發(fā)布時(shí)間：2018-03-10 15:46

  本文選題：降水　切入點(diǎn)：蒸發(fā)　出處：《蘭州大學(xué)》2017年博士論文　論文類型：學(xué)位論文

【摘要】：水分循環(huán)是研究氣候變化中的一個(gè)基本內(nèi)容,也是降水發(fā)生的基本條件之一。水分循環(huán)過(guò)程既影響著陸氣之間水分交換的變化,也影響著大氣的能量收支,既對(duì)氣候變化響應(yīng),也對(duì)氣候產(chǎn)生影響。干旱區(qū)降水稀少,水汽來(lái)源匱乏,水分循環(huán)中的局地水分循環(huán)在降水中占有多大比例是一個(gè)基本科學(xué)問(wèn)題;同時(shí),蒸發(fā)是水分循環(huán)中的重要環(huán)節(jié),蒸發(fā)量的估算是定量評(píng)估水分循環(huán)的關(guān)鍵,和同緯度其他氣候區(qū)相比,干旱區(qū)平均氣溫偏高,土壤濕度偏低,使得蒸發(fā)的估算具有較大不確定性,如何客觀準(zhǔn)確的估算蒸發(fā)是一個(gè)值得探索的科學(xué)問(wèn)題。本文通過(guò)使用NCEP、EAR-Interim、GLDAS等多種再分析及模式輸出資料的綜合計(jì)算、診斷分析,在比較不同蒸發(fā)估算方法的基礎(chǔ)上,探索、發(fā)展了一個(gè)相對(duì)合理、且客觀定量的蒸發(fā)計(jì)算方法;分析了全球溫度顯著升高的近30年(1981-2010),北半球典型干旱區(qū)水分循環(huán)中降水轉(zhuǎn)化及再循環(huán)的時(shí)空特征,并利用CMIP5結(jié)果對(duì)21世紀(jì)不同時(shí)期(初期:2017—2036,中期:2047—2066,后期:2077—2096)、典型干旱區(qū)的水分循環(huán)時(shí)空變化進(jìn)行了預(yù)估,并探討了溫度升高情況下水分循環(huán)變化的可能機(jī)制。首先,本文把北半球干旱區(qū)分為中蒙、西亞、北非和北美干旱區(qū)四個(gè)區(qū)域,利用Penman—Monteith蒸發(fā)及Brubaker再循環(huán)模型,計(jì)算了北半球典型干旱區(qū)的年平均降水再循環(huán)率。結(jié)果顯示,中蒙、西亞、北非和北美干旱區(qū)的年降水再循環(huán)率分別為5%、12%、18%和8%。降水量最少的西亞、北非干旱區(qū)的降水再循環(huán)率大于中蒙、北美干旱區(qū),表明在干旱地區(qū),局地水汽貢獻(xiàn)對(duì)總降水的貢獻(xiàn)更大。在過(guò)去的30余年來(lái),隨著全球氣溫的上升,西亞干旱區(qū)的降水再循環(huán)率呈現(xiàn)出增加趨勢(shì),而降水呈現(xiàn)出減少趨勢(shì),尤其自1981年以來(lái),該地區(qū)降水減少,同時(shí)降水再循環(huán)率以0.43%10a-1的速率增加,表明在全球變暖背景下,由于水汽輸送在該地區(qū)為凈輸出,因此降水再循環(huán)率在降水減少過(guò)程中起著補(bǔ)償作用;在北美和北非干旱區(qū)的再循環(huán)率為減少趨勢(shì)(-0.45%10a-1和-0.26%10a-1)。在北美干旱區(qū),Penman蒸發(fā)增加(0.07 mm day-1 10a-1)、可降水量增加(0.12 kg m-2 10a-1),但總降水減少(-0.02 mm day-1 10a-1),表明通過(guò)蒸發(fā)從下墊面進(jìn)入大氣的水汽增多,但是并未轉(zhuǎn)化為實(shí)際降水。而在北非干旱區(qū),降水為增加趨勢(shì)(0.06 mm day-1 10a-1),對(duì)應(yīng)降水再循環(huán)率減小,外部水汽輸送增加。這表明外部水汽輸送增加使得北非干旱區(qū)局地貢獻(xiàn)水汽在總降水中的比率降低,降水增加�？傮w而言,外部水汽輸送仍然是降水的主要來(lái)源,降水再循環(huán)在降水出現(xiàn)減少趨勢(shì)時(shí)起到補(bǔ)償?shù)淖饔�。蒸發(fā)的估算對(duì)于水分循環(huán)起著決定性的作用。但是,實(shí)際的蒸發(fā)很難估算。為了減小參考蒸發(fā)和實(shí)際蒸發(fā)之間的差別,本文通過(guò)對(duì)比Penman蒸發(fā)以及利用土壤濕度修正后的改進(jìn)蒸發(fā),應(yīng)用動(dòng)力降水再循環(huán)模型DRM,計(jì)算亞非干旱區(qū)降水再循環(huán)率,分析結(jié)果表明受限于有限的土壤水分,干旱區(qū)蒸發(fā)量(0.3—0.8mm day-1)小于參考蒸發(fā)量(4.4—11.0 mm day-1)。通過(guò)比較降水再循環(huán)率與ET-P發(fā)現(xiàn),中蒙、北非干旱區(qū)降水再循環(huán)率降低,同時(shí)外部水汽輸送在總水汽中比例升高,對(duì)應(yīng)ET-P減小,陸面水汽支出減少,西亞干旱區(qū)水汽為凈輸出、降水再循環(huán)率增加,局地水汽貢獻(xiàn)在總水汽中增加,對(duì)應(yīng)ET-P增加。這表明降水再循環(huán)過(guò)程對(duì)于在亞非干旱區(qū)的干旱有負(fù)反饋機(jī)制:降水再循環(huán)率降低,對(duì)應(yīng)更多外部水汽輸送進(jìn)入干旱區(qū),總降水中局地水汽貢獻(xiàn)比例降低,外部水汽供應(yīng)與內(nèi)部水分循環(huán)相配合,表現(xiàn)為干旱區(qū)ET-P減小,陸面水汽支出減少,干旱程度減弱。與此相反,當(dāng)降水再循環(huán)率增加時(shí),外部水汽輸送減弱,局地水汽作為補(bǔ)償更多參與降水過(guò)程,ET-P增加,陸面水汽輸出增加。水汽在大氣中存在的時(shí)間也影響著降水的再循環(huán)率。本文選取中蒙干旱區(qū)3次典型個(gè)例,分別代表對(duì)流型及平流型降水過(guò)程,利用WRF和FLEXPART模式對(duì)3次個(gè)例進(jìn)行了模擬分析。結(jié)果表明:中蒙干旱區(qū)降水及再循環(huán)過(guò)程中,正午局地蒸發(fā)大于降水,陸面水汽通過(guò)蒸發(fā)進(jìn)入大氣,局地水汽貢獻(xiàn)達(dá)到最大(0.1mm),再循環(huán)過(guò)程開(kāi)始增強(qiáng),在傍晚達(dá)到最大(10%),降水再循環(huán)對(duì)降水有增強(qiáng)作用,降水轉(zhuǎn)化率同時(shí)達(dá)到最大(7%),降水、蒸發(fā)也同時(shí)達(dá)到最大。此后局地水汽貢獻(xiàn)量逐漸減小,在凌晨至清晨蒸發(fā)達(dá)到全天最低,局地水汽貢獻(xiàn)為負(fù)(ET-P-0.2 mm)。而這一特征在平流型降水過(guò)程中更為明顯。此外,通過(guò)分析選取個(gè)例中降水等變量的日變化特征,結(jié)果表明中蒙干旱區(qū)降水、蒸發(fā)、降水轉(zhuǎn)化及降水再循環(huán)率均存在準(zhǔn)10天的變化周期,這與氣候平均的結(jié)果相近。并且在日尺度上降水再循環(huán)對(duì)于降水變化存在負(fù)的反饋機(jī)制:當(dāng)降水減小后蒸發(fā)增加,更多水汽由地面進(jìn)入通過(guò)蒸發(fā)進(jìn)入大氣,參與降水再循環(huán),補(bǔ)償降水減少。而在空間分布上,中蒙干旱區(qū)降水再循環(huán)率分布不均勻,在湖泊,徑流及地面濕度較大地區(qū),由于蒸發(fā)較強(qiáng),降水再循環(huán)率偏強(qiáng)。在降水過(guò)程中,外部水汽貢獻(xiàn)主要以緯向水汽輸送為主,占總水汽量40%左右。而經(jīng)向輸送水汽則占7%~20%,且經(jīng)向水汽輸送偏強(qiáng)時(shí),降水量較大,反之亦然。全球變暖對(duì)水分循環(huán)有著重要的影響。本文分析了未來(lái)不同排放情景下水分循環(huán)的變化特征。