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Evaluation of landscape climate phenomena in the Haean Catchment

TERRECO WP 1-03

Von 03/2009 bis 12/2012

Projektleiter: Gwangyong Choi, Sinkyu Kang, Christopher L. Shope, Johannes Lüers
Mitarbeiter: Bora Lee, Ralf Geyer
Bewilligung: IRTG 1565 WP I TERRECO - Complex Terrain and Ecological Heterogeneity - Evaluating ecosystem services in production versus water yield and water quality in mountainous landscapes

Temperature Lapse Rates:

In a first step of this study, diurnal and intra-seasonal variations of summertime temperature lapse rate (TLR) by synoptic weather conditions in a mountainous basin are examined based on hourly temperature data observed in 2009 summer at an Automated Weather Station (AWS) network deployed in Haean Basin (called Punch Bowl), Yangu basin in the Republic of Korea. Summertime average TLR between the top and bottom of the basin is -0.53℃/100m. Due to its diurnal variations, TLR is lowest at -0.25℃/100m at 6AM, while it increases up to -0.85℃/100m between 4PM-5PM. Comparisons of daily average TLRs according to synoptic weather patterns reveals that the magnitude of TLRs is greatest in the order rainy days (-0.63℃/100m), strong rainfall days (-0.53℃/100m), partly cloudy days (-0.47℃/100m), and sunny days (-0.39℃/100m). At dawn on sunny days in summer, strong cooling pools accompanying temperature inversion patterns are formed within the basin, while on strong rainfall days, warming pools are observed due to relatively low TLRs associated with the reduction of radiation cooling by clouds.

project description in detail from proceedings of 2011 TERRECO Science Conference GAP


Rainfall Distribution:

A second theme currently under study is the gradient in rainfall found from the rim of Haean Basin to the center of the valley as it varies with synoptic weather events. The patterning is important to understand in order to obtain reliable estimates of water balance for the catchment and accurately estimate energy fluxes and mass transport based on local conditions. A unique set of algorithms are being developed to integrate the substantial field based meteorological data including aspect, slope, temperature, relative humidity, etc.. Data collected in 2009 indicate that precipitation varies throughout the basin up to 25 mm/hr, however overall trends and amplitudes are consistent throughout the basin. It suggests that higher precipitation occurs at lower elevations and rises to upper elevation throughout early season events. As the monsoon season progresses, upper elevation precipitation tends to occur prior to lower elevation precipitation. 

Spatial Climate Inputs:

Terrestrial ecosystem models and statistical analysis requires fine spatial climate data as input drivers. In this study, 14 AWS have been installed according to elevations (500-1200m) and topographic condition since June 2009 in Haean Basin. Air temperature, relative humidity, precipitation, wind speed, wind direction and radiation are recorded. Data are measured every 20 seconds, averaged, and logged every 5 minutes. The average air temperature has 3-5 degree difference between AWS located at the rim (1200m) and bottom area (500m) of the Haean Basin. Precipitation slightly decreases with increased elevations during the growing season. Weather condition for Haean Basin of the topographic gradients is continuously recorded, it can be used as basic input data for all TERRECO projects.

More analysis of the topographic gradients of temperature and precipitation and the wind field and the atmospheric exchange conditions in the Haean Basin in comparision with the synoptic weather events and a detailed climate description will be available soon from the recordings from summer 2010.

 

Abstract 2013: Mountains cover approximately 70% of Korea. Highland crops in the mountain areas, such as napa and radish for Kimchi, guarantee profits due to their high quality and seasonality. However, changing climate hinders highland farmers from developing their market competitiveness. To date, information on the climatology and climate change in the mountainous terrain is limited. This is attributable partly to poor spatial resolution of climate observational networks along major mountain ranges with harsh and strong environmental gradients. Cumulative climatic data from tens of automatic synoptic observational systems (ASOS; 1973~2012) and from hundreds of automatic weather stations (AWS; 2001~2010) are available in Korea, but they are not sufficient to examine the details of mountain climate change due to their poor spatial coverage in complex mountainous terrain.

In this study, current and future changes in mountain climate associated with highland crops in Republic of Korea are examined using high resolution (1 km by 1 km) statistically-down-scaled reanalysis data and dynamically-downscaled climate change scenario data. This study focuses on projections of mountain climate changes in the later 21st century (2020~2100). Agroclimatic indices, representing extreme climatic events, thermal/cooling requirements and crop phenology will be extracted from climate change scenario data simulated by several regional climate models in East Asia based on low (RCP 4.5) and high (RCP 8.5) greenhouse gas emission scenarios. The latitudinal and altitudinal ranges of optimal growing areas as well as phenology for highland crops in Korea may be changing in the warmer and more monsoonal climate. In the context of better ecosystem services targeted by the TERRECO project, maps projecting the optimal growing regions of highland crops in a changing climate will help farmers in the mountainous areas adapt to future climate changes.

 

Key words: mountain climate change, highland crops, agroclimatic indices, regional climate models, East Asia

 

Poster Workshop Ecosystem Change and Society, Bayreuth, January 2013








Letzte Änderung 31.10.2014