Anthropogenically forced increases in compound dry and hot events at the global and continental scales

Abstract Remarkable increases in compound dry and hot events (CDHEs) have been observed in different regions in recent decades. However, the anthropogenic influence on the long-term changes in CDHEs at the global scale has been largely unquantified. In this study, we provide evidence that anthropogenic forcings have contributed to the increased CDHEs over global land areas. We compare the spatial and temporal changes in CDHEs based on climate model simulations from Coupled Model Intercomparison Project Phase 6 (CMIP6) and observations from different datasets. Results show observed occurrences of CDHEs have increased over most regions across global land areas during 1956–2010 relative to 1901–1955. In addition, we find a temporal increase in observed occurrences of CDHEs averaged over global land areas and different continents (except Antarctica) for the period 1901–2010 (with a larger increase during 1951–2010). The spatial and temporal changes in historical all-forcing simulations (with both anthropogenic and natural components) are overall consistent with observations, while those in historical natural-forcing simulations diverge substantially from observations, heightening the key role of anthropogenic forcings in increased CDHEs. Furthermore, we use the probability ratio (PR) to quantify the contribution of anthropogenic forcings to the likelihood of CDHEs since the mid-20th century (1951–2010). We find anthropogenic influences have increased the risk of CDHEs in large regions across the globe except for parts of Eurasia and North America. Overall, our study highlights the important role of anthropogenic influences in increased CDHEs from a global perspective. The mitigation of climate change is thus paramount to reduce the risk of compound dry and hot events.

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The Impact of the Global, Extensible Electronic Health Record

Managing Healthcare Information Systems with Web-Enabled Technologies ◽

10.4018/978-1-878289-65-0.ch001 ◽

2011 ◽

pp. 3-13 ◽

Cited By ~ 2

Author(s):

David W. Forslund ◽

David G. Kilman

Keyword(s):

Electronic Health Records ◽

Negative Impact ◽

Global Scale ◽

Global Perspective ◽

Health Records ◽

Technological Advances ◽

The World ◽

Electronic Health ◽

The Impact

With the arrival of the “World Wide Web,” we have witnessed a transition toward a truly global perspective with respect to electronic health records. In recent years, much more discussion has focused on the potential for international virtual electronic health records and what is required for them to become a reality in the world today (Kilman & Forslund, 1997). As the Internet becomes more ubiquitous and Web-enabled, we see access to electronic health records using these technologies becoming more commonplace. Even so, these Web-enabled health records still remain technologically isolated from other medical records in the distributed continuum of care; much of the standardization challenge still stands before us. We have witnessed startling technological advances, but we still face considerable obstacles to the goal of having globally standardized electronic health records. In this chapter we describe some of the issues associated with Web-enabled health records, the role of standards in the evolution of Web-enabled health records, and some of the barriers to the development of globally accessible electronic health records. We discuss possible ways to overcome these barriers and the kinds of benefits and opportunities that global health records will help provide. The global scale perspective makes more evident the very real and potentially tragic consequences of prolonged and unnecessary delays in deploying these technologies. Therefore, in an effort to promote a fuller consciousness of health safety, the chapter concludes with a comparative look at the negative impact of impediments in the movement toward global extensible electronic health records.

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Review of “Further Insights on the Role of Accurate State Estimation in Coupled Model Parameter Estimation by a Simple Climate Model Study” by Yu et al.

10.5194/npg-2016-52-rc2 ◽

2016 ◽

Author(s):

Anonymous

Keyword(s):

Parameter Estimation ◽

State Estimation ◽

Climate Model ◽

Coupled Model ◽

Simple Climate Model ◽

Model Parameter ◽

Model Parameter Estimation ◽

Model Study

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Spatial and temporal changes in SO<sub>2</sub> regimes over China in the recent decade and the driving mechanism

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-18063-2018 ◽

2018 ◽

Vol 18 (24) ◽

pp. 18063-18078 ◽

Cited By ~ 16

Author(s):

Ting Wang ◽

Pucai Wang ◽

Nicolas Theys ◽

Dan Tong ◽

François Hendrick ◽

...

Keyword(s):

