scholarly journals Research Note:Derivation of temperature lapse rates in semi-arid south-eastern Arizona

2004 ◽  
Vol 8 (6) ◽  
pp. 1179-1185 ◽  
Author(s):  
R. C. Harlow ◽  
E. J. Burke ◽  
R. L. Scott ◽  
W. J. Shuttleworth ◽  
C. M. Brown ◽  
...  
Keyword(s):  
Regional Scale ◽  
Basin And Range ◽  
Lapse Rate ◽  
Radiosonde Data ◽  
Near Surface ◽  
South Eastern ◽  
Wide Range ◽  
The Mean ◽  
Lapse Rates ◽  
Semi Arid

Abstract. Ecological and hydrological modelling at the regional scale requires distributed information on weather variables, and temperature is important among these. In an area of basin and range topography with a wide range of elevations, such as south-eastern Arizona, measurements are usually available only at a relatively small number of locations and elevations, and temperatures elsewhere must be estimated from atmospheric lapse rate. This paper derives the lapse rates to estimate maximum, minimum and mean daily temperatures from elevation. Lapse rates were calculated using air temperatures at 2 m collected during 2002 at 18 locations across south-eastern Arizona, with elevations from 779 to 2512 m. The lapse rate predicted for the minimum temperature was lower than the mean environmental lapse rate (MELR), i.e. 6 K km–1, whereas those predicted for the mean and maximum daily temperature were very similar to the MELR. Lapse rates were also derived from radiosonde data at 00 and 12 UTC (5 pm and 5 am local time, respectively). The lapse rates calculated from radiosonde data were greater than those from the 2 m measurements, presumably because the effect of the surface was less. Given temperatures measured at Tucson airport, temperatures at the other sites were predicted using the different estimates of lapse rates. The best predictions of temperatures used the locally predicted lapse rates. In the case of maximum and mean temperature, using the MELR also resulted in accurate predictions. Keywords: near surface lapse rates, semi-arid climate, mean minimum and maximum temperatures, basin and range topography

scholarly journals A Multidiagnostic Intercomparison of Tropical-Width Time Series Using Reanalyses and Satellite Observations

2012 ◽  
Vol 25 (4) ◽  
pp. 1061-1078 ◽  
Author(s):  
Sean M. Davis ◽  
Karen H. Rosenlof
Keyword(s):  
Longwave Radiation ◽  
Hadley Cell ◽  
Radiosonde Data ◽  
Full Time ◽  
Robust Detection ◽  
Time Period ◽  
Wide Range ◽  
The Mean ◽  
Yield Trends ◽  
The Tropics

Abstract Poleward migration of the latitudinal edge of the tropics of 0.25°–3.0° decade−1 has been reported in several recent studies based on satellite and radiosonde data and reanalysis output covering the past ~30 yr. The goal of this paper is to identify the extent to which this large range of trends can be explained by the use of different data sources, time periods, and edge definitions, as well as how the widening varies as a function of hemisphere and season. Toward this end, a suite of tropical edge latitude diagnostics based on tropopause height, winds, precipitation–evaporation, and outgoing longwave radiation (OLR) are analyzed using several reanalyses and satellite datasets. These diagnostics include both previously used definitions and new definitions designed for more robust detection. The wide range of widening trends is shown to be primarily due to the use of different datasets and edge definitions and only secondarily due to varying start–end dates. This study also shows that the large trends (>~1° decade−1) previously reported in tropopause and OLR diagnostics are due to the use of subjective definitions based on absolute thresholds. Statistically significant Hadley cell expansion based on the mean meridional streamfunction of 1.0°–1.5° decade−1 is found in three of four reanalyses that cover the full time period (1979–2009), whereas other diagnostics yield trends of −0.5°–0.8° decade−1 that are mostly insignificant. There are indications of hemispheric and seasonal differences in the trends, but the differences are not statistically significant.

scholarly journals Neutral Saturated Lapse Rate: An Experimental Check from CALJET-1998 and PACJET-2001

