Observational Analysis of Summer Atmospheric Downward Longwave Radiation at 4 Sites on the Tibetan Plateau

Liu Mengqi; Zheng Xiangdong; Zhao Chunsheng

doi:10.11898/1001-7313.20180508

Vol.29, NO.5, 2018

Turn off MathJax

Article Contents

Article Navigation > Journal of Applied Meteorological Science > 2018 > 29(5): 596-608

Liu Mengqi, Zheng Xiangdong, Zhao Chunsheng. Observational analysis of summer atmospheric downward longwave radiation at 4 sites on the Tibetan Plateau. J Appl Meteor Sci, 2018, 29(5): 596-608. DOI: 10.11898/1001-7313.20180508.

Citation:

Liu Mengqi, Zheng Xiangdong, Zhao Chunsheng. Observational analysis of summer atmospheric downward longwave radiation at 4 sites on the Tibetan Plateau. J Appl Meteor Sci, 2018, 29(5): 596-608. DOI: 10.11898/1001-7313.20180508.

Citation:

PDF( 16562 KB)

Observational Analysis of Summer Atmospheric Downward Longwave Radiation at 4 Sites on the Tibetan Plateau

DOI: 10.11898/1001-7313.20180508

1.
Chinese Academy of Meteorological Sciences, Beijing 100081
2.
Department of Atmospheric Science, School of Physics, Peking University, Beijing 100871

Received Date: 2018-03-01
Rev Recd Date: 2018-05-16
Publish Date: 2018-09-30

Abstract

Abstract

The summer downward longwave radiation (L_↓) observed in Naqu, Lhasa, Nyingchi and Ali is analyzed. The averaged L_↓ at 4 sites are 299, 319, 368 and 305 W·m^-2, respectively. L_↓ is lower in the local morning and subsequently increases significantly in the afternoon. The mean diurnal variation at Naqu and Ali is about 30 W·m^-2, while it's 9 and 19 W·m^-2 in Lhasa and Nyingchi respectively. Based on solar shortwave radiation observations, a method to determine the daytime sky cloud-coverage index (cloud fraction, C_F) is presented by the solar radiation comparisons between the empirically calculation for cloud-free situation and the observed. C_F of -5% to 5% is assumed as daytime cloud-free situation to test the suitability of 10 empirical formula of L_↓ on the Plateau. It shows that the empirical formula of Ångström (1915) is most suitable for the Nyingchi where the vapor pressure is high, while the empirical formula of Konzelmann (1994) is most suitable for Naqu, Lhasa and Ali. Errors of the calculated daytime cloud-free L_↓ from the observed at Naqu, Lhasa, Nyingchi and Ali are 2.1%, -0.27%, -0.89% and 0.94%. The cloud-induced L_↓ enhancement effect (measured L_↓ minus the calculated cloud-free values given the surface temperature and humidity) clearly shows that the mean L_↓ enhancement effect at Naqu, Lhasa, Nyingchi and Ali are 30.8, 22.1, 38.8 and 15.6 W·m^-2 with the median values of 24.4, 17.3, 42.7 and 6.8 W·m^-2. With the increase of artificially visual total cloud amount, the increasing trend of L_↓ enhancement is obvious, especially when the cloud amount increase from less than 20% to 70% and above, the corresponding L_↓ enhancement effects rapidly increases from above 20 to more than 50 W·m^-2 at all the 4 sites. Given the same visual cloud mount, the L_↓ enhancement effects induced by the low clouds in Lhasa and Ali are obviously higher than those induced by the total cloud. The effect from cloud coverage and height on the L_↓ enhancement is further confirmed by the aerosol lidar cloud base height at zenith direction and the C_F. The decreasing cloud base height (no available cloud base height data in Lhasa) corresponding to increasing trends of C_F and L_↓ enhancement is detected. The L_↓ enhancement effects are only about 5 W·m^-2 with cloud-free condition, but they may rise to 60 W·m^-2 when C_F is above 90% (the average cloud base height is less than 3.5 km). Given the fixed cloud base height, the L_↓ enhancement obviously increases with the growth of C_F. C_F, significantly more than the zenith cloud base height, which affects the enhancement of L_↓ on the Tibetan Plateau.
- downward longwave radiation;
- cloud fraction;
- cloud-induced enhancement effect

FullText(HTML)

References(37)

