1
|
Lam R, Sanchez-Gonzalez A, Willson M, Wirnsberger P, Fortunato M, Alet F, Ravuri S, Ewalds T, Eaton-Rosen Z, Hu W, Merose A, Hoyer S, Holland G, Vinyals O, Stott J, Pritzel A, Mohamed S, Battaglia P. Learning skillful medium-range global weather forecasting. Science 2023; 382:1416-1421. [PMID: 37962497 DOI: 10.1126/science.adi2336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 11/01/2023] [Indexed: 11/15/2023]
Abstract
Global medium-range weather forecasting is critical to decision-making across many social and economic domains. Traditional numerical weather prediction uses increased compute resources to improve forecast accuracy but does not directly use historical weather data to improve the underlying model. Here, we introduce GraphCast, a machine learning-based method trained directly from reanalysis data. It predicts hundreds of weather variables for the next 10 days at 0.25° resolution globally in under 1 minute. GraphCast significantly outperforms the most accurate operational deterministic systems on 90% of 1380 verification targets, and its forecasts support better severe event prediction, including tropical cyclone tracking, atmospheric rivers, and extreme temperatures. GraphCast is a key advance in accurate and efficient weather forecasting and helps realize the promise of machine learning for modeling complex dynamical systems.
Collapse
|
2
|
Tropopause Characteristics Based on Long-Term ARM Radiosonde Data: A Fine-Scale Comparison at the Extratropical SGP Site and Arctic NSA Site. ATMOSPHERE 2022. [DOI: 10.3390/atmos13060965] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The variations in the characteristics of the tropopause are sensitive indicators for the climate system and climate change. By using Atmospheric Radiation Measurement (ARM) radiosonde data that were recorded at the extratropical Southern Great Plains (SGP) and Arctic North Slope of Alaska (NSA) sites over an 18-year period (January 2003 to December 2020), this study performs a fine-scale comparison of the climatological tropopause features between these two sites that are characterized by different climates. The static stability increases rapidly above the tropopause at both sites, indicating the widespread existence of a tropopause inversion layer. The structures of both the tropopause inversion layer and the stability transition layer are more obvious at NSA than at SGP, and the seasonal variation trends of the tropopause inversion layer and stability transition layer are distinctly different between the two sites. A fitting method was used to derive the fitted tropopause height and tropopause sharpness (λ). Although this fitting method may determine a secondary tropopause rather than the primary tropopause when multiple tropopause heights are identified on one radiosonde profile, the fitted tropopause heights generally agree well with the observed tropopause heights. Broad tropopause sharpness values (λ > 2 km) occur more frequently at SGP than at NSA, resulting in a greater average tropopause sharpness at SGP (1.0 km) than at NSA (0.6 km). Significant positive trends are exhibited by the tropopause heights over the two sites, with rates of increase of 23.7 ± 6.5 m yr−1 at SGP and 28.0 ± 4.0 m yr−1 at NSA during the study period.
Collapse
|
3
|
Relationships between Extratropical Precipitation Systems and UTLS Temperatures and Tropopause Height from GPM and GPS-RO. ATMOSPHERE 2022. [DOI: 10.3390/atmos13020196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
This study characterizes the relationship between extratropical precipitation systems to changes in upper troposphere and lower stratosphere (UTLS) temperature and tropopause height within different environments. Precipitation features (PFs) observed by the Global Precipitation Measurement (GPM) satellite are collocated with GPS radio occultation (RO) temperature profiles from 2014 to 2017 and classified as non-deep stratospheric intrusion (non-DSI; related to convective instability) or deep stratospheric intrusion (DSI; related to strong dynamic effects on the tropopause). Non-DSI PFs introduce warming (up to 1 K) in the upper troposphere, transitioning to strong cooling (up to −3.5 K) around the lapse rate tropopause (LRT), and back to warming (up to 2.5 K, particularly over the ocean) in the lower stratosphere. UTLS temperature anomalies for DSI events are driven predominantly by large scale dynamics, with major cooling (up to −6 K) observed from the mid-troposphere to the LRT, which transitions to strong warming (up to 4 K) in the lower stratosphere. Small and deep non-DSI PFs typically result in a lower LRT (up to 0.4 km), whereas large but weaker PFs lead to a higher LRT with similar magnitudes. DSI events are associated with larger LRT height decreases, with anomalies of almost −2 km near the deepest PFs. These results suggest intricate relationships between precipitation systems and the UTLS temperature structure. Importantly, non-DSI PF temperature anomalies show patterns similar to tropical convection, which provides unification of previous tropical research with extratropical barotropic convective impacts to UTLS temperatures.
