Surface energy balance on a polythermal glacier, Arctic, and the role of poleward atmospheric moisture transport

In recent years, increasing moisture over the Arctic and subarctic regions shows that the Arctic is experiencing wetting conditions, and poleward atmospheric moisture transport (PAMT) plays a vital role in the atmosphereice/snow interactions in the Arctic. To identify the effect of PAMT on the surface energy balance (SEB) for the Arctic glacier, meteorological data from an automatic weather station (AWS) at 377 m a.s.l. on the Austre Love & PRIME;nbreen glacier, as well as the ERA5 reanalysis data from 30 April 2014 to 30 April 2015, were analyzed in this paper. Our results show that the net shortwave radiation (Snet) (18 W m- 2, 55%), turbulent sensible (H) (14 W m- 2, 43%) and subsurface heat flux (G) (1 W m- 2, 2%) act as the energy sources, while the net longwave radiation (Lnet) (-19 W m- 2, 56%), melt energy (Qm) (-12 W m- 2, 35%) and turbulent latent heat flux (LE) (-3 W m- 2, 9%) represent the heat sink. The development process of Atmospheric River (AR), primary form of PAMT, near the Svalbard in February 2015 was revealed according to the total column water vapor, 850 hPa winds and geopotential height fields. Compared to summer, the glacier SEB was more affected in winter by PAMT, leading to a frequent overcast and thus increasing air temperature, moisture, and wind speed, all of which are variables governing the SEB by decreasing H, LE and G less than increasing the Lnet. Our findings obtained here can help to better understand the diverse SEB change on the high Arctic glacier from the perspective of PAMT and large-scale atmospheric circulations anomalies.

Automated summary

In recent years, increased moisture in the Arctic and subarctic regions indicates wetting conditions in the Arctic, with poleward atmospheric moisture transport (PAMT) playing a crucial role in the interactions between the atmosphere, ice, and snow. This study analyzed meteorological data from an automatic weather station on the Austre Love & PRIME;nbreen glacier and ERA5 reanalysis data to examine the effect of PAMT on the surface energy balance (SEB) of the Arctic glacier. The results showed that Snet, H, and G acted as energy sources, while Lnet, Qm, and LE represented the heat sink. The study revealed the development process of an Atmospheric River (AR), a primary form of PAMT near Svalbard in February 2015. The findings highlight the stronger influence of PAMT on the glacier's SEB in winter, affecting variables such as air temperature, moisture, and wind speed.