Figures and Tables

Fig. 1 Diurnal and daily L_↓at Naqu, Lhasa, Nyingchi and Ali

DownLoad: Full-Size Img PowerPoint

Fig. 2 Observed and calculated solar shortwave radiation at Naqu, Lhasa, Nyingchi and Ali under cloud-free condition in daytime

DownLoad: Full-Size Img PowerPoint

Fig. 3 Observed and calculated L_↓ at Naqu, Lhasa, Nyingchi and Ali under

DownLoad: Full-Size Img PowerPoint

Fig. 4 All observed and calculated cloud-free L_↓ at Naqu, Lhasa, Nyingchi and Ali

DownLoad: Full-Size Img PowerPoint

图 5 那曲、拉萨、林芝和阿里L_↓增强变化与人工观测云量

(总(低)云量所对应L_↓增强的误差棒分别是下(上)方向)

Fig. 5 Enhancements of L_↓ and the artificially observed cloud amount (error bars of L_↓ enhancement corresponding to total(low) cloud amount are the downward(upward) direction) at Naqu, Lhasa, Nyingchi and Ali

DownLoad: Full-Size Img PowerPoint

Fig. 6 L_↓enhancement effect, C_F and its corresponding variations of zenith averaged cloud basement height at Naqu, Lhasa, Nyingchi and Ali

DownLoad: Full-Size Img PowerPoint

Fig. 7 Given the fixed zenith cloud base height, L_↓ enhancement effects as functions of C_F variations at Naqu, Nyingchi and Ali in daytime

DownLoad: Full-Size Img PowerPoint

Table 1 General descriptions of 4 sites deploying L_↓ observations

观测站	观测时段	观测时段日平均气象要素				辅助观测
观测站	观测时段	气温/℃	水汽压/hPa	云量/成	日照/h	辅助观测
那曲	2011-07—08	9.4±8.0	7.4±5.0	6.8	5.4	CM21，激光雷达
拉萨	2012-05—07	18.0±10.0	8.39±5.0	6.9	5.4	CM21
林芝	2014-06—07	16.8±10.0	13.4±4.0	9.0	2.6	CM21，激光雷达
阿里	2016-05—09	14.0±8.0	4.8±4.0	4.9	7.2	CM21，激光雷达

DownLoad: Download CSV

Table 2 General descriptions of surface L_↓ parameterization schemes under cloud-free condition

来源	晴天比辐射率ε	a	b	c
文献[17]	a-be^-ce	0.83	0.18	0.067
文献[18]	a+b(e)^1/2	0.52	0.065
文献[19]	aT²	9.365×10^-6
文献[20]	1-ae^-b(273-T)²	0.261	7.77×10^-4
文献[21]	a(e/T)^1/b	1.24	7
文献[22]	a(1-e^{-e^(T/b)})	1.08	2016
文献[23]	a+bee^c/T	0.7	5.95×10^-5	1500
文献[24]	0.23+a(e/T)^(1/b)	0.484	8
文献[25]	1-(1+a)e^{-(b+ca)^0.5}	46.5(e/T)	1.2	3
文献[26]	1-ae^-be/T	0.43	11.5
注：e为近地面水汽压，单位为hPa; T为近地面气温，单位为K。

DownLoad: Download CSV

Table 3 Statistics of day-time cloud base height frequency distribution and its corresponding C_F and L_↓ enhancements

台站	统计变量	(0 km，1 km]	(1 km，2 km]	(2 km，3 km]	(3 km，4 km]	(4 km，5 km]	>5 km
那曲	出现频率/%	6.2	31.4	33.4	8.6	1.2	18.4
	云底高度/km	0.8±0.15	1.5±0.28	2.5±0.28	3.3±0.26	4.4±0.28	10.6±2.7
	C_F/%	60±24	54±33	33±36	40±35	47±29	41±34
	L_↓增强/(W·m^-2)	55±19	44±25	24±27	31±26	33±20	24±24
林芝	出现频率/%	1.3	15.9	50.5	16.7	6.2	9.1
	云底高度/km	0.8±0.16	1.8±0.24	2.4±0.29	3.4±0.25	4.4±0.27	10.0±3.5
	C_F/%	76±13	68±17	55±25	41±29	36±32	27±34
	L_↓增强/(W·m^-2)	57±5	52±5	45±9	35±11	26±13	18±15
阿里	出现频率/%	15.4	15.6	30.2	15.8	3.4	19.4
	云底高度/km	0.5±0.21	1.6±0.3	2.5±0.28	3.3±0.24	4.5±0.28	7.77±1.4
	C_F/%	27±36	44±35	31±35	15±34	21±33	20±31
	L_↓增强/(W·m^-2)	26±27	45±16	33±16	20±14	22±15	19±15