結(jié)果表明,大氣的可降水量在未來(lái)不同升溫階段均出現(xiàn)了不同程度的增長(zhǎng)趨勢(shì)和分布,這是由氣溫升高增加了大氣的持水能力所致。并且ET-P存在干旱區(qū)增加、濕潤(rùn)區(qū)減小的趨勢(shì),表現(xiàn)出干旱區(qū)越干,濕潤(rùn)區(qū)越濕的變化趨勢(shì),同時(shí)干旱區(qū)降水轉(zhuǎn)化率及降水再循環(huán)率為減小趨勢(shì),表明隨著全球溫度的上升,干旱區(qū)局地水分循環(huán)減弱。在未來(lái)的21世紀(jì)的不同時(shí)期,全球陸地平均降水轉(zhuǎn)化率和再循環(huán)率均表現(xiàn)為減弱趨勢(shì),分別減少1.5%和0.7%,RCP8.5情景下減小更為明顯,負(fù)距平為-2.7%和-0.9%。其中在典型干旱區(qū),可降水量將隨溫度升高而增加,增加趨勢(shì)最大可達(dá)1.85 mm day-1 10a-1。雖然大氣的水汽含量增加顯著,但干旱區(qū)水汽的轉(zhuǎn)換率降低,表明全球溫度升高使得大氣的持水能力增加。而干旱區(qū)總體表現(xiàn)為水汽凈輸出,降水再循環(huán)率的減少表明,局地蒸散水汽由于平流作用輸出,并未參與局地降水再循環(huán)�？偪山邓恐�,來(lái)自外部平流水汽的輸送增強(qiáng)且加快,這表示全球變暖,大氣的水分循環(huán)加快。而ET-P無(wú)顯著的變化趨勢(shì),表明大尺度水分循環(huán)加速并不會(huì)使得中蒙干旱區(qū)發(fā)生顯著的干濕變化。
[Abstract]:The water cycle is one of the basic contents of climate change, but also one of the basic conditions of the occurrence of precipitation change. Water cycle not only affects the gas exchange between the water landing, also affects the energy balance of the atmosphere, as well as response to climate change, but also have an effect on the climate. In arid area of precipitation, water vapor sources, local water circulating water circulation in occupy much of the precipitation which is a basic scientific problem; at the same time, evaporation is an important part of the hydrologic cycle, estimated evaporation is a quantitative assessment of key water cycle, compared with the same latitude climate region, arid area average high temperatures, low soil moisture, the evaporation the estimation with uncertainty, how to objectively and accurately estimate the evaporation is worth exploring scientific problems. In this paper, through the use of NCEP, EAR-Interim, GLDAS and other analysis and mode Comprehensive calculation, output data diagnostic analysis, exploration based on comparison of different estimation methods of evaporation, and the development of a relatively reasonable, objective and quantitative calculation of evaporation method; analysis of the global temperature increased significantly over the past 30 years (1981-2010), temporal and spatial characteristics of precipitation conversion and recycling water in typical arid area in north loop hemisphere, and the use of CMIP5 results of different periods in twenty-first Century (early: 2017 - 2036, 2047 - 2066, the middle late: 2077 - 2096), water cycle temporal changes in typical arid area were estimated, and explore the possible mechanism of temperature change of water cycle conditions. First, the northern hemisphere drought Mongolia is divided into four regions, West Asia, North Africa and North America arid area, using Penman - Monteith and Brubaker evaporation recycling model, the average annual precipitation recycling in typical arid region of the northern hemisphere was calculated. The results show that in Mongolia, West Asia, North Africa and North America arid area of annual precipitation recycling rates were 5%, 12%, 18% and 8%. precipitation in arid area of North West Asia, precipitation recycling rate is greater than the Mongolia, arid region of North America, shows that in arid areas, local water vapor contribution to the total precipitation is greater in the past 30 years. Come, as global temperatures rise, the rate of precipitation recycling in arid area of West Asia showed increasing trend, and the precipitation showed a decreasing trend, especially since 1981, the rainfall decreased, while precipitation recycling rate increased at the rate of 0.43%10a-1 showed that, under the background of global warming, due