Climate change in the 21st century simulated by HadGEM2-AO under representative concentration pathways

We present climate responses of Representative Concentration Pathways (RCPs) using the coupled climate model HadGEM2-AO for the Coupled Model Intercomparison Project phase 5 (CMIP5). The RCPs are selected as standard scenarios for the IPCC Fifth Assessment Report and these scenarios include time paths for emissions and concentrations of greenhouse gas and aerosols and land-use/land cover. The global average warming and precipitation increases for the last 20 years of the 21st century relative to the period 1986-2005 are +1.1°C/+2.1% for RCP2.6, +2.4°C/+4.0% for RCP4.5, +2.5°C/+3.3% for RCP6.0 and +4.1°C/+4.6% for RCP8.5, respectively. The climate response on RCP 2.6 scenario meets the UN Copenhagen Accord to limit global warming within two degrees at the end of 21st century, the mitigation effect is about 3°C between RCP2.6 and RCP8.5. The projected precipitation changes over the 21st century are expected to increase in tropical regions and at high latitudes, and decrease in subtropical regions associated with projected poleward expansions of the Hadley cell. Total soil moisture change is projected to decrease in northern hemisphere high latitudes and increase in central Africa and Asia whereas near-surface soil moisture tends to decrease in most areas according to the warming and evaporation increase. The trend and magnitude of future climate extremes are also projected to increase in proportion to radiative forcing of RCPs. For RCP 8.5, at the end of the summer season the Arctic is projected to be free of sea ice.     

Ecosystem responses to climate change in a large on-river reservoir, Lake Paldang, Korea

The impact of climate change on a large river reservoir ecosystem was investigated. Long-term meteorological data showed that recent climate change, including warmer winters, increased precipitation intensity and extended dry periods, may have influenced the basin of Lake Paldang, the most downstream reservoir of a series of on-river reservoirs. Extreme hydrologic events and climate warming, acting independently and in combination, appear to be related to changes in the Lake Paldang ecosystem. A significant increase in chlorophyll a concentrations in early spring corresponded to the timing of ice break-up. An increase in winter temperatures, which resulted in a shorter time period of ice-cover and earlier ice break-up, appears to have stimulated phytoplankton growth in winter and early spring. Repeated intensive and extended influxes of turbid water, associated with more frequent extreme rainfall events, have increased concentration of suspended solids and may have influenced the biotic community structure of Lake Paldang. In the mid-2000s, the area vegetated by submerged hydrophytes, the abundance and biomass of the phylum Mollusca, as well as the abundance of fish from the subfamily Acheilognathinae, which spawn in the body of bivalve molluscs, was all smaller than in the late 1980s and early 1990s. Together, these results suggest that climate change may have contributed directly and indirectly to changes in each trophic level of the Lake Paldang ecosystem.     

Active Region Coronal Rain Event Observed by the Fast Imaging Solar Spectrograph on the NST

The Fast Imaging Solar Spectrograph (FISS) is being operated on the New Solar Telescope of the Big Bear Solar Observatory. It simultaneously records spectra of Hα and Ca ii 8542 Å lines, and this dual-spectra measurement provides an estimate of the temperature and nonthermal speed components. We observed a loop structure in AR 11305 using the FISS, SDO/AIA, and STEREO/EUVI in 304 Å, and found plasma material falling along the loop from a coronal height into the umbra of a sunspot, which accelerated up to 80 km?s^?1. We also observed C2 and C7 flare events near the loop. The temperature of the downflows was in the range of 10?000?–?33?000 K, increasing toward the umbra. The temperature of the flow varied with time, and the temperature near the footpoint rose immediately after the C7 flare, but the temperature toward the umbra remained the same. There seemed to be a temporal correlation between the amount of downflow material and the observed C-class flares. The downflows decreased gradually soon after the flares and then increased after a few hours. These high-speed red-shift events occurred continuously during the observations. The flows observed on-disk in Hα and Ca ii 8542 Å appeared as fragmented, fuzzy condensed material falling from the coronal heights when seen off-limb with STEREO/EUVI at 304 Å. Based on these observations, we propose that these flows were an on-disk signature of coronal rain.     

