Using Historical Climate Data to Evaluate Climate Trends: Issues of Statistical Inference

Abstract The design of reclamation soil covers at oil sands mines in northern Alberta, Canada, has been conventionally based on the calibration of soil–vegetation–atmosphere transfer (SVAT) models against field monitoring observations collected over several years, followed by simulations of long-term performance using historical climate data. This paper evaluates the long-term water balances for reclamation covers on two oil sands landforms and three natural coarse-textured forest soil profiles using both historical climate data and future climate projections. Twenty-first century daily precipitation and temperature data from CanESM2 were downscaled based on three representative concentration pathways (RCPs) employing a stochastic weather generator [Long Ashton Research Station Weather Generator (LARS-WG)]. Relative humidity, wind speed, and net radiation were downscaled using the delta change method. Downscaled precipitation and estimated potential evapotranspiration were used as inputs to simulate soil water dynamics using physically based models. Probability distributions of growing season (April–October) actual evapotranspiration (AET) and net percolation (NP) for the baseline and future periods show that AET and NP at all sites are expected to increase throughout the twenty-first century regardless of RCP, time period, and soil profile. Greater increases in AET and NP are projected toward the end of the twenty-first century. The increases in future NP at the two reclamation covers are larger (as a percentage increase) than at most of the natural sites. Increases in NP will result in greater water yield to surface water and may accelerate the rate at which chemical constituents contained within mine waste are released to downstream receptors, suggesting these potential changes need to be considered in mine closure designs.

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Assessment of Historical Climate Trends of Surface Air Temperature in CMIP5 Models

Atmospheric and Oceanic Science Letters ◽

10.1080/16742834.2014.11447149 ◽

2014 ◽

Vol 7 (2) ◽

pp. 137-142 ◽

Cited By ~ 1

Author(s):

Feng Xiao-Li ◽

Zhi Hai ◽

Lin Peng-Fei ◽

Liu Hai-Long

Keyword(s):

Air Temperature ◽

Surface Air Temperature ◽

Cmip5 Models ◽

Climate Trends ◽

Historical Climate

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Glacier changes and climate trends derived from multiple sources in the data scarce Cordillera Vilcanota region, southern Peruvian Andes

The Cryosphere ◽

10.5194/tc-7-103-2013 ◽

2013 ◽

Vol 7 (1) ◽

pp. 103-118 ◽

Cited By ~ 66

Author(s):

N. Salzmann ◽

C. Huggel ◽

M. Rohrer ◽

W. Silverio ◽

B. G. Mark ◽

...

Keyword(s):

Air Temperature ◽

Specific Humidity ◽

Spatial And Temporal Variability ◽

Moderate Increase ◽

Climate Data ◽

Climate Trends ◽

Multiple Sources ◽

Mountain Areas ◽

Peruvian Andes ◽

Glacier Changes

Abstract. The role of glaciers as temporal water reservoirs is particularly pronounced in the (outer) tropics because of the very distinct wet/dry seasons. Rapid glacier retreat caused by climatic changes is thus a major concern, and decision makers demand urgently for regional/local glacier evolution trends, ice mass estimates and runoff assessments. However, in remote mountain areas, spatial and temporal data coverage is typically very scarce and this is further complicated by a high spatial and temporal variability in regions with complex topography. Here, we present an approach on how to deal with these constraints. For the Cordillera Vilcanota (southern Peruvian Andes), which is the second largest glacierized cordillera in Peru (after the Cordillera Blanca) and also comprises the Quelccaya Ice Cap, we assimilate a comprehensive multi-decadal collection of available glacier and climate data from multiple sources (satellite images, meteorological station data and climate reanalysis), and analyze them for respective changes in glacier area and volume and related trends in air temperature, precipitation and in a more general manner for specific humidity. While we found only marginal glacier changes between 1962 and 1985, there has been a massive ice loss since 1985 (about 30% of area and about 45% of volume). These high numbers corroborate studies from other glacierized cordilleras in Peru. The climate data show overall a moderate increase in air temperature, mostly weak and not significant trends for precipitation sums and probably cannot in full explain the observed substantial ice loss. Therefore, the likely increase of specific humidity in the upper troposphere, where the glaciers are located, is further discussed and we conclude that it played a major role in the observed massive ice loss of the Cordillera Vilcanota over the past decades.

