here - CEOP-HE

cause turbid lakes to become more UV transparent (Sommaruga, 1997). In both cases the change of
radiation intensity will considerably influence the distribution of organisms in the lake water and
all biochemical reactions, for instance photosynthesis and respiration.
An increase in global temperatures may in turn cause water scarcity in some regions and increased
precipitation in others, and changes in mountain snowpack, with considerable effects also on
terrestrial plant and animal communities. In fact, climate change will cause geographical shifts in
the ranges of individual plant species and vegetation zone (Gonzales et al., 2005). In particular, in
the high mountains, plant species responding to higher temperatures may migrate upwards thus
threatening the upper vegetation zones (Peters and Darling, 1985; Ozenda and Borel 1991),
altering the availability of natural resources and the geographic location and extent of herbivore
and carnivore habitats (Danby and Hik, 2007; IPCC, 2007).
2.5. Regional issues
Climate conditions in the mountains and high-elevations, such as temperature and precipitation
amounts, differ from one region to another.
In the following section, regional issues of six major mountain areas are introduced to identify the
common/unique problems to address in HE activities to study EWC.
2.5.1 Tibet/Himalayas
Tibet/Himalayas are the most massive high elevation features in the world located in subtropical
regions. The plateau area extends on a scale of several 1000 km over 4000 m asl, and the
topography of the Himalayas consists of extreme deep valleys between 2000-7000 m levels.
To investigate the EWC, GAME-Tibet conducted pilot intensive observations focusing on
land-atmosphere interactions with modern instruments and remote sensing (Koike et al., 2002).
Moreover, currently, intensive observation network, TORP/NOIST (Ma et al., 2008; Xu e t al., 2008),
operated in collaboration with the JICA project and SHARE networking in the Nepal Himalayas by
the EV-K2-CNR, with two reference sites (RS) have been functioning over the TP under the CEOP
Phase II.
So far, many studies have been carried out in multiple timescales to evaluate the function of
TP/Himalayas on the Asian monsoon system, including the geological timescale (e.g. Abe et al.,
2003), year-to year or intra-seasonal variability (e.g., Yanai and Wu, 2006; Sato and Kimura, 2006),
and diurnal changes (e.g. Barros and Lang, 2003; Yasunari and Miwa, 2006), and their processes
are linked strictly. Studies leading to the establishment of observation networks and data
management systems are expected to facilitate the improvement of weather/climate forecasting in
the neighboring countries of East Asia.
Himalayan glaciers are maintained by huge moisture intrusions associated with the Indian
monsoon (Fujita et al., 1997), and provide important water resources during the dry season in the
surrounding areas. For this reason, recently, glacier retreat in the Himalayan mountain regions has
led to serious environmental problems (UNEP, 2008: Global Glacier Changes), such as the Glacier
Lake Outburst Flood (GLOF) phenomenon and shortage of urban water. Furthermore, over a longer
time scale, eco-environmental degradation and permafrost reduction have been recorded in the
northeast TP (e.g. Wang et al., 2007), even if the causes are still unclear.
Water vapor transport is a key element for controlling the variability of EWC (Thomas, 2002; Chen
et al, 2006). Recent studies have focused on the importance of intraseasonal variability during
monsoons coupled with mid-latitude baroclinic waves, suggesting it to be the cause of mutual
changes of water vapor transportation between the recycling phase within the plateau area and the
intrusion phase from the outside (e.g., Sugimoto et al., 2008). To clarify the WEC, a comprehensive
observation network, numerical simulations, and aerological observations are fundamental element,
together with isotope studies (e.g. Kurita and Yamada, 2008).
Recently, the mechanism and impact of evident convective activity during non-monsoon season
(Fujinami and Yasunari, 2001) has been highlighted. The seasonal transition from winter to
CEOP-HE
14