South China ◽

North China ◽

Function Analysis ◽

General Rule ◽

Industrial Sector ◽

Temporal Changes ◽

Driving Mechanism ◽

So2 Emissions ◽

Spatial And Temporal Changes

Abstract. The spatial and temporal changes in SO2 regimes over China during 2005 to 2016 and their associated driving mechanism are investigated based on a state-of-the-art retrieval dataset. Climatological SO2 exhibits pronounced seasonal and regional variations, with higher loadings in wintertime and two prominent maxima centered in the North China Plain and the Cheng-Yu District. In the last decade, overall SO2 decreasing trends have been reported nationwide, with spatially varying downward rates according to a general rule – the higher the SO2 loading, the more significant the decrease. However, such decline is in fact not monotonic, but instead four distinct temporal regimes can be identified by empirical orthogonal function analysis. After an initial rise at the beginning, SO2 in China undergoes two sharp drops in the periods 2007–2008 and 2014–2016, amid which 5-year moderate rebounding is sustained. Despite spatially coherent behaviors, different mechanisms are tied to North China and South China. In North China, the same four regimes are detected in the time series of emission that is expected to drive the regime of atmospheric SO2, with a percentage of explained variance amounting to 81 %. Out of total emission, those from the industrial sector dominate SO2 variation throughout the whole period, while the role of household emission remains uncertain. In contrast to North China, SO2 emissions in South China exhibit a continuous descending tendency, due to the coordinated cuts of industrial and household emissions. As a result, the role of emissions only makes up about 45 % of the SO2 variation, primarily owing to the decoupled pathways of emission and atmospheric content during 2009 to 2013 when the emissions continue to decline but atmospheric content witnesses a rebound. Unfavorable meteorological conditions, including deficient precipitation, weaker wind speed and increased static stability, outweigh the effect of decreasing emissions and thus give rise to the rebound of SO2 during 2009 to 2013.

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The role of the winter residual circulation in the summer mesopause regions in WACCM

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-4217-2018 ◽

2018 ◽

Vol 18 (6) ◽

pp. 4217-4228 ◽

Cited By ~ 1

Author(s):

Maartje Sanne Kuilman ◽

Bodil Karlsson

Keyword(s):

Planetary Wave ◽

Climate Model ◽

Zonal Flow ◽

Global Scale ◽

Wave Activity ◽

Latitudinal Gradients ◽

Residual Circulation ◽

Mean Flow ◽

Vertically Propagating

Abstract. High winter planetary wave activity warms the summer polar mesopause via a link between the two hemispheres. Complex wave–mean-flow interactions take place on a global scale, involving sharpening and weakening of the summer zonal flow. Changes in the wind shear occasionally generate flow instabilities. Additionally, an altering zonal wind modifies the breaking of vertically propagating gravity waves. A crucial component for changes in the summer zonal flow is the equatorial temperature, as it modifies latitudinal gradients. Since several mechanisms drive variability in the summer zonal flow, it can be hard to distinguish which one is dominant. In the mechanism coined interhemispheric coupling, the mesospheric zonal flow is suggested to be a key player for how the summer polar mesosphere responds to planetary wave activity in the winter hemisphere. We here use the Whole Atmosphere Community Climate Model (WACCM) to investigate the role of the summer stratosphere in shaping the conditions of the summer polar mesosphere. Using composite analyses, we show that in the absence of an anomalous summer mesospheric temperature gradient between the equator and the polar region, weak planetary wave forcing in the winter would lead to a warming of the summer mesosphere region instead of a cooling, and vice versa. This is opposing the temperature signal of the interhemispheric coupling that takes place in the mesosphere, in which a cold and calm winter stratosphere goes together with a cold summer mesopause. We hereby strengthen the evidence that the variability in the summer mesopause region is mainly driven by changes in the summer mesosphere rather than in the summer stratosphere.

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The Met Office Unified Model Global Atmosphere 7.0/7.1 and JULES Global Land 7.0 configurations

Geoscientific Model Development ◽

10.5194/gmd-12-1909-2019 ◽

2019 ◽

Vol 12 (5) ◽

pp. 1909-1963 ◽

Cited By ~ 106

Author(s):

David Walters ◽

Anthony J. Baran ◽

Ian Boutle ◽

Malcolm Brooks ◽

Paul Earnshaw ◽

...

Keyword(s):

Land Surface ◽

Radiative Forcing ◽

Climate Model ◽

Land Surface Model ◽

Coupled Model ◽

Unified Model ◽

Surface Radiation ◽

Surface Model ◽

Anthropogenic Aerosol ◽

Global Land

Abstract. We describe Global Atmosphere 7.0 and Global Land 7.0 (GA7.0/GL7.0), the latest science configurations of the Met Office Unified Model (UM) and the Joint UK Land Environment Simulator (JULES) land surface model developed for use across weather and climate timescales. GA7.0 and GL7.0 include incremental developments and targeted improvements that, between them, address four critical errors identified in previous configurations: excessive precipitation biases over India, warm and moist biases in the tropical tropopause layer (TTL), a source of energy non-conservation in the advection scheme and excessive surface radiation biases over the Southern Ocean. They also include two new parametrisations, namely the UK Chemistry and Aerosol (UKCA) GLOMAP-mode (Global Model of Aerosol Processes) aerosol scheme and the JULES multi-layer snow scheme, which improve the fidelity of the simulation and were required for inclusion in the Global Atmosphere/Global Land configurations ahead of the 6th Coupled Model Intercomparison Project (CMIP6). In addition, we describe the GA7.1 branch configuration, which reduces an overly negative anthropogenic aerosol effective radiative forcing (ERF) in GA7.0 whilst maintaining the quality of simulations of the present-day climate. GA7.1/GL7.0 will form the physical atmosphere/land component in the HadGEM3–GC3.1 and UKESM1 climate model submissions to the CMIP6.