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A New Highly Stable Multi-Decade Satellite Climate Data Set Derived from Polar Hyperspectral Infrared Sensors

10.5194/egusphere-egu2020-3754 ◽

2020 ◽

Author(s):

Chris Hepplewhite ◽

Larrabee Strow ◽

Howard Motteler ◽

Sergio de Souza-Machad ◽

Steven Buczkowski

Keyword(s):

Spectral Resolution ◽

Virtual Instrument ◽

Spectral Response ◽

Short Wave ◽

High Spectral Resolution ◽

Climate Data ◽

Climate Trends ◽

Polar Orbit ◽

Data Set ◽

Long Wave

NASA's Atmospheric Infrared Sounder (AIRS) started the continuous measurement of the Earth's upwelling infrared radiation at high spectral resolution in Sept. 2002 in a 13:30 polar orbit. &#160;The AIRS record was supplemented by the CrIS sensor flying on the NASA SNPP platform, also in the 13:30 polar orbit, in 2012. &#160;In 2018 a second CrIS sensor on NOAA's JPSS-1 platform (NOAA-20) began operation, also in the 13:30 orbit. &#160;Two more CrIS sensors are presently being procured for the JPSS-2 and 3 satellites, which will extend this record from 2002 through ~2040. &#160;EUMETSAT's METOP-A/B/C provide very similar hyperspectral observations starting with the IASI sensors in the 09:30 orbit, starting in 2007, which will be continued with METOP-SG for years to come. &#160;Inter-calibration of all of the operating sensors shows agreement generally to 0.2K or better in brightness temperature. &#160;More importantly, we have shown that the radiometric stability of the AIRS sensors is in the 0.002 K/year range or 0.02K/decade, based on measurements of CO2 and SST trends. &#160; Similar stability is expected for CrIS and IASI. &#160;Community consensus suggests that direct radiance trending, followed by conversion of these trends to geophysical quantities will yield the most accurate climate trends. &#160;Here we introduce a new satellite hyperspectral infrared radiance product we call the "Climate Hyperspectral InfraRed Product (CHIRP)" that combines AIRS, CrIS, and IASI into a homogeneous Level 1 radiance product with a common spectral response and channel centers for all three satellites. &#160;This grid is equivalent to an interferometer with optical path differences of 0.8/0.6/0.4 cm for the long-wave/mid-wave/short-wave spectral bands. &#160;This corresponds to a virtual instrument with the same spectral resolution of the JPSS-1 CrIS sensor in the long-wave, with 25/50% degradation in spectral resolution in the mid-wave/short-wave. &#160;This choice allows accurate conversion of the long AIRS record to an equivalent interferometer record. &#160;Conversion of IASI to CHIRP is trivial. &#160;Conversion of all sensors to the CHIRP spectra grid permits simple adjustments of inter-satellite radiometric bias differences since all measurements are first converted to a common spectral grid. &#160;Multiple methods (SNOs, statistical inter-comparisons) indicate these adjustments can be made to the 0.03K level or better. &#160;&#160;A sample application of CHIRP to climate trending will be given by showing multi-decade anomalies of temperature, humidity, and ozone profiles retrieved from CHIRP radiance anomalies, a retrieval that requires almost no a-priori information. &#160;This data set should yield definitive measurements of water-vapor feedback and heavily contribute to our understanding of both tropospheric and stratospheric temperature trends. &#160; Initial production of CHIRP radiances that combine AIRS and CrIS are expected to begin in late 2020. &#160;

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Stratospheric Temperature Climate Data Record from Merged SSU and AMSU-A Observations

