Multiproxy surface air temperature field reconstruction for the Arctic covering the past millennium

Abstract. Sea ice melting is proposed as a primary reason for the Artic amplification, although physical mechanism of the Arctic amplification and its connection with sea ice melting is still in debate. In the present study, monthly ERA-interim reanalysis data are analyzed via cyclostationary empirical orthogonal function analysis to understand the seasonal mechanism of sea ice melting in the Arctic Ocean and the Arctic amplification. While sea ice melting is widespread over much of the perimeter of the Arctic Ocean in summer, sea ice remains to be thin in winter only in the Barents-Kara Seas. Excessive turbulent heat flux through the sea surface exposed to air due to sea ice melting warms the atmospheric column. Warmer air increases the downward longwave radiation and subsequently surface air temperature, which facilitates sea surface remains to be ice free. A 1 % reduction in sea ice concentration in winter leads to ~ 0.76 W m−2 increase in upward heat flux, ~ 0.07 K increase in 850 hPa air temperature, ~ 0.97 W m−2 increase in downward longwave radiation, and ~ 0.26 K increase in surface air temperature. This positive feedback mechanism is not clearly observed in the Laptev, East Siberian, Chukchi, and Beaufort Seas, since sea ice refreezes in late fall (November) before excessive turbulent heat flux is available for warming the atmospheric column in winter. A detailed seasonal heat budget is presented in order to understand specific differences between the Barents-Kara Seas and Laptev, East Siberian, Chukchi, and Beaufort Seas.

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Tropopause height at 78° N 16° E: average seasonal variation 2007–2010

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-39-2011 ◽

2011 ◽

Vol 11 (1) ◽

pp. 39-52

Author(s):

C. M. Hall ◽

G. Hansen ◽

F. Sigernes ◽

K. M. Kuyeng Ruiz

Keyword(s):

Climate Change ◽

Seasonal Variation ◽

Air Temperature ◽

High Latitude ◽

Column Density ◽

Surface Air Temperature ◽

The Arctic ◽

Tropopause Height ◽

Vhf Radar ◽

Ozone Column

Abstract. We present a seasonal climatology of tropopause altitude for 78° N 16° E derived from observations 2007–2010 by the SOUSY VHF radar on Svalbard. The spring minimum occurs one month later than that of surface air temperature and instead coincides with the maximum in ozone column density. This confirms similar studies based on radiosonde measurements in the arctic and demonstrates downward control by the stratosphere. If one is to exploit the potential of tropopause height as a metric for climate change at high latitude and elsewhere, it is imperative to observe and understand the processes which establish the tropopause – an understanding to which this study contributes.

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Modeling the climatic implications of the Guliya δ<sup>18</sup>O record during the past 130 ka

Climate of the Past Discussions ◽

10.5194/cpd-8-1885-2012 ◽

2012 ◽

Vol 8 (3) ◽

pp. 1885-1914

Author(s):

D. Xiao ◽

P. Zhao ◽

Y. Wang ◽

X. Zhou

Keyword(s):

North Atlantic ◽

Climate Model ◽

Surface Air Temperature ◽

Late Summer ◽

The Arctic ◽

The Past ◽

The North ◽

Precession Cycle ◽

The North Atlantic ◽

Anomalous Pattern

Abstract. Using an intermediate-complexity UVic Earth System Climate Model (UVic Model), the geographical and seasonal implications and an indicative sense of the historical climate found in the δ18O record of the Guliya ice core (hereinafter, the Guliya δ18O) are investigated under time-dependent orbital forcing with an acceleration factor of 100 over the past 130 ka. The results reveal that the simulated late-summer (August–September) Guliya surface air temperature (SAT) reproduces the 23-ka precession and 43-ka obliquity cycles in the Guliya δ18O. Furthermore, the Guliya δ18O is significantly correlated with the SAT over the Northern Hemisphere (NH), which suggests the Guliya δ18O is an indicator of the late-summer SAT in the NH. Corresponding to the warm and cold phases of the precession cycle in the Guliya temperature, there are two anomalous patterns in the SAT and sea surface temperature (SST) fields. The first anomalous pattern shows an increase in the SAT (SST) toward the Arctic, possibly associated with the joint effect of the precession and obliquity cycles, and the second anomalous pattern shows an increase in the SAT (SST) toward the equator, possibly due to the influence of the precession cycle. Additionally, the summer (winter) Guliya and NH temperatures are higher (lower) in the warm phases of Guliya late-summer SAT than in the cold phases. Furthermore, the Guliya SAT is closely related to the North Atlantic SST, in which the Guliya precipitation may act as a "bridge" linking the Guliya SAT and the North Atlantic SST.

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On Anomalous Ocean Heat Transport toward the Arctic and Associated Climate Predictability

Journal of Climate ◽

10.1175/jcli-d-15-0448.1 ◽

2016 ◽

Vol 29 (2) ◽

pp. 689-704 ◽

Cited By ~ 39

Author(s):

Marius Årthun ◽

Tor Eldevik

Keyword(s):

Heat Transport ◽

Air Temperature ◽

Time Scale ◽

Heat Content ◽

Surface Air Temperature ◽

Meridional Overturning Circulation ◽

Ocean Heat Content ◽

The Arctic ◽

Ocean Heat Transport ◽

Climate Predictability

Abstract A potential for climate predictability is rooted in anomalous ocean heat transport and its consequent influence on the atmosphere above. Here the propagation, drivers, and atmospheric impact of heat anomalies within the northernmost limb of the Atlantic meridional overturning circulation are assessed using a multicentury climate model simulation. Consistent with observation-based inferences, simulated heat anomalies propagate from the eastern subpolar North Atlantic into and through the Nordic seas. The dominant time scale of associated climate variability in the northern seas is 14 years, including that of observed sea surface temperature and modeled ocean heat content, air–sea heat flux, and surface air temperature. A heat budget analysis reveals that simulated ocean heat content anomalies are driven by poleward ocean heat transport, primarily related to variable volume transport. The ocean’s influence on the atmosphere, and hence regional climate, is manifested in the model by anomalous ocean heat convergence driving subsequent changes in surface heat fluxes and surface air temperature. The documented northward propagation of thermohaline anomalies in the northern seas and their consequent imprint on the regional atmosphere—including the existence of a common decadal time scale of variability—detail a key aspect of eventual climate predictability.

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