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Role of macroalgal biomass and clam fishing on spatial and temporal changes in N and P sedimentary pools in the central part of the Venice lagoon

Oceanologica Acta ◽

10.1016/s0399-1784(02)00008-7 ◽

2003 ◽

Vol 26 (1) ◽

pp. 3-13 ◽

Cited By ~ 37

Author(s):

Adriana Sfriso ◽

Chiara Facca ◽

Sonia Ceoldo ◽

Silvia Silvestri ◽

Pier Francesco Ghetti

Keyword(s):

Venice Lagoon ◽

Temporal Changes ◽

Macroalgal Biomass ◽

Spatial And Temporal Changes

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Free and Forced Variability of the Tropical Atlantic Ocean: Role of the Wind–Evaporation–Sea Surface Temperature Feedback

Journal of Climate ◽

10.1175/2010jcli3304.1 ◽

2010 ◽

Vol 23 (22) ◽

pp. 5958-5977 ◽

Cited By ~ 14

Author(s):

Salil Mahajan ◽

R. Saravanan ◽

Ping Chang

Keyword(s):

Atlantic Ocean ◽

Surface Temperature ◽

Sea Surface Temperature ◽

Climate Model ◽

Coupled Model ◽

Sea Surface ◽

Tropical Atlantic ◽

Wes Feedback ◽

Meridional Mode

Abstract The role of the wind–evaporation–sea surface temperature (WES) feedback in the low-frequency natural variability of the tropical Atlantic is studied using an atmospheric global climate model—the NCAR Community Climate Model, version 3 (CCM3)—thermodynamically coupled to a slab ocean model (SOM). The coupled model is modified to suppress the WES feedback and is compared to a control run. Singular value decomposition (SVD) analysis over the tropical Atlantic reveals that the coupled meridional mode of the Atlantic Ocean is amplified in the presence of the WES feedback. In its absence, the meridional mode still exists, but with a weaker amplitude. A feedback mechanism that involves the near-surface specific humidity is proposed to sustain the weaker Atlantic meridional mode in the absence of the WES feedback. Similar analysis of coupled model integrations when forced with an artificial El Niño–Southern Oscillation (ENSO)-like SST cycle in the Pacific reveals that in the presence of the WES feedback, the meridional mode is the preferred mode of response of the tropical Atlantic to ENSO forcing. In the absence of the WES feedback, the tropical Atlantic response is unlike the meridional mode and the effects of tropospheric warming and subsidence dominate. Regression analysis over the tropical Atlantic reveals that the meridional mode response to ENSO peaks in the spring and begins to decay in the fall in the coupled model in the presence of the WES feedback. The WES feedback also appears to be responsible for the northward migration of the ITCZ during ENSO events.

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Global-Scale Atmospheric Change with the Tibetan Plateau Uplift in a Coupled Climate Model (CESM)

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.962-965.1392 ◽

2014 ◽

Vol 962-965 ◽

pp. 1392-1399

Author(s):

Yan You Guo ◽

Cheng Shan Wang ◽

Jie Yang

Keyword(s):

Tibetan Plateau ◽

Climate Model ◽

Global Climate ◽

Regional Climate ◽

Coupled Model ◽

Vertical Motion ◽

Global Scale ◽

South Asian High ◽

The Tibetan Plateau ◽

Upper Troposphere

Large topography can affect the global climate change significantly. Many studies have revealed that the altitude of the Tibetan Plateau (TP) is related to the Asian regional climate. In order to find how the global-scale atmospheric circulation changes in response to the TP uplift in summer, a fully coupled model, Community Earth System Model (CESM), was used in this paper. Four experiments were run with the altitude of TP set to 25%, 50%, 75%, and 100% of the modern height, respectively (referred to as TP25, TP50, TP75, TP100 experiments). The results show that the uplift of the TP causes the change of the subtropical circulation over the northern hemisphere as well as the southern hemisphere. In the TP25 experiment, the South Asian High (SAH) at the 150mb is comparatively weak, and with the elevated surface heating, the vertical motion in the middle troposphere strengthens greatly. The ascending air over the TP leads to the forming and sustaining of the SAH, a dominate subsystem of the upper troposphere. The perturbation of the SAH propagates in the upper troposphere and stimulates stronger planetary waves on the globe and it also affects the circulation in the low level atmosphere. The subtropical highs over seal level strengthen over the Southern Ocean as well as the North Pacific and Atlantic Oceans. Furthermore, the westerlies around the Antarctica become stronger with the increasing altitude of the TP. This is meaningful that the stronger westerlies may be a forcing to accelerate the Cenozoic global cooling during the geological history.

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