Whether the CMIP5 Models Can Reproduce the Long-Range Correlation of Daily Precipitation?

In this study, we investigated the performance of nine CMIP5 models for global daily precipitation by comparing with NCEP data from 1960 to 2005 based on the detrended fluctuation analysis (DFA) method. We found that NCEP daily precipitation exhibits long-range correlation (LRC) characteristics in most regions of the world. The LRC of daily precipitation over the central of North American continent is the strongest in summer, while the LRC of precipitation is the weakest for the equatorial central Pacific Ocean. The zonal average scaling exponents of NCEP daily precipitation are smaller in middle and high latitudes than those in the tropics. The scaling exponents are above 0.9 over the tropical middle and east Pacific Ocean for the year and four seasons. Most CMIP5 models can capture the characteristic that zonal mean scaling exponents of daily precipitation reach the peak in the tropics, and then decrease rapidly with the latitude increasing. The zonal mean scaling exponents simulated by CMCC-CMS, GFDL-ESM2G and IPSL-CM5A-MR show consistencies with those of NCEP, while BCC_CSM1.1(m) and FGOALS-g2 cannot capture the seasonal variations of daily precipitation’s LRC. The biases of scaling exponents between CMIP5 models and NCEP are smaller in the high latitudes, and even less than the absolute value of 0.05 in some regions, including Arctic Ocean, Siberian, Southern Ocean and Antarctic. However, for Western Africa, Eastern Africa, Tropical Eastern Pacific and Northern South America, the simulated biases of scaling exponents are greater than the absolute value of 0.05 for the year and all four seasons. In general, the spatial biases of LRC simulated by GFDL-ESM2G, HadGEM2-AO and INM-CM4 are relatively small, which indicating that the LRC characteristics of daily precipitation are well simulated by these models.

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Evaluation of the Performance of CMIP5 Models to Simulate Land Surface Air Temperature Based on Long-Range Correlation

Frontiers in Environmental Science ◽

10.3389/fenvs.2021.628999 ◽

2021 ◽

Vol 9 ◽

Author(s):

Shanshan Zhao ◽

Wenping He ◽

Tianyun Dong ◽

Jie Zhou ◽

Xiaoqiang Xie ◽

...

Keyword(s):

Long Range ◽

Air Temperature ◽

Land Surface ◽

Surface Air Temperature ◽

Cmip5 Models ◽

Fluctuation Analysis ◽

Distribution Characteristics ◽

Scaling Exponents ◽

Zonal Distribution ◽

Range Correlation

The daily average land surface air temperature (SAT) simulated by 8 CMIP5 models historical experiments and that from NCEP data during 1960–2005, are used to evaluate the performance of the CMIP5 model based on detrended fluctuation analysis (DFA) method. The DFA results of NCEP data show that SAT in most regions of the world exhibit long-range correlation. The scaling exponents of NCEP SAT show the zonal distribution characteristics of larg in tropics while small in medium and high latitudes. The distribution characteristics of the zonal average scaling exponents of CMCC-CMS, GFDL-ESM2G, IPSL-CM5A-MR are similar to that of NCEP data. From the DFA errors of model-simulated SAT, the performance of IPSL-CM5A-MR is the best among the 8 models throughout the year, the performance of FGOALS-g2 is good in spring and summer, GFDL-ESM2G is the best in autumn, CNRM-CM5 and CMCC-CMS is good in winter. The scaling exponents of model-simulated SAT are closer to that of NCEP data in most areas of the mid-high latitude on the northern hemisphere. However, simulations of SAT in East Asia and Central North American are generally less effective. In spring, most models have better performance in Siberian (SIB), Central Asia (CAS) and Tibetan (TIB). SAT in Northern Europe area are well simulated by most models in summer. In autumn, areas with better performance of most models are Mediterranean, SIB and TIB regions. In winter, SAT in Greenland, SIB and TIB areas are well simulated by most models. Generally speaking, the performance of CMIP5 models for SAT on global continents varies in different seasons and different regions.

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Comparison of land surface humidity between observations and CMIP5 models

Earth System Dynamics ◽

10.5194/esd-8-719-2017 ◽

2017 ◽

Vol 8 (3) ◽

pp. 719-747 ◽

Cited By ~ 9

Author(s):

Robert J. H. Dunn ◽

Kate M. Willett ◽

Andrew Ciavarella ◽

Peter A. Stott

Keyword(s):

