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1.
Atmospheric teleconnection mechanisms of extratropical North Atlantic SST influence on Sahel rainfall 总被引：1，自引：0，他引：1
Yuwei Liu John C. H. Chiang Chia Chou Christina M. Patricola 《Climate Dynamics》2014,43(9-10):2797-2811
Extratropical North Atlantic cooling has been tied to droughts over the Sahel in both paleoclimate observations and modeling studies. This study, which uses an atmospheric general circulation model (GCM) coupled to a slab ocean model that simulates this connection, explores the hypothesis that the extratropical North Atlantic cooling causes the Sahel droughts via an atmospheric teleconnection mediated by tropospheric cooling. The drying is also produced in a regional climate model simulation of the Sahel when reductions in air temperature (and associated geopotential height and humidity changes) from the GCM simulation are imposed as the lateral boundary conditions. This latter simulation explicitly demonstrates the central role of tropospheric cooling in mediating the atmospheric teleconnection from extratropical North Atlantic cooling. Diagnostic analyses are applied to the GCM simulation to infer teleconnection mechanisms. An analysis of top of atmosphere radiative flux changes diagnosed with a radiative kernel technique shows that extratropical North Atlantic cooling is augmented by a positive low cloud feedback and advected downstream, cooling Europe and North Africa. The cooling over North Africa is further amplified by a reduced greenhouse effect from decreased atmospheric specific humidity. A moisture budget analysis shows that the direct moisture effect and monsoon weakening, both tied to the ambient cooling and resulting circulation changes, and feedbacks by vertical circulation and evaporation augment the rainfall reduction. Cooling over the Tropical North Atlantic in response to the prescribed extratropical cooling also augments the Sahel drying. Taken together, they suggest a thermodynamic pathway for the teleconnection. The teleconnection may also be applicable to understanding the North Atlantic influence on Sahel rainfall over the twentieth century. 相似文献
2.
Samson Hagos L. Ruby Leung Yongkang Xue Aaron Boone Fernando de Sales Naresh Neupane Maoyi Huang Jin-Ho Yoon 《Climate Dynamics》2014,43(9-10):2765-2775
Land use and land cover (LULC) over Africa have changed substantially over the last 60 years and this change has been proposed to affect monsoon circulation and precipitation. This study examines the uncertainties of model simulated response in the African monsoon system and Sahel precipitation due to LULC change using a set of regional model simulations with different combinations of land surface and cumulus parameterization schemes. Although the magnitude of the response covers a broad range of values, most of the simulations show a decline in Sahel precipitation due to the expansion of pasture and croplands at the expense of trees and shrubs and an increase in surface air temperature. The relationship between the model responses to LULC change and the climatologists of the control simulations is also examined. Simulations that are climatologically too dry or too wet compared to observations and reanalyses have weak response to land use change because they are in moisture or energy limited regimes respectively. The ones that lie in between have stronger response to the LULC changes, showing a more significant role in land–atmosphere interactions. Much of the change in precipitation is related to changes in circulation, particularly to the response of the intensity and latitudinal position of the African Easterly Jet, which varies with the changes in meridional surface temperature gradients. The study highlights the need for measurements of the surface fluxes across the meridional cross-section of the Sahel to evaluate models and thereby allowing human impacts such as land use change on the monsoon to be projected more realistically. 相似文献
3.
Impact of Indian summer monsoon on the South Asian High and its influence on summer rainfall over China 总被引：4，自引：0，他引：4
By using the monthly ERA-40 reanalysis data and observed rainfall data, we investigated the effect of the Indian summer monsoon (ISM) on the South Asian High (SAH) at 200 hPa, and the role played by the SAH in summer rainfall variation over China. It is found that in the interannual timescale the east–west shift is a prominent feature of the SAH, with its center either over the Iranian Plateau or over the Tibetan Plateau. When the ISM is stronger (weaker) than normal, the SAH shifts westward (eastward) to the Iranian Plateau (Tibetan Plateau). The east–west position of SAH has close relation to the summer rainfall over China. A westward (eastward) location of SAH corresponds to less (more) rainfall in the Yangtze-Huai River Valley and more (less) rainfall in North China and South China. A possible physical process that the ISM affects the summer rainfall over China via the SAH is proposed. A stronger (weaker) ISM associated with more (less) rainfall over India corresponds to more (less) condensation heat release and anomalous heating (cooling) in the upper troposphere over the northern Indian peninsula. The anomalous heating (cooling) stimulates positive (negative) height anomalies to its northwest and negative (positive) height anomalies to its northeast in the upper troposphere, causing a westward (eastward) shift of the SAH with its center over the Iranian Plateau (Tibetan Plateau). As a result, an anomalous cyclone (anticyclone) is formed over the eastern Tibetan Plateau and eastern China in the upper troposphere. The anomalous vertical motions in association with the circulation anomalies are responsible for the rainfall anomalies over China. Our present study reveals that the SAH may play an important role in the effect of ISM on the East Asian summer monsoon. 相似文献
4.
