Observation-Based Estimates of Present-Day and Future Climate Change Impacts on Heavy Rainfall in Harris County

This report describes the results of an extreme value analysis of precipitation in and around Harris County, Texas, in order to determine whether the newly-promulgated NOAA Atlas 14 rainfall design values are valid in a changing climate. The analysis in this report is based on the original NOAA Atlas 14 data set as well as a set of composite stations for the Gulf and Southeast Coasts. As of this writing, this report and its findings have not yet been peer-reviewed. • The recent upward trend in extreme precipitation in the Houston area has contributed to extreme rainfall design values in the area that far exceed those of comparable locations. This is in part due to some stations not having a sufficiently lengthy set of observations and in part due to southeast Texas receiving more than its fair share of storms. We assess that the design values of 100-year rainfall amounts would be 7% smaller if a longer period of record was available at all observation locations. • Coastal southeast Texas has the largest single-day and multi-day return values anywhere along the Gulf and Atlantic coasts for return periods of 100 years or more. This is in part due to some recent storms that could have occurred anywhere along the Gulf coast concentrating their activity around Houston. There is no known factor that would make storms such as Harvey more likely to happen in Texas than elsewhere along the northern Gulf Coast. We assess that extreme rainfall risk in Southeast Texas should consider storms from a broader portion of the Gulf Coast, decreasing return values by an additional 1%-18%, with the larger values applying to the larger return periods. • A robust upward trend in extreme precipitation is present across the southern and southeastern United States. The trend is larger in southeast Texas, but we have no reason to expect that climate change would cause trend variations on such a small scale. Using averaged trends across areas near the Gulf Coast, we assess the best estimate of the climate-driven trend in southeast Texas to be 11%-15% over the past 60 years, with the remainder of the observed trend caused by regionally unusual storms (like Harvey) that are not likely to recur in the same places. • The three factors listed above effectively cancel each other out for 2-year return values. We assess that the present-day nonstationary return values are approximately equal to the stationary estimates of NOAA Atlas 14 for 2-year return periods. • Because of the three factors listed above, the NOAA Atlas 14 100-year and 500-year return values generally overestimate the present-day and near-term future extreme rainfall risk in and around the Houston area. We assess that for 100-year return periods, current nonstationary values are still about 10-12% below the NOAA Atlas 14 values. • The historic upward trend is very likely to continue with global warming. Because of this, we assess that NOAA Atlas 14 return values underestimate the intensity of all future 2-year rainfall events in the Harris County area. We also assess that, depending on the rate of future warming, the nonstationary 100-year return values will exceed the NOAA Atlas 14 values around the middle of the 21st century.Harris County Flood Control Distric

Extreme Rainfall in Texas: Patterns and Predictability

Extreme rainfall, with storm total precipitation exceeding 500 mm, occurs several times per decade in Texas. According to a compositing analysis, the large-scale weather patterns associated with extreme rainfall events involve a northward deflection of the tropical trade winds into Texas, with deep southerly winds extending into the middle troposphere. One such event, the July 2002 South-Central Texas flood, is examined in detail. This particular event was associated with a stationary upper-level trough over central Texas and northern Mexico that established a steady influx of tropical moisture from the south. While the onset of the event was triggered by destabilization caused by an upper-level vortex moving over the northeast Mexican coast, a succession of upper-level processes allowed the event to become stationary over south-central Texas and produce heavy rain for several days. While the large-scale signatures of such extreme rain events evolve slowly, the many interacting processes at smaller scales make numerical forecasts highly sensitive to details of the simulations