DownLoad: Download CSV

References

[1]	张瑛, 高庆先.硫酸盐和碳黑气溶胶辐射效应的研究.应用气象学报, 1997, 8(增刊Ⅰ):87-91. http://www.cnki.com.cn/Article/CJFDTotal-YYQX7S1.011.htm
[2]	李维亮, 程耕奎.1979年夏季青藏高原地区云对辐射周期振荡的作用.气象科学研究院院刊, 1988(1):64-69. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=QK000004908151
[3]	Ohmura A.Physical basis for the temperature-based melt-index method.J Appl Meteor, 2001, 40(4):753-761. doi: 10.1175/1520-0450(2001)040<0753:PBFTTB>2.0.CO;2
[4]	Zhao W, William R, Roland S.The significance of detailed structure in the boundary layer to thermal radiation at the surface in climate model.Geophys Res Lett, 1994, 21(15):1631-1634. doi: 10.1029/94GL01393
[5]	汪方, 丁一汇, 徐影.辐射参数化方案对一个海气耦合模式云和辐射模拟的影响.应用气象学报, 2007, 18(3):257-265. doi: 10.3969/j.issn.1001-7313.2007.03.001
[6]	彭丽春, 李万彪, 叶晶, 等.地表向下短波和长波辐射遥感参数化方案研究综述.北京大学学报, 2015, 51(4):772-782. http://d.old.wanfangdata.com.cn/Periodical/bjdxxb201504024
[7]	Crawford T, Duchon C.An improved parameterization for estimating effective atmospheric emissivity for use in calculating daytime downwelling Longwave Radiation.J Appl Meteor, 1999, 38(4):474-480. doi: 10.1175/1520-0450(1999)038<0474:AIPFEE>2.0.CO;2
[8]	杨汉波, 吕华芳, 胡庆芳, 等.华北平原的大气逆辐射参数化方法比较.清华大学学报, 2014, (5):590-595. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=SciencePaper201407310000017673
[9]	江灏, 吴青柏, 王可丽, 等.青藏铁路沿线地表和路基表面热力学模式(Ⅲ):参数化方案.冰川冻土, 2005, 27(5):680-685. http://d.wanfangdata.com.cn/Periodical/bcdt200505010
[10]	中国气象局监测网络司, 译.地面辐射基准站网操作手册.北京:气象出版社, 2004.
[11]	宋建洋, 郑向东, 程兴宏, 等.临安与龙凤山辐射数据质量及初步结果比较.应用气象学报, 2013, 24(1):65-74. doi: 10.3969/j.issn.1001-7313.2013.01.007
[12]	Liang Hong, Zhang Renhe, Liu Jingmiao, et al.Estimation of hourly solar radiation at the surface under cloudless conditions on the Tibetan Plateau using a simple radiati6on model.Adv Atmos Sci, 2012, 29(4):675-689. doi: 10.1007/s00376-012-1157-1
[13]	赵兴炳.青藏高原不同地区夏季近地面能量输送与微气象特征比较分析.高原山地气象研究, 2011, 31(1):6-11. doi: 10.3969/j.issn.1674-2184·2011.01.002
[14]	Gubler S, Gruber S, Purves R S.Uncertainties of parameterized surface downward clear-sky shortwave and all-sky longwave radiation.Atmospheric Chemistry & Physics, 2012, 12(11):5077-5098. http://d.old.wanfangdata.com.cn/OAPaper/oai_doaj-articles_1e4da72c649065bb65503023646aad24
[15]	盛裴轩, 毛节泰, 李建国, 等.大气物理学.北京:北京大学出版社, 2003.
[16]	Staley D, Jurica G.Effective atmospheric emissivity under clear skies.J Appl Meteor, 1972, 11:349-356. doi: 10.1175/1520-0450(1972)011<0349:EAEUCS>2.0.CO;2
[17]	Angström A.A Study of the Radiation of the Atmosphere: Smithsonian Institution.1915.
[18]	Brunt D.Notes on radiation in the atmosphere.Quart J Roy Meteor Soc, 1932, 58(247):389-420. doi: 10.1002-qj.49705824704/
[19]	Swinbank W.Long-wave radiation from clear skies.Quart J Roy Meteor Soc, 1963, 89:339-348. doi: 10.1002/(ISSN)1477-870X
[20]	Idso S B, Jackson R D.Thermal radiation from the atmosphere.J Geophys Res, 1969, 74(23):5397-5403. doi: 10.1029/JC074i023p05397
[21]	Brutsaert W.On a derivable formula for long-wave radiation from clear skies.Water Resour Res, 1975, 11(5):742-744. doi: 10.1029/WR011i005p00742