Ground based measurements which were carried out in the Northern Sahel in southern Tunisia showed the following results:
- The albedo difference between ground and protected land is about 10%, half of the amount Charney (1975) used in his model.
- Bare soil is always warmer during times of bright sunshine than vegetated soil, which is in agreement with Jackson and Idso (1975). Temperature differences in excess of the 10 °C were observed between plants and the surrounding soil.
- For bare soil, the surface temperature increases with declining albedo. However the opposite holds true for plants. Here, when lowering the albedo, a decrease in temperature was found.
- In a sand dune field, the surface temperature depends strongly on the exposure. Surface temperature differences of 8 °C were observed for slopes of different exposures for measurements carried out around noon.
5.
Previous studies have revealed some common biases in coupled general circulation model’s simulations of the East Asian (EA) winter monsoon (EAWM), including colder surface air temperature and more winter precipitation over the EA region. In this study, we examined 41 fully coupled atmosphere–ocean models from fifth phase of the Coupled Model Intercomparison Project (CMIP5), which will be widely used in the fifth assessment report of the Intergovernmental Panel on Climate Change (IPCC), and address whether the current state-of-the-art CMIP5 models can characterise the climatology of the East Asian winter monsoon. We also compared the results with the models from third phase of CMIP, which was extensively used in the fourth assessment report of the IPCC. The results show that the cold surface air temperature (SAT) bias is lessened and the precipitation amount decreased with the current CMIP5 models. Moreover, the CMIP5 models performbetter at predicting surface winds and high-level jet streams than the CMIP3 models. Moreover, CMIP5 models show more model consistency in most EAWM parameters, and the interannual variability of the SAT is closer to the observations. We also examined the change in the radiation energy budget in the CMIP5 models and compared with CMIP3 models. Although the improvements are significant, deficiencies still exist in the simulation of the EAWM, e.g., the stronger EA major trough and the stronger zonal sea level pressure gradient. 相似文献
6.
Ian D. Goodwin Stuart Browning Andrew M. Lorrey Paul A. Mayewski Steven J. Phipps Nancy A. N. Bertler Ross P. Edwards Tim J. Cohen Tas van Ommen Mark Curran Cameron Barr J. Curt Stager 《Climate Dynamics》2014,43(5-6):1197-1219
Subtropical and extratropical proxy records of wind field, sea level pressure (SLP), temperature and hydrological anomalies from South Africa, Australia/New Zealand, Patagonian South America and Antarctica were used to reconstruct the Indo-Pacific extratropical southern hemisphere sea-level pressure anomaly (SLPa) fields for the Medieval Climate Anomaly (MCA ~700–1350 CE) and transition to the Little Ice Age (LIA 1350–1450 CE). The multivariate array of proxy data were simultaneously evaluated against global climate model output in order to identify climate state analogues that are most consistent with the majority of proxy data. The mean SLP and SLP anomaly patterns derived from these analogues illustrate the evolution of low frequency changes in the extratropics. The Indo-Pacific extratropical mean climate state was dominated by a strong tropical interaction with Antarctica emanating from: (1) the eastern Indian and south-west Pacific regions prior to 1100 CE, then, (2) the eastern Pacific evolving to the central Pacific La Niña-like pattern interacting with a +ve SAM to 1300 CE. A relatively abrupt shift to –ve SAM and the central Pacific El Niño-like pattern occurred at ~1300. A poleward (equatorward) shift in the subtropical ridge occurred during the MCA (MCA–LIA transition). The Hadley Cell expansion in the Australian and Southwest Pacific, region together with the poleward shift of the zonal westerlies is contemporaneous with previously reported Hadley Cell expansion in the North Pacific and Atlantic regions, and suggests that bipolar climate symmetry was a feature of the MCA. 相似文献
7.