Relative Humidity ◽

Land Surface ◽

Radiative Forcing ◽

Specific Humidity ◽

Cmip5 Models ◽

High Latitudes ◽

Entire Study ◽

Temporal Behaviour ◽

Global Average ◽

The Tropics

Abstract. We compare the latest observational land surface humidity dataset, HadISDH, with the latest generation of climate models extracted from the CMIP5 archive and the ERA-Interim reanalysis over the period 1973 to present. The globally averaged behaviour of HadISDH and ERA-Interim are very similar in both humidity measures and air temperature, on decadal and interannual timescales. The global average relative humidity shows a gradual increase from 1973 to 2000, followed by a steep decline in recent years. The observed specific humidity shows a steady increase in the global average during the early period but in the later period it remains approximately constant. None of the CMIP5 models or experiments capture the observed behaviour of the relative or specific humidity over the entire study period. When using an atmosphere-only model, driven by observed sea surface temperatures and radiative forcing changes, the behaviour of regional average temperature and specific humidity are better captured, but there is little improvement in the relative humidity. Comparing the observed climatologies with those from historical model runs shows that the models are generally cooler everywhere, are drier and less saturated in the tropics and extra-tropics, and have comparable moisture levels but are more saturated in the high latitudes. The spatial pattern of linear trends is relatively similar between the models and HadISDH for temperature and specific humidity, but there are large differences for relative humidity, with less moistening shown in the models over the tropics and very little at high latitudes. The observed drying in mid-latitudes is present at a much lower magnitude in the CMIP5 models. Relationships between temperature and humidity anomalies (T–q and T–rh) show good agreement for specific humidity between models and observations, and between the models themselves, but much poorer for relative humidity. The T–q correlation from the models is more steeply positive than the observations in all regions, and this over-correlation may be due to missing processes in the models. The observed temporal behaviour appears to be a robust climate feature rather than observational error. It has been previously documented and is theoretically consistent with faster warming rates over land compared to oceans. Thus, the poor replication in the models, especially in the atmosphere-only model, leads to questions over future projections of impacts related to changes in surface relative humidity. It also precludes any formal detection and attribution assessment.

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Plant gross primary production, plant respiration and carbonyl sulfide emissions over the globe inferred by atmospheric inverse modelling

10.5194/acp-2021-326 ◽

2021 ◽

Author(s):

Marine Remaud ◽

Frédéric Chevallier ◽

Fabienne Maignan ◽

Sauveur Belviso ◽

Antoine Berchet ◽

...

Keyword(s):

Pacific Ocean ◽

Primary Production ◽

Gross Primary Production ◽

Inverse System ◽

Striking Similarity ◽

High Latitudes ◽

The Pacific ◽

The Pacific Ocean ◽

The Tropics ◽

Plant Respiration

Abstract. Carbonyl Sulphide (COS), a trace gas showing striking similarity to CO2 in terms of biochemical diffusion pathway into leaves, has been recognized as a promising indicator of the plant gross primary production (GPP), the amount of carbon dioxide that is absorbed through photosynthesis by terrestrial ecosystems. However, large uncertainties about the other components of its atmospheric budget prevent us from directly relating the atmospheric COS measurements to GPP. The largest uncertainty comes from the closure of its atmospheric budget, with a source component missing. Here, we explore the benefit of assimilating both COS and CO2 measurements into the LMDz atmospheric transport model to obtain consistent information on GPP, plant respiration and COS budget. To this end, we develop an analytical inverse system that optimizes biospheric fluxes for the 15 plant functional types (PFTs) defined in the ORCHIDEE global land surface model. Plant uptake of COS is parameterized as a linear function of GPP of the leaf relative uptake (LRU), which is the ratio of COS to CO2 deposition velocities in plants. A possible scenario for the period 2008–2019 leads to a global biospheric sink of 800 GgS.yr−1, with higher absorption in the high latitudes and higher oceanic emissions between 400 and 600 GgS.yr−1 most of which is located in the tropics. As for the CO2 budget, the inverse system increases GPP in the high latitudes by a few GtC.yr−1 without modifying the respiration compared to the ORCHIDEE fluxes used as a prior. In contrast, in the tropics the system tends to weaken both respiration and GPP. The optimized components of the COS and CO2 have been evaluated against independent measurements over Northern America, the Pacific Ocean, at three sites in Japan and at one site in France. Overall, the posterior COS concentrations are in better agreement with the COS retrievals at 250 hPa from the MIPAS satellite and with airborne measurements made over North America and the Pacific Ocean. The system seems to have rightly corrected the underestimated GPP over the high latitudes. However, the change in seasonality of GPP in the tropics disagrees with Solar Induced Fluorescence (SIF) data. The decline in biospheric sink in the Amazon driven by the inversion also disagrees with MIPAS COS retrievals at 250 hPa, highlighting the lack of observational constraints in this region. Moreover, the comparison with the surface measurements in Japan and France suggests misplaced sources in the prior anthropogenic inventory, emphasizing the need for an improved inventory to better partition oceanic and continental sources in Asia and Europe.

