A two-dimensional energy balance climate model on Mars

A two-dimensional energy balance climate model has been built to investigate the climate on Mars.The model takes into account the balance among solar radiation,longwave radiation,and energy transmission and can be solved analytically by Legendre polynomials.With the parameters for thermal diffusion and radiation processes being properly specified,the model can simulate a reasonable surface atmospheric temperature distribution but not a very perfect vertical atmospheric temperature distribution compared with numerical results,such as those from the Mars Climate Database.With varying solar radiation in a Martian year,the model can simulate the seasonal variation of the air temperature on Mars.With increasing dust content,the Martian atmosphere gradually warms.However,the warming is insignificant in the cold and warm scenarios,in which the dust mixing ratio varies moderately,whereas the warming is significant in the storm scenario,in which the dust mixing ratio increases dramatically.With an increasing albedo value of either the polar cap or the non-ice region,Mars gradually cools.The mean surface atmospheric temperature decreases moderately with an increasing polar ice albedo,whereas it increases dramatically with an increasing non-ice albedo.This increase occurs because the planetary albedo of the ice regions is smaller than that of the non-ice region.

Energy Security and Climate Change in the European Union,China and Latin American Relationships:Major Challenges and Areas of International Cooperation

The author discusses the subject in both ecological and political perspectives based on a most comprehensive,authoritative and updated bibliography.Hence,Latin America and the Caribbean(LAC) is as much diversified as there are sub-regions and regional organizations in geopolitical and geo-economical terms and often dialectic regarding energy security,climate change and LAC ties with Europeans and China and so is the tripartite relations with the rest of the world so far as energy security and climate cha...

Sustainability of Wind Energy under Changing Wind Regimes—A Case Study

A method was introduced to assess the sustainability of energy production over the lifetime (~20 y) of wind turbines. Community Earth System Model simulations were downscaled for the tourist seasons (mid-May to mid-September) of 2006 to 2012 (CESM-P1) and 2026 to 2032 (CESM-P2) to obtain a reference and projected wind-speed climatology, respectively. The wind speeds served to calculate the potential power output and capacity factors of seven turbine types. CESM-P1 wind-speed climatology, power output, and capacity factors were compared to those derived from wind speeds obtained by numerical weather forecasts for reference to known standard to wind-farm managers. Juneau, Alaska served as a virtual testbed as this region is known to experience changes in wind speeds in response to the Pacific Decadal Oscillation. CESM-P2 suggested about 2% decrease for wind speeds between the speeds at cut-in and rated power, and about 8% - 10% decrease in potential wind-power output. This means that in regions of decadal climate variations, the sustainability of wind-energy production should be part of the decision-making process. The study demonstrated that using mean values of wind-speeds can provide qualitative knowledge about decreases/increases in potential energy production, but not about the magnitude. Using the total individual wind-speed data of all seasons provided the same amount of total power output than summing up the power outputs of individual seasons. The main advantage of calculating individual seasonal wind-power outputs, however, is that it theoretically permits assessment of interannual variability in power output and capacity factors. Comparison to a known standard may help stakeholders in understanding of uncertainty and interpretation of projected changes.

China and the United States’ Critical Roles in Tackling Climate Change and Shaping the International Regimes

This paper argues that major powers can play critical roles in a complicated regime system,as evidenced by China and the U.S.which have had pivotal influence in the construction of the post-2020 climate regime.China and the U.S.have participated in multilateral consultations beyond the scope of the United Nations Framework Convention on Climate Change(UNFCCC)while making use of many political platforms,such as Asia-Pacific Economic Cooperation(APEC),G20,and informal meetings and dialogues to bridge the gap among various approaches to mitigating climate impacts.China-U.S.bilateral cooperation has incorporated energy and climate issues into the strategic and economic dialogue(S&ED)and launched other schemes,such as EcoPartnerships and wide-ranging dialogues and initiatives on clean energy/clean vehicles.These schemes support the reconciliation of ideas related to domestic abatement policies in the areas of energy,climate change,and environmental protection.Since the Trump administration came to power in 2017,the bilateral cooperation at national level has been retreated significantly and therefore slowdown the UN’s institutional response to climate change.At the stage,the U.S.may not be able to play a critical role in shaping the regime,yet China is regarded to be the most important player in negotiations under the Paris Agreement.

China-Brazil Forum on Climate Change and Energy Technology Innovation

The China-Brazil Forum on Climate Change and Energy Technology Innovation opened in Tsinghua＇s Main Building on January 14, 2009. Mr. Samuel Pinheiro Guimaraes, Brazilian Vice-Minister for Foreign Issues, Professor Luiz Pinguelli Rosa, Federal University of Rio de Janeiro, Director of COPPE, and representatives from Brazil＇s Embassy in China attended the Forum.

Choosing heat sinks for cooling in tropical climates

Efforts to limit CO2 emissions from buildings in the tropics either focus on reducing energy demand, i.e., air-conditioning, or on replacing fossil with renewable sources. The link between energy demand and supply is often overlooked, especially the effect of the temperature lift of air-conditioning systems on energy consumption. But while heat and humidity gains define energy demand, operating temperatures of the system define the necessary energy input. We aim to transfer our experience of usin~ the LowEx paradigm for heat pump systems in moderate climates to the tropical climate of Sinsapore. In this paper, we took a systematic overview of a range of heat sinks, to which we refer to as anergy sinks. We analysed their thermal properties and their effect on the performance of air-conditioning systems, expressed as COP. The predominantly used dry air-cooled condenser units performed worst, especially when subject to a stack effect in （semi-）confined spaces. The performance is highest for cooling towers using the wet bulb temperature followed by water body based anergy sinks and the soil. The wide spread of results confirms that the heat rejection temperature is a decisive factor for the performance of the overall cooting system and the input of primary energy.