Polar plotting of seasonal hydrologic and climatic data (original) (raw)
A methodology for investigation of the seasonal evolution in proglacial hydrograph form
Hydrological Processes, 1999
This paper advances an objective method of diurnal hydrograph classi®cation as an aid to exploring changes in the hydrological functioning of glacierized catchments over the ablation season. The temporal sequencing of dierent hydrograph classes allows identi®cation of seasonal evolution in hydrograph form and also assists delimitation of hydrologically-meaningful time periods of similar diurnal discharge response. The eectiveness of this approach is illustrated by applying it to two contrasting summer discharge records for a small cirque basin. By comparing the results with patterns of surface energy receipt and glacier ablation, the seasonally transient relative in¯uences of: (i) surface meltwater production and (ii) meltwater routing and storage conditions within the intervening glacier drainage system in determining runo are elucidated. The method successfully characterizes distinct seasonal-scale changes in the diurnal out¯ow hydrograph during the ablation-dominated 1995 melt season but is also able to reveal underlying trends and short-term¯uctuations in the precipitation-dominated, poorly ablation-regulated 1996 melt season. The limitations and bene®ts of this hydrograph classi®cation technique are evaluated.
Journal of Hydrology, 2003
We are in agreement with Burn and Hag Elnur [J. Hydrol. 255 (2002) 107] that streamflow trends and variability are related to meteorological factors. We expanded the analysis of streamflow variability by relating annual peaks and spring (April, May, June) discharges to ENSO (El Niño-Southern Oscillation) events. Since geophysical considerations suggest that western Canada is warmer and drier than usual during El Niño but cooler and wetter under La Nina influences, flow variability of many western Canadian rivers is found to be correlated with winter values of such indices as the Southern Oscillation Index (SOI), Multivariate ENSO Index (MEI) or PNA (Pacific/North American Index). The spatial pattern of the non-parametric Spearman's r 2 (for streamflow vs SOI) indicates a general correspondence with the correlation pattern of SOI-precipitation reported by Shabbar et al. [J. Climate 10 (1997) 3016]. This reinforces the linkage between streamflow variability, precipitation and climatic forcing.
IPCC SROCC Chapter 3: Polar Regions
2019
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2014
We present a new technique to study the seasonal cycle of climatic trends in the expected value, variance, and other moments of the statistical distribution. The basis of the technique is multiple linear regression, but with periodic basis functions. The technique allows us to provide comprehensive information on statistical parameters of climate for every day of an observational period. Using daily data, the technique has no problems caused by different lengths of months or the leap-year cycle. Without needing to assume the stationarity of contemporary climate, the technique allows the study of statistical parameters of climatic records of arbitrary length. We illustrate the technique with applications to trends in the satellite observed variations of sea ice extent in the Northern and Southern Hemispheres. We show that a significant part of the variability in hemispheric sea ice extents for the period 1978-1999 is related to linear trends.
Canadian Journal of Remote Sensing
Wetlands provide important ecological benefits at both local and regional scales, thus wetland conservation and effective management are goals at many levels of government. Radar systems are a useful data source for providing information about wetlands and thus play a complementary role to optical data in wetland mapping and monitoring applications. This paper explores the use of polarization diversity and polarimetry for wetland classification and mapping using airborne CV-580 C-band synthetic aperture radar (SAR) data. The results show that dual polarization with an HH polarized component is superior to single polarization but does not contain as much information for wetland classification as full polarimetry. However, polarization ratios using HH are adequate for mapping water and flooded and nonflooded vegetation for a generalized land-cover map. The implications of this research are discussed with respect to wetland classification and land cover information needs for waterfowl-productivity estimates that Ducks Unlimited Canada uses for its wetland conservation programs. These results can help end-users in selecting the appropriate SAR imaging mode when evaluating trade-offs between resolution, swath width, and polarization diversity.
20th-century glacial-marine sedimentation in Vitus Lake, Bering Glacier, Alaska, U. S. A
Annals of Glaciology, 1996
ABSTR \. eT. \ ' itus La ke, th e ice-m a rgin a l b as in a t th e so uth eas tern ed ge o f Bcr in g Gl ac ie r. Al as ka, U .S.A. , is a sit e o f m od e rn. r a pid , g lacia l-m a rin e sedim enta tio n, R a th er th a n be ing a fr es h-w a te r la ke, \ ' itll s L a ke is a tid a ll \' influ e nced , m a rin e to brac ki sh emba \'l11 ent co nn ec ted to the Pac ifi c O cea n b\' a n inl e t, th e Sea l Ri\"C J". \ ' itus L a ke co nsists o f fi \'e d ee p bedroc k b as in s, se p a ra tc~1 by interbas in a l hi g hs, G la c ia l eros io n h as c ut th ese bas ins as mu c h as 250 m belo w sea IC\"C I. H ig h-resoluti o n se ismi c re fl ec t io n su rveys co ndu c ted in 199 1 a nd 1993 o f"rcJLlr o r \ ' itu s L a ke's b as ins rC\'ea l a co mplex. \'a r ia b le three-compo nel1l aco usti c stra ti g ra phy. Al t ho ug h no t full y sa mpled , th e stra ti g r a ph y is in fC rred to b e prima ril y g lacia l-m a rin e units of (I) basa l co nto rted a nd d efo rmed g lac ia l-marin e a nd g lacia l sedim e nts d eposited b y basa l ice-contac t proccsses a nd submarine m ass-was ting; (2) aco ustica ll y we ll-stra tifi ed g la c ia l-m a rin e sedim enl. \\'hi ch un co nform a bh-O\'e rli es th e basa l unit a nd \\'hi c h g ra d es up\\'a rd into (3) aco usti ca ll y tra nsp a re nt o r nea rl y tra nsp a rent g lac ia l-m ar in e sedim e nt. ~[ ax i mum th ic kn esses o f co nfo rm a ble g lac ia l-m a r in e sedim ent cxceed 100 m. A ll o f" th e a co ustica ll y tra nspare nt and stra t ifi cd d ep os its in Vi rus L a ke a re m od crn in age. ha \'in g acc umu la ted be t\\'ee n 196 7 a nd 1993. Th e b asin s \\•h e re th ese three-p a rt sequ en ces of " present-d a \'" g lac ia l-m a rin e sedim e nt a rc <tec um u la rin g a re th ell1 se h'es c u t i nLO o ld er seC] uen ces o f Slra rifi ed g lac ia l and g la cialm a rin e d e pos its, Th esc old er un its o utcro p o n thc island s in \ ' itu s L a ke. In 1967 , a s th c res ult ora m a jo r su rge, g lae icr ice compl e tcly fill ed a ll fi ve b as in s. S ubsequ e nt terminu s re treat. \\" hi c h co ntinu ed thro ug h ,-\u g ust 199 3. cx posed th ese b a si ns. pro\'icli ng n c\\" loca li o ns fo r g lac ia I-m <l rin e sed i m e n t acc um ul a ti o n. :\ co rre la ti o n o f" sedim ent th ic kn esses m eas ured from se ismic pro fi les a t spec ifi c loca ti o ns \\'ithin th e b asins. \\'ith th e \,ea r th a t eac h loca ti o n beca m e ice-fr ee, sh o ws th a t th e sedim ent acc umu la ti o n a t so'm e loca ti o n s exceeds 10 m yea r I .