Collapse
|
4
|
Stability of CubeSat Clocks and Their Impacts on GNSS Radio Occultation. REMOTE SENSING 2022. [DOI: 10.3390/rs14020362] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Global Navigation Satellite Systems’ radio occultation (GNSS-RO) provides the upper troposphere-lower stratosphere (UTLS) vertical atmospheric profiles that are complementing radiosonde and reanalysis data. Such data are employed in the numerical weather prediction (NWP) models used to forecast global weather as well as in climate change studies. Typically, GNSS-RO operates by remotely sensing the bending angles of an occulting GNSS signal measured by larger low Earth orbit (LEO) satellites. However, these satellites are faced with complexities in their design and costs. CubeSats, on the other hand, are emerging small and cheap satellites; the low prices of building them and the advancements in their components make them favorable for the GNSS-RO. In order to be compatible with GNSS-RO requirements, the clocks of the onboard receivers that are estimated through the precise orbit determination (POD) should have short-term stabilities. This is essential to correctly time tag the excess phase observations used in the derivation of the GNSS-RO UTLS atmospheric profiles. In this study, the stabilities of estimated clocks of a set of CubeSats launched for GNSS-RO in the Spire Global constellation are rigorously analysed and evaluated in comparison to the ultra-stable oscillators (USOs) onboard the Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC-2) satellites. Methods for improving their clock stabilities are proposed and tested. The results (i) show improvement of the estimated clocks at the level of several microseconds, which increases their short-term stabilities, (ii) indicate that the quality of the frequency oscillator plays a dominant role in CubeSats’ clock instabilities, and (iii) show that CubeSats’ derived UTLS (i.e., tropopause) atmospheric profiles are comparable to those of COSMIC-2 products and in situ radiosonde observations, which provided external validation products. Different comparisons confirm that CubeSats, even those with unstable onboard clocks, provide high-quality RO profiles, comparable to those of COSMIC-2. The proposed remedies in POD and the advancements of the COTS components, such as chip-scale atomic clocks and better onboard processing units, also present a brighter future for real-time applications that require precise orbits and stable clocks.
Collapse
|
5
|
Zheng M, Sjolte J, Adolphi F, Aldahan A, Possnert G, Wu M, Muscheler R. Solar and meteorological influences on seasonal atmospheric 7Be in Europe for 1975 to 2018. CHEMOSPHERE 2021; 263:128318. [PMID: 33297251 DOI: 10.1016/j.chemosphere.2020.128318] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 09/03/2020] [Accepted: 09/09/2020] [Indexed: 06/12/2023]
Abstract
Assessing the transport of natural radionuclides in the atmosphere provides a powerful tool to study air mass circulation. Here, we investigated the seasonal atmospheric distribution of the naturally produced 7Be in surface air over Europe between 40° N and 68° N during the period 1975-2018. The results suggest that the inter-annual variability of 7Be reflects production rates of the radionuclide induced by solar modulation of cosmic rays. Further analysis of the meteorological influences indicates that the meteorological influences on 7Be concentrations are geographically and seasonally dependent. We found that, in general, the tropopause pressure plays an important factor influencing 7Be activity for winter and spring seasons while the sea level pressure and temperature are more dominant during summer and autumn seasons. The combination of tropospheric production rates and meteorological parameters explains 24%-79% variances of the seasonal 7Be activity. We further applied a three-box model to study the influence of stratosphere-troposphere exchanges on 7Be concentrations. The simulation supports that the seasonal cycle of 7Be in Europe is controlled by two main factors: the changing height of the troposphere (seasonality of the tropopause height) and seasonal variations of the stratosphere-troposphere exchanges.
