scholarly journals A Preliminary Assessment of the “Undercatching” and the Precipitation Pattern in an Alpine Basin

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1061 ◽  
Author(s):  
Patricia Jimeno-Sáez ◽  
David Pulido-Velazquez ◽  
Antonio-Juan Collados-Lara ◽  
Eulogio Pardo-Igúzquiza ◽  
Javier Senent-Aparicio ◽  
...  
Keyword(s):  
Sierra Nevada ◽  
Hydrological Model ◽  
Precipitation Pattern ◽  
Wind Fields ◽  
Preliminary Assessment ◽  
Alpine Regions ◽  
Temperature And Precipitation ◽  
Geostatistical Approach ◽  
Geostatistical Techniques ◽  
Two Parameters

Gauges modify wind fields, producing important systematic errors (undercatching) in the measurement of solid precipitation (Ps), especially under windy conditions. A methodology that combines geostatistical techniques and hydrological models to perform a preliminary assessment of global undercatch and precipitation patterns in alpine regions is proposed. An assessment of temperature and precipitation fields is performed by applying geostatistical approaches assuming different hypothesis about the relationship between climatic fields and altitude. Several experiments using different approximations of climatic fields in different approaches to a hydrological model are evaluated. A new hydrological model, the Snow-Témez Model (STM), is developed including two parameters to correct the solid (Cs) and liquid precipitation (Cr). The procedure allows identifying the best combination of geostatistical approach and hydrological model for estimating streamflow in the Canales Basin, an alpine catchment of the Sierra Nevada (Spain). The sensitivity of the results to the correction of the precipitation fields is analyzed, revealing that the results of the streamflow simulation are improved when the precipitation is corrected considerably. High values of solid Cs are obtained, while Cr values, although smaller than the solid one, are also significant.

Response of high-elevation limber pine (Pinus flexilis) to multiyear droughts and 20th-century warming, Sierra Nevada, California, USA

2007 ◽  
Vol 37 (12) ◽  
pp. 2508-2520 ◽  
Author(s):  
Constance I. Millar ◽  
Robert D. Westfall ◽  
Diane L. Delany
Keyword(s):  
20Th Century ◽  
Sierra Nevada ◽  
Mountain Pine Beetle ◽  
Tree Mortality ◽  
High Elevation ◽  
Dwarf Mistletoe ◽  
Lower Growth ◽  
Pinus Flexilis ◽  
Limber Pine ◽  
Temperature And Precipitation

Limber pine ( Pinus flexilis James) stands along the eastern escarpment of the Sierra Nevada, California, experienced significant mortality from 1985 to 1995 during a period of sustained low precipitation and high temperature. The stands differ from old-growth limber pine forests in being dense, young, more even-aged, and located in warmer, drier microclimates. Tree growth showed high interannual variability. Relative to live trees, dead trees over their lifetimes had higher series sensitivity, grew more variably, and had lower growth. Although droughts recurred during the 20th century, tree mortality occurred only in the late 1980s. Significant correlations and interactions of growth and mortality dates with temperature and precipitation indicate that conditions of warmth plus sustained drought increased the likelihood of mortality in the 1985–1995 interval. This resembles a global-change-type drought, where warming combined with drought was an initial stress, trees were further weakened by dwarf mistletoe ( Arceuthobium cyanocarpum (A. Nels. ex Rydb.) A. Nels.), and proximally killed by mountain pine beetle ( Dendroctonus ponderosae Hopkins). However, the thinning effect of the drought-related mortality appears to have promoted resilience and improved near-term health of these stands, which suffered no additional mortality in the subsequent 1999–2004 drought.

scholarly journals Comparison of GPM Core Observatory and Ground-Based Radar Retrieval of Mass-Weighted Mean Raindrop Diameter at Midlatitude

2018 ◽  
Vol 19 (10) ◽  
pp. 1583-1598 ◽  
Author(s):  
Leo Pio D’Adderio ◽  
Gianfranco Vulpiani ◽  
Federico Porcù ◽  
Ali Tokay ◽  
Robert Meneghini
Keyword(s):  
High Sensitivity ◽  
Sensitivity Study ◽  
Three Dimensions ◽  
Convective Precipitation ◽  
Precipitation Pattern ◽  
Dual Frequency ◽  
Weighted Mean ◽  
Raindrop Size Distribution ◽  
Two Parameters ◽  
Good Agreement

