scholarly journals The Changing Energy Balance of the Polar Regions in a Warmer Climate

2013 ◽  
Vol 26 (10) ◽  
pp. 3112-3129 ◽  
Author(s):  
Lennart Bengtsson ◽  
Kevin I. Hodges ◽  
Symeon Koumoutsaris ◽  
Matthias Zahn ◽  
Paul Berrisford

Abstract Energy fluxes for polar regions are examined for two 30-yr periods, representing the end of the twentieth and twenty-first centuries, using data from high-resolution simulations with the ECHAM5 climate model. The net radiation to space for the present climate agrees well with data from the Clouds and the Earth’s Radiant Energy System (CERES) over the northern polar region but shows an underestimation in planetary albedo for the southern polar region. This suggests there are systematic errors in the atmospheric circulation or in the net surface energy fluxes in the southern polar region. The simulation of the future climate is based on the Intergovernmental Panel on Climate Change (IPCC) A1B scenario. The total energy transport is broadly the same for the two 30-yr periods, but there is an increase in the moist energy transport on the order of 6 W m−2 and a corresponding reduction in the dry static energy. For the southern polar region the proportion of moist energy transport is larger and the dry static energy correspondingly smaller for both periods. The results suggest a possible mechanism for the warming of the Arctic that is discussed. Changes between the twentieth and twenty-first centuries in the northern polar region show the net ocean surface radiation flux in summer increases ~18 W m−2 (24%). For the southern polar region the response is different as there is a decrease in surface solar radiation. It is suggested that this is caused by changes in cloudiness associated with the poleward migration of the storm tracks.

2008 ◽  
Vol 21 (17) ◽  
pp. 4223-4241 ◽  
Author(s):  
Seiji Kato ◽  
Fred G. Rose ◽  
David A. Rutan ◽  
Thomas P. Charlock

Abstract The zonal mean atmospheric cloud radiative effect, defined as the difference between the top-of-the-atmosphere (TOA) and surface cloud radiative effects, is estimated from 3 yr of Clouds and the Earth’s Radiant Energy System (CERES) data. The zonal mean shortwave effect is small, though it tends to be positive (warming). This indicates that clouds increase shortwave absorption in the atmosphere, especially in midlatitudes. The zonal mean atmospheric cloud radiative effect is, however, dominated by the longwave effect. The zonal mean longwave effect is positive in the tropics and decreases with latitude to negative values (cooling) in polar regions. The meridional gradient of the cloud effect between midlatitude and polar regions exists even when uncertainties in the cloud effect on the surface enthalpy flux and in the modeled irradiances are taken into account. This indicates that clouds increase the rate of generation of the mean zonal available potential energy. Because the atmospheric cooling effect in polar regions is predominately caused by low-level clouds, which tend to be stationary, it is postulated here that the meridional and vertical gradients of the cloud effect increase the rate of meridional energy transport by the dynamics of the atmosphere from the midlatitudes to the polar region, especially in fall and winter. Clouds then warm the surface in the polar regions except in the Arctic in summer. Clouds, therefore, contribute toward increasing the rate of meridional energy transport from the midlatitudes to the polar regions through the atmosphere.


2021 ◽  
Author(s):  
Giandomenico Pace ◽  
Tatiana Di Iorio ◽  
Alcide di Sarra ◽  
Antonio Iaccarino ◽  
Daniela Meloni ◽  
...  

<p>The radiative effects of clouds and their microphysical structure in Polar regions are still object of large uncertainty, that contribute to determine the large inaccuracies of climate model in the representation of clouds and their effects.</p><p>In the frame of the CLouds And Radiation in the Arctic and Antarctica (CLARA2) project, a celiometer has been installed in November 2019 at the Thule High Arctic Atmospheric Observatory, THAAO, an international infrastructure located in proximity of Thule Air Base (76.5°N, 68.8°W), Greenland (http://www.thuleatmos-it.it/) with the aim of strengthening the cloud observational capability at the Observatory already including, among the other instruments, a microwave profiler and upward- and downward-looking pyranometers and pyrgeometers operating since July 2016.</p><p>CLARA2 should have contributed to the YOPP 2020 Arctic Special Observing Period (SOP) in February-March with intensive measurements of the atmospheric vertical structure by means of a microwave profiler, a celiometer and daily radiosoundings, but the arrival of the COVID19 prevented the involved researchers to carry out the field campaign at THAAO. Nonetheless the automatic measurements were collected regularly also during the 2020 SOP.</p><p>The temporal evolution of the cloud’s presence and characteristics during the two months SOP will be presented and discussed in terms of meteorological conditions, broadband surface radiation fluxes, cloud’s geometrical characteristics, phase and liquid water path.</p>


2005 ◽  
Vol 18 (13) ◽  
pp. 2515-2530 ◽  
Author(s):  
Tido Semmler ◽  
Daniela Jacob ◽  
K. Heinke Schlünzen ◽  
Ralf Podzun