Collapse
Affiliation(s)
- Minjie Zheng
- Department of Geology, Lund University, Lund, Sweden.
| | - Jesper Sjolte
- Department of Geology, Lund University, Lund, Sweden
| | - Florian Adolphi
- Department of Geology, Lund University, Lund, Sweden; Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research, Bremerhaven, Germany; Department of Geosciences, University of Bremen, Germany
| | - Ala Aldahan
- Department of Geology, United Arab Emirates University, Al Ain, United Arab Emirates.
| | | | - Mousong Wu
- International Institute for Earth System Science, Nanjing University, Nanjing, China
| | | |
Collapse
|
6
|
High-Resolution Fengyun-4 Satellite Measurements of Dynamical Tropopause Structure and Variability. REMOTE SENSING 2020. [DOI: 10.3390/rs12101600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The dynamical tropopause is the interface between the stratosphere and the troposphere, whose variation gives indication of weather and climate changes. In the past, the dynamical tropopause height determination mainly depends on analysis and diagnose methods. While, due to the high computational cost, it is difficult to obtain tropopause structures with high spatiotemporal resolution in real time by these methods. To solve this problem, the statistical method is used to establish the dynamical tropopause pressure retrieval model based on Fengyun-4A geostationary meteorological satellite observations. Four regression schemes including random forest (RF) regression are evaluated. By comparison with GEOS-5 (the Goddard Earth Observing System Model of version 5) and ERA-Interim (European Center for Medium-Range Weather Forecasts Reanalysis-Interim) reanalysis, it is found that among the four schemes, the RF-based retrieval model is most accurate and reliable (RMSEs (root mean square errors) are 25.99 hPa and 43.05 hPa, respectively, as compared to GEOS-5 and ERA-Interim reanalysis). A series of sensitivity experiments are performed to investigate the contributions of the predictors in the RF-based model. Results suggest that 6.25 μm channel information representing the distributions of the potential vorticity and water vapor in upper troposphere has the greatest contribution, while 10.8 and 12 μm channels information have relatively weak influences. Therefore, a simplified model without involving a brightness temperature of 10.8 and 12 μm can be adopted to improve the calculation efficiency.
Collapse
|
7
|
Scherllin‐Pirscher B, Steiner AK, Kirchengast G, Schwärz M, Leroy SS. The power of vertical geolocation of atmospheric profiles from GNSS radio occultation. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2017; 122:1595-1616. [PMID: 28516029 PMCID: PMC5412943 DOI: 10.1002/2016jd025902] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Revised: 01/10/2017] [Accepted: 01/11/2017] [Indexed: 06/07/2023]
Abstract
High-resolution measurements from Global Navigation Satellite System (GNSS) radio occultation (RO) provide atmospheric profiles with independent information on altitude and pressure. This unique property is of crucial advantage when analyzing atmospheric characteristics that require joint knowledge of altitude and pressure or other thermodynamic atmospheric variables. Here we introduce and demonstrate the utility of this independent information from RO and discuss the computation, uncertainty, and use of RO atmospheric profiles on isohypsic coordinates-mean sea level altitude and geopotential height-as well as on thermodynamic coordinates (pressure and potential temperature). Using geopotential height as vertical grid, we give information on errors of RO-derived temperature, pressure, and potential temperature profiles and provide an empirical error model which accounts for seasonal and latitudinal variations. The observational uncertainty of individual temperature/pressure/potential temperature profiles is about 0.7 K/0.15%/1.4 K in the tropopause region. It gradually increases into the stratosphere and decreases toward the lower troposphere. This decrease is due to the increasing influence of background information. The total climatological error of mean atmospheric fields is, in general, dominated by the systematic error component. We use sampling error-corrected climatological fields to demonstrate the power of having different and accurate vertical coordinates available. As examples we analyze characteristics of the location of the tropopause for geopotential height, pressure, and potential temperature coordinates as well as seasonal variations of the midlatitude jet stream core. This highlights the broad applicability of RO and the utility of its versatile vertical geolocation for investigating the vertical structure of the troposphere and stratosphere.