2009 ◽  
Vol 137 (12) ◽  
pp. 4382-4385 ◽  
Author(s):  
Renzo Richiardone ◽  
Massimiliano Manfrin
Keyword(s):  
High Resolution ◽  
Normal Distribution ◽  
Mean Value ◽  
Lapse Rate ◽  
Temperature Profiles ◽  
Experimental Check ◽  
Rate Distribution ◽  
The Mean ◽  
Lapse Rates ◽  
Good Agreement

Abstract The lapse rates of high-resolution temperature profiles during nearly neutral, saturated conditions are compared with the saturated adiabatic lapse rate and with that proposed by Richiardone and Giusti. A good agreement between the latter and the mean value of the observed lapse rate is found, whereas the saturated adiabatic lapse rate differs significantly, confirming experimentally that it is not completely correct to assess the moist neutrality from a comparison with the saturated adiabatic lapse rate. The lapse-rate distribution supports the hypothesis that the lapse-rate statistics is a local collection of saturated adiabatic lapse rates in a background normal distribution centered around the neutrality.

scholarly journals Treehopper (Membracidae, Auchenorrhyncha) assemblages in four semi-arid areas of caatinga of Northeast Brazil

2019 ◽  
Vol 19 (2) ◽  
Author(s):  
Rembrandt Romano Andrade Dantas Rotheá ◽  
Aline Lourenço ◽  
Alexandre Vasconcellos ◽  
Antonio José Creão-Duarte
Keyword(s):  
Species Richness ◽  
Host Plant ◽  
Regional Scale ◽  
Wide Distribution ◽  
Northeast Brazil ◽  
Arid Areas ◽  
General Behavior ◽  
The Mean ◽  
Semi Arid ◽  
Different Climates

Abstract Treehopper assemblages were sampled in four semi-arid areas of caatinga in Northeast Brazil during the rainy seasons of 2016 and 2017, using three different capture methods. The areas are located in two Ecoregions of the Caatinga: “Depressão Sertaneja Setentrional” (Northern Sertaneja Depression) and “Planalto da Borborema” (Borborema Plateau). A total of 2,394 individuals of 43 species were sampled, corresponding to approximately 87% of the mean estimated species richness for all four areas. The species richness varied among the areas from 14 to 21, while the abundance of individuals ranged from 129 to 1860. Eighteen species were shared among areas, of which only Enchenopa eunicea, Sundarion sp. 1, Ceresa vitulus and Erosne parvula occurred in all four due to the general behavior of the first three and the wide distribution of host plant of Erosne parvula - Mimosa tenuiflora. Twenty-five species occurred only in one area, of which 23 were categorized as rare with a maximum of eight individuals sampled, and seven with only one individual collected (singletons). Considering that the Caatinga Domain possesses at least nine Ecoregions with different climates, geomorphology and vegetation, along with marked endemism of plants, it is expected that the species richness of treehoppers will increase substantially on a regional scale.

Lapse rate deviations from the moist adiabat in the tropical upper troposphere in climate models

2020 ◽  
Author(s):  
Paul Keil ◽  
Hauke Schmidt ◽  
Bjorn Stevens
Keyword(s):  
Climate Models ◽  
Lower Troposphere ◽  
Lapse Rate ◽  
Cmip5 Models ◽  
Upper Troposphere ◽  
Microphysical Parameters ◽  
The Mean ◽  
Lapse Rates ◽  
The Tropics ◽  
Mean State

<p>The tropospheric lapse rate in the tropics follows a moist adiabat quite closely and is mainly set by surface temperature and humidity in the convecting regions. Therefore, warming or biases at the surface are transferred via the moist adiabat to the upper troposphere. However, climate models show large discrepancies in the upper troposphere and recent observed upper tropospheric warming is around 0.5K weaker than predicted by the moist adiabat theory. Here we use the control simulations of the CMIP5 ensemble to show that large differences in the upper troposphere exist in the mean state that are unrelated to inter-model differences in the lower troposphere. In fact, CMIP5 models diverge (positively and negatively) from the moist pseudoadiabat by up to 2K at 300hPa. Precipitation weighted SSTs have recently been used to resolve the discrepancy between models and observations in upper tropospheric warming, but we show that they are not able to explain the differences in the mean state. While it is difficult to exactly depict the reasons for the inter-model spread, we demonstrate how the upper tropospheric lapse rate can deviate from the moist adiabat for the same lower tropospheric state with AMIP experiments. For this we use the ICON-A model, in which we tune convective and microphysical parameters. An improved understanding of the effect of different parameterisations on the models' lapse rates may help to better understand differences in the response to global warming.</p>