Abstract The Arctic plays a major role in the global circulation, and its water and energy budget is not as well explored as that in other regions of the world. The aim of this study is to calculate the climatological mean water and energy fluxes depending on the season and on the North Atlantic Oscillation (NAO) through the lower, lateral, and upper boundaries of the Arctic atmosphere north of 70°N. The relevant fluxes are derived from results of the regional climate model (REMO 5.1), which is applied to the Arctic region for the time period 1979–2000. Model forcing data are a combination of 15-yr European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-15) data and analysis data. The annual and seasonal total water and energy fluxes derived from REMO 5.1 results are very similar to the fluxes calculated from observational and reanalysis data, although there are some differences in the components. The agreement between simulated and observed total fluxes shows that these fluxes are reliable. Even if differences between high and low NAO situations occur in our simulation consistent with previous studies, these differences are mostly smaller than the large uncertainties due to a small sample size of the NAO high and low composites.


2021 ◽  
Author(s):  
Ines Höschel ◽  
Dörthe Handorf ◽  
Christoph Jacobi ◽  
Johannes Quaas

<p>The loss of Arctic sea ice as a consequence of global warming is changing the forcing of the atmospheric large-scale circulation.  Areas not covered with sea ice anymore may act as an additional heat source.  Associated changes in Rossby wave propagation can initiate tropospheric and stratospheric pathways of Arctic - Mid-latitude linkages.  These pathways have the potential to impact on the large-scale energy transport into the Arctic.  On the other hand, studies show that the large-scale circulation contributes to Arctic warming by poleward transport of moist static energy. This presentation shows results from research within the Transregional Collaborative Research Center “ArctiC Amplification: Climate Relevant Atmospheric and SurfaCe Processes, and Feedback Mechanisms (AC)3” funded by the Deutsche Forschungsgemeinschaft.  Using the ERA interim and ERA5 reanalyses the meridional moist static energy transport during high ice and low ice periods is compared.  The investigation discriminates between contributions from planetary and synoptic scale.  Special emphasis is put on the seasonality of the modulations of the large-scale energy transport.</p>


2014 ◽  
Vol 27 (13) ◽  
pp. 5174-5197 ◽  
Author(s):  
Jason M. English ◽  
Jennifer E. Kay ◽  
Andrew Gettelman ◽  
Xiaohong Liu ◽  
Yong Wang ◽  
...  

The Arctic radiation balance is strongly affected by clouds and surface albedo. Prior work has identified Arctic cloud liquid water path (LWP) and surface radiative flux biases in the Community Atmosphere Model, version 5 (CAM5), and reductions to these biases with improved mixed-phase ice nucleation schemes. Here, CAM5 net top-of-atmosphere (TOA) Arctic radiative flux biases are quantified along with the contributions of clouds, surface albedos, and new mixed-phase ice nucleation schemes to these biases. CAM5 net TOA all-sky shortwave (SW) and outgoing longwave radiation (OLR) fluxes are generally within 10 W m−2 of Clouds and the Earth’s Radiant Energy System Energy Balanced and Filled (CERES-EBAF) observations. However, CAM5 has compensating SW errors: Surface albedos over snow are too high while cloud amount and LWP are too low. Use of a new CAM5 Cloud–Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) lidar simulator that corrects an error in the treatment of snow crystal size confirms insufficient cloud amount in CAM5 year-round. CAM5 OLR is too low because of low surface temperature in winter, excessive atmospheric water vapor in summer, and excessive cloud heights year-round. Simulations with two new mixed-phase ice nucleation schemes—one based on an empirical fit to ice nuclei observations and one based on classical nucleation theory with prognostic ice nuclei—improve surface climate in winter by increasing cloud amount and LWP. However, net TOA and surface radiation biases remain because of increases in midlevel clouds and a persistent deficit in cloud LWP. These findings highlight challenges with evaluating and modeling Arctic cloud, radiation, and climate processes.


2021 ◽  
Author(s):  
Ines Höschel ◽  
Dörthe Handorf ◽  
Annette Rinke ◽  
Hélène Bresson

<p>Understanding the variability of energy transport and its components, and the mechanisms involved, is critical to improve our understanding of the Arctic amplification. Large amounts of energy are transported from the equator to the poles by the large-scale atmospheric circulation. At the Arctic Circle, this represents an annual average net transport of about two PW. The energy transport can be divided into latent and dry static components which, when increasing, indirectly contribute to the Arctic amplification. While the enhanced dry static energy transport favors sea ice melt and changes the lapse rate, the enhanced influx of latent energy affects the water vapor content and cloud formation, and thus also the lapse rate and sea ice melt via radiative effects.</p> <p>In this study, 40 years (1979-2018) of 6-hourly ERA-Interim reanalysis data are used to calculate the energy transport and its components. Inconsistencies due to spurious mass-flux are accounted for by barotropic wind field correction before the calculation. The first and last decade of the ERA-Interim period differ in terms of sea ice cover, sea surface temperature, and greenhouse gas concentrations, all of which affect the atmospheric circulation.</p> <p>The comparison between these periods shows significant changes in monthly and annual vertically integrated energy transport across the Arctic Circle. On an annual average, energy transport significantly increases in the late period for both total energy and its components, whereas the transport of dry static energy decreases in the winter season. The analysis of the atmospheric circulation reveals variations in the frequency of occurrence of preferred circulation regimes and the associated anomalies in energy transport as a potential cause for the observed changes.</p> <p>The hemispheric-scale and climatological view provides an expanded overall picture in terms of poleward energy transport to atmospheric events as cold air outbreaks and atmospheric rivers. This is demonstrated using the example of the atmospheric river which occurred over Svalbard on 6<sup>th</sup> & 7<sup>th</sup> June 2017.</p>