Collapse
Affiliation(s)
- Barbara Scherllin‐Pirscher
- Wegener Center for Climate and Global Change (WEGC) and Institute for Geophysics, Astrophysics, and Meteorology/Institute of PhysicsUniversity of GrazGrazAustria
- Zentralanstalt für Meteorologie und Geodynamik (ZAMG)ViennaAustria
| | - Andrea K. Steiner
- Wegener Center for Climate and Global Change (WEGC) and Institute for Geophysics, Astrophysics, and Meteorology/Institute of PhysicsUniversity of GrazGrazAustria
| | - Gottfried Kirchengast
- Wegener Center for Climate and Global Change (WEGC) and Institute for Geophysics, Astrophysics, and Meteorology/Institute of PhysicsUniversity of GrazGrazAustria
| | - Marc Schwärz
- Wegener Center for Climate and Global Change (WEGC) and Institute for Geophysics, Astrophysics, and Meteorology/Institute of PhysicsUniversity of GrazGrazAustria
| | - Stephen S. Leroy
- School of Engineering and Applied SciencesHarvard UniversityCambridgeMassachusettsUSA
| |
Collapse
|
8
|
Aquila V, Swartz WH, Waugh DW, Colarco PR, Pawson S, Polvani LM, Stolarski RS. Isolating the roles of different forcing agents in global stratospheric temperature changes using model integrations with incrementally added single forcings. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2016; 121:8067-8082. [PMID: 29593948 PMCID: PMC5868970 DOI: 10.1002/2015jd023841] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Satellite instruments show a cooling of global stratospheric temperatures over the whole data record (1979-2014). This cooling is not linear, and includes two descending steps in the early 1980s and mid-1990s. The 1979-1995 period is characterized by increasing concentrations of ozone depleting substances (ODS) and by the two major volcanic eruptions of El Chichón (1982) and Mount Pinatubo (1991). The 1995-present period is characterized by decreasing ODS concentrations and by the absence of major volcanic eruptions. Greenhouse gas (GHG) concentrations increase over the whole time period. In order to isolate the roles of different forcing agents in the global stratospheric temperature changes, we performed a set of AMIP-style simulations using the NASA Goddard Earth Observing System Chemistry-Climate Model (GEOSCCM). We find that in our model simulations the cooling of the stratosphere from 1979 to present is mostly driven by changes in GHG concentrations in the middle and upper stratosphere and by GHG and ODS changes in the lower stratosphere. While the cooling trend caused by increasing GHGs is roughly constant over the satellite era, changing ODS concentrations cause a significant stratospheric cooling only up to the mid-1990s, when they start to decrease because of the implementation of the Montreal Protocol. Sporadic volcanic events and the solar cycle have a distinct signature in the time series of stratospheric temperature anomalies but do not play a statistically significant role in the long-term trends from 1979 to 2014. Several factors combine to produce the step-like behavior in the stratospheric temperatures: in the lower stratosphere, the flattening starting in the mid 1990's is due to the decrease in ozone depleting substances; Mount Pinatubo and the solar cycle cause the abrupt steps through the aerosol-associated warming and the volcanically induced ozone depletion. In the middle and upper stratosphere, changes in solar irradiance are largely responsible for the step-like behavior of global temperatures anomalies, together with volcanically induced ozone depletion and water vapor increases in the post-Pinatubo years.