Journal of Atmospheric and Oceanic Technology ◽

10.1175/jtech-d-16-0018.1 ◽

2016 ◽

Vol 33 (9) ◽

pp. 1967-1984 ◽

Cited By ~ 20

Author(s):

Cheng-Zhi Zou ◽

Haifeng Qian

Keyword(s):

Piecewise Linear ◽

Vital Role ◽

Climate Data ◽

Climate Trends ◽

Weighting Functions ◽

Stratospheric Temperature ◽

Data Record ◽

Temperature Climate ◽

Climate Data Record

AbstractObservations from the Stratospheric Sounding Unit (SSU) on board historical NOAA polar-orbiting satellites have played a vital role in investigations of long-term trends and variability in the middle- and upper-stratospheric temperatures during 1979–2006. The successor to SSU is the Advanced Microwave Sounding Unit-A (AMSU-A) starting from 1998 until the present. Unfortunately, the two observations came from different sets of atmospheric layers, and the SSU weighting functions varied with time and location, posing a challenge to merge them with sufficient accuracy for development of an extended SSU climate data record. This study proposes a variational approach for the merging problem, matching in both temperatures and weighting functions. The approach yields zero means with a small standard deviation and a negligible drift over time in the temperature differences between SSU and its extension to AMSU-A. These features made the approach appealing for reliable detection of long-term climate trends. The approach also matches weighting functions with high accuracy for SSU channels 1 and 2 and reasonable accuracy for channel 3. The total decreases in global mean temperatures found from the merged dataset were from 1.8 K in the middle stratosphere to 2.4 K in the upper stratosphere during 1979–2015. These temperature drops were associated with two segments of piecewise linear cooling trends, with those during the first period (1979–97) being much larger than those of the second period (1998–2015). These differences in temperature trends corresponded well to changes of the atmospheric ozone amount from depletion to recovery during the respective time periods, showing the influence of human decisions on climate change.

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Where the wild things are: Seasonal variation in caribou distribution in relation to climate change

Rangifer ◽

10.7557/2.25.4.1770 ◽

2005 ◽

Vol 25 (4) ◽

pp. 51 ◽

Cited By ~ 10

Author(s):

Philippa McNeil ◽

Don E. Russell ◽

Brad Griffith ◽

Anne Gunn ◽

Gary P. Kofinas

Keyword(s):

Climate Change ◽

Environmental Factor ◽

Rangifer Tarandus ◽

Early Summer ◽

Climatic Conditions ◽

Mitigation Measures ◽

Climate Data ◽

Climate Trends ◽

Migration Patterns ◽

Mining Sites

In this study, we develop a method to analyse the relationships between seasonal caribou distribution and climate, to estimate how climatic conditions affect interactions between humans and caribou, and ultimately to predict patterns of distribution relative to climate change. Satellite locations for the Porcupine (Rangifer tarandus granti) and Bathurst (R. t. groenlandicus) caribou herds were analysed for eight ecologically-defined seasons. For each season, two levels of a key environmental factor influencing caribou distribution were identified, as well as the best climate data available to indicate the factor's annual state. Satellite locations were grouped according to the relevant combination of season and environmental factor. Caribou distributions were compared for opposing environmental factors; this comparison was undertaken relative to hunting access for the Porcupine Herd and relative to exposure to mining activity for the Bathurst Herd. Expected climate trends suggest an overall increase in access to Porcupine caribou for Aklavik (NWT) hunters during the winter and rut seasons, for Venetie (Alaska) hunters during midsummer and fall migration and for Arctic Village (Alaska) during midsummer. Arctic Village may experience reduced availability with early snowfalls in the fall, but we expect there to be little directional shift in the spring migration patterns. For the Bathurst Herd, we expect that fewer caribou would be exposed to the mines during the winter, while more caribou would be exposed to the combined Ekati and Diavik mining zone in the early summer and to the Lupin-Jericho mining zone during the fall migration. If changes in climate cause an increased presence of caribou in the mining sites, monitoring and mitigation measures may need to be intensified.

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