2016 ◽  
Vol 29 (11) ◽  
pp. 4137-4153 ◽  
Author(s):  
Hansi K. A. Singh ◽  
Cecilia M. Bitz ◽  
Dargan M. W. Frierson

Abstract A global climate model is used to study the effect of flattening the orography of the Antarctic Ice Sheet on climate. A general result is that the Antarctic continent and the atmosphere aloft warm, while there is modest cooling globally. The large local warming over Antarctica leads to increased outgoing longwave radiation, which drives anomalous southward energy transport toward the continent and cooling elsewhere. Atmosphere and ocean both anomalously transport energy southward in the Southern Hemisphere. Near Antarctica, poleward energy and momentum transport by baroclinic eddies strengthens. Anomalous southward cross-equatorial energy transport is associated with a northward shift in the intertropical convergence zone. In the ocean, anomalous southward energy transport arises from a slowdown of the upper cell of the oceanic meridional overturning circulation and a weakening of the horizontal ocean gyres, causing sea ice in the Northern Hemisphere to expand and the Arctic to cool. Comparison with a slab-ocean simulation confirms the importance of ocean dynamics in determining the climate system response to Antarctic orography. This paper concludes by briefly presenting a discussion of the relevance of these results to climates of the past and to future climate scenarios.


2021 ◽  
Vol 3 ◽  
Author(s):  
Michelle A. Walvoord ◽  
Robert G. Striegl

The spatial distribution and depth of permafrost are changing in response to warming and landscape disturbance across northern Arctic and boreal regions. This alters the infiltration, flow, surface and subsurface distribution, and hydrologic connectivity of inland waters. Such changes in the water cycle consequently alter the source, transport, and biogeochemical cycling of aquatic carbon (C), its role in the production and emission of greenhouse gases, and C delivery to inland waters and the Arctic Ocean. Responses to permafrost thaw across heterogeneous boreal landscapes will be neither spatially uniform nor synchronous, thus giving rise to expressions of low to medium confidence in predicting hydrologic and aquatic C response despite very high confidence in projections of widespread near-surface permafrost disappearance as described in the 2019 Intergovernmental Panel on Climate Change Special Report on the Ocean and Cryosphere in a Changing Climate: Polar Regions. Here, we describe the state of the science regarding mechanisms and factors that influence aquatic C and hydrologic responses to permafrost thaw. Through synthesis of recent topical field and modeling studies and evaluation of influential landscape characteristics, we present a framework for assessing vulnerabilities of northern permafrost landscapes to specific modes of thaw affecting local to regional hydrology and aquatic C biogeochemistry and transport. Lastly, we discuss scaling challenges relevant to model prediction of these impacts in heterogeneous permafrost landscapes.


Author(s):  
Andrew Yu. Belonosov ◽  
◽  
Michael N. Baldin ◽  
Sergey A. Sheshukov ◽  
Vladimir M. Gruznov ◽  
...  

At present, the method of passive adsorption, using German technology sorbers, is widely used to search for hydrocarbon deposits in the Polar region. Their efficiency is about 55%. The advantages of using domestic technology "ЭХО с ПКК" in the areal conditions of the Arctic are shown. This is the formation of a digital geochemical database directly during field work. To increase efficiency in the Arctic, methods of passive adsorption require significant refinement.


2010 ◽  
Vol 40 (11) ◽  
pp. 2496-2510 ◽  
Author(s):  
Leela M. Frankcombe ◽  
Henk A. Dijkstra

Abstract Observations of sea ice extent and atmospheric temperature in the Arctic, although sparse, indicate variability on multidecadal time scales. A recent analysis of one of the global climate models [the Geophysical Fluid Dynamics Laboratory Climate Model, version 2.1 (CM2.1)] in the Fourth Assessment Report (AR4) of the Intergovernmental Panel on Climate Change has indicated that Arctic Ocean variability on these time scales is associated with changes in basin-wide salinity patterns. In this paper the internal modes of variability in an idealized Arctic Basin are determined by considering the stability of salinity-driven flows. An internal ocean mode with a multidecadal time scale is found, with a spatial pattern similar to that obtained in the analysis of the CM2.1 results. The modes propagate as a “saline Rossby wave” induced by the background salinity gradient.


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