Feasibility Study for Development of Statewide Evapotranspiration Network

Information was collected on existing mesonets, potential evapotranspiration networks, and stakeholder needs, in support of a comprehensive feasibility study for a Texas statewide evapotranspiration network. This report summarizes the data and information collected from interviews and online resources regarding the purpose, design, operation, and value of these mesonets. It analyzes existing network data within Texas and evaluates the costs and benefits associated with operating a more comprehensive or integrated network. Finally, it presents options for a sustainable Texas mesonet based on successes elsewhere and the specific needs and resources of Texas. A mesonet here refers to a set of weather stations designed to detect and monitor weather phenomena ranging in size from several miles to hundreds of miles (the "mesoscale"). Such disturbances include flooding and thunderstorms (i.e. convective precipitation), high winds, droughts, and heatwaves. Instruments may be located as high as 10 m above the ground, and stations are generally located to avoid influences from urban landscapes, irrigation, forests, and large bodies of water. This report restricts the term mesonet to networks that serve a variety of needs or stakeholders. ET (Evapotranspiration) networks differ in both their objectives and measurements. Their objective is to determine the atmospheric demand for water evaporation and transpiration from land covered by a well-watered reference crop – either alfalfa or clipped grass. Such data is valuable for irrigation scheduling for agricultural production and for improving efficiencies in landscape watering for homes and businesses. ET networks use specific instruments often at 2 m heights sited well within a homogenous field of a well-maintained reference crop. Requirements of growers and stakeholders often drive the siting and spacing. An ET network has a particular specialized use while a mesonet is more of a multi-purpose network. Many existing mesonets in other states were originally established for agricultural purposes, while others were established in support of public safety. Most have been in operation for an average of twenty years and by now serve a broad range of sectors and constituencies. In Texas, there are three mesonets that serve a variety of purposes: the West Texas Mesonet, the Lower Colorado River Authority (LCRA) Hydromet Network, and the TexMesonet. There is one dedicated ET network, the TexasET Network, and there are numerous other single-purpose networks. All surveyed mesonets and ET networks measure air temperature, relative humidity, wind, and precipitation. Solar radiation is measured at all stations in the TexasET and TexMesonet networks, but only partially in the other two networks. In addition, many also measure soil temperature and soil moisture at a variety of subsurface levels as well as wind or temperature at multiple above-ground levels. Data transmission from individual stations is predominantly by cellular network. Users access the data via web sites, text alerts, apps, and through retransmission of data to larger aggregation networks such as the Meteorological Assimilation Data Ingest System, the National Mesonet Program, and MesoWest. Most mesonets quality control their data to either World Meteorological Organization or National Weather Service standards. Individual startup costs range from $6,200 to$25,000 per station, and network maintenance and operating costs range from $1,600 to$6,000 per station. Differences in cost largely reflect differences in instrumentation and maintenance needs. Maintenance costs for ET stations can be high due to irrigation infrastructure and land management required to maintain the reference grasses. Staffing needs depend on the mix of employees and outside contractors; labor-intensive tasks include station, instrumentation, and communication maintenance, calibration, product development, and administration. The benefits gained from fully functional ET networks are substantial. Analyses of benefits of existing ET networks find typical water savings of several inches per year on irrigated cropland, implying potential water savings exceeding one million acre-feet per year within the agriculture sector alone. Overall, the potential economic return on investment is substantial, with one study estimating it at 20:1. Mesonet business models range from comprehensive centralized networks with fully integrated operations to secondhand aggregators of data from existing networks. Most of the successful networks examined in this report operate on a partnership model with some centralized tasks and funding and some tasks and funding shouldered at the local level. Nearly all mesonets function through university or multi-university partnerships. In most cases, data is free of charge. In Texas, an appropriate model would be a consortium model, consisting of the Texas Water Development Board, universities such as Texas Tech University, Texas A&M University, and the University of Texas, and other statewide or regional stakeholders/operators such as the the Texas A&M Agrilife Extension Service, Lower Colorado River Authority and the Electricity Reliability Council of Texas. Additional stakeholder participation can be formalized through an advisory board. Successful mesonets elsewhere have avoided challenges which can potentially lead to failure of the network, including: 1. lacking an overall network vision; 2. failing to properly engage potential stakeholders; 3. misdiagnosing local needs; 4. lacking diversification in revenue streams; 5. not fully exploring potential government partners; 6. not properly budgeting for maintenance costs; understaffing; 7. lacking data and metadata standards; 8. insufficient communications infrastructure; and 9. not providing reliable web/automated dissemination of data.Texas Water Development Boar

Electron spin dynamics in quantum dots and related nanostructures due to hyperfine interaction with nuclei

We review and summarize recent theoretical and experimental work on electron spin dynamics in quantum dots and related nanostructures due to hyperfine interaction with surrounding nuclear spins. This topic is of particular interest with respect to several proposals for quantum information processing in solid state systems. Specifically, we investigate the hyperfine interaction of an electron spin confined in a quantum dot in an s-type conduction band with the nuclear spins in the dot. This interaction is proportional to the square modulus of the electron wave function at the location of each nucleus leading to an inhomogeneous coupling, i.e. nuclei in different locations are coupled with different strength. In the case of an initially fully polarized nuclear spin system an exact analytical solution for the spin dynamics can be found. For not completely polarized nuclei, approximation-free results can only be obtained numerically in sufficiently small systems. We compare these exact results with findings from several approximation strategies.Comment: 26 pages, 9 figures. Topical Review to appear in J. Phys.: Condens. Matte

Genome-wide association analysis of more than 120,000 individuals identifies 15 new susceptibility loci for breast cancer.

