Light Snowfall Research Articles

Historical and Future Changes of Snowfall Events in China under a Warming Background

AbstractUsing station data and Regional Climate Model version 4 (RegCM4) simulations under the representative concentration pathway 4.5 (RCP4.5) scenario, this article addresses historical and future changes of the wintertime snowfall over China. The observational results generally show a decrease in the frequency and an increase in the mean intensity of snowfalls in northwestern China (NWC), northeastern China (NEC), the eastern Tibetan Plateau (ETP), and southeastern China (SEC) since the 1960s. The total amount of wintertime snowfall, however, has increased in NWC, NEC, and ETP but decreased in SEC. The decrease in snow days is primarily due to the reduction of light snowfall events. The increase in the total amount is primarily explained by increases in heavy snowfalls, and the corresponding decrease is the result of decreases in light-to-heavy snowfalls. The RegCM4 ensemble, which can well simulate the observed snowfall climatology, projects that the snow days will be further reduced by the end of the twenty-first century relative to 1986–2005, primarily owing to the decline of light snowfall events. The total amount is projected to increase in NWC but decrease in the other three subregions. The increase in the total amount in NWC is attributed to increases in heavy and large snowfalls. Decreases in light snowfalls play a leading role in the decrease of the total amount in NEC. In ETP and SEC, the decrease in the total amount is the result of overall decreases in light-to-heavy snowfalls. The mechanism for such changes is an interesting topic to study in the future.

A Case Study of Cloud Radar Observations and Large-Eddy Simulations of a Shallow Stratiform Orographic Cloud, and the Impact of Glaciogenic Seeding

AbstractThe impact of glaciogenic seeding on precipitation remains uncertain, mainly because of the noisy nature of precipitation. Operational seeding programs often target cold-season orographic clouds because of their abundance of supercooled liquid water. Such clouds are complicated because of common natural seeding from above (seeder–feeder effect) or from below (blowing snow). Here, observations, mainly from a profiling airborne Doppler radar, and numerical simulations are used to examine the impact of glaciogenic seeding on a very shallow (<1 km), largely blocked cloud that is not naturally seeded from aloft or from below. This cloud has limited but persistent supercooled liquid water, a cloud-base (top) temperature of −12°C (−16°C), and produces only very light snowfall naturally. A Weather Research and Forecasting Model large-eddy simulation at 100-m resolution captures the observed upstream stability and wind profiles and reproduces the essential characteristics of the orographic flow, cloud, and precipitation. Both observations and simulations indicate that seeding locally increases radar (or computed) reflectivity in the target area, even after removal of the natural trend between these two periods in a nearby control region. A model sensitivity run suggests that seeding effectively glaciates the mostly liquid cloud and substantially increases snowfall within the seeding plume. This is due to a dramatic increase in the number of ice particles and not to their size. The increased ice particle concentration facilitates snow growth by vapor deposition in a cloud the temperature range of which is conducive to the Bergeron process.

Uncertainties of ground-based microwave radiometer retrievals in zenith and off-zenith observations under snow conditions

Abstract. This paper is to investigate the uncertainties of microwave radiometer (MWR) retrievals in snow conditions and also explore the discrepancies of MWR retrievals in zenith and off-zenith observations. The MWR retrievals were averaged in a ±15 min period centered at sounding times of 00:00 and 12:00 UTC and compared with radiosonde observations (RAOBs). In general, the MWR retrievals have a better correlation with RAOB profiles in off-zenith observations than in zenith observations, and the biases (MWR observations minus RAOBs) and root mean square errors (RMSEs) between MWR and RAOB are also clearly reduced in off-zenith observations. The biases of temperature, relative humidity, and vapor density decrease from 4.6 K, 9 %, and 1.43 g m−3 in zenith observations to −0.6 K, −2 %, and 0.10 g m−3 in off-zenith observations, respectively. The discrepancies between MWR retrievals and RAOB profiles by altitude present the same situation. Cases studies show that the impact of snow on accuracies of MWR retrievals is more serious in heavy snowfall than in light snowfall, but off-zenith observation can mitigate the impact of snowfall. The MWR measurements become less accurate in snowfall mainly due to the retrieval algorithm, which does not consider the effect of snow, and the accumulated snow on the top of the radome increases the signal noise of MWR measurements. As the snowfall drops away by gravity on the sides of the radome, the off-zenith observations are more representative of the atmospheric conditions for RAOBs.