Hyoung-Gu Nam Byung-Gon Kim Sang-Ok Han Chulkyu Lee Seoung-Soo Lee 《Asia-Pacific Journal of Atmospheric Sciences》2014,50(4):541-552
Characteristics of snowfall episodes have been investigated for the past ten years in order to study its association with lowlevel stability and air-sea temperature difference over the East Sea. In general, the selected snowfall episodes have similar synoptic setting such as the Siberian High extended to northern Japan along with the Low passing by the southern Korean Peninsula, eventually resulting in the easterly flow in the Yeongdong region. Especially in the heavy snowfall episodes, convective unstable layers have been identified over the East sea due to relatively warm sea surface temperature (SST) about 8～10°C and specifically cold pool around 1～2 km above the surface level (ASL), which can be derived from Regional Data Assimilation and Prediction System (RDAPS), but that have not been clearly exhibited in the weak snowfall episodes. The basic mechanism to initiate snowfall around Yeongdong seems to be similar to that of lake-effect snowstorms around Great Lakes in the United States (Kristovich et al., 2003). Difference of equivalent potential temperature (θ e ) between 850 hPa and surface as well as difference between air and sea temperatures altogether gradually began to increase in the pre-snowfall period and reached their maximum values in the course of the period, whose air (850 hPa) — sea temperature difference and snowfall intensity in case of the heavy snowfall episodes are almost larger than 20°C and 6 tims greater than the weak snowfall episodes, respectively. Interestingly, snowfall appeared to begin in case of an air-sea temperature difference exceeding over 15°C. The current analysis is overall consistent with the previous finding (Lee et al., 2012) that an instabilityinduced moisture supply to the lower atmosphere from the East sea, being cooled and saturated in the lower layer, so to speak, East Sea-Effect Snowfall (SES), would make a low-level ice cloud which eventually moves inland by the easterly flow. In addition, a longlasting synoptic characteristics and convergence-induced invigoration also appear to play the important roles in the severe snowstorms. Improvements in our understanding of mesoscale sea-effect snowstorms require detailed in-situ and remote sensing observations over and around East Sea since observations of the concurrent thermodynamic and microphysical characteristics have not been available there and this study emphasizes the importance of low level stability as quantitative estimation of moist static energy generation over the East Sea. 相似文献
8.
Using pentad rainfall data we demonstrate the benefits of using accumulated rainfall and fractional accumulated rainfall for the evaluation of the annual cycle of rainfall over various monsoon domains. Our approach circumvents issues related to using threshold-based analysis techniques for investigating the life-cycle of monsoon rainfall. In the Coupled Model Intercomparison Project-5 models we find systematic errors in the phase of the annual cycle of rainfall. The models are delayed in the onset of summer rainfall over India, the Gulf of Guinea, and the South American Monsoon, with early onset prevalent for the Sahel and the North American Monsoon. This, in combination with the rapid fractional accumulation rate, impacts the ability of the models to simulate the fractional accumulation observed during summer. The rapid fractional accumulation rate and the time at which the accumulation begins are metrics that indicate how well the models concentrate the monsoon rainfall over the peak rainfall season, and the extent to which there is a phase error in the annual cycle. The lack of consistency in the phase error across all domains suggests that a “global” approach to the study of monsoons may not be sufficient to rectify the regional differences. Rather, regional process studies are necessary for diagnosing the underlying causes of the regionally-specific systematic model biases over the different monsoon domains. Despite the afore-mentioned biases, most models simulate well the interannual variability in the date of monsoon onset, the exceptions being models with the most pronounced dry biases. Two methods for estimating monsoon duration are presented, one of which includes nonlinear aspects of the fractional accumulation. The summer fractional accumulation of rainfall provides an objective way to estimate the extent of the monsoon domain, even in models with substantial dry biases for which monsoon is not defined using threshold-based techniques. 相似文献
9.
Bryan C. Weare 《Climate Dynamics》2014,43(5-6):1285-1301
El Niño/Southern Oscillation (ENSO) is the predominant interannual variability of the global climate system. How might ENSO change in a warmer world? The dominant two Combined Empirical Orthogonal Functions (CEOF) of the equatorial ocean temperature and zonal and vertical motion identify two modes that shown a transition in the eastern Pacific from a warming eastward/downward motion to a cooling westward/upward flow. These results also suggest consistent changes to the west and at depths down to 300 m. These dominate CEOFs provide a compact tool for assessing Coupled Model Intercomparison Project Phase 5 ocean model output for both the recent historical period and for the latter part of the twenty first century. Most of the analyzed models replicate well the spatial patterns of the dominant observational CEOF modes, but nearly always underestimate the magnitudes. Comparing model output for the twentieth and twenty first centuries there is very little change between the spatial patterns of the ENSO modes of the two periods. This lack of response to climate change is shown to be partly related to competing influences of climatic changes in the mean ocean circulation. 相似文献
10.