Collapse
Affiliation(s)
- V Aquila
- Goddard Earth Science Technology & Research (GESTAR), Columbia, MD
- Johns Hopkins University, Department of Earth and Planetary Science, Baltimore, MD
- Laboratory for Atmospheric Chemistry and Dynamics (Code 614), NASA Goddard Space Flight Center, Greenbelt, MD
| | - W H Swartz
- Johns Hopkins University Applied Physics Laboratory, Laurel, MD
| | - D W Waugh
- Johns Hopkins University, Department of Earth and Planetary Science, Baltimore, MD
| | - P R Colarco
- Laboratory for Atmospheric Chemistry and Dynamics (Code 614), NASA Goddard Space Flight Center, Greenbelt, MD
| | - S Pawson
- Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD
| | | | - R S Stolarski
- Johns Hopkins University, Department of Earth and Planetary Science, Baltimore, MD
| |
Collapse
|
9
|
Jung YR, Choi DH, Baek HJ, Cho C. Changes in the Low Latitude Atmospheric Circulation at the End of the 21stCentury Simulated by CMIP5 Models under Global Warming. ATMOSPHERE 2013. [DOI: 10.14191/atmos.2013.23.4.377] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
|
10
|
Xu Y, Ke C, Wang J, Sun J, Liu Y, Harris W, Kou C. Satellite-derived estimations of spatial and seasonal variation in tropospheric carbon dioxide mass over China. Ecol Evol 2013; 3:4310-25. [PMID: 24340174 PMCID: PMC3856733 DOI: 10.1002/ece3.823] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 08/19/2013] [Accepted: 09/04/2013] [Indexed: 11/18/2022] Open
Abstract
China has frequently been questioned about the data transparency and accuracy of its energy and emission statistics. Satellite-derived remote sensing data potentially provide a useful tool to study the variation in carbon dioxide (CO2) mass over areas of the earth's surface. In this study, Greenhouse gases Observing SATellite (GOSAT) tropospheric CO2 concentration data and NCEP/NCAR reanalysis tropopause data were integrated to obtain estimates of tropospheric CO2 mass variations over the surface of China. These variations were mapped to show seasonal and spatial patterns with reference to China's provincial areas. The estimates of provincial tropospheric CO2 were related to statistical estimates of CO2 emissions for the provinces and considered with reference to provincial populations and gross regional products (GRP). Tropospheric CO2 masses for the Chinese provinces ranged from 53 ± 1 to 14,470 ± 63 million tonnes were greater for western than for eastern provinces and were primarily a function of provincial land area. Adjusted for land area troposphere CO2 mass was higher for eastern and southern provinces than for western and northern provinces. Tropospheric CO2 mass over China varied with season being highest in July and August and lowest in January and February. The average annual emission from provincial energy statistics of CO2 by China was estimated as 10.3% of the average mass of CO2 in the troposphere over China. The relationship between statistical emissions relative to tropospheric CO2 mass was higher than 20% for developed coastal provinces of China, with Shanghai, Tianjin, and Beijing having exceptionally high percentages. The percentages were generally lower than 10% for western inland provinces. Provincial estimates of emissions of CO2 were significantly positively related to provincial populations and gross regional products (GRP) when the values for the provincial municipalities Shanghai, Tianjin, and Beijing were excluded from the linear regressions. An increase in provincial GRP per person was related to a curvilinear increase in CO2 emissions, this being particularly marked for Beijing, Tianjin, and especially Shanghai. The absence of detection of specific elevation of CO2 mass in the troposphere above these municipalities may relate to the rapid mixing and dispersal of CO2 emissions or the proportion of the depth of the troposphere sensed by GOSAT.
Collapse
Affiliation(s)
- Yuyue Xu
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, Nanjing University Nanjing, 210093, Jiangsu Province, China
| | | | | | | | | | | | | |
Collapse
|
11
|
Feng S, Fu Y, Xiao Q. Is the tropopause higher over the Tibetan Plateau? Observational evidence from Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) data. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd016140] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Sha Feng
- Laboratory of Satellite Remote Sensing and Climate Environment, School of Earth and Space Sciences; University of Science and Technology of China; Hefei China
| | - Yunfei Fu
- Laboratory of Satellite Remote Sensing and Climate Environment, School of Earth and Space Sciences; University of Science and Technology of China; Hefei China
| | - Qingnong Xiao
- Laboratory of Satellite Remote Sensing and Climate Environment, School of Earth and Space Sciences; University of Science and Technology of China; Hefei China