The Rhetoric of Photography in Modern Japanese Literature: Materiality in the Visual Register as Narrated by Tanizaki Jun’ichirō, Abe Kōbō, Horie Toshiyuki, and Kanai Mieko by Atsuko Sakaki

Reviewed by: The Rhetoric of Photography in Modern Japanese Literature: Materiality in the Visual Register as Narrated by Tanizaki Jun’ichirō, Abe Kōbō, Horie Toshiyuki, and Kanai Mieko by Atsuko Sakaki Mark Silver The Rhetoric of Photography in Modern Japanese Literature: Materiality in the Visual Register as Narrated by Tanizaki Jun’ichirō, Abe Kōbō, Horie Toshiyuki, and Kanai Mieko. By Atsuko Sakaki. Leiden: Brill, 2016. 276pages. Hard-cover €103.00/$133.00. There is something mind-bending about encountering a photograph embedded in a work of fiction. A photograph that appears to represent someone or something mentioned in a fictional narrative throws into doubt its own provenance, its relation to the surrounding text, and the relation of both photo and text to reality. The reputation of the German author W. G. Sebald rests in large part on books that seem to float in an ambiguous and hybrid world between the fictitious and the real, the novel and the memoir, thanks to this device of the embedded photograph and the questions it prompts. Does the photograph simply evoke things of the kind the text describes, even if they are not precisely the same things? Does it succeed in verifying the existence of some subset of things described in the narrative, pulling the narrative at least partly out of the fictional realm? Does the proximity of the fictional narrative compromise the photograph, undercutting its supposed connection to reality and rendering it “fictional,” or otherwise highlighting its artifice? Or, conversely, might the artifice of the photograph undercut the apparent realism of the fiction? And what of cases where there is no easily discernible relationship between the photograph and the accompanying text at all? Atsuko Sakaki’s deeply researched and thought-provoking new book addresses intricate questions like these, working mainly with examples drawn from twentieth-century Japanese literature and photography. As Sakaki says at the outset, the book “aspires to critically investigate how the photographic way of seeing and processing what one sees has inspired and transformed the way prose narratives have been [End Page 128] written and what that amounts to in terms of the registration of human experience of time and space” (p. 2). Each of the book’s four main chapters takes up the role of photography in the works of a different writer. Sakaki begins with the two canonical figures Tanizaki Jun’ichirō and Abe Kōbō, followed by the less familiar Horie Toshiyuki (academic, art critic, book designer, novelist, and photographer active since the 1980s) and Kanai Mieko (poet, short-story writer, film and photography critic, and novelist most active from the 1970s to the 1990s). Her treatment of each writer is focused on a particular theme or concern: the family with Tanizaki, the city with Abe, what she calls “the community of connoisseurship” with Horie, and all three of these with Kanai. Despite this variety of emphases, Sakaki sees a strong similarity in the authors’ engagement with photography. “All four writers,” she says, sounding what will become a familiar refrain, “reveal the slipperiness of the enterprise of encapsulating facts by way of photography. . . . Upon close examination, the photographic image turns out to be not as transparent or objective as commonly supposed” (p. 1). The chapter on Tanizaki Jun’ichirō treats a number of his fictional works including Shunkinshō (A Portrait of Shunkin), Chijin no ai (A Fool’s Love; published in English as Naomi), Yoshinokuzu (Arrowroot; analyzed in its 1937 limited edition, which includes photographs by Kitao Ryōnosuke), Sasameyuki (A Light Snowfall; published in English as The Makioka Sisters), and Kagi (The Key). Of these works, only one—the limited edition of Yoshinokuzu—contains actual photographs in the text, but the others all devote some degree of narrative energy to photographers and photography. Sakaki’s intent in this chapter is “to account for the ambiguous and dynamic relationship between image and text that Tanizaki brings to our attention as he writes about (or around) photographs” (p. 19). Her central insight is that photographs in Tanizaki “often contribute to a destabilization of present reality, leaving the viewer feeling disoriented rather than steady in space-time” (p. 18). So, for example, in Shunkinshō, the memory that...

