The synoptic climatology of ablation on a New Zealand glacier

Hay, John E.; Fitzharris, B. B.

doi:10.1002/joc.3370080207

Cited by 67 publications

(90 citation statements)

References 18 publications

(12 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Measured average mass loss was approximately 40 mm w.e. d −1 , which is very similar to that measured by Hay and Fitzharris (1988) on the Ivory Glacier over two summer periods at a similar elevation (38 mm w.e. d −1 ).…”

Section: Degree-day Modelsupporting

confidence: 85%

“…On other glaciers in the Southern Alps, Anderton and Chinn (1978) and Hay and Fitzharris (1988) found radiative heat to be the most important source of ablation (on the Ivory Glacier between 1400 and 1800 m a.s.l.). Recent energy and mass balance modelling of Brewster Glacier over the period 2004-2008 by Anderson et al (2010), using primarily meteorological data not collected on the glacier, showed that 48% of energy available for melt is sourced from net all-wave radiation.…”

Section: Introductionmentioning

confidence: 99%

“…Recent energy and mass balance modelling of Brewster Glacier over the period 2004-2008 by Anderson et al (2010), using primarily meteorological data not collected on the glacier, showed that 48% of energy available for melt is sourced from net all-wave radiation. Importantly, Hay and Fitzharris (1988) revealed that changes in synoptic circulation control variability in the energy available for melt, with radiation important during southerly circulation patterns, while turbulent heat fluxes are often higher during phases of northerly airflow, prompting the effort to investigate controls of circulation changes in glacier behaviour.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Atmospheric controls on summer ablation over Brewster Glacier, New Zealand

Gillett

Cullen

2010

Intl Journal of Climatology

107

View full text Add to dashboard Cite

Micrometeorological data collected from an automatic weather station over a total of 85 days during the summer of 2007/2008 in the ablation zone (1770 m a.s.l.) of the Brewster Glacier, New Zealand, were used to determine the main atmospheric processes controlling the magnitude and variability of daily ablation. During the field season, ablation was measured and modelled using an energy balance model (EBM) and a degree-day model (DDM). Calculation of the energy balance over the glacier using the EBM revealed that net radiation provided the largest source of energy for ablation (52%). The turbulent sensible heat flux was the next largest energy source (25%), followed by the turbulent latent heat flux (20%) and the rain heat flux (3%). While daily measured and modelled (EBM) ablation were both equal to approximately 40 mm w.e. d −1 , the EBM was used to demonstrate that rates were highly variable, ranging from less than 10 mm w.e. d accounted for almost 25% of total ablation, despite such events occurring on only 11 of the 85 days monitored. The contribution of the individual terms of the energy balance to observed air temperature is complex on Brewster Glacier, leading to a larger uncertainty in DDM ablation estimates (under prediction of total ablation by 11%). Advection of warm and moisture-laden air over Brewster Glacier, which is not uncommon given its close proximity to the ocean, is not well accounted for by the DDM. This is because the turbulent latent heat flux and the rain heat flux are poorly correlated to air temperature but are, nonetheless, important sources of energy during large ablation events.

show abstract

Section: Degree-day Modelsupporting

confidence: 85%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Atmospheric controls on summer ablation over Brewster Glacier, New Zealand

Gillett

Cullen

2010

Intl Journal of Climatology

107

View full text Add to dashboard Cite

show abstract

“…During periods confined to melting, R NET is the largest source of energy for ablation (88 W m -2 ), accounting for 64% of QM (Table 4), which is larger than previously reported (e.g. Hay and Fitzharris, 1988b;Gillett and Cullen, 2011). The main contributor to R NET during melt (QM > 0) is SW NET , which is sensitive to changes in surface albedo and variability in cloud conditions .…”

Section: Comparison To Other Multi-annual Glacier Climate Recordsmentioning

confidence: 76%

A 22 month record of surface meteorology and energy balance from the ablation zone of Brewster Glacier, New Zealand

2015

View full text Add to dashboard Cite

ABSTRACT. Multi-annual records of glacier surface meteorology and energy balance are necessary to resolve glacier-climate interactions but remain sparse, especially in the Southern Hemisphere. To address this, we present a record from the ablation zone of Brewster Glacier, New Zealand, between October 2010 and September 2012. The mean air temperature was 1.2°C at 1760 m a.s.l., with only a moderate temperature difference between the warmest and coldest months (�8°C). Long-term annual precipitation was estimated to exceed 6000 mm a -1 , with the majority of precipitation falling within a few degrees of the freezing level. The main melt season was between November and March (83% of annual ablation), but melt events occurred during all months. Annually, net radiation was positive (a source of energy) and supplied 64% of the melt energy, driven primarily by net shortwave radiation. Net longwave radiation was often positive during cloudy conditions in summer, demonstrating the radiative importance of clouds during melt. Turbulent sensible and latent heat fluxes were directed towards the surface in the summer months, accounting for just over a third of the energy for melt (34%). The energy gain associated with rainfall was small except during heavy events in summer.

show abstract

“…We use a degree day factor of 4.5 mm day-1 deg-1 as was derived for Franz Josef Glacier in the central Southern Alps (Anderson, 2003). H S is ablation from latent heat (rain on snow) which contributes ∼2% to annual ablation in the Southern Alps (Hay and Fitzharris, 1988). We tested the model by predicting ablation at the present ELA where annual snowfall is 4432 mm and no net accumulation occurs (mass balance 0).…”

Section: Temperature Effects On Snow Mass Balances In the Southern Alpsmentioning

confidence: 99%

Synoptic climate change as a driver of late Quaternary glaciations in the mid-latitudes of the Southern Hemisphere

Rother

Shulmeister

2006

Clim. Past

View full text Add to dashboard Cite

Abstract. The relative timing of late Quaternary glacial advances in mid-latitude (40-55 • S) mountain belts of the Southern Hemisphere (SH) has become a critical focus in the debate on global climate teleconnections. On the basis of glacial data from New Zealand (NZ) and southern South America it has been argued that interhemispheric synchrony or asynchrony of Quaternary glacial events is due to Northern Hemisphere (NH) forcing of SH climate through either the ocean or atmosphere systems. Here we present a glacial snow-mass balance model that demonstrates that large scale glaciation in the temperate and hyperhumid Southern Alps of New Zealand can be generated with moderate cooling. This is because the rapid conversion of precipitation from rainfall to snowfall drives massive ice accumulation at small thermal changes (1-4 • C). Our model is consistent with recent paleo-environmental reconstructions showing that glacial advances in New Zealand during the Last Glacial Maximum (LGM) and the Last Glacial Interglacial Transition (LGIT) occurred under very moderate cooling. We suggest that such moderate cooling could be generated by changes in synoptic climatology, specifically through enhanced regional flow of moist westerly air masses. Our results imply that NH climate forcing may not have been the exclusive driver of Quaternary glaciations in New Zealand and that synoptic style climate variations are a better explanation for at least some late Quaternary glacial events, in particular during the LGIT (e.g. Younger Dryas and/or Antarctic Cold Reversal).

show abstract

The synoptic climatology of ablation on a New Zealand glacier

Cited by 67 publications

References 18 publications

Atmospheric controls on summer ablation over Brewster Glacier, New Zealand

Atmospheric controls on summer ablation over Brewster Glacier, New Zealand

A 22 month record of surface meteorology and energy balance from the ablation zone of Brewster Glacier, New Zealand

Synoptic climate change as a driver of late Quaternary glaciations in the mid-latitudes of the Southern Hemisphere

Contact Info

Product

Resources

About