to water vapor transport in the region is a net output. The precipitation recycling rate in precipitation reduction plays a role in the process of compensation; in order to reduce the trend in the arid region of North America and North Africa recirculation rate (-0.45%10a-1 and -0.26%10a-1). In the arid region of North America, Penman (0.07 increase in evaporation Mm day-1, 10a-1) can be increased precipitation (0.12 kg m-2 10a-1), but the total precipitation reduced (-0.02 mm day-1 10a-1), that enters from the surface and atmosphere through evaporation of water vapor increased, but did not translate into actual precipitation. In the arid region of North Africa, an increasing trend in precipitation (0.06 mm day-1 10a-1). The corresponding precipitation recycling rate decreases and the increase of transport water vapor. This suggests that external external water vapor increases the local arid region of North Africa with water vapor ratio in total precipitation decreased in precipitation increased. Overall, the external water vapor transport is still the major source of precipitation, precipitation recycling in precipitation decrease when the role of compensation evaporation. The estimation plays a decisive role in the water cycle. However, it is difficult to estimate the actual evaporation. In order to decrease between the reference evaporation and actual evaporation difference, through the comparison of Penman and the use of soil evaporation The improved soil moisture evaporation after modification, application of dynamic precipitation recycling model DRM, the calculation of precipitation recycling ratio arid region in Asia and Africa. The analysis results show that due to the limited soil water evaporation, arid area (0.3 0.8mm day-1) less than the reference evapotranspiration (4.4 - 11 mm day-1). By comparing the precipitation recycling ratio and ET-P found Mongolia, arid region of North Africa precipitation recycling rate decreased, while the external water vapor increased proportion in the total water vapor, the corresponding ET-P decreases, the land surface moisture spending, west arid region water vapor net output, precipitation recycling ratio increased, the local moisture contribution in the total water vapor increases, the corresponding ET-P increased. This suggests that the precipitation recycling process negative feedback mechanism in arid region of Africa and Asia: drought precipitation recycling rate, corresponding to more external water vapor into the arid area, the proportion of total precipitation reduced water vapor with local, external water vapor The supply is matched with the internal water circulation, for arid area ET-P land surface water vapor decreases, spending, the degree of drought weakened. On the contrary, when the precipitation recycling rate is increased, weakening external water vapor transport, local water vapor as compensation for more participation in the precipitation process, the increase of ET-P, the land surface vapor output increased. In the presence of water vapor in the atmosphere the time also affects the precipitation recirculation rate. This paper chooses 3 typical cases in arid area of Mongolia, representing the convection and advection precipitation process, the 3 cases are simulated and analyzed by using WRF and FLEXPART model. The results show that the precipitation and recycling process in arid area of Mongolia, noon local evaporation exceeds precipitation, land surface water vapor by means of evaporation into the atmosphere, local water vapor