We present an efficient and flexible tool that finds a subset of models with improved mean performance compared to the multi-model mean while at the same time maintaining the spread and addressing the problem of model interdependence. Out-of-sample skill and reliability are demonstrated using model-as-truth experiments. Atmospheric Infrared Sounder (AIRS) satellite observations are used to quantify the scale-dependent variance of temperature and water vapor in the atmosphere. The scale dependence is much more variable than thought previously, using a new methodology based on individual satellite swaths. A break in the scale dependence is found to vary from less than 100 to greater than 1000 km.
Focus is placed on the evaluation of newly implemented parameterisations of the biological carbon pump (i.e. the sinking of particular organic carbon). We find that the model previously underestimated the carbon transport into the deep ocean below 2000 m depth. is increased at a rate of 1 % annually until stabilized. Our study suggests that expansion in the Pacific Ocean within the model is controlled largely by changes in particulate organic carbon export (POC). The vertical expansion of the OMZs in the Indian and Atlantic oceans is linked to reduced oxygen solubility.
It is known that its conductivity mechanisms are governed by a redox comproportionation reaction. However, most studies devoted to the redox chemistry of eumelanin lack the data on the temperature behavior of its properties. We use broadband dielectric spectroscopy and heat capacity measurements to study the influence of hydration and temperature on eumelanin’s conductivity.
Finally, this allows for process discussion. We have applied the HTAP phase II multi-model data to investigate the long-range transport impacts on surface concentration and column density of PM from Europe and Russia, Belarus, and Ukraine to eastern Asia, with a special focus on the long-range transport contribution during haze episodes in China. We found that long-range transport plays a more important role in elevating the background concentration of surface PM during the haze days. This paper provides an overview of a coordinated international experiment to determine the strengths and weaknesses in how climate models treat snow.
The Scenario Model Intercomparison Project (ScenarioMIP) will provide multi-model climate projections based on alternative scenarios of future emissions and land use changes produced with integrated assessment models. The design consists of eight alternative 21st century scenarios plus one large initial condition ensemble and a set of long-term extensions. Climate model projections will facilitate integrated studies of climate change as well as address targeted scientific questions.
temperature change for short-lived pollutants, such as methane and black carbon. Emissions from different seasons and regions are compared, for instance Europe and East Asia. The responses are calculated for four regions, where we see that the responses can be much higher in the Arctic than globally in some cases. emissions. This paper investigates atmospheric nitrate using multiple global models and measurements.
The paper introduces a novel database of global potential surface albedo validation sites which are very well characterized in terms of their spatial heterogeneity. The database might be usefull for the validation and longterm monitoring of satellite data products and validation of satellite derived geophysical datasets. Detection and attribution of climate change is the process of determining the causes of observed climate changes, which has underpinned key conclusions on the role of human influence on climate in the reports of the Intergovernmental Panel on Climate Change (IPCC).
The MACC project is preparing the operational atmosphere service of the European Copernicus Programme, and uses data assimilation to combine atmospheric models with available observations. Our paper provides an overview of the aerosol and trace gas validation activity of MACC. Topics are the validation requirements, the measurement data, the assimilation systems, the upgrade procedure, operational aspects and the scoring methods.
We describe data sets and a methodology to quantify all major components of the global carbon budget, including their uncertainties, . based on a range of models and data and their interpretation by a broad scientific community. Dynamic global vegetation models (DGVMs) are used to predict the response of vegetation to climate change. We improved the representation of carbon uptake by ecosystems in a DGVM by including a wider range of trade-offs between nutrient allocation to photosynthetic capacity and leaf structure, based on observed plant traits from a worldwide data base.
We report on the experimental study of scattering and the near-field interaction of a THz electromagnetic field with graphene layers near the probe of a terahertz near-field microscope. There are resonance lines in the spectrum for a graphene monolayer-based transistor structure, which is possibly due to the strong plasmon response at terahertz frequencies and the manifestation of plasmon interference in the graphene strip.
News from the Art and Academic Worlds
This highlights the important interplay between atmospheric chemistry and dynamics. Dynamic global vegetation models are used for studying historical and future changes to vegetation and the terrestrial carbon cycle. JULES is a DGVM that represents the land surface in the UK Earth System Model. We compared simulated gross and net primary productivity of vegetation, vegetation distribution, and aspects of the transient carbon cycle to observational datasets. JULES was able to accurately reproduce many aspects of the terrestrial carbon cycle with the recent improvements.
Terrestrial carbon feedbacks are a large uncertainty in climate change. We separate modeled feedback responses into those governed by changed carbon inputs (productivity) and changed outputs (turnover).
We used two different sea-level data sets and several climatic data sets. The results of this study showed that precipitation has a lagged effect on decadal sea-level trend variations from which the signature of atmospheric effect is removed. This detected underlying factor is not connected to oceanic forcing driven from the North Atlantic region. Long-term variations in the Siberian river discharges of the Lena in the east and the Ob in the west were examined based on the observations, tree-ring reconstructions, and simulations with atmospheric and climate models.
How should climate model simulations be combined to produce an overall assessment that reflects both their performance and their interdependencies? This paper presents a strategy for weighting climate model output such that models that are replicated or models that perform poorly in a chosen set of metrics are appropriately weighted.
This paper presents new laboratory measurements of the shortwave mass absorption efficiency (MAE) used by climate models for mineral dust of different origin and at different sizes. We found that small particles are more efficient, by given mass, in absorbing radiation, particularly at shorter wavelength. Because dust has high concentrations in the atmosphere, light absorption by mineral dust can be competitive to other absorbing atmospheric aerosols such as black and brown carbon.