The preparation of time- and space-dependent input surface parameters for the climate model REMO was one task of the Baltimos project “Validation of Boundary Layer Parameters and Extension of Boundary conditions of Climate Model REMO”. The leaf area index (LAI) is one of these parameters. It is used in REMO as defined value per month for each land-use class with a defined seasonal trend during the year. Since 1982 at the Institute of Meteorology of the Free University Berlin, a high-resolved AVHRR data set of the NOAA satellite has been available (1/100 degree, approximately 1?×?1 km at nadir in a geographic coordination system) (Koslowsky 1996). The vegetation periods of the years 1997 until 2001 were selected from the dataset to estimate the LAI within the Baltimos region on the basis of an algorithm by Sellers et al. (J Climate 9:706–737, 1996) and a modified United States Geological Survey (USGS) land-use classification. The calculated high-resolved NOAA LAI values were converted to the 1/6 degree grid of the REMO climate model. Then, they were compared to the fixed LAI values, which are used in the model. 相似文献
11.
M. A. Abduev 《Russian Meteorology and Hydrology》2014,39(7):483-490
To study the modulus of the ion runoff of Azerbaijan mountain rivers, the data for the period of 1950–2010 are used. It is revealed that the values of the ion runoff modulus increase as the height rises on the whole territory with the exception of the Lankaran natural area. The dependences between runoff modulus and height M R = f(H) are obtained. The derived equation can be used for the determination of the ion runoff modulus of unexplored rivers. 相似文献
12.
13.
Yanfang Wang Yanjun Shen Fubao Sun Yaning Chen 《Theoretical and Applied Climatology》2014,118(3):569-579
Temperature has long been accepted as the major controlling factor in determining vegetation phenology in the middle and higher latitudes. The influence of water availability is often overlooked even in arid and semi-arid environments. We compared vegetation phenology metrics derived from both in situ temperature and satellite-based normalized difference vegetation index (NDVI) observations from 1982 to 2006 by an example of the arid region of northwestern China. From the satellite-based results, it was found the start of the growing season (SOS) advanced by 0.37 days year?1 and the end of the growing season (EOS) delayed by 0.61 days year?1 in Southern Xinjiang over 25 years. In the Tianshan Mountains, the SOS advanced by 0.35 days year?1 and the EOS delayed by 0.31 days year?1. There were almost no changes in Northern Xinjiang. Compared with satellite-based results, those estimates based on temperature contain less details of spatial variability of vegetation phenology. Interestingly, they show different and at times reversed spatial patterns from the satellite results arising from water limitation. Phenology metrics derived from temperature and NDVI conclude that water limitation of onset of the growing season is more severe than the cessation. Phenology spatial patterns of four oases in Southern Xingjiang show that, on average, there is a delay of the SOS of 1.6 days/10 km of distance from the mountain outlet stations. Our results underline the importance of water availability in determining the vegetation phenology in arid regions and can lead to important consequences in interpreting the possible change of vegetation phenology with climate. 相似文献
14.
Most coupled general circulation models suffer from a prominent warm sea surface temperature bias in the southeast tropical Atlantic Ocean off the coast of Africa. The origin of the bias is not understood and remains highly controversial. Previous studies suggest that the origin of the bias stems from systematic errors of atmospheric models in simulating surface heat flux and coastal wind, or poorly simulated coastal upwelling. In this study, we show, using different reanalysis and observational data sets combined with a set of eddy-resolving regional ocean model simulations, that systematic errors in ocean models also make a significant contribution to the bias problem. In particular (1) the strong warm bias at the Angola-Benguela front that is maintained by the local wind and the convergence of Angola and Benguela Currents is caused by an overshooting of the Angola Current in ocean models and (2) the alongshore warm bias to the south of the front is caused by ocean model deficiencies in simulating the sharp thermocline along the Angola coast, which is linked to biases in the equatorial thermocline, and the complex circulation system within the Benguela upwelling zone. 相似文献
15.