contribution reaches the maximum (0.1mm), recycling process began to increase, reached the maximum in the evening (10%), precipitation recycling could strengthen the effect of reducing water and precipitation in turn At the same time, the rate reached the maximum (7%), precipitation, evaporation also reaches the maximum. Then the local moisture contribution gradually decreased, reached the lowest in the morning to morning all day long evaporation, local water vapor contribution is negative (ET-P-0.2 mm). This feature in the advective precipitation process is more obvious. In addition, through the analysis on the change the characteristics of rainfall variables such as the case. Results show that the precipitation, evaporation in arid area of Mongolia, precipitation transformation and precipitation recycling rate variation periods of quasi 10 day, which is similar to the average precipitation and climate. In daily scale recycling for the precipitation change has negative feedback mechanism: when the precipitation decreases after evaporation add more water vapor from the ground, into the atmosphere through evaporation, precipitation in recycling, compensation precipitation. In spatial distribution, arid area Mongolia precipitation recycling uneven distribution in lakes, runoff and ground Humidity areas, due to strong evaporation, precipitation recycling rate is strong. In the precipitation process, the main contribution to the external water vapor zonal moisture transport, the total precipitable water in about 40%. While the meridional water vapor transport accounted for 7%~20%, and the meridional moisture transport is strong, large rainfall, global warming and vice versa. Have an important impact on the water cycle. This paper analyzes the different emission scenarios of water cycle variations. The results show that the Atmospheric Precipitable Water in the future in different stages of heating showed a growth trend and distribution in different degree, which is determined by the temperature increase of atmospheric water holding capacity and ET-P are due. Arid area increased, humid area decreased, showing the trend of dry arid, humid area and arid area is wet, precipitation conversion rate and precipitation recycling rate was decreased, with global temperature show Rise, arid area local water circulation weakened. In different periods the next twenty-first Century, the global land average precipitation conversion rate and recycling rate showed a weakening trend, reduced by 1.5% and 0.7% respectively, the RCP8.5 scenario decreased more significantly, the negative anomaly of -2.7% and -0.9%. in the typical arid region, precipitation will be temperature increases, increased up to 1.85 mm day-1 10a-1. although the atmospheric water vapor content increased significantly, but the conversion of arid region water vapor rate decreased, indicated that the global temperature rise makes the water holding capacity of the atmosphere increases. And the overall performance of arid area net water output, reduced precipitation recirculation rate showed that the local evapotranspiration due to the flat current output, did not participate in the local precipitation recycling. Total precipitation, water vapor transport from external advection is enhanced and accelerated, the said global warming, atmospheric water circulation speed But there is no significant change in ET-P, which indicates that the acceleration of large scale water cycle does not make significant dry and wet changes in the arid regions of China and Mongolia.