Seasonal and Synoptic Variations in Near-Surface Air Temperature Lapse Rates in a Mountainous Basin

2008 ◽  
Vol 47 (1) ◽  
pp. 249-261 ◽  
Author(s):  
Troy R. Blandford ◽  
Karen S. Humes ◽  
Brian J. Harshburger ◽  
Brandon C. Moore ◽  
Von P. Walden ◽  
...  
Keyword(s):  
Air Temperature ◽  
Surface Air Temperature ◽  
Lapse Rate ◽  
Maximum Temperature ◽  
Weather Types ◽  
Near Surface ◽  
Air Masses ◽  
Synoptic Weather ◽  
South Central ◽  
Lapse Rates

Abstract To accurately estimate near-surface (2 m) air temperatures in a mountainous region for hydrologic prediction models and other investigations of environmental processes, the authors evaluated daily and seasonal variations (with the consideration of different weather types) of surface air temperature lapse rates at a spatial scale of 10 000 km2 in south-central Idaho. Near-surface air temperature data (Tmax, Tmin, and Tavg) from 14 meteorological stations were used to compute daily lapse rates from January 1989 to December 2004 for a medium-elevation study area in south-central Idaho. Daily lapse rates were grouped by month, synoptic weather type, and a combination of both (seasonal–synoptic). Daily air temperature lapse rates show high variability at both daily and seasonal time scales. Daily Tmax lapse rates show a distinct seasonal trend, with steeper lapse rates (greater decrease in temperature with height) occurring in summer and shallower rates (lesser decrease in temperature with height) occurring in winter. Daily Tmin and Tavg lapse rates are more variable and tend to be steepest in spring and shallowest in midsummer. Different synoptic weather types also influence lapse rates, although differences are tenuous. In general, warmer air masses tend to be associated with steeper lapse rates for maximum temperature, and drier air masses have shallower lapse rates for minimum temperature. The largest diurnal range is produced by dry tropical conditions (clear skies, high solar input). Cross-validation results indicate that the commonly used environmental lapse rate [typically assumed to be −0.65°C (100 m)−1] is solely applicable to maximum temperature and often grossly overestimates Tmin and Tavg lapse rates. Regional lapse rates perform better than the environmental lapse rate for Tmin and Tavg, although for some months rates can be predicted more accurately by using monthly lapse rates. Lapse rates computed for different months, synoptic types, and seasonal–synoptic categories all perform similarly. Therefore, the use of monthly lapse rates is recommended as a practical combination of effective performance and ease of implementation.

scholarly journals Air temperature variability in the vertical profile over the coastal area of Petuniabukta, central Spitsbergen

2017 ◽  
Vol 38 (1) ◽  
pp. 41-60 ◽  
Author(s):  
Klára Ambrožová ◽  
Kamil Láska
Keyword(s):  
Air Temperature ◽  
Annual Cycle ◽  
Relative Frequency ◽  
Temperature Inversion ◽  
Lapse Rate ◽  
Data Set ◽  
Near Surface ◽  
Air Layers ◽  
Lapse Rates ◽  
Temperature Inversions

AbstractA two-year-long data set of air temperature from four different altitudes above Petuniabukta, central Spitsbergen, was analysed in order to assess the near-surface temperature lapse rates and the relative frequency of air temperature inversion occurrence. From August 2013 to July 2015, air temperatures at adjacent altitudes in Petuniabukta were strongly correlated. The near-surface lapse rates in all three layers differed significantly both from the average lapse rate in the international standard atmosphere (0.65°C 100 m−1) and the lapse rate calculated by linear regression. A pronounced annual cycle was detected in the lowermost air layer (from 23 to 136 m a.s.l.) with a variable near-surface lapse rate in the winter months, while an annual cycle was not apparent in the air layers above 136 m a.s.l. The lowermost layer was also characterized by a notable daily cycle in near-surface lapse rate in spring and autumn. Air temperature inversions occurred in up to 80% of the study period in the air layer below 136 m a.s.l., with the relative frequency being much lower in the other two air layers. The air temperature inversions lasted as long as 139 hours. A case study revealed that one of the strongest air temperature inversions was connected to an area of lower pressure gradients at the 850-hPa pressure level.