- College of Marine Science; University of South Florida; St. Petersburg Florida USA
| |
Collapse
|
12
|
Castanheira JM, Gimeno L. Association of double tropopause events with baroclinic waves. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd016163] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
13
|
Fang Y, Fiore AM, Horowitz LW, Gnanadesikan A, Held I, Chen G, Vecchi G, Levy H. The impacts of changing transport and precipitation on pollutant distributions in a future climate. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2011jd015642] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
14
|
|
15
|
Añel JA, Antuña JC, de la Torre L, Castanheira JM, Gimeno L. Climatological features of global multiple tropopause events. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009697] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
16
|
Pawson S, Stolarski RS, Douglass AR, Newman PA, Nielsen JE, Frith SM, Gupta ML. Goddard Earth Observing System chemistry-climate model simulations of stratospheric ozone-temperature coupling between 1950 and 2005. ACTA ACUST UNITED AC 2008. [DOI: 10.1029/2007jd009511] [Citation(s) in RCA: 136] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
17
|
Seidel DJ, Randel WJ. Recent widening of the tropical belt: Evidence from tropopause observations. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2007jd008861] [Citation(s) in RCA: 205] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
18
|
Seidel DJ, Randel WJ. Variability and trends in the global tropopause estimated from radiosonde data. ACTA ACUST UNITED AC 2006. [DOI: 10.1029/2006jd007363] [Citation(s) in RCA: 177] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
|
19
|
Añel JA, Gimeno L, de la Torre L, Nieto R. Changes in tropopause height for the Eurasian region determined from CARDS radiosonde data. Naturwissenschaften 2006; 93:603-9. [PMID: 17047909 DOI: 10.1007/s00114-006-0147-5] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2005] [Revised: 06/22/2006] [Accepted: 06/25/2006] [Indexed: 10/24/2022]
Abstract
Previous studies have identified the tropopause height (TH) as a promising fingerprint of climatic change. In the present paper, we report variations in TH for the Eurasian region over the period 1973-1998 and analyse the influence of the Northern Annular Mode (NAM) on these variations. As previous studies indicate that the greatest increases in TH occur in the extratropics, we focused our attention on this area. We applied a set of homogenization procedures to radiosonde data and considered three different scenarios that take into account change points and the main volcanic eruptions over the study period. Our results demonstrate that the number of stations with positive TH trends is very sensitive to the quality of data and the methods used to remove inhomogeneities. Consequently, when change points were included in the analysis, the number of stations with positive trends decreased markedly. Furthermore, stratospheric NAM appears to control TH in stations located at latitudes higher than 55 degrees N.
Collapse
Affiliation(s)
- Juan A Añel
- Facultad de Ciencias de Ourense, Universidad de Vigo, Ourense, Spain.
| | | | | | | |
Collapse
|
20
|
|
21
|
Manning MR, Lowe DC, Moss RC, Bodeker GE, Allan W. Short-term variations in the oxidizing power of the atmosphere. Nature 2005; 436:1001-4. [PMID: 16107844 DOI: 10.1038/nature03900] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2005] [Accepted: 06/07/2005] [Indexed: 11/09/2022]
Abstract
The hydroxyl radical is the predominant atmospheric oxidant, responsible for removing a wide range of trace gases, including greenhouse gases, from the atmosphere. Determination of trends and variability in hydroxyl radical concentrations is critical to understanding whether the 'cleansing' properties of the atmosphere are changing. The variability in hydroxyl radical concentrations on annual to monthly timescales, however, is difficult to quantify. Here we show records of carbon monoxide containing radiocarbon (14CO), which is oxidized by hydroxyl radicals, from clean-air sites at Baring Head, New Zealand, and Scott Base, Antarctica, spanning 13 years. Using a model study, we correct for known variations in production of 14CO (refs 6, 7), allowing us to exploit this species as a diagnostic for short term changes in hydroxyl radical concentrations. We find no significant long-term trend in hydroxyl radical concentrations but provide evidence for recurring short-term variations of around ten per cent persisting for a few months. We also find decreases in hydroxyl radical concentrations of up to 20 per cent, apparently triggered by the eruption of Mt Pinatubo in 1991 and by the occurrence of extensive fires in Indonesia in 1997.
Collapse
Affiliation(s)
- Martin R Manning
- IPCC Working Group I Support Unit, Boulder, Colorado 80305, USA.
