Knowledge Management System of Northwest Institute of Plateau Biology, CAS
Infrared heater arrays for warming ecosystem field plots | |
Kimball, Bruce A.1; Conley, Matthew M.1; Wang, Shiping2; Lin, Xingwu2; Luo, Caiyun2; Morgan, Jack3; Smith, David3 | |
2008-02-01 | |
发表期刊 | GLOBAL CHANGE BIOLOGY |
卷号 | 14期号:2页码:309-320 |
文章类型 | Article |
摘要 | There is a need for methodology to warm open-field plots in order to study the likely effects of global warming on ecosystems in the future. Herein, we describe the development of arrays of more powerful and efficient infrared heaters with ceramic heating elements. By tilting the heaters at 45 degrees from horizontal and combining six of them in a hexagonal array, good uniformity of warming was achieved across 3-m-diameter plots. Moreover, there do not appear to be obstacles (other than financial) to scaling to larger plots. The efficiency [eta(h) (%); thermal radiation out per electrical energy in] of these heaters was higher than that of the heaters used in most previous infrared heater experiments and can be described by: eta(h) = 10 + 25exp(-0.17 u), where u is wind speed at 2 m height (m s(-1)). Graphs are presented to estimate operating costs from degrees of warming, two types of plant canopy, and site windiness. Four such arrays were deployed over plots of grass at Haibei, Qinghai, China and another at Cheyenne, Wyoming, USA, along with corresponding reference plots with dummy heaters. Proportional integral derivative systems with infrared thermometers to sense canopy temperatures of the heated and reference plots were used to control the heater outputs. Over month-long periods at both sites, about 75% of canopy temperature observations were within 0.5 degrees C of the set-point temperature differences between heated and reference plots. Electrical power consumption per 3-m-diameter plot averaged 58 and 80 kW h day(-1) for Haibei and Cheyenne, respectively. However, the desired temperature differences were set lower at Haibei (1.2 degrees C daytime, 1.7 degrees C night) than Cheyenne (1.5 degrees C daytime, 3.0 degrees C night), and Cheyenne is a windier site. Thus, we conclude that these hexagonal arrays of ceramic infrared heaters can be a successful temperature free-air-controlled enhancement (T-FACE) system for warming ecosystem field plots.; There is a need for methodology to warm open-field plots in order to study the likely effects of global warming on ecosystems in the future. Herein, we describe the development of arrays of more powerful and efficient infrared heaters with ceramic heating elements. By tilting the heaters at 45 degrees from horizontal and combining six of them in a hexagonal array, good uniformity of warming was achieved across 3-m-diameter plots. Moreover, there do not appear to be obstacles (other than financial) to scaling to larger plots. The efficiency [eta(h) (%); thermal radiation out per electrical energy in] of these heaters was higher than that of the heaters used in most previous infrared heater experiments and can be described by: eta(h) = 10 + 25exp(-0.17 u), where u is wind speed at 2 m height (m s(-1)). Graphs are presented to estimate operating costs from degrees of warming, two types of plant canopy, and site windiness. Four such arrays were deployed over plots of grass at Haibei, Qinghai, China and another at Cheyenne, Wyoming, USA, along with corresponding reference plots with dummy heaters. Proportional integral derivative systems with infrared thermometers to sense canopy temperatures of the heated and reference plots were used to control the heater outputs. Over month-long periods at both sites, about 75% of canopy temperature observations were within 0.5 degrees C of the set-point temperature differences between heated and reference plots. Electrical power consumption per 3-m-diameter plot averaged 58 and 80 kW h day(-1) for Haibei and Cheyenne, respectively. However, the desired temperature differences were set lower at Haibei (1.2 degrees C daytime, 1.7 degrees C night) than Cheyenne (1.5 degrees C daytime, 3.0 degrees C night), and Cheyenne is a windier site. Thus, we conclude that these hexagonal arrays of ceramic infrared heaters can be a successful temperature free-air-controlled enhancement (T-FACE) system for warming ecosystem field plots. |
关键词 | Canopy Temperature Climate Change Ecosystems Gis Global Change Global Warming Infrared Heater Rangeland Thermal Radiation Wind Speed |
WOS标题词 | Science & Technology ; Life Sciences & Biomedicine |
学科领域 | 生物科学 |
关键词[WOS] | CLIMATE-CHANGE ; TERRESTRIAL ECOSYSTEMS ; NORTHERN PEATLANDS ; ELEVATED CO2 ; TEMPERATURE ; MICROCLIMATE ; PERFORMANCE ; GRASSLAND ; PRAIRIE |
收录类别 | SCI |
语种 | 英语 |
WOS研究方向 | Biodiversity & Conservation ; Environmental Sciences & Ecology |
WOS类目 | Biodiversity Conservation ; Ecology ; Environmental Sciences |
WOS记录号 | WOS:000253313400010 |
引用统计 | |
文献类型 | 期刊论文 |
条目标识符 | http://210.75.249.4/handle/363003/1233 |
专题 | 中国科学院西北高原生物研究所 |
作者单位 | 1.USDA ARS, US Arid Land Agr Res Ctr, Maricopa, AZ 85238 USA 2.Chinese Acad Sci, NW Inst Plateau Biol, Key Lab Adaptat & Evolut Plateau Biota, Xining 810008, Peoples R China 3.USDA ARS, Crops Res Lab, Ft Collins, CO USA |
推荐引用方式 GB/T 7714 | Kimball, Bruce A.,Conley, Matthew M.,Wang, Shiping,et al. Infrared heater arrays for warming ecosystem field plots[J]. GLOBAL CHANGE BIOLOGY,2008,14(2):309-320. |
APA | Kimball, Bruce A..,Conley, Matthew M..,Wang, Shiping.,Lin, Xingwu.,Luo, Caiyun.,...&Smith, David.(2008).Infrared heater arrays for warming ecosystem field plots.GLOBAL CHANGE BIOLOGY,14(2),309-320. |
MLA | Kimball, Bruce A.,et al."Infrared heater arrays for warming ecosystem field plots".GLOBAL CHANGE BIOLOGY 14.2(2008):309-320. |
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