Atmospheric Properties Associated With Large Wildfires

1996 ◽  
Vol 6 (2) ◽  
pp. 71 ◽  
Author(s):  
BE Potter
Keyword(s):  
United States ◽  
Wind Shear ◽  
Surface Wind ◽  
Surface Air Temperature ◽  
The United States ◽  
Lower Atmosphere ◽  
Lapse Rate ◽  
Near Surface ◽  
Significance Level ◽  
Lapse Rates

Lower atmosphere moistures, temperatures, winds, and lapse rates are examined for the days of 339 fires over 400 ha in the United States from 1971 through 1984. These quantities are compared with a climatology dataset from the same 14-year period using 2-way unbalanced analysis of variance. The results show that the fire-day surface-air temperature and moisture differ from the climatology at the 0.001 significance level. Near-surface wind shear does not appear to differ significantly between fire and climatology days. Results are inconclusive for wind speed and surface lapse rate.

scholarly journals Rain or snow: hydrologic processes, observations, prediction, and research needs

2017 ◽  
Vol 21 (1) ◽  
pp. 1-22 ◽  
Author(s):  
Adrian A. Harpold ◽  
Michael L. Kaplan ◽  
P. Zion Klos ◽  
Timothy Link ◽  
James P. McNamara ◽  
...  
Keyword(s):  
Complex Terrain ◽  
Hydrological Modeling ◽  
Regional Scale ◽  
Atmospheric Modeling ◽  
Hydrological Models ◽  
Scientific Cooperation ◽  
Near Surface ◽  
Hydrologic Processes ◽  
Wide Range ◽  
Precipitation Phase

Abstract. The phase of precipitation when it reaches the ground is a first-order driver of hydrologic processes in a watershed. The presence of snow, rain, or mixed-phase precipitation affects the initial and boundary conditions that drive hydrological models. Despite their foundational importance to terrestrial hydrology, typical phase partitioning methods (PPMs) specify the phase based on near-surface air temperature only. Our review conveys the diversity of tools available for PPMs in hydrological modeling and the advancements needed to improve predictions in complex terrain with large spatiotemporal variations in precipitation phase. Initially, we review the processes and physics that control precipitation phase as relevant to hydrologists, focusing on the importance of processes occurring aloft. There is a wide range of options for field observations of precipitation phase, but there is a lack of a robust observation networks in complex terrain. New remote sensing observations have the potential to increase PPM fidelity, but generally require assumptions typical of other PPMs and field validation before they are operational. We review common PPMs and find that accuracy is generally increased at finer measurement intervals and by including humidity information. One important tool for PPM development is atmospheric modeling, which includes microphysical schemes that have not been effectively linked to hydrological models or validated against near-surface precipitation-phase observations. The review concludes by describing key research gaps and recommendations to improve PPMs, including better incorporation of atmospheric information, improved validation datasets, and regional-scale gridded data products. Two key points emerge from this synthesis for the hydrologic community: (1) current PPMs are too simple to capture important processes and are not well validated for most locations, (2) lack of sophisticated PPMs increases the uncertainty in estimation of hydrological sensitivity to changes in precipitation phase at local to regional scales. The advancement of PPMs is a critical research frontier in hydrology that requires scientific cooperation between hydrological and atmospheric modelers and field scientists.

scholarly journals The Vertical Structure of Tropospheric Water Vapor: Comparing Radiative and Ocean-Driven Climate Changes