Abstract One of the main goals of the National Aeronautics and Space Administration (NASA) Global Precipitation Measurement (GPM) mission is to retrieve parameters of the raindrop size distribution (DSD) globally. As a standard product of the Dual-Frequency Precipitation Radar (DPR) on board the GPM Core Observatory satellite, the mass-weighted mean diameter Dm and the normalized intercept parameter Nw are estimated in three dimensions at the resolution of the radar. These are two parameters of the three-parameter gamma model DSD adopted by the GPM algorithms. This study investigates the accuracy of the Dm retrieval through a comparative study of C-band ground radars (GRs) and GPM products over Italy. The reliability of the ground reference is tested by using two different approaches to estimate Dm. The results show good agreement between the ground-based and spaceborne-derived Dm, with an absolute bias being generally lower than 0.5 mm over land in stratiform precipitation for the DPR algorithm and the combined DPR–GMI algorithm. For the DPR–GMI algorithm, the good agreement extends to convective precipitation as well. Estimates of Dm from the DPR high-sensitivity (HS) Ka-band data show slightly worse results. A sensitivity study indicates that the accuracy of the Dm estimation is independent of the height above surface (not shown) and the distance from the ground radar. On the other hand, a nonuniform precipitation pattern (interpreted both as high variability and as a patchy spatial distribution) within the DPR footprint is usually associated with a significant error in the DPR-derived estimate of Dm.

scholarly journals Generalization of parameters in the storage–discharge relation for a low flow based on the hydrological analysis of sensitivity

2015 ◽  
Vol 371 ◽  
pp. 69-73 ◽  
Author(s):  
K. Fujimura ◽  
Y. Iseri ◽  
S. Kanae ◽  
M. Murakami
Keyword(s):  
Climate Change ◽  
Sensitivity Analysis ◽  
Water Resource Management ◽  
Hydrological Model ◽  
Low Flow ◽  
Optimum Parameters ◽  
Proportional Relationship ◽  
Two Parameters ◽  
The Impact ◽  
Different Climates

Abstract. The storage-discharge relations have been widely used for water resource management and have led to reliable estimation of the impact of climate change on water resources. In a previous study, we carried out a sensitivity analysis of the parameters in a discharge-storage relation in the form of a power function and found that the optimum parameters can be characterized by an exponential function (Fujimura et al., 2014). The aim of this study is to extend the previous study to clarify the properties of the parameters in the storage–discharge relations by carrying out a sensitivity analysis of efficiency using a hydrological model. The study basins are four mountainous basins in Japan with different climates and geologies. The results confirm that the two parameters in the storage–discharge relations can be expressed in an inversely proportional relationship. In addition, we can conveniently assume a practical function for the storage–discharge relations where only one parameter is used on the basis of the new relationship between the two parameters.

scholarly journals Is Diminishing Solar Activity Detrimental to Canadian Prairie Agriculture?

2020 ◽  
Vol 3 (3) ◽  
Keyword(s):  
Solar Activity ◽  
Large Scale ◽  
Time Frame ◽  
Precipitation Pattern ◽  
Canadian Prairie ◽  
Canadian Prairies ◽  
Temperature And Precipitation ◽  
Mean Temperature ◽  
Grain Yield And Quality ◽  
The Impact

During the grain growing months of May-July, the mean temperature on the Canadian prairies has cooled down by 2ºC in the last 30 years. The cooling appears to be most certainly linked to diminishing solar activity as the Sun approaches a Grand Solar Minimum in the next decade or so. This cooling has led to a reduction in Growing Degree Days (GDDs) and has also impacted the precipitation pattern. The GDDs in conjunction with mean temperature and precipitation are important parameters for the growth of various grains (wheat, barley, canola etc.) on the prairies. In this study, we investigate the impact of declining GDDs and associated temperature and precipitation patterns on Prairie grain yields and quality. Our analysis shows that there has been a loss of about 100 GDDs over the time frame of 1985-2019. The loss in GDDs is also linked to some of the large-scale Atmosphere-Ocean parameters like the Pacific Decadal Oscillation (PDO), North Pacific Index (NPI) and Arctic Oscillation (AO). Our analysis suggests grain yield and quality could be significantly impacted in the coming years as solar activity continues to diminish.

scholarly journals Contrasting Temperature and Precipitation Patterns of Trees in Different Seasons and Responses of Infrared Canopy Temperature in Two Asian Subtropical Forests