Comparison of snowfall estimates from the NASA CloudSat Cloud Profiling Radar and NOAA/NSSL Multi-Radar Multi-Sensor System

The latest global snowfall product derived from the CloudSat Cloud Profiling Radar (2C-SNOW-PROFILE) is compared with NOAA/National Severe Storms Laboratory’s Multi-Radar Multi-Sensor (MRMS/Q3) system precipitation products from 2009 through 2010. The results show that: (1) Compared to Q3, CloudSat tends to observe more extremely light snowfall events (<0.2mm/h) and snowfall rate (SR) between 0.6 to 1mm/h, and detects less snowfall events with SR between 0.2–0.5mm/h. (2) CloudSat identifies 69.40% of snowfall events detected by Q3 as certain snow and 10% as certain mixed. When possible snow, possible mixed, and certain mixed precipitation categories are assumed to be snowfall events, CloudSat has a high snowfall POD (86.10%). (3) CloudSat shows less certain snow precipitation than Q3 by 26.13% with a low correlation coefficient (0.41) with Q3 and a high RMSE (0.6mm/h). (4) With Q3 as reference, CloudSat underestimates (overestimates) certain snowfall when the bin height of detected snowfall events are below (above) 3km, and generally overestimates light snowfall (<1mm/h) by 7.53%, and underestimates moderate snowfall (1–2.5mm/h) by 42.33% and heavy snowfall (⩾2.5mm/h) by 68.73%. (5) The bin heights of most (99.41%) CloudSat surface snowfall events are >1km high above the surface, whereas 76.41% of corresponding Q3 observations are low below 1km to the near ground surface. This analysis will provide helpful reference for CloudSat snowfall estimation algorithm developers and the Global Precipitation Measurement (GPM) snowfall product developers to understand and quantify the strengths and weaknesses of remote sensing techniques and precipitation estimation products.

Glaciers in equilibrium, McMurdo Dry Valleys, Antarctica

ABSTRACTThe McMurdo Dry Valleys are a cold, dry polar desert and the alpine glaciers therein exhibit small annual and seasonal mass balances, often &lt;±0.06 m w.e. Typically, winter is the accumulation season, but significant snow storms can occur any time of year occasionally making summer the accumulation season. The yearly equilibrium line altitude is poorly correlated with mass balance because the elevation gradient of mass balance on each glacier can change dramatically from year to year. Most likely, winds redistribute the light snowfall disrupting the normal gradient of increasing mass balance with elevation. Reconstructed cumulative mass balance shows that the glaciers have lost &lt;2 m w.e. over the past half century and area changes show minimal retreat. In most cases these changes are less than the uncertainty and the glaciers are considered in equilibrium. Since 2000, however, the glaciers have lost mass despite relatively stable summer air temperatures suggesting a different mechanism in play. Whether this trend is a harbinger of future changes or a temporary excursion is unclear.

Assessing the Vulnerability of Winter Maintenance Material Storage Facilities

AbstractThis research examines the vulnerability of the winter maintenance salt supply to depletion and the associated risk costs in Ohio using Ohio Department of Transportation (ODOT)-specific data pertaining to the amount of salt storage, number of trucks, and lane kilometers maintained by each county. These data were combined with the number of snowfall events in each county to determine the failure probability. The results indicated that the probability of exceeding the salt capacity ranged from less than 0.01 to 61%, with an average of 23.1%. Sensitivity and importance analyses were conducted to determine the change in probability of exceedance due to a one-unit change in each parameter and to examine the influence of each random variable in the reliability analysis on the variance of the limit state, respectively. The parameter with the highest importance was the salt applied during light snowfall, while the brine applied has a low importance. Annual risk costs were estimated using the purchase and ...

Impacts of air–sea exchange coefficients on snowfall events over the Korean Peninsula