2016 ◽  
Vol 29 (11) ◽  
pp. 4251-4268 ◽  
Author(s):  
Brian E. J. Rose ◽  
M. Cameron Rencurrel
Keyword(s):  
Water Vapor ◽  
Surface Temperature ◽  
Diagnostic Technique ◽  
Lapse Rate ◽  
Ocean Heat Uptake ◽  
Surface Warming ◽  
Wide Range ◽  
Single Column ◽  
Transient Climate Change ◽  
Lapse Rates

Abstract Changes in column-integrated water vapor (Q) in response to increased CO2 and ocean heat uptake (OHU) are investigated in slab-ocean aquaplanet simulations. The simulations span a wide range of warming and moistening patterns due to the spatial structures of the imposed OHU. Fractional changes in Q per degree of surface warming range from 0% to 20% K−1 locally and from 3.6% to 11% K−1 globally. A new diagnostic technique decomposes these changes into relative humidity (RH), surface temperature, and lapse rate contributions. Single-column calculations demonstrate substantial departures from apparent (surface temperature based) Clausius–Clapeyron (CC) scaling due to lapse rates changes; a moist-adiabatic column with fixed, uniform RH exceeds the CC rate by 2.5% K−1. The RH contribution is very small in most simulations. The various Q scalings are thus all consistent CC, but result from different patterns of polar amplification and lapse rate change. Lapse rates are sensitive to location and magnitude of OHU, with implications for Q under transient climate change. CO2 with subpolar (tropical) OHU results in higher (lower) Q scalings than CO2 alone. The weakest Q scaling (and largest RH effects) is found for increased poleward ocean heat transport, which causes strongly polar-amplified warming and near-zero tropical temperature change. Despite weak RH changes and fidelity to the CC relation, Q is expected to vary widely on different time scales in nature due to sensitivity of lapse rates to OHU along with the nonlinearity of the diagnostics.

scholarly journals Planetary Layer Lapse Rate Comparison of Tropical,Montane and hot Semi-Arid Climates of Nigeria

2020 ◽  
Vol 3 (2) ◽  
Author(s):  
David O. Edokpa ◽  
Precious N. Ede
Keyword(s):  
Arid Zone ◽  
Analysis Data ◽  
Substantial Effect ◽  
Lapse Rate ◽  
Entire Region ◽  
Rate Condition ◽  
Port Harcourt ◽  
Montane Zone ◽  
Lapse Rates ◽  
Semi Arid

This study assessed the pattern of planetary layer lapse rate across the major climate belts of Nigeria. Six years’ data (2010-2015) for air temperature values between 1000 mbar and 850 mbar atmospheric pressure levels were acquired from Era-Interim Re-analysis data centre. The data was retrieved at 6-hourly synoptic hours: 0000H, 0600H, 1200H and 1800H at 0.125o grid resolution. Results showed that the lower tropospheric layers throughout the various climate belts has a positive lapse rate. Findings also revealed that the average annual lapse rate condition were: Tropical wet zone (Port Harcourt) -5.6 oC/km; Bi-modal Tropical continental zone (Enugu) 5.8 oC/km; Montane zone (Jos) -6.5 oC/km; Mono-modal Tropical continental zone (Kano) -6.6 oC/km; and Hot semi-arid zone (Maiduguri) -6.6 oC/km. This average values presents the lapse rates to be close to the Saturated Adiabatic Lapse Rate (SALR). Average diurnal results for the climate belts showed that lapse rate is higher during the afternoon and transition periods than the rest periods and increases from the coastal areas northward. The seasonal periods of highest lapse rates during the day time are from December – May (i.e. 5.8-9.5 oC/km) with slight decrease from June – November. The positive lapse rate of range -1.8 –    -5.9 oC/km observed during the period of dawn across the entire region showed that infrared radiation was still being released and modified by less energetic mechanical turbulence that characterizes the surface layer across Nigeria. This also indicates that global warming is real and in substantial effect. The study findings imply that conditional instability prevailed over the entire region, therefore, the planetary layer environment will be of slow to moderate dispersive potential and will require forceful mechanism to lift emissions are introduced into it. It is recommended that industrial stacks are above 50 m to enhance the dispersion of emissions aloft.

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