Skip to main content
Advanced Search

Filters: Contacts: Imtiaz Rangwala (X)

60 results (38ms)   

Filters
Date Range
Extensions
Types
Contacts
Categories
Tag Types
Tag Schemes
View Results as: JSON ATOM CSV
Climate policy developers and natural resource managers frequently desire high-resolution climate data to prepare for future effects of climate change. But they face a long-standing problem: the vast majority of climate models have been run at coarse resolutions—from hundreds of kilometers in global climate models (GCMs) down to 25–50 kilometers in regional climate models (RCMs).
Abstract (from http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0174045): Several studies have projected increases in drought severity, extent and duration in many parts of the world under climate change. We examine sources of uncertainty arising from the methodological choices for the assessment of future drought risk in the continental US (CONUS). One such uncertainty is in the climate models’ expression of evaporative demand (E0), which is not a direct climate model output but has been traditionally estimated using several different formulations. Here we analyze daily output from two CMIP5 GCMs to evaluate how differences in E0 formulation, treatment of meteorological driving data, choice of GCM,...
Evaporative demand (E0) both drives and responds to droughts based on interactions across the land surface-atmosphere interface, and can be exploited to signal agricultural, hydrologic, and ecological droughts. In this chapter, we argue that using a fully physically based measure of E0 moves the drought community toward a more complete understanding of drought processes that will enhance its abilities with regard to early warning and drought monitoring in the present day and drought-risk assessment under future climate change scenarios. We examine regional characteristics in E0 and their behavior during droughts in the recent historical period across different hydroclimates. We review physical mechanisms driving...
Categories: Publication; Types: Citation
thumbnail
These datasets contain time series of anomalies, relative to 1950-1999 period, in the annual and seasonal soil moisture (%) and runoff (%) in the Pinyon-Juniper ecosystem of Southwest Colorado for the three future climate scenarios considered in the Social Ecological and Climate Resiliency (SECR) project.
An estimated 50–80% of North America’s ducks use the millions of wetland basins in the Prairie Pothole Region as breeding habitat. The U.S. Fish and Wildlife Service (USFWS) National Wildlife Refuge System has conserved approximately 1.3 million hectares of grasslands and wetlands in the United States portion of the Prairie Pothole Region with the primary purpose to support breeding duck habitat. A major assumption inherent to the current conservation approach is that wetlands that have historically provided the highest value to breeding ducks will continue to do so into the future. The dynamic nature of climate in the Northern Great Plains and continued increases in air temperatures and precipitation variability...
Categories: Publication; Types: Citation
thumbnail
We mapped potential climate change refugia for riparian areas in the central and western USA for 2040-2069 and 2070-2099. Riparian refugia are existing riparian areas that are projected to maintain riparian vegetation and associated ecological function under plausible future climates. Four input variables were included in the riparian refugia index: two landscape variables that represent where existing riparian areas may be more resilient to climatic changes (riparian connectedness and landscape diversity) and two climate variables that reflect projected exposure to climate change (runoff and warm days). For the climate variables, we considered two global circulation models: moderately hot and wet (CNRM-CM5) and...
thumbnail
Grasslands in the northern Great Plains are important ecosystems that support local economies, tribal communities, livestock grazing, diverse plant and animal communities, and large-scale migrations of big game ungulates, grassland birds, and waterfowl. Climate change and variability impact how people and animals live on and interact with grasslands, and can bring more frequent droughts, fires, or new plant species that make managing these landscapes challenging. Understanding how climate change and variability will impact grassland ecosystems and their management in the 21st century first requires a synthesis of what is known across all of these scales and a gap analysis to identify key areas of focus for future...
The Evaporative Demand Drought Index (EDDI) is an experimental drought monitoring and early warning guidance tool. It examines how anomalous the atmospheric evaporative demand (E0; also known as "the thirst of the atmosphere") is for a given location and across a time period of interest. EDDI is multi-scalar, meaning that this period—or "timescale"—can vary to capture drying dynamics that themselves operate at different timescales; we generate EDDI at 1-week through 12-month timescales. This webpage offers a frequently updated assessment of current conditions across CONUS, southern parts of Canada, and northern parts of Mexico; a tool to generate historical time series of EDDI for a user-selected region; introductions...
thumbnail
As climate change progresses, profound environmental changes are becoming a widespread concern. A new management paradigm is developing to address this concern with a framework that encourages strategic decisions to resist, accept, or direct ecological trajectories. Effective use of the Resist-Accept-Direct (RAD) framework requires the scientific community to describe the range of plausible ecological conditions managers might face, while recognizing limits to our ability to predict precisely where or how specific climatic changes may unfold or how complex environmental systems will respond - the climatic future does not fully determine the ecological one. Recent advances have improved development and delivery...
thumbnail
The Climate Science Support Platform is a network of NC CASC scientists and partners that provides climate science support to the NC CASC community of scientists and stakeholders through collaborative research and integration of diverse science expertise. In an effort to increase understanding of climate science and to identify stakeholders’ climate science needs, the Climate Science Support Platform facilitates iterative engagement with the NC CASC community of scientists and stakeholders through direct interactions, science calls to engage with the entire network, and science webinars that bring together researchers and managers. In addition to engaging with stakeholders, the Climate Science Support Platform also...
thumbnail
Pan evaporation is a measure of atmospheric evaporative demand (E0) for which long term and spatially distributed observations are available from the NOAA Cooperative Observer (COOP) Network. However, this data requires extensive quality control and homogenization due to documented and undocumented station moves and other factors including human errors in recording or digitization. Station-based Pan Evaporation measurements (in mm) from 247 stations across the continental United States were compiled and quality controlled for the analysis shown in Dewes et al., 2017. This dataset reports warm season (May-October; for 21 stations the data is only available for May-September) pan evaporation with at least 20 years...
thumbnail
This dataset provides downscaled climate projections at 800m spatial resolution for nine ecologically-relevant climate variables for the north central US region between 35.5N-49N latitude and 88W-118W longitude from the Met Office Hadley Center (UK) model, HadGEM2-ES, simulations (r1i1p1) from two emissions scenarios (RCP 4.5 and 8.5), which are downscaled using the Multivariate Adaptive Constructed Analog (MACA) method. These projections are available as five different (approximately) 30-year climate normals between 1950 and 2099 as monthly values, except for Aridity Index which are annual values. The five periods for which these climate normals are provided are 1950-1979 and 1980-2005 in the historic, and 2011-2040,...
thumbnail
This dataset provides downscaled climate projections at 800m spatial resolution for nine ecologically-relevant climate variables for the north central US region between 35.5N-49N latitude and 88W-118W longitude from the NOAA Geophysical Fluid Dynamics Laboratory (USA) model, GFDL-ESM2M, simulations (r1i1p1) from two emissions scenarios (RCP 4.5 and 8.5), which are downscaled using the Multivariate Adaptive Constructed Analog (MACA) method. These projections are available as five different (approximately) 30-year climate normals between 1950 and 2099 as monthly values, except for Aridity Index which are annual values. The five periods for which these climate normals are provided are 1950-1979 and 1980-2005 in the...
Under climate change, ecosystems are experiencing novel drought regimes, often in combination with stressors that reduce resilience and amplify drought’s impacts. Consequently, drought appears increasingly likely to push systems beyond important physiological and ecological thresholds, resulting in substantial changes in ecosystem characteristics persisting long after drought ends (i.e., ecological transformation). In the present article, we clarify how drought can lead to transformation across a wide variety of ecosystems including forests, woodlands, and grasslands. Specifically, we describe how climate change alters drought regimes and how this translates to impacts on plant population growth, either directly...
Categories: Publication; Types: Citation
thumbnail
Pinyon pine woodlands are among the most widespread and iconic vegetation types in the western United States and support recreation, resource extraction, grazing, and cultural enrichment. However, severe drought conditions have recently caused dramatic mortality of pinyon pines, creating concern about the long-term impact of increasing aridity on the viability of pinyon woodlands. Ecological transformations, or regime shifts, are rapid reorganizations of an ecosystem’s species composition, governing processes, and functions. The goal of this project is to investigate ecological transformation across the Western U.S, characterize the environmental drivers of these changes in vegetation, and apply those insights...
thumbnail
Project Overview Prairie dog colonies in North America’s Central Grasslands undergo cycles of collapse and recovery caused by the non-native sylvatic plague, and each phase of the cycle negatively affects wildlife or livestock. Researchers supported by this North Central-CASC project will develop a decision-support web tool for users to predict prairie dog colony dynamics under changing climatic conditions to help optimize management strategies of wildlife and cattle. Project Summary Prairie dogs are crucial to North America’s Central Grasslands, creating habitat for other wildlife by digging burrows and clipping vegetation, and serving as a key food source for many predators. However, the sylvatic plague, a non-native...