【學(xué)位授予單位】：蘭州大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2017
【分類號(hào)】：P467;P339

【參考文獻(xiàn)】

相關(guān)期刊論文 前10條

1 徐棟;李若麟;王澄海;;全球變暖背景下亞非典型干旱區(qū)降水變化及其與水汽輸送的關(guān)系研究[J];氣候與環(huán)境研究;2016年06期

2 蔡英;宋敏紅;錢正安;吳統(tǒng)文;欒晨;;西北干旱區(qū)夏季強(qiáng)干、濕事件降水環(huán)流及水汽輸送的再分析[J];高原氣象;2015年03期

3 何曉鳳;周榮衛(wèi);孫逸涵;;3個(gè)全球模式對(duì)近地層風(fēng)場(chǎng)預(yù)報(bào)能力的對(duì)比檢驗(yàn)[J];高原氣象;2014年05期

4 胡永云;陶利軍;劉驥平;;Poleward Expansion of the Hadley Circulation in CMIP5 Simulations[J];Advances in Atmospheric Sciences;2013年03期

5 趙玲玲;夏軍;許崇育;王中根;蘇磊;龍藏瑞;;水文循環(huán)模擬中蒸散發(fā)估算方法綜述(英文)[J];Journal of Geographical Sciences;2013年02期

6 王澄海;李健;李小蘭;許曉光;;近50a中國(guó)降水變化的準(zhǔn)周期性特征及未來(lái)的變化趨勢(shì)[J];干旱區(qū)研究;2012年01期

7 李子祥;陳建宇;甄榮磊;;Projection of Extreme Temperatures in Hong Kong in the 21st Century[J];Acta Meteorologica Sinica;2011年01期

8 錢正安;宋敏紅;李萬(wàn)源;蔡英;;全球、中蒙干旱區(qū)及其部分地區(qū)降水分布細(xì)節(jié)[J];高原氣象;2011年01期

9 ;Comparative Analysis of China Surface Air Temperature Series for the Past 100 Years[J];Advances in Climate Change Research;2010年01期

10 ;The interdecadal trend and shift of dry/wet over the central part of North China and their relationship to the Pacific Decadal Oscillation (PDO)[J];Chinese Science Bulletin;2007年15期

相關(guān)碩士學(xué)位論文 前1條

1 郭毅鵬;近40年青藏高原地區(qū)水汽循環(huán)變化特征研究[D];蘭州大學(xué);2013年

，

本文編號(hào)：1594002