Revisiting Solar and Heliospheric 1.3-Year Signals during 1970 – 2007

We revisit the 1.3-year (yr) signals observed on the Sun, in the interplanetary space, and in the Earth’s magnetosphere to study the coupling among signals from the three regions for about 40 years (1970?–?2007) covering the three solar cycles 21, 22, and 23. For this, we make dynamic spectra of datasets including three different regions. From this, we estimate the peak frequency around 1.3 yr for each region and the corresponding band power. We found that coherent power only appears during 1987?–?1995 and the coherent behavior is found only in the interplanetary space and Earth, not in the Sun. Although the solar surface magnetic field shows significant power around 1.3 yr, their peak frequencies are statistically different from those of the outer regions, which make us dismiss the existence of coherence among the three regions. But it is notable that the peaks in band power corresponding to the 1.3-yr period are clearly simultaneous in the interplanetary space and Earth.     

APEX-SZ a Sunyaev–Zel’dovich galaxy cluster survey

The APEX-SZ experiment is a sky survey designed to discover galaxy clusters via the Sunyaev–Zel’dovich effect at millimeter wavelengths. We describe the components of the instrument, including the 12 m Atacama Pathfinder Experiment telescope, optics, Transition-edge sensor bolometer array and SQUID readout. APEX-SZ will begin observations in 2004.     

Ternary forecast of heavy snowfall in the Honam area,Korea

The objective of this study is to improve the statistical modeling for the ternary forecast of heavy snowfall in the Honam area in Korea. The ternary forecast of heavy snowfall consists of one of three values, 0 for less than 50 mm, 1 for an advisory (50–150 mm), and 2 for a warning (more than 150 mm). For our study, the observed daily snow amounts and the numerical model outputs for 45 synoptic factors at 17 stations in the Honam area during 5 years (2001 to 2005) are used as observations and potential pre...     

Super earth explorer: a coronagraphic off-axis space telescope

The Super-Earth Explorer is an Off-Axis Space Telescope (SEE-COAST) designed for high contrast imaging. Its scientific objective is to make the physico-chemical characterization of exoplanets possibly down to 2 Earth radii. For that purpose it will analyze the spectral and polarimetric properties of the parent starlight reflected by the planets, in the wavelength range 400–1,250 nm.     

The thermal conductivity for granite with various water contents

The thermal conductivities of granite were measured under different conditions of porosity and water content to investigate the effects of the porosity and water content on the thermal conductivity. For the dry samples, the thermal conductivities range from 2.12 W/mK for the rocks with a high porosity to 3.12 W/mK for the ones with a low porosity. Water-sorbed samples have greater thermal conductivities than dry samples of the same granite. The thermal conductivities range from 2.99 W/mK for granites with a high porosity to 3.62 W/mK for ones with a low porosity under saturated condition.     

Real Data Assimilation Using the Local Ensemble Transform Kalman Filter (LETKF) System for a Global Non-hydrostatic NWP model on the Cubed-sphere

An ensemble data assimilation system using the 4-dimensional Local Ensemble Transform Kalman Filter is implemented to a global non-hydrostatic Numerical Weather Prediction model on the cubed-sphere. The ensemble data assimilation system is coupled to the Korea Institute of Atmospheric Prediction Systems Package for Observation Processing, for real observation data from diverse resources, including satellites. For computational efficiency in a parallel computing environment, we employ some advanced software engineering techniques in the handling of a large number of files. The ensemble data assimilation system is tested in a semi-operational mode, and its performance is verified using the Integrated Forecast System analysis from the European Centre for Medium-Range Weather Forecasts. It is found that the system can be stabilized effectively by additive inflation to account for sampling errors, especially when radiance satellite data are additionally used.