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AN EMPIRICAL STUDY ON THE STATISTICAL PROPERTIES OF ROMANIAN EMERGING STOCK MARKET RASDAQ

International Journal of Theoretical and Applied Finance ◽

10.1142/s021902490400261x ◽

2004 ◽

Vol 07 (06) ◽

pp. 723-739 ◽

Cited By ~ 1

Author(s):

MIRCEA GLIGOR

Keyword(s):

Stock Market ◽

Long Range ◽

Composite Index ◽

Nonlinear Function ◽

Stock Index ◽

Absolute Value ◽

New Information ◽

Range Correlation ◽

Long Time ◽

Index Changes

An empirical analysis of the Romanian emerging stock market RASDAQ based on the statistical study of the composite index RASDAQ-C reveals the leptokurtic profile of the probability density function (p.d.f.) of the stock index changes, the power law asymptotic behaviour of the p.d.f., the breakdown of scaling at long time scales, the absence of linear correlation in the stock index changes but existence of long-range correlation in nonlinear function such as the absolute value or the square of index changes (implicitly the long-range correlation in the index volatility). These results, consistent with the similar referring to the more liquid markets, suggest the presence of several universal features, in addition to several particularities related to the quickness of assimilation of the new information and its impact over the investors.

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Quantifying Fractal Dynamics of Metallogenic Systems with Detrended Fluctuation Analysis

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.249-250.26 ◽

2012 ◽

Vol 249-250 ◽

pp. 26-30 ◽

Cited By ~ 1

Author(s):

Li Wan ◽

Peng Chen ◽

Zhao Xian Gong

Keyword(s):

Long Range ◽

Scale Invariance ◽

Detrended Fluctuation Analysis ◽

Dynamic Mechanism ◽

Fluctuation Analysis ◽

Fractional Dynamics ◽

Scaling Exponents ◽

Range Correlation ◽

Detrended Fluctuation

In this paper, we analysed fractional dynamics behavior in metallogenic elements grade series, using detrended fluctuation analysis (DFA), with the objective to explore and understand the underlying dynamic mechanism. Our results show that the metallogenic elements grade series are the scale invariance and the long-range correlation. As in the case of element grade dynamics, the DFA scaling exponents can be used to discriminate mineral intensity.

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Comparison of land–surface humidity between observations and CMIP5 models

10.5194/esd-2017-9 ◽

2017 ◽

Cited By ~ 1

Author(s):

Robert J. H. Dunn ◽

Kate M. Willett ◽

Andrew Ciavarella ◽

Peter A. Stott

Keyword(s):

Relative Humidity ◽

Land Surface ◽

Radiative Forcing ◽

Specific Humidity ◽

Cmip5 Models ◽

High Latitudes ◽

Entire Study ◽

Temporal Behaviour ◽

Global Average ◽

The Tropics

Abstract. We compare the latest observational land-surface humidity dataset, HadISDH, with the latest generation of climate models extracted from the CMIP5 archive and the ERA-Interim reanalysis over the period 1973 to present. The globally averaged behaviour of HadISDH and ERA-Interim are very similar in both humidity measures and air temperature, at decadal and interannual timescales. The global average relative humidity shows a gradual increase from 1973 to 2000, followed by a steep decline in recent years. The observed specific humidity shows a steady increase in the global average during the early period but in the later period it remains approximately constant. None of the CMIP5 models or experiments capture the observed behaviour of the relative or specific humidity over the entire study period. When using an atmosphere-only model, driven by observed sea-surface temperatures and radiative forcing changes, the behaviour of regional average temperature and specific humidity are better captured, but there is little improvement in the relative humidity. Comparing the observed and historical model climatologies show that the models are generally cooler everywhere, are drier and less saturated in the tropics and extra tropics, and have comparable moisture levels but are more saturated in the high latitudes. The spatial pattern of linear trends are relatively similar between the models and HadISDH for temperature and specific humidity, but there are large differences for relative humidity, with less moistening shown in the models over the Tropics, and very little at high latitudes. The observed drying in mid-latitudes is present at a much lower magnitudes. Relationships between temperature and humidity anomalies (T–q and T–rh) show good agreement for specific humidity between models and observations, and between the models themselves, but much poorer for relative humidity. The T–q correlation from the models is more steeply positive in all regions than the observations, and this over-correlation may be due to missing processes in the models. The observed temporal behaviour appears to be a robust climate feature rather than observational error. It has been previously documented and is theoretically consistent with faster warming rates over land compared to oceans. Thus, the poor replication in the models, especially in the atmosphere only model, leads to questions over future projections of impacts related to changes in surface relative humidity. It also precludes any formal detection and attribution assessment.

Download Full-text