map background search result map search result map GFDL-ESM2M: Downscaled climate projections at 800m spatial resolution for the north central United States based on the Multivariate Adaptive Constructed Analog (MACA) method HadGEM2-ES: Downscaled climate projections at 800m spatial resolution for the north central United States based on the Multivariate Adaptive Constructed Analog (MACA) method Mapping the Risk of Ecological Transformation Across Pinyon Woodlands and the U.S. West Time Series of the Anomalies in Soil Moisture and Runoff Between 1950-2099 for the Pinyon-Juniper Ecosystem of Southwest Colorado Under Three Future Climate Scenarios Synthesis of Climate Impacts and Adaptation on Grassland Ecosystems in the Northern Great Plains Climate Science Support Platform Crafting Ecological Scenarios to Implement the Resist-Accept-Direct (RAD) Framework Riparian climate refugia data in western and central USA for 2040-2069 and 2070-2099 A Decision Support Tool for Prairie Dog and Cattle Coexistence in a Changing Climate Time Series of the Anomalies in Soil Moisture and Runoff Between 1950-2099 for the Pinyon-Juniper Ecosystem of Southwest Colorado Under Three Future Climate Scenarios Synthesis of Climate Impacts and Adaptation on Grassland Ecosystems in the Northern Great Plains Climate Science Support Platform Crafting Ecological Scenarios to Implement the Resist-Accept-Direct (RAD) Framework A Decision Support Tool for Prairie Dog and Cattle Coexistence in a Changing Climate Riparian climate refugia data in western and central USA for 2040-2069 and 2070-2099 GFDL-ESM2M: Downscaled climate projections at 800m spatial resolution for the north central United States based on the Multivariate Adaptive Constructed Analog (MACA) method HadGEM2-ES: Downscaled climate projections at 800m spatial resolution for the north central United States based on the Multivariate Adaptive Constructed Analog (MACA) method Mapping the Risk of Ecological Transformation Across Pinyon Woodlands and the U.S. West