The northern area of Okinawa Island is a unique forest area in Japan, with a distinctive ecosystem and subtropical climate. The area is a central region of forestry in Okinawa Prefecture. However, quantitative evaluat...The northern area of Okinawa Island is a unique forest area in Japan, with a distinctive ecosystem and subtropical climate. The area is a central region of forestry in Okinawa Prefecture. However, quantitative evaluation of the effects of the forest environment is inadequate. The authors began meteorological observation of this forested area to address this situation by setting up a weather station in 2009. In this study, we performed research on one of the major factors of the water cycle in forest ecosystems, evapotranspiration. We calculate seasonal changes in potential evapotranspiration through analysis of data from our weather station in 2013, because all measurement elements were assembled. To calculate potential evapotranspiration, we used the Penman equation. We found that the potential evapotranspiration in this forest area was 1170.5 mm in 2013. The mean temperature in 2013 was 20.7°C, yearly average relative humidity was 84.7%, and average wind speed was 1.40 m/s. Regarding the amount of evapotranspiration in the forests of northern Okinawa Island, which has not been previously obtained, it has become possible to calculate the amount of potential evapotranspiration using the Penman equation.展开更多
利用1961-2000年赣州站、南昌站的年太阳总辐射与相关气象要素资料，结合Penman公式，运用6种计算净长波辐射的方法估算了两站的年太阳总辐射；建立了估算该地区年太阳总辐射的绝对误差权重法（Method of Absolute Errors，MAE），并给...利用1961-2000年赣州站、南昌站的年太阳总辐射与相关气象要素资料，结合Penman公式，运用6种计算净长波辐射的方法估算了两站的年太阳总辐射；建立了估算该地区年太阳总辐射的绝对误差权重法（Method of Absolute Errors，MAE），并给出了适用于江西省的绝对误差权重系数，以此方法计算了江西省其他76站的年太阳总辐射；并分析了该地区年太阳总辐射的时空分布特征及其变化趋势，发现：（1）1961～2000年间，江西省大部分地区太阳总辐射在3800-4400MJ·m-2·a-1；南部偏东地区较大，且存在有一大值中心；西部地区为江西省太阳总辐射最小的地区；（2）40年间，江西省年太阳总辐射呈明显下降趋势，每10年减少143．70MJ·m-2。78站中，有63站的太阳总辐射的下降趋势通过了a=0．05的显著性检验，8站表现为上升趋势；江西省北部及南部地区太阳总辐射下降较大；中部地区下降相对较小，且在鄱阳湖东侧有一低值中心。展开更多
文摘The northern area of Okinawa Island is a unique forest area in Japan, with a distinctive ecosystem and subtropical climate. The area is a central region of forestry in Okinawa Prefecture. However, quantitative evaluation of the effects of the forest environment is inadequate. The authors began meteorological observation of this forested area to address this situation by setting up a weather station in 2009. In this study, we performed research on one of the major factors of the water cycle in forest ecosystems, evapotranspiration. We calculate seasonal changes in potential evapotranspiration through analysis of data from our weather station in 2013, because all measurement elements were assembled. To calculate potential evapotranspiration, we used the Penman equation. We found that the potential evapotranspiration in this forest area was 1170.5 mm in 2013. The mean temperature in 2013 was 20.7°C, yearly average relative humidity was 84.7%, and average wind speed was 1.40 m/s. Regarding the amount of evapotranspiration in the forests of northern Okinawa Island, which has not been previously obtained, it has become possible to calculate the amount of potential evapotranspiration using the Penman equation.
文摘利用1961-2000年赣州站、南昌站的年太阳总辐射与相关气象要素资料，结合Penman公式，运用6种计算净长波辐射的方法估算了两站的年太阳总辐射；建立了估算该地区年太阳总辐射的绝对误差权重法（Method of Absolute Errors，MAE），并给出了适用于江西省的绝对误差权重系数，以此方法计算了江西省其他76站的年太阳总辐射；并分析了该地区年太阳总辐射的时空分布特征及其变化趋势，发现：（1）1961～2000年间，江西省大部分地区太阳总辐射在3800-4400MJ·m-2·a-1；南部偏东地区较大，且存在有一大值中心；西部地区为江西省太阳总辐射最小的地区；（2）40年间，江西省年太阳总辐射呈明显下降趋势，每10年减少143．70MJ·m-2。78站中，有63站的太阳总辐射的下降趋势通过了a=0．05的显著性检验，8站表现为上升趋势；江西省北部及南部地区太阳总辐射下降较大；中部地区下降相对较小，且在鄱阳湖东侧有一低值中心。