Snowfall over the Korean Peninsula is mainly associated with air mass transformation by the fluxes across the air–sea interface during cold-air outbreaks over the warm Yellow Sea. The heat and momentum exchange coefficients in the surface flux parameterization are key parameters of flux calculations across the air–sea interface. This study investigates the effects of the air–sea exchange coefficients on the simulations of snowfall events over the Korean Peninsula using the Weather Research and Forecasting (WRF) model. Two snowfall cases are selected for this study. One is a heavy snowfall event that took place on January 4, 2010, and the other is a light snowfall event that occurred on December 23–24, 2011.Several sensitivity tests are carried out with increased and decreased heat and momentum exchange coefficients. The domain-averaged precipitation is increased (decreased) with increased (decreased) heat exchange coefficient because the increased (decreased) surface heat flux leads to more (less) moist conditions in the low level of the atmosphere. On the other hand, the domain-averaged precipitation is decreased (increased) with increased (decreased) momentum exchange coefficient because the increased (decreased) momentum coefficient causes reduction (increase) of wind speed and heat flux. The variation of precipitation in the heat exchange coefficient experiments is much larger than that in the momentum exchange coefficient experiments because the change of heat flux has a more direct impact on moisture flux and snowfall amount, while the change of momentum flux has a rather indirect impact via wind speed changes. The low-pressure system is intensified and moves toward North when the heat exchange coefficient is increased because warming and moistening of the lower atmosphere contributes to destabilize the air mass, resulting in the change of precipitation pattern over the Korean Peninsula in the heat exchange coefficient experiments.

Snow depth estimation accuracy using a dual-interface GPS-IR model with experimental results

Measuring snow depth using the GPS interferometric reflectometry is an active microwave remote sensing technique and an emerging approach because of its relatively large spatial coverage and high temporal sampling capability. The current geodetic GPS networks are capable of measuring snow depth in the vicinity of the antenna installation at no additional hardware cost. However, the performance is constrained by the geodetic GPS antenna which was originally designed to minimize the reception of the reflected signal. In our prior work, we proposed a horizontally polarized antenna which has equal gain for both direct and reflected signals and tested its performance for a single snow event. In order to comprehensively assess its performance, we set up a horizontally polarized snow monitor (HPSM) using the improved antenna at Marshall, Colorado, USA, over the 2013---2014 water year. The data from the HPSM clearly shows that the proposed design has high sensitivity to even very light snowfalls. However, some anomalies are observed from the HPSM measurements, which tend to either overestimate or underestimate the actual snow depth. We explain the observed measurement anomalies by replacing the traditional air---snow single-interface model with an air---snow---soil dual-interface model. The effectiveness of the new model is validated by comparing the simulated results to the HPSM measurements. Utilizing the dual-interface model, we simulate the error curve for snow depth estimation given various snow depths and snow permittivities. The error curve shows that the estimation biases can be observed only for shallow snow with a relatively small permittivity value.

Variations in seasonal snow surface energy exchange during a snowmelt period: an example from the Tianshan Mountains, China

ABSTRACTThe energy exchange on a snow surface is important for snowmelt and sublimation. Furthermore, a comparison of the snow surface energy exchange between different years at the same location is beneficial for understanding the influence of climate change on snowmelt. In the present study, based in the Tianshan Mountains, China, meteorological factors and the snowmelt rate were measured using an automatic weather station and snow lysimeter during the snowmelt period in a normal snowfall year (2009), an abnormally light snowfall year (2012) and two abnormally heavy snowfall years (2010 and 2013). The energy exchange was calculated according to these meteorological data sets. The climate during the snowmelt periods in 2010 and 2013 was warmer and wetter than that in 2009 and 2012. For all years, net short wave radiation and sensible heat flux were positive, and net long wave radiation and latent heat flux were negative. The maximum difference in the snow surface energy exchange for each of the different years is given as net turbulence. The snowmelt periods in 2010 and 2013 were 15–20 days longer than those in 2009 and 2012. The snowmelt rates in 2010 and 2013 were higher than those in 2009 and 2012, especially during the latter days of the snowmelt period. Against the background of a warming and more humid climate in the western Tianshan Mountains, the snowmelt rate will inevitably increase, especially towards the end of the snowmelt period.

Shear strength of new deposited snow in cold regions of mountainous heavy snowfall area and of inland light snowfall area

積雪変質モデルによる精度の高い雪崩発生予測を目的として，北海道の山岳多雪地域にある中山峠と内陸少雪地域にある陸別町で各3冬期に，降雪開始から72時間以内の新積雪を対象に，密度とせん断強度の関係式を求めるための断面観測を行った．その結果，中山峠での新雪がしまり雪に変態する過程の積雪のせん断強度は，これまでわが国の積雪変質モデルで一般的に使われてきた，主に本州平地で行われた観測結果に基づく式と比べると，密度150，220 kg m−3では30，21% にしかならなかったが，カナダの山岳域で観測された式と比べると密度60〜220 kg m−3でほぼ一致した．一方，陸別町での観測結果ではこれまで明らかにされてこなかった降雪直後の新雪がしもざらめ雪に変態する過程の積雪の関係式が得られ，これをカナダの弱層で観測された式と比べると，密度150，250 kg m−3で50，33% と小さかった．これは，陸別町での表層の温度勾配が大きいためしもざらめ雪粒子が急成長し粗大化した上，低温下のままで経過し焼結が進んでいないためと考えられる．寒冷地域での乾雪表層雪崩の発生予測では，本研究成果を用いた見直しが必要である．