[22]	Satterlund D R.An improved equation for estimating long-wave radiation from the atmosphere.Water Resour Res, 1979, 15(6):1649-1650. doi: 10.1029/WR015i006p01649
[23]	Idso S B.A set of equations for full spectrum and 8 to 14μm and 10.5 to 12.5μm thermal radiation from cloudless skies.Water Resour Res, 1981, 17(2):295-304. doi: 10.1029/WR017i002p00295
[24]	Konzelmann T, Wal R, Greuell W, et al.Parameterization of global and longwave incoming radiation for the Greenland Ice Sheet.Global and Planetary Change, 1994, 9(1-2):143-164. doi: 10.1016/0921-8181(94)90013-2
[25]	Prata A J.A new long-wave formula for estimating downward clear-sky radiation at the surface.Quart J Roy Meteor Soc, 1996, 122(533):1127-1151. doi: 10.1002/(ISSN)1477-870X
[26]	Iziomon M G, Mayer H, Matzarakis A.Downward atmospheric longwave irradiance under clear and cloudy skies:Measurement and parameterization.Journal of Atmospheric and Solar-Terrestrial Physics, 2010, 65(10):1107-1116. http://d.old.wanfangdata.com.cn/NSTLQK/NSTL_QKJJ024993953/
[27]	Wang K, Liang S.Global atmospheric downward longwave radiation over land surface under all-sky conditions from 1973 to 2008.J Geophys Res, 2009, 114, D19101, DOI: 10.1029/2009JD011800.
[28]	陆龙骅, 周国贤.1992年夏季珠穆朗玛峰地区的太阳直接辐射和总辐射.太阳能学报, 1995, 16(3):229-233. http://www.cnki.com.cn/Article/CJFDTotal-TYLX503.000.htm
[29]	Dahlback A, Gelsor N, Stamnes J, et al.UV measurements in the 3000-5000 m altitude region in Tibet.J Geophys Res, 2007, 112(9):139-155. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=JJ021584410
[30]	陈树, 郑向东, 林伟立, 等.西藏当雄地基紫外线指数观测研究.应用气象学报, 2015, 26(4):482-291. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20150410&flag=1
[31]	李清泉, 王兰宁, 徐影, 等.辐射参数化方案对气候模拟和回报的影响.应用气象学报, 2005, 16(增刊Ⅰ):12-21. http://kns.cnki.net/KCMS/detail/detail.aspx?filename=YYQX2005S1001&dbname=CJFD&dbcode=CJFQ
[32]	沈元芳, Baer F, 王超.初始场和长波辐射对气候模拟的影响.应用气象学报, 2003, 14(3):266-276. doi: 10.3969/j.issn.1001-7313.2003.03.002
[33]	周广强, 赵春生, 丁守国, 等.不同辐射传输方案对中尺度降水影响的对比分析.应用气象学报, 2005, 16(2):148-158. doi: 10.3969/j.issn.1001-7313.2005.02.003
[34]	Dupont J C, Haeffelin M, Drobinski P, et al.Parametric model to estimate clear-sky longwave irradiance at the surface on the basis of vertical distribution of humidity and temperature.J Geophys Res, 2008, 113(7):1829-1836. doi: 10.1029-2007JD009046/
[35]	Gr bner J, Wacker S, Vuilleumier L, et al.Effective atmospheric boundary layer temperature from longwave radiation measurements.J Geophys Res, 2009, 114, D19116, DOI: 10.1029/2009JD012274.
[36]	Dupont J, Haeffelin M, Long C N.Evaluation of cloudless-sky periods detected by shortwave and longwave algorithms using lidar measurements.Geophys Res Lett, 2008, 35(10):237-255. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=JJ024300696
[37]	Dürr B, Philipona R.Automatic cloud amount detection by surface longwave downward radiation measurements.J Geophys Res, 2004, 109, D05201, DOI: 10.1029/2003JD004182.