A5073711786- Climate variability and models
- Meteorological Phenomena and Simulations
- Ocean Waves and Remote Sensing
- Tropical and Extratropical Cyclones Research
- Oceanographic and Atmospheric Processes
- Hydrology and Drought Analysis
- Arctic and Antarctic ice dynamics
- Atmospheric and Environmental Gas Dynamics
- Cryospheric studies and observations
- Climate change and permafrost
- Precipitation Measurement and Analysis
- Geophysics and Gravity Measurements
- Statistical Methods and Inference
- Statistical and numerical algorithms
- Solar Radiation and Photovoltaics
- Atmospheric aerosols and clouds
- Coastal and Marine Dynamics
- Complex Systems and Time Series Analysis
- Advanced Statistical Methods and Models
- Plant Water Relations and Carbon Dynamics
- Atmospheric Ozone and Climate
- Atmospheric chemistry and aerosols
- Energy, Environment, Economic Growth
- demographic modeling and climate adaptation
- Regional Economic and Spatial Analysis
Environment and Climate Change Canada
2015-2024
York University
2007-2014
Metric Systems Corporation (United States)
2005
University of Victoria
1997-2001
Canadian Hydrographic Service
2001
University of Toronto
1997
Historical reanalyses that span more than a century are needed for wide range of studies, from understanding large‐scale climate trends to diagnosing the impacts individual historical extreme weather events. The Twentieth Century Reanalysis (20CR) Project is an effort fill this need. It supported by National Oceanic and Atmospheric Administration (NOAA), Cooperative Institute Research in Environmental Sciences (CIRES), U.S. Department Energy (DOE), facilitated collaboration with...
The variability of results from different automated methods detection and tracking extratropical cyclones is assessed in order to identify uncertainties related the choice method. Fifteen international teams applied their own algorithms same dataset—the period 1989–2009 interim European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERAInterim) data. This experiment part community project Intercomparison Mid Latitude Storm Diagnostics (IMILAST; see...
This study assesses trends in seasonal extremes (90- and 99-percentiles) of Significant Wave Height (SWH) the North Atlantic Pacific, as simulated a 40-yr global wave hindcast using National Centers for Environmental Prediction–National Center Atmospheric Research reanalysis wind fields. For last four decades, statistically significant changes SWH (NA) are detected only winter (January–March) season. These found to be intimately connected with oscillation (NAO). To specific, increases...
Abstract This study proposes an empirical approach to account for lag-1 autocorrelation in detecting mean shifts time series of white or red (first-order autoregressive) Gaussian noise using the penalized maximal t test F test. is embedded a stepwise testing algorithm, so that new algorithms can be used detect single multiple changepoints series. The detection power analyzed through Monte Carlo simulations. It has been shown work very well and fast changepoints. Examples their application...
This study presents a second generation of homogenized monthly mean surface air temperature data set for Canadian climate trend analysis. Monthly means daily maximum and minimum temperatures were examined at 338 locations. Data from co‐located observing sites sometimes combined to create longer time series use in Time observations then adjusted account nation‐wide change July 1961, affecting recorded 120 synoptic stations; these using hourly the same sites. Next, homogeneity testing was...
Abstract In this paper, a penalized maximal t test (PMT) is proposed for detecting undocumented mean shifts in climate data series. PMT takes the relative position of each candidate changepoint into account, to diminish effect unequal sample sizes on power detection. Monte Carlo simulation studies are conducted evaluate performance PMT, comparison with most popularly used method, standard normal homogeneity (SNHT). An application two methods atmospheric pressure series recorded at Canadian...
Abstract In this study, a penalized maximal F test (PMFT) is proposed for detecting undocumented mean shifts that are not accompanied by any sudden change in the linear trend of time series. PMFT aims to even out uneven distribution false alarm rate and detection power corresponding unpenalized based on common-trend two-phase regression model (TPR3). The performance compared with TPR3 using Monte Carlo simulations real climate data It shown that, due effect unequal sample sizes, has W-shaped...
Abstract This study integrates a Box–Cox power transformation procedure into common trend two-phase regression-model-based test (the extended version of the penalized maximal F test, or “PMFred,” algorithm) for detecting changepoints to make applicable non-Gaussian data series, such as nonzero daily precipitation amounts wind speeds. The detection-power aspects transformed method (transPMFred) are assessed by simulation that shows this new algorithm is much better than corresponding...