Following IPCC guidelines (IPCC 2006), we estimate greenhouse gas emissions related to livestock in 237 countries and 11 livestock categories during the period 1961–2010. We find that in 2010 emissions of methane and nitrous oxide related to livestock worldwide represented approximately 9 % of total greenhouse gas (GHG) emissions. Global GHG emissions from livestock increased by 51 % during the analyzed period, mostly due to strong growth of emissions in developing (Non-Annex I) countries (+117 %). In contrast, developed country (Annex I) emissions decreased (?23 %). Beef and dairy cattle are the largest source of livestock emissions (74 % of global livestock emissions). Since developed countries tend to have lower CO2-equivalent GHG emissions per unit GDP and per quantity of product generated in the livestock sector, the amount of wealth generated per unit GHG emitted from the livestock sector can be increased by improving both livestock farming practices in developing countries and the overall state of economic development. Our results reveal important details of how livestock production and associated GHG emissions have occurred in time and space. Discrepancies with higher tiers, demonstrate the value of more detailed analyses, and discourage over interpretation of smaller-scale trends in the Tier 1 results, but do not undermine the value of global Tier 1 analysis. 相似文献
16.
Convection activity over the Guinean coast and Central Africa during northern spring from synoptic to intra-seasonal timescales 总被引：1，自引：1，他引：0
This study proposes an overview of the main synoptic, medium-range and intraseasonal modes of convection and precipitation in northern spring (March–June 1979–2010) over West and Central Africa, and to understand their atmospheric dynamics. It is based on daily National Oceanic and Atmospheric Administration outgoing longwave radiation and Cloud Archive User Service Tb convection data, daily TRMM and Global Precipitation Climatology Project rainfall products and daily ERA-Interim reanalysis atmospheric fields. It is first shown that mesoscale convective systems can be modulated in terms of occurrences number and intensity at such time scales. Based on empirical orthogonal function analyses on the 2–90-day filtered data it is shown that the main mode of convective and rainfall variability is located along the Guinean coast with a moderate to weak extension over Central Africa. Corresponding regressed deseasonalised atmospheric fields highlight an eastward propagation of patterns consistent with convectively coupled equatorial Kelvin wave dynamics. Then a singular spectrum analysis combined with a Hierarchical Ascendant Classification enable to define objectively the main spectral bands of variability within the 2–90-day band, and highlight three main bands, 2–8-, 8–22- and 20–90-day. Within these three bands, space–time spectral decomposition is used to identify the relative impacts of convectively coupled equatorial Kelvin, Rossby and inertia–gravity waves, as well as Madden–Julian Oscillation (MJO) signal. It confirms that eastward propagating signals (convectively coupled equatorial Kelvin wave and MJO) are highly dominant in these convection and precipitation variability modes over the Guinean coast during northern spring. So, while rain-producing individual systems are moving westward, their activity are highly modulated by sub-regional and regional scales envelops moving to the east. This is a burning issue for operational forecasting centers to be able to monitor and predict such eastward propagating envelops of convective activity. 相似文献
17.
Björn Maronga Oscar K. Hartogensis Siegfried Raasch Frank Beyrich 《Boundary-Layer Meteorology》2014,153(3):441-470
We conduct a high-resolution large-eddy simulation (LES) case study in order to investigate the effects of surface heterogeneity on the (local) structure parameters of potential temperature \(C_T^2\) and specific humidity \(C_q^2\) in the convective boundary layer (CBL). The kilometre-scale heterogeneous land-use distribution as observed during the LITFASS-2003 experiment was prescribed at the surface of the LES model in order to simulate a realistic CBL development from the early morning until early afternoon. The surface patches are irregularly distributed and represent different land-use types that exhibit different roughness conditions as well as near-surface fluxes of sensible and latent heat. In the analysis, particular attention is given to the Monin–Obukhov similarity theory (MOST) relationships and local free convection (LFC) scaling for structure parameters in the surface layer, relating \(C_T^2\) and \(C_q^2\) to the surface fluxes of sensible and latent heat, respectively. Moreover we study possible effects of surface heterogeneity on scintillometer measurements that are usually performed in the surface layer. The LES data show that the local structure parameters reflect the surface heterogeneity pattern up to heights of 100–200 m. The assumption of a blending height, i.e. the height above the surface where the surface heterogeneity pattern is no longer visible in the structure parameters, is studied by means of a two-dimensional correlation analysis. We show that no such blending height is found at typical heights of scintillometer measurements for the studied case. Moreover, \(C_q^2\) does not follow MOST, which is ascribed to the entrainment of dry air at the top of the boundary layer. The application of MOST and LFC scaling to elevated \(C_T^2\) data still gives reliable estimates of the surface sensible heat flux. We show, however, that this flux, derived from scintillometer data, is only representative of the footprint area of the scintillometer, whose size depends strongly on the synoptic conditions. 相似文献
18.