A new perspective on Australian snow

AbstractThe Australian Alps have a unique climatological, ecological and hydrological environment and play a key role in water supply for southeastern Australia. Using resort observations we compile a new and robust snow accumulation data set. Both maximum snow depth and total snow accumulation have declined over the last 25 years. A significant decreasing trend was observed for the total number of light snow days, whereas the total number of heavy snow occurrences has remained constant. Maximum temperatures are highly related to all snow variables. It is suggested that global warming is already impacting light snowfall events, while heavy events are less affected.

Experimental assessment of snow‐induced attenuation on an Earth‐space link operating at Ka‐band

AbstractThis investigation assesses the attenuation induced by snowfall on an experimental slant‐path link that monitors the 20.199 GHz beacon signal of the Anik F2 satellite. Beacon data collected at Communications Research Centre Canada (CRC) in Ottawa over 2 years, including the winters of 2010–2011 and 2011–2012, were analyzed as part of this study. The antenna of one of the two receivers used in the propagation campaign with Anik F2 was shielded, the first year under a tent and the second year under the roof of a building, in order to prevent degradations on the measured beacon signal due to snow or ice accumulation on the parabolic reflector surface. One of the main challenges of the study was the unambiguous identification of snow events. Information provided by several weather sensors, a profiling radiometer, and meteorological reports were used to help identify the type of precipitation. Events of wet and dry snow along with freezing rain are presented and discussed. Radiometric measurements of sky noise temperature were particularly useful to detect light snowfall events and to estimate event durations. Statistics of snow attenuation were derived for the winter months of the study. It is found that snow attenuation is modest at 20.2 GHz; however, modest attenuation may be important for small‐margin communication systems.

Resilience, Agency and Resistance in the Storytelling Practice of Aunty Hilda Wilson (1911-2007), Ngarrindjeri Aboriginal Elder

Resilience, Agency and Resistance in the Storytelling Practice of Aunty Hilda Wilson (1911-2007), Ngarrindjeri Aboriginal Elder

Detection Thresholds of Falling Snow From Satellite-Borne Active and Passive Sensors

There is an increased interest in detecting and estimating the amount of falling snow reaching the Earth's surface in order to fully capture the global atmospheric water cycle. An initial step toward global spaceborne falling snow algorithms for current and future missions includes determining the thresholds of detection for various active and passive sensor channel configurations and falling snow events over land surfaces and lakes. In this paper, cloud resolving model simulations of lake effect and synoptic snow events were used to determine the minimum amount of snow (threshold) that could be detected by the following instruments: the W-band radar of CloudSat, Global Precipitation Measurement (GPM) Dual-Frequency Precipitation Radar (DPR) Ku- and Ka-bands, and the GPM Microwave Imager. Eleven different nonspherical snowflake shapes were used in the analysis. Notable results include the following: 1) The W-band radar has detection thresholds more than an order of magnitude lower than the future GPM radars; 2) the cloud structure macrophysics influences the thresholds of detection for passive channels (e.g., snow events with larger ice water paths and thicker clouds are easier to detect); 3) the snowflake microphysics (mainly shape and density) plays a large role in the detection threshold for active and passive instruments; 4) with reasonable assumptions, the passive 166-GHz channel has detection threshold values comparable to those of the GPM DPR Ku- and Ka-band radars with ~ 0.05 g·m <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-3</sup> detected at the surface, or an ~ 0.5-1.0-mm·h <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">-1</sup> melted snow rate. This paper provides information on the light snowfall events missed by the sensors and not captured in global estimates.

