurasia (top, unit: million sq. km) and the Tibetan Plateau ( bottom, unit: ten thousand sq. km) Sea Ice: During the boreal winter (Dec. 2011 – Feb. 2012), the sea ice extent in the Northern Hemisphere was below normal, while that in the Southern Hemisphere was above normal. The distributions of sea ice concentrations and anomalies are showed in Fig.8 and Fig.9 respectively.

Fig. 8 Sea ice concentrations (left) and anomalies (right) (unit: %)

in the Northern Hemisphere. Dec. 2011 – Feb. 2012.

Fig. 9 Sea ice concentrations (left) and anomalies (right) (unit: %)

in the Southern Hemisphere. Dec. 2011 – Feb. 2012.

3．ENSO outlook Among 13 La Nina events since 1951, 6 La Nina events ended in winter, 4 in spring, and only 3 in summer. Recent monitoring results show that the La Nina conditions peaked from December 2011 to January 2012. Moreover, subsurface and surface cold waters in the tropical central and eastern Pacific have persisted to warm up obviously since February, which means the attenuation of La Nina conditions. In addition, taking into account the predictions of most statistical and dynamic ENSO models, the current La Nina conditions is expected to shift towards neutral conditions during the early-middle spring 2012.

4. Summer climate prediction for Asia in 2012 I Precipitation prediction

The precipitation prediction for JJA 2012 by BCC-CGCM of BCC/CMA indicates high probability for less-than-normal precipitation in western and central Siberia, Central Asia, West Asia, most South Asia; While high probability for more-than-normal precipitation in eastern Siberia, eastern East Asia, most Southeast Asia (Fig.10).

Fig.10 The prediction of the most likely precipitation categories from June to August, 2012 by BCC-CGCM II Temperature prediction

The temperation prediction for JJA 2012 by BCC-CGCM of BCC/CMA indicates that most of Asia will have a high probability of higher-than-normal temperature in central East Asia, northwestern South Asia, most West Asia and southern Southeast Asia; While high probability for lower-than-normal temperature in most Siberia, eastern and western East Asia, western Central Asia and part of Southeast Asia (Fig.11).

Fig.11 The prediction of the most likely temperature categories from June to August, 2012 by BCC-CGCM