| | | | | | | | | |
Collapse
|
22
|
Santer BD, Wigley TML, Simmons AJ, Kållberg PW, Kelly GA, Uppala SM, Ammann C, Boyle JS, Brüggemann W, Doutriaux C, Fiorino M, Mears C, Meehl GA, Sausen R, Taylor KE, Washington WM, Wehner MF, Wentz FJ. Identification of anthropogenic climate change using a second-generation reanalysis. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jd005075] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Benjamin D. Santer
- Program for Climate Model Diagnosis and Intercomparison; Lawrence Livermore National Laboratory; Livermore California USA
| | | | | | - Per W. Kållberg
- European Centre for Medium-Range Weather Forecasts; Reading UK
| | - Graeme A. Kelly
- European Centre for Medium-Range Weather Forecasts; Reading UK
| | | | - Caspar Ammann
- National Center for Atmospheric Research; Boulder Colorado USA
| | - James S. Boyle
- Program for Climate Model Diagnosis and Intercomparison; Lawrence Livermore National Laboratory; Livermore California USA
| | - Wolfgang Brüggemann
- School of Mathematics and Statistics; University of Birmingham; Birmingham UK
| | - Charles Doutriaux
- Program for Climate Model Diagnosis and Intercomparison; Lawrence Livermore National Laboratory; Livermore California USA
| | - Mike Fiorino
- Program for Climate Model Diagnosis and Intercomparison; Lawrence Livermore National Laboratory; Livermore California USA
| | - Carl Mears
- Remote Sensing Systems; Santa Rosa California USA
| | - Gerald A. Meehl
- National Center for Atmospheric Research; Boulder Colorado USA
| | - Robert Sausen
- Institut für Physik der Atmosphäre; Deutsches Zentrum für Luft- und Raumfahrt, Oberpfaffenhofen; Wessling Germany
| | - Karl E. Taylor
- Program for Climate Model Diagnosis and Intercomparison; Lawrence Livermore National Laboratory; Livermore California USA
| | | | | | | |
Collapse
|
23
|
Schmidt T, Wickert J, Beyerle G, Reigber C. Tropical tropopause parameters derived from GPS radio occultation measurements with CHAMP. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jd004566] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- T. Schmidt
- Department 1: Geodesy and Remote Sensing; GeoForschungsZentrum Potsdam; Potsdam Germany
| | - J. Wickert
- Department 1: Geodesy and Remote Sensing; GeoForschungsZentrum Potsdam; Potsdam Germany
| | - G. Beyerle
- Department 1: Geodesy and Remote Sensing; GeoForschungsZentrum Potsdam; Potsdam Germany
| | - C. Reigber
- Department 1: Geodesy and Remote Sensing; GeoForschungsZentrum Potsdam; Potsdam Germany
| |
Collapse
|
24
|
Pielke RA, Chase TN. Response to Comment on "Contributions of Anthropogenic and Natural Forcing to Recent Tropopause Height Changes". Science 2004; 303:1771; author reply 1771. [PMID: 15031480 DOI: 10.1126/science.1092441] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Roger A Pielke
- Department of Atmospheric Science, 1371 Campus Delivery, Colorado State University, Fort Collins, CO 80523, USA.
| | | |
Collapse
|
25
|
Lamsal LN. Ozone column classified climatology of ozone and temperature profiles based on ozonesonde and satellite data. ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2004jd004680] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
26
|
Hare SHE. Can stratospheric temperature trends be attributed to ozone depletion? ACTA ACUST UNITED AC 2004. [DOI: 10.1029/2003jd003897] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
|
27
|
Santer BD, Wehner MF, Wigley TML, Sausen R, Meehl GA, Taylor KE, Ammann C, Arblaster J, Washington WM, Boyle JS, Brüggemann W. Contributions of anthropogenic and natural forcing to recent tropopause height changes. Science 2003; 301:479-83. [PMID: 12881562 DOI: 10.1126/science.1084123] [Citation(s) in RCA: 343] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Observations indicate that the height of the tropopause-the boundary between the stratosphere and troposphere-has increased by several hundred meters since 1979. Comparable increases are evident in climate model experiments. The latter show that human-induced changes in ozone and well-mixed greenhouse gases account for approximately 80% of the simulated rise in tropopause height over 1979-1999. Their primary contributions are through cooling of the stratosphere (caused by ozone) and warming of the troposphere (caused by well-mixed greenhouse gases). A model-predicted fingerprint of tropopause height changes is statistically detectable in two different observational ("reanalysis") data sets. This positive detection result allows us to attribute overall tropopause height changes to a combination of anthropogenic and natural external forcings, with the anthropogenic component predominating.
Collapse
Affiliation(s)
- B D Santer
- Program for Climate Model Diagnosis and Intercomparison, Lawrence Livermore National Laboratory, Livermore, CA 94550, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|