The cause of severe droughts over the Southwest China (SWC) during the local dry season is investigated based on the station rainfall data and the National Centers for Environmental Prediction/National Center for Atmospheric Research reanalysis data during 1951–2010. The droughts are in general consistent with local anomalous descent in the middle troposphere. The diagnosis of the vertical motion (omega) equation indicates that the local descent is primarily maintained by the anomalous cold temperature advection processes. Both the advection of anomalous temperature by mean wind and the advection of mean temperature by anomalous wind contribute to maintaining the anomalous descent over the SWC region. A composite analysis shows that the circulation anomaly over SWC is induced by remote forcing from the tropical Pacific and North Atlantic Oceans. During La Niña years, enhanced heating over the Maritime Continent induces anomalous downward motion over SWC through the connection of local Hadley circulation. Adiabatic warming associated with the downward motion helps to set up and maintain the local anomalous anticyclone. Another possible route is through the North Atlantic-Asia teleconnection, in which downstream Rossby wave energy propagation plays a crucial role. A negative-phase North Atlantic Oscillation may trigger a large-scale wave train pattern that induces an anomalous anticyclone over the subtropical Asia and promotes the dry condition over SWC. 相似文献
19.
Burghard Brümmer Amélie Kirchgäßner Gerd Müller 《Theoretical and Applied Climatology》2014,118(4):641-653
The regional model REMO, which is the atmospheric component of the coupled atmosphere–ice–ocean–land climate model system BALTIMOS, is tested with respect to its ability to simulate the atmospheric boundary layer over the open and ice-covered Baltic Sea. REMO simulations are compared to ship, radiosonde, and aircraft observations taken during eight field experiments. The main results of the comparisons are: (1) The sharpness and strength of the temperature inversion are underestimated by REMO. Over open water, this is connected with an overestimation of cloud coverage and moisture content above the inversion. (2) The vertical temperature stratification in the lowest 200 m over sea ice is too stable. (3) The horizontal inhomogeneity of sea ice concentration as observed by aircraft could not be properly represented by the prescribed ice concentration in REMO; large differences in the surface heat fluxes arise especially under cold-air advection conditions. The results of the comparisons suggest a reconsideration of the parameterization of subgrid-scale vertical exchange both under unstable und stable conditions. 相似文献
20.
Jianxiu Qiu Xingguo Mo Suxia Liu Zhonghui Lin 《Theoretical and Applied Climatology》2014,118(1-2):159-171
Soil moisture variability of various spatial scales is analyzed based on empirical orthogonal function (EOF) method using soil moisture datasets with various spatial resolutions: 1 km eco-hydrological model simulation, 0.25° passive microwave (Advanced Microwave Scanning Radiometer for the Earth Observing System, AMSR-E) dataset, and 0.5° land surface model simulation from Climate Predictor Center (CPC). All three datasets generate EOFs that explain similar variances with those generated from in situ observations from agro-meteorological network. Using AMSR-E product and eco-hydrological model simulation, it is found that the primary spatial pattern of soil moisture obtained from watershed scale has a strong connection to topographic attributes, followed by soil texture and rainfall variability, as suggested by the correlation between the primary EOF mode (EOF1) of soil moisture and landscape attributes. However, the EOF analysis of both AMSR-E and CPC datasets at regional scale reaches the conclusion that soil texture indices, such as sand and clay content, is of higher importance to soil moisture EOF1 spatial pattern (explaining 61 % variance) than topography is. Furthermore, correlation between soil moisture EOF1 and soil property is higher in spring than in autumn, which indicates that soil water-holding and drainage capabilities are more important under dry conditions. At national scale, the combined effects of topographic feature and soil property are clearly exhibited in EOF1. The study results reveal that different emphases should be placed on accurate acquisition of landscape attributes for soil moisture estimation according to various spatial scales. 相似文献