Forests ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 902
Author(s):  
Zhi Chen ◽  
Guirui Yu ◽  
Junhua Yan ◽  
Huimin Wang
Keyword(s):  
Air Temperature ◽  
Seasonal Variations ◽  
Canopy Temperature ◽  
Ambient Air ◽  
Future Climate Change ◽  
Precipitation Pattern ◽  
Canopy Conductance ◽  
Subtropical Forests ◽  
Precipitation Patterns ◽  
Temperature And Precipitation

Canopy temperature (Tc), one of the most important plant ecophysiological parameters, has been known to respond rapidly to environmental change. However, how environmental factors—especially the temperature and precipitation pattern—impact Tc has been less discussed for forest stands. In this study, we investigated seasonal variations and responses of the Tc and canopy-to-air temperature difference (ΔT) associated with environmental conditions in two subtropical forests with contrasting temperature and precipitation patterns—Dinghushan (DHS) (temperature and precipitation synchronous site: hot and wet in the summer) and Qianyanzhou (QYZ) (temperature and precipitation asynchronous site: hot and arid in the summer). The results showed that Tc exhibits clear diurnal and seasonal variations above air temperature throughout the day and year, suggesting that the canopy of both DHS and QYZ is typically warmer than ambient air. However, the canopy-warming effect was substantially intensified in QYZ, and the difference of ΔT between dry and wet seasons was small (−0.07 °C) in DHS, while it was up to 0.9 °C in QYZ. Regression analysis revealed that this resulted from the combined effects of the increased solar radiation and vapor pressure deficit (VPD), but reduced canopy conductance (gc) caused by drought in the summer in QYZ. Sensitivity analysis further indicated that the responses of ΔT to VPD and gc changes were quite divergent, presenting negative responses to the enhanced VPD and gc in QYZ, while there were positive responses in DHS. The high productivity coupled with low transpiration cooling that occurs in a temperature and precipitation synchronous condition mainly contributes to the positive responses of ΔT in DHS. This study reveals the seasonal variations, environmental responses, and underlying causes of Tc under different temperature and precipitation patterns, providing useful information for the regional assessment of plant responses to future climate change.

scholarly journals Effects of stratified active layers on high-altitude permafrost warming: a case study on the Qinghai–Tibet Plateau

2016 ◽  
Vol 10 (4) ◽  
pp. 1591-1603 ◽  
Author(s):  
Xicai Pan ◽  
Yanping Li ◽  
Qihao Yu ◽  
Xiaogang Shi ◽  
Daqing Yang ◽  
...  
Keyword(s):  
Thermal State ◽  
Variable Thermal Conductivity ◽  
Tibet Plateau ◽  
Precipitation Pattern ◽  
Thermal Dynamics ◽  
Temperature And Precipitation ◽  
Active Layers ◽  
Permafrost Warming ◽  
Soil Hydraulic ◽  
Qinghai Tibet Plateau

Abstract. Seasonally variable thermal conductivity in active layers is one important factor that controls the thermal state of permafrost. The common assumption is that this conductivity is considerably lower in the thawed than in the frozen state, λt/λf < 1. Using a 9-year dataset from the Qinghai–Tibet Plateau (QTP) in conjunction with the GEOtop model, we demonstrate that the ratio λt/λf may approach or even exceed 1. This can happen in thick (> 1.5 m) active layers with strong seasonal total water content changes in the regions with summer-monsoon-dominated precipitation pattern. The conductivity ratio can be further increased by typical soil architectures that may lead to a dry interlayer. The unique pattern of soil hydraulic and thermal dynamics in the active layer can be one important contributor for the rapid permafrost warming at the study site. These findings suggest that, given the increase in air temperature and precipitation, soil hydraulic properties, particularly soil architecture in those thick active layers must be properly taken into account in permafrost models.

scholarly journals The design, deployment and testing of Kriging models in GEOframe

2018 ◽  
Author(s):  
Marialaura Bancheri ◽  
Francesco Serafin ◽  
Michele Bottazzi ◽  
Wuletawu Abera ◽  
Giuseppe Formetta ◽  
...  
Keyword(s):  
Real Time ◽  
River Basin ◽  
Hydrological Model ◽  
R Package ◽  
Rainfall Data ◽  
Reproducible Research ◽  
Software Applications ◽  
Temperature And Precipitation ◽  
Time Optimization ◽  
Real Time Optimization

Abstract. This work presents a package for the interpolation of climatological variables, such as temperature and precipitation, using Kriging techniques. The purposes of the study are (1) to present a geostatistical software easy to use and easy to plug-in in a hydrological model, (2) to show a practical example of an accurately designed software in the perspective of reproducible research, (3) to show the goodness of the software applications, in order to have a reliable alternative to other traditionally used tools. Ten 5 types of theoretical semivariograms and four types of Kriging were implemented and gathered into ObjectModelling System compliant components. The package provides real time optimization for semivariogram and kriging parameters. The software was tested using temperature and rainfall data retrieved from 97 meteorological stations in the Isarco River basin, Italy. For both variables, good interpolation results were obtained and then compared to the results from the R package, gstat.