Genome-wide association studies (GWAS) and large-scale replication studies have identified common variants in 79 loci associated with breast cancer, explaining ∼14% of the familial risk of the disease. To identify new susceptibility loci, we performed a meta-analysis of 11 GWAS, comprising 15,748 breast cancer cases and 18,084 controls together with 46,785 cases and 42,892 controls from 41 studies genotyped on a 211,155-marker custom array (iCOGS). Analyses were restricted to women of European ancestry. We generated genotypes for more than 11 million SNPs by imputation using the 1000 Genomes Project reference panel, and we identified 15 new loci associated with breast cancer at P < 5 × 10(-8). Combining association analysis with ChIP-seq chromatin binding data in mammary cell lines and ChIA-PET chromatin interaction data from ENCODE, we identified likely target genes in two regions: SETBP1 at 18q12.3 and RNF115 and PDZK1 at 1q21.1. One association appears to be driven by an amino acid substitution encoded in EXO1.BCAC is funded by Cancer Research UK (C1287/A10118, C1287/A12014) and by the European Community's Seventh Framework Programme under grant agreement 223175 (HEALTH-F2-2009-223175) (COGS). Meetings of the BCAC have been funded by the European Union COST programme (BM0606). Genotyping on the iCOGS array was funded by the European Union (HEALTH-F2-2009-223175), Cancer Research UK (C1287/A10710, C8197/A16565), the Canadian Institutes of Health Research (CIHR) for the CIHR Team in Familial Risks of Breast Cancer program and the Ministry of Economic Development, Innovation and Export Trade of Quebec, grant PSR-SIIRI-701. Combination of the GWAS data was supported in part by the US National Institutes of Health (NIH) Cancer Post-Cancer GWAS initiative, grant 1 U19 CA148065-01 (DRIVE, part of the GAME-ON initiative). For a full description of funding and acknowledgments, see the Supplementary Note.This is the author accepted manuscript. The final version is available from NPG via http://dx.doi.org/10.1038/ng.324

Observation-Based Estimates of Present-Day and Future Climate Change Impacts on Heavy Rainfall in Harris County

This report describes the results of an extreme value analysis of precipitation in and around Harris County, Texas, in order to determine whether the newly-promulgated NOAA Atlas 14 rainfall design values are valid in a changing climate. The analysis in this report is based on the original NOAA Atlas 14 data set as well as a set of composite stations for the Gulf and Southeast Coasts. As of this writing, this report and its findings have not yet been peer-reviewed. • The recent upward trend in extreme precipitation in the Houston area has contributed to extreme rainfall design values in the area that far exceed those of comparable locations. This is in part due to some stations not having a sufficiently lengthy set of observations and in part due to southeast Texas receiving more than its fair share of storms. We assess that the design values of 100-year rainfall amounts would be 7% smaller if a longer period of record was available at all observation locations. • Coastal southeast Texas has the largest single-day and multi-day return values anywhere along the Gulf and Atlantic coasts for return periods of 100 years or more. This is in part due to some recent storms that could have occurred anywhere along the Gulf coast concentrating their activity around Houston. There is no known factor that would make storms such as Harvey more likely to happen in Texas than elsewhere along the northern Gulf Coast. We assess that extreme rainfall risk in Southeast Texas should consider storms from a broader portion of the Gulf Coast, decreasing return values by an additional 1%-18%, with the larger values applying to the larger return periods. • A robust upward trend in extreme precipitation is present across the southern and southeastern United States. The trend is larger in southeast Texas, but we have no reason to expect that climate change would cause trend variations on such a small scale. Using averaged trends across areas near the Gulf Coast, we assess the best estimate of the climate-driven trend in southeast Texas to be 11%-15% over the past 60 years, with the remainder of the observed trend caused by regionally unusual storms (like Harvey) that are not likely to recur in the same places. • The three factors listed above effectively cancel each other out for 2-year return values. We assess that the present-day nonstationary return values are approximately equal to the stationary estimates of NOAA Atlas 14 for 2-year return periods. • Because of the three factors listed above, the NOAA Atlas 14 100-year and 500-year return values generally overestimate the present-day and near-term future extreme rainfall risk in and around the Houston area. We assess that for 100-year return periods, current nonstationary values are still about 10-12% below the NOAA Atlas 14 values. • The historic upward trend is very likely to continue with global warming. Because of this, we assess that NOAA Atlas 14 return values underestimate the intensity of all future 2-year rainfall events in the Harris County area. We also assess that, depending on the rate of future warming, the nonstationary 100-year return values will exceed the NOAA Atlas 14 values around the middle of the 21st century.Harris County Flood Control Distric

Effective Stratification for Pseudoadiabatic Ascent

Effective stratification can be interpreted as the resistance to upward motion of saturated air parcels experiencing condensation. Previously published expressions for effective stratification conflict with each other, and the most widely distributed expression contains an O(1) error. A derivation of effective stratification is presented that exposes its physical interpretation and that reveals the origin of the flaw in the incorrect derivation