This study first homogenizes time series of daily maximum and minimum temperatures recorded at 825 stations in China over the period from 1951 to 2010, using both metadata penalized t test with first‐order autocorrelation being accounted for detect change points quantile‐matching algorithm adjust data diminish discontinuities. Station relocation was found be main cause discontinuities, followed by station automation. The effects discontinuities on estimation long‐term trends annual mean...
Ocean surface waves can be major hazards in coastal and offshore activities. However, there exists very limited information on ocean wave behavior response to climate change, because such is not simulated current global models. This study made statistical projections of changes heights using sea level pressure (SLP) from 20 CMIP5 (Coupled Model Intercomparison Project Phase 5) models for the 21st century. The results show significant height increases tropics (especially eastern tropical...
The International Surface Pressure Databank ( ISPD ) is the world's largest collection of global surface and sea‐level pressure observations. It was developed by extracting observations from established international archives, through cooperation with data recovery facilitated Atmospheric Circulation Reconstructions over Earth ACRE initiative, directly contributing universities, organizations, countries. dataset period currently 1768–2012 consists three components: land stations, marine...
Abstract In this study, a cyclone detection/tracking algorithm was used to identify cyclones from two gridded 6-hourly mean sea level pressure datasets: the 40-yr ECMWF Re-Analysis (ERA-40) and NCEP–NCAR reanalysis (NNR) for 1958–2001. The activity climatology changes inferred reanalyses are intercompared. climatologies trends found be in reasonably good agreement with each other over northern Europe eastern North America, while ERA-40 shows systematically stronger boreal extratropical...
Abstract Near-surface wind speeds recorded at 117 stations in Canada for the period from 1953 to 2006 were analyzed this study. First, metadata and a logarithmic profile used adjust hourly measured nonstandard anemometer heights standard 10-m level. Monthly mean near-surface speed series then derived subjected statistical homogeneity test, with homogeneous monthly geostrophic (geowind) being as reference series. Homogenized obtained by adjusting all significant shifts, using results of test...
Using the observed relationships between sea level pressure (SLP) and significant wave height (SWH) as represented by regression models, climate change scenarios of SWH in North Atlantic were constructed means redundancy analysis (for seasonal 90th percentiles SWH) nonstationary generalized extreme value SWH). are using output from a coupled model under three different forcing scenarios. Scenarios future anomaly statistics projections mean SLP while made gradient index. The projected changes...
[1] Trends in soil temperature are important, but rarely reported, indicators of climate change. On the basis data from 30 stations across Canada during 1958–2008, trends temperatures at 5, 10, 20, 50, 100, and 150 cm depths were analyzed, together with atmospheric variables, such as air temperature, precipitation, depth snow on ground, observed same locations. There was a significant positive trend spring summer means, not for winter annual means. A time detected about two-thirds all below...
Corresponding author address: Dr. Xiaolan L. Wang, Climate Research Branch, Meteorological Service of Canada, 4905 Dufferin Street, Downsview, ON M3H 5T4, Canada. Email: xiaolan.wang@ec.gc.ca
Abstract Radiosonde humidity records represent the only in situ observations of tropospheric water vapor content with multidecadal length and quasi-global coverage. However, their use has been hampered by ubiquitous large discontinuities resulting from changes to instrumentation observing practices. Here a new approach is developed homogenize historical (up 100 hPa) dewpoint depression (DPD), archived radiosonde parameter. Two statistical tests are used detect changepoints, which most...
Abstract Based on the homogenized data set, we analyze changes in mean temperature and some extreme indices over China since 1961 especially during recent warming hiatus period (1998–2012) a global average context. The result shows that decrease of annual maximum has contributed most to decreases overall diurnal range (DTR) period. In parts except southwest, summer ( T xS ) largest increase, while winter minimum nW indicates slight cooling trends. These have augmented seasonal cycle...
This scientific assessment examines changes in three climate extremes—extratropical storms, winds, and waves—with an emphasis on U.S. coastal regions during the cold season. There is moderate evidence of increase both extratropical storm frequency intensity season Northern Hemisphere since 1950, with suggestive geographic shifts resulting slight upward trends offshore/coastal regions. also extreme winds (at least annually) over parts ocean early to mid-1980s, but land surface inconclusive....