Growth–climate relationships for six subalpine tree species in a Mediterranean climate

2013 ◽  
Vol 43 (12) ◽  
pp. 1114-1126 ◽  
Author(s):  
Christopher R. Dolanc ◽  
Robert D. Westfall ◽  
Hugh D. Safford ◽  
James H. Thorne ◽  
Mark W. Schwartz
Keyword(s):  
Sierra Nevada ◽  
Tree Species ◽  
Radial Growth ◽  
Pinus Contorta ◽  
Summer Drought ◽  
Pinus Monticola ◽  
Abies Magnifica ◽  
Temperature And Precipitation ◽  
Jeffrey Pine ◽  
Mediterranean Mountains

A better understanding of the growth–climate relationship for subalpine trees is key to improving predictions about their future distributions under climate change. In subalpine regions of Mediterranean mountains, drought is an annual event, yet many sites can have long-lasting snowpack. We analyzed the growth–climate relationship from 1896 to 2006 for the six most abundant subalpine tree species (red fir (Abies magnifica A. Murray bis), whitebark pine (Pinus albicaulis Engelm.), Sierra/Cascade lodgepole pine (Pinus contorta var. murrayana (Balf.) Engelm.), Jeffrey pine (Pinus jeffreyi Balf.), western white pine (Pinus monticola Douglas ex D. Don), and mountain hemlock (Tsuga mertensiana (Bong.) Carrière)) of the central Sierra Nevada, California, USA, a region with deep spring snowpack followed by strong summer drought. Chronologies for the six species exhibited a high degree of synchrony in their response to annual fluctuations in temperature and precipitation. For all six species, cool, wet conditions in the year prior to growth are conducive to good radial growth, as well as warm springs with sufficient moisture during the year of growth. For species more common on protected slopes, such as mountain hemlock, deep spring snowpack can limit growth. Although predictions of future precipitation trends in the region are uncertain, drought stress appears to already be increasing. If this trend continues, radial growth is likely to be inhibited for most or all species in our study. Trees growing where snowpack is deep may be least likely to suffer reduced growth.

Reconstruction of LGM ice extents in Europe indicates a cold and dry climate with precipitation patterns similar to present day

2020 ◽  
Author(s):  
Vjeran Višnjević ◽  
Frederic Herman ◽  
Günther Prasicek
Keyword(s):  
Precipitation Pattern ◽  
Mountain Range ◽  
Ice Flow ◽  
Last Glacial Period ◽  
Temperature And Precipitation ◽  
Westerly Winds ◽  
The Alps ◽  
Precipitation Changes ◽  
Climate Proxies ◽  
The Last Glacial

&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;During the pinnacle of the last glacial period 21 kyr ago, the Alps and the Pyrenees were largely covered by ice. Climate was colder and most likely drier, but the magnitudes of temperature and precipitation changes remain poorly constrained. This is in part because climate proxies are not sufficiently accurate, and because there are unknowns on the past position of the Westerly winds and, consequently, the intensity of the moisture flow towards Europe. A new inverse method combined with an ice flow model enables us to infer past climate from mapped ice extents. In the case of the Alps, all of the presented scenarios recover an increase in the position of the ELA across the mountain range from west to east, and a decrease from north to south, pointing to a dominantly zonal circulation with Westerlies bringing moisture from the Atlantic. This is supported by the Pyrenees reconstruction, where the method recovers a clear N-S gradient for all scenarios, indicating that the moisture source from the direction of the Atlantic. While the precipitation pattern was probably not much different from today, mean temperatures were ~9.3 &amp;#177; 2.97&amp;#730;C lower in the Alps and ~6.6 &amp;#177; 1.6&amp;#730;C lower in the Pyrenees. Our results match pollen-based reconstructions if the climate was 60% dryer than today.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;

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