Total snow water distributions in Tohoku region, Japan, averaged for twenty-seven years : Their application to heavy and light snowfall winters

Total snow water distributions in Tohoku region, Japan, averaged for twenty-seven years : Their application to heavy and light snowfall winters

Daily Activity Pattern and Habitat Use of Greater White-fronted Geese Wintering in Japan: Factors of the Population Increase

Abstract During 20 years, numbers of Greater White-fronted Geese (Anser albifrons) wintering in Japan have increased 5.6 times (ca. 46,000 in 1999), with over 80% of the geese concentrated around Lake Izunuma-Uchinuma, in northern Japan. Detailed information on the wintering ecology of the geese had not been investigated in Japan and the daily activity pattern and habitat use of the geese were studied around the lake in three winters (October-February), 1996/97, 1997/98 and 1998/99. The daily activity pattern, i.e., flight timing and behavior relating to environmental factors (light intensity, snowfall, temperature and wind speed), was similar to that for several other geese species in temperate areas. The geese wintering in Japan depended exclusively on rice in fields; they foraged in stubble fields, where the density of rice grains was much higher than that in plowed fields. However, the area of stubble fields around the lake has decreased from 1980 to 2000, while combine harvesters replaced machinery, ...

Why is Aucuba japonica Smaller in Heavy Snowfall Areas? A Growth Simulation of Evergreen Broad-leaved Shrubs based on Shoot Allometry, Critical Shoot Sizes for Flowering and Photosynthetic Production

, an evergreen broad-leaved shrub. The model is based on the allometry of plant organs and incorporates the processes of flowering, branching, and allocation of biomass among different organs. Growth of model plants was simulated under different values of annual gross production per leaf area (LGP) for 15 years. The tree form was mainly determined by the critical shoot size for initiating flowering (SF), but the average increase of new shoot mass (INM) for two successive years had marked effects on the growth pattern of A. japonica in addition to SF. Under small LGP conditions, plants with larger SF did not flower or postponed the initiation of flowering. With increasing LGP, plants with larger SF had a greater advantage because of their high efficiency for vertical growth. A smaller SF was observed in A. japonica var. borealis, which is distributed in heavy snowfall areas, and resulted in precocious flowering with a higher reproductive rate. The small plant size and shoot size of var. borealis may be the result of selection for preventing the delay of the year in which reproduction starts under smaller LGP conditions. On the other hand, the large SF of A. japonica var. japonica, which is distributed in light snowfall areas, suppresses flowering under small LGP conditions, and flowering occurs only after achieving a certain amount of vertical growth.

InSAR for estimation of changes in snow water equivalent of dry snow

This paper describes the theoretical relation between interferometric phase and changes in snow water equivalent (SWE) and show results from experiments using ERS- 1/2 tandem data. The main scattering contribution from a dry snow cover is from the snow-ground interface. However, the radar wave will be refracted in the snow. Thus, only small changes in the snow properties between two interferometric synthetic aperture radar (SAR) images will change the interferometric phase. This phase change is shown to introduce a significantly increase in the digital elevation model (DEM) height error, although no effects are observed on the degree of coherence. The phase change is also shown to affect the differential interferometric results and may wrongly be interpreted as range displacement. The presented theory and results implies that light snowfall and/or small changes in snow properties between interferometric SAR (InSAR) image acquisitions, may introduce significant height errors in DEM derived from glaciers, ice sheets, or bare ground, even in the case of high degree of coherence. Thus, meteorological observations in addition to degree of coherence must be considered when generating DEM in areas covered with snow or where snow fall is likely to have occurred.

Differences in Shoot Size and Allometry between Two Evergreen Broad-Leaved Shrubs, Aucuba japonica Varieties in Two Contrasting Snowfall Habitats

, an evergreen broad-leaved shrub. Aucuba Japonica var. borealis is widely distributed in heavy snowfall areas in Japan and is covered, shaded and physically pressured by snow for more than four months of the year. On the other hand, var. japonica is widely distributed in light snowfall areas. The sizes of new shoots and leaves were significantly different between the two varieties with different critical shoot sizes for flowering. The average new shoot dry mass of var. borealis was about one third of that of var. japonica. Despite the differences in growing conditions and shoot size, no significant differences were observed in the allometry of their shoot organs between the two varieties. Large new shoots had thicker and longer stems per biomass than small shoots because of their larger pith volume. The large shoots showed higher efficiency of stem growth per invested biomass and had a higher rate of annual height increase than small shoots. When the size of new shoot rapidly increased from year to year, i.e. the plants are growing well, initiation of flowering was postponed and vegetative growth continued. Small new shoots were tolerant of low productivity conditions but traded vertical growth for an increase in matter allocation to leaves.