Spatial aggregation of vegetation parameters in a coupled land surface-atmosphere model

The aggregation of heterogeneous land surface cover parameters to calculate effective area-average energy fluxes at microscale using a realistic coupled land surfaceatmosphere model are been investigated in this study. The Biosphere-Atmosphere Transfer Scheme (BATS) was merged with a two dimensional atmospheric boundary layer simulation model (ABLE) to develop a coupled model, BAT-ABLE. Observed land surface and atmospheric forcing data from the FIFE site in Kansas were used to initialize and run the time series of this model. The initial model states were obtained from seasonal runs of a stand-alone version of BATS using observed data. The horizontal model domain was set to 2 km, while the size of each patch was 1 km. The height of the first model grid level above the ground was set to 2 m to match the screen height at the FIFE site. Simple aggregation rules were used to aggregate BATS parameters to obtain area-average energy fluxes. Four cover types (short grass, long grass, mixed crop and irrigated crop) with five different patch combinations were tested using July 7, August 15, and October 11, 1987 observed data. The aggregation scheme worked well in almost all cases for these different days and times (am, noon, pm). However the aggregation scheme failed in the particular cases of artificially wet soil patches set in a landscape of dry soil. However, analysis of fluxes in this situation showed that this failure is not due to a difference in efficiency of atmospheric advection in this case, rather it is due to a real net change in the area-average turbulent fluxes returned to the atmosphere.hydrology collectio

Experience with Extra Hepatic Intra Abdominal Hydatid Cyst

Introduction: Hydatid disease is a signi cant health problem with their location at Extrahepatic Intra abdominal sites is a very rare disease. Disease in these sites usually found concurrently with liver hydatid disease. Diagnosis is based blood tests & imaging studies. Surgery is the mainstay of treatment. This study will help us in determining the frequency of Extra Hepatic Intra Abdominal Hydatid Disease. Also different methods to diagnose & treat the disease will be evaluated.  Methods: It includes patients of extra hepatic intra abdominal Hydatid cyst above 13 years and underwent surgery from 2009 to 2014. Variables include age, sex, clinical ndings, diagnostic investigations, operative ndings, operative procedure, post operative complications. Results: Eleven patients; 07 male & 04 female; mean age 37.54 years. Most common symptoms were mass in abdomen in 11 patients & dull pain abdomen in 09 (81.8%) patients. Examination revealed non tender mass in epigastric & umbilical region in 04 (36.3%) patients. Ultrasound Abdomen showed hydatid cyst spleen in 02 (18.1%) patients, epigastrium in 04 (36.3%) patients, beneath left crus of diaphragm in 02 (18.1%) patients & right iliac fossa & pelvis in 1 (9.09%) patient. In 02 (18.1%) patients multiple Hydatid cysts were noted. Hydatid cysts liver found in 07 (63.6%) patients. C.T scan Abdomen was performed in 09 (81.8%) patients. Surgical procedures performed include Saucerization & omental packing in liver Hydatid cysts; Splenectomy for Splenic disease & complete excision of remaining intra-abdominal Hydatid cysts. Postoperative complications noted in 05 (45.4%) patients. Conclusion: Extra hepatic intra abdominal is an infrequent disease presents signicant diagnostic & therapeutic challenge for surgeons.  Keywords: extra hepatic; hydatid disease; intra abdominal

Future smartphone: MIMO antenna system for 5G mobile terminals

In this article, an inverted L-shaped monopole eight elements Multiple Input Multiple Output (MIMO) antenna system is presented. The multi-antenna system is designed on a low cost 0.8 mm thick FR4 substrate having dimensions of 136 x 68 mm(2) resonating at 3.5GHz with a 6dB measured bandwidth of 450MHz, and with inter element isolation greater than 15 dB and gain of 4 dBi. The proposed design consists of eight inverted L-shaped elements and parasitic L-shaped strips extending from the ground plane. These shorted stripes acted as tuning stubs for the four inverted L-shaped monopole elements on the side of chassis. This is done to achieve the desired frequency range by increasing the electrical length of the antennas. A prototype is fabricated, and the experimental results show good impedance matching with reasonable measured isolation within the desired frequency range. The MIMO performances, such as envelope correlation coefficient (ECC) and mean effective gain (MEG) are also calculated along with the channel capacity of 38.1bps/Hz approximately 2.6 times that of 4 x 4 MIMO system. Due to its simple shape and slim design, it may be a potential chassis for future handsets. Therