Cross-Calibration of TIMED SEE and SOHO EIT Irradiances     

R. A. Hock  F. G. Eparvier 《Solar physics》2008,250(1):207-219

Absolutely calibrated solar images are necessary for a variety of solar physics problems, such as the identification of solar variability sources and the derivation of differential emission measure (DEM) maps. SOHO EIT is absolutely calibrated by using TIMED SEE spectra to provide a method of determining physical values of irradiance for EIT images. EIT images from 1 April 2002 to 15 March 2005 in the 28.4- and 30.4-nm channels are compared to SEE daily spectra from the same time period. The resulting fitted EIT irradiances are well correlated to SEE irradiance measurements and are within the uncertainties of both instruments. The new cross-calibration results are compared to the currently used calibration based on the UARS SUSIM Mg ii index.  相似文献   

基于地基宽带辐射观测资料的云检测算法改进   总被引：1，自引：0，他引：1  

汤金平  王普才  夏祥鳌 《气候与环境研究》2011,16(5):609-619

利用地表太阳总辐射和散射辐射对Long and Ackerman (2000)的云检测算法进行了改进,提高了云判别的准确率.首先采用比值概率密度峰值法,初步选出晴天时刻.然后根据晴天时刻的地表太阳总辐射和太阳天顶角余弦值,拟合得到该日晴天总辐射近似表达式.在此基础上,计算各时刻实际观测值与用该拟合式估计的总辐射的比值,...  相似文献   

南极大气外太阳辐射的能谱分布          下载免费PDF全文

张善礼  李其德  朱翠莲  孔繁熙 《极地研究》1990,2(3):57-60

本文阐述了在中国南极长城站进行太阳能谱测量所用的仪器设备、测量原理、方法和结果。给出了大气外日地平均距离处太阳的绝对分光辐照值、能谱分布曲线及太阳常数。同时,对所得的结果作了分析讨论。  相似文献   

温度、光照强度及硝酸盐对拟柱孢藻(Cylindrospermopsis raciborskii N8)生长的影响   总被引：4，自引：3，他引：1  

于婷  戴景峻  雷腊梅  彭亮 《湖泊科学》2014,26(3):441-446

以从南亚热带水库中分离的拟柱孢藻(Cylindrospermopsis raciborskii N8)为材料,研究了不同温度(12、16、20、24、28、32℃)、光照强度(6.6、12.4、21.5、30.7、62.9、106.4μmol/(m²·s))和硝态氮浓度(0.5、1、2、4、8、16、32、64、128 mg/L)下拟柱孢藻的生长特性.结果表明:在实验设置的温度范围(16~32℃)内拟柱孢藻能够正常生长;最适温度范围为24~28℃,在28℃条件下,具有最大比生长速率,为0.189 d^-1;当温度为12℃时,拟柱孢藻叶绿素a浓度一直降低,显著低于其他温度组(16~32℃).在6.6~106.4μmol/(m²·s)光照强度范围内,拟柱孢藻均呈指数增长趋势,最适光照强度为30.7μmol/(m²·s),其比生长速率达到最大值,为0.156 d^-1;高光照强度(62.9~106.4μmol/(m²·s))下拟柱孢藻的比生长速率显著大于低光照强度(6.6~12.4μmol/(m²·s))处理组.拟柱孢藻开始指数增长的最低硝态氮浓度为4 mg/L;硝态氮浓度为8 mg/L时,拟柱孢藻达到最大比生长速率(0.155 d^-1);当硝态氮浓度高于16 mg/L时比生长速率增加不显著.高硝态氮浓度组(16~128 mg/L)拟柱孢藻的叶绿素a浓度和比生长速率显著高于低硝态氮浓度组(0.5~2 mg/L).研究结果说明拟柱孢藻对温度、光照和氮源均有较宽的生态位,有利于在较大空间尺度上进行扩散.  相似文献   

COMBINED EFFECTS OF TEMPERATURE, IRRADIANCE AND SALINITY ON GROWTH OF DIATOM SKELETONEMA COSTATUM     

颜天  周名江  钱培元 《中国海洋湖沼学报》2002,20(3)

ＩＮＴＲＯＤＵＣＴＩＯＮＶａｒｉｏｕｓｃａｕｓａｔｉｖｅｆａｃｔｏｒｓ,ｓｕｃｈａｓｉｎｃｒｅａｓｅｄｓｃｉｅｎｔｉｆｉｃａｗａｒｅｎｅｓｓ,ｕｔｉｌｉｚａｔｉｏｎｏｆｃｏａｓｔａｌｗａｔｅｒｓｆｏｒａｑｕａｃｕｌｔｕｒｅ,ｅｕｔｒｏｐｈｉｃａｔｉｏｎａｎｄｃｙｓｔｔｒａｎｓｐｏｒｔａｔｉｏｎ (Ｈａｌｌｅｇｒｅａｆｆｅｔａｌ.,1 995)ｈａｓｌｅｄｔｏｅｘｔｅｎｓ ｉｖｅｓｔｕｄｉｅｓｏｎｔｈｅｇｌｏｂａｌｉｎｃｒｅａｓｅｉｎＨＡＢ (ＨａｒｍｆｕｌＡｌｇａｌＢｌｏｏｍ) .ＹｅｔｔｈｅＨＡＢｍｅｃｈａｎｉ…  相似文献   

不同光照强度下仙掌藻(Halimeda opuntia)对海洋酸化的生理响应     

韦章良  莫嘉豪  胡群菊  严锐飞  龙超  丁德文  杨芳芳  龙丽娟 《海洋通报》2019,38(5):574-584

为探讨海洋酸化和光照强度变化对海洋钙化生物的影响,本文选用广泛分布在热带珊瑚礁区的大型钙化海藻仙掌藻(Halimeda opuntia)为研究对象,在室内通过CO2加富(pH=7.50、7.80和8.10)和调控光照强度(30和180μmol photons m2·s-1)的方式,探究其生长、钙化作用和光合作用等生理特征对海洋酸化和光照强度变化的响应。结果表明:海水酸化可以显著抑制仙掌藻的生长率、钙化速率和光合效率,且随酸化程度的加深而加强。酸化条件下(p H 7.50～7.80),生长率、钙化速率和Fv/Fm分别下降了48.29%～58.80%、51.78%～62.29%和2.37%～13.79%;光照强度的增加可以缓解这一抑制作用,高光照下生长率、钙化速率和Fv/Fm分别升高了2.01%～44.55%、29.61%～40.68%和1.68%～6.92%。酸化处理和光照强度变化对色素含量、丙二醛(MDA)和脯氨酸含量影响显著(P 0.01);酸化处理组中的Chl-a含量下降了32.69%～43.44%;而实验第20-28天,低光条件下的类胡萝卜素含量比高光照组高出12.12%～57.45%;酸化胁迫下,MDA在组织中逐渐积累;同时脯氨酸明显升高,以增加藻体自身的抗逆性,缓解胁迫带来的损伤。此外,组织中总碳(TC)和总氮(TN)含量在酸化条件下显著增加(P 0.05),光照强度的增加也一定程度上有利于提高TC和TN含量。通过分析可知,海洋酸化对仙掌藻的威胁是多方面的,对其生长、钙化作用和光合作用等生理过程的抑制作用随着酸化程度的加深而增加,而光照强度的增加一定程度上可以缓解酸化带来的负面效应。这些结果可以为预测未来海洋酸化对钙质生物的影响和珊瑚礁生物的多样性保护提供理论参考。  相似文献   

COMBINED EFFECTS OF TEMPERATURE, IRRADIANCE AND SALINITY ON GROWTH OF DIATOM SKELETONEMA COSTATUM   总被引：2，自引：0，他引：2  

Yan Tian  Zhou Mingjiang  Qian Peiyuan 《中国海洋湖沼学报》2002,20(3):237-243

3-factor experiment was used to study the combined effects of temperature, irradiance and salinity on the growth of an HAB species diatomSkeletonema costatum (Grev.) Cleve. The results showed that temperature (12, 19, 25, 32 °C), irradiance (0.02, 0.08, 0.3, 1.6)×10¹⁶ quanta/(s·cm²)) and salinity (10, 18, 25, 30, 35) significantly influenced the growth of this species. There were interactive effects between any two of and among all three physical factors on the growth. In the experiment, the most optimal growth condition forS. costatum was temperature of 25°C, salinity of 18–35 and irradiance of 1.6×10¹⁶ quanta/(s·cm²). The results indicatedS. costatum could divide at higher rate and were more likely to bloom under high temperature and high illumination from spring to fall. It was able to distribute widely in ocean and estuary due to its adaptation to a wide range of salinities. This study was supported by the PREPP and National Key Basic Research Project (2001CB4097) NNSFC No. 39950001, 20177023, 49576301, 49906007 and KZCX2-206.  相似文献   

Photosynthetic characteristics of sinking microalgae under the sea ice     

《Polar Science》2014,8(4):385-396

The photosynthetic characteristics of sinking a microalgal community were studied to compare with the ice algal community in the sea ice and the phytoplankton community in the water column under the sea ice at the beginning of the light season in the first-year sea ice ecosystem on the Mackenzie Shelf, in the western Canadian Arctic. The phytoplankton community was collected using a water bottle, whereas the sinking algal community was collected using particle collectors, and the ice algal community was obtained by using an ice-core sampler from the bottom portion of ice core. Photosynthesis versus irradiance (P-E) incubation experiments were conducted on deck to obtain the initial slope (α^B) and the maximum photosynthetic rate (P_m^B) of the three algal communities. The α^B and the P_m^B of the light saturation curve, and chlorophyll a (Chl a) specific absorption coefficient (ā_ph*) between the sinking microalgal community and the ice algal community were similar and were distinctly different from the phytoplankton community. The significant linear relationship between α^B and P_m^B, which was obtained among the three groups, may suggest that a photo-acclimation strategy is common for all algal communities under the low light regime of the early season. Although the sinking algal community could be held for the entire duration of deployment at maximum, this community remained photosynthetically active once exposed to light. This response suggests that sinking algal communities can be the seed population, which results in a subsequent phytoplankton bloom under the sea ice or in a surface layer, as well as representing food for the higher trophic level consumers in the Arctic Ocean even before the receding of the sea ice.  相似文献   

太阳直接辐射光量子通量的气候学计算方法   总被引：4，自引：0，他引：4  

周允华  项月琴 《地理学报》1987,(2)

为了把太阳直接辐射通量密度换算成光量子通量密度,取用了一个简单的大气模式,计算了各种太阳高度、地面气压和大气浑浊度下太阳直接辐射中的光合有效辐射能量通量和光量子通量,从而得到了单位光合有效辐射能量所具有的光量子数。结果表明:这个数是比较稳定的。在平原地区,10—90°的太阳高度范围内,1W.m~(-2)的光合有效辐射通量密度具有4.72±0.11μmol.m~(-2).s~(-1)的光量子通量密度。本文还采用北京地区四个季节定时的太阳直接辐射分光测量资料和高原观测资料检验了模式计算结果的可靠性,获得了满意的结果。  相似文献   

太阳辐射短时临近预报R模型的构建及验证          下载免费PDF全文

姚德贵  刘唯佳  韩永翔  李哲  梁允 《干旱区地理》2023,46(1):47-55

提高太阳辐射短时临近预报（<6 h）的准确率是确保电网调度的重要举措,也是极具挑战性的技术瓶颈之一。基于云-辐射关系,利用地面观测的太阳辐照度反演的云相对辐射强迫比值,构建了太阳辐射短时临近预报模型（R模型）,并用美国南部大平原中心站16 a的辐照度观测数据,对R模型的预报性能进行了评估。结果表明：（1）有云存在的个例中,R模型较传统的简单持续性模型（Simple模型）的预报性能有很大提升,相比于预报性能较高的智能持续性模型（Smart模型或RCRF模型）仍有2%～25%的改进。（2）在16 a包含2.9×105个8类云状个例的总体检验中,当预报时效超过1 h时,R模型的预报性能显著优于Simple模型和RCRF模型。相对于RCRF模型,R模型在6 h预报时效下,对总辐射和直接辐射的预报性能可分别提高25%和19%,预报时效分别延长了1.5 h和1 h。（3）R模型为太阳辐射短时临近预报提供了准确率更高的基准模型。同时,该模型可仅依靠地面短期的辐照度观测资料即可预报,为缺少同期气象要素观测的光伏电厂的辐射预报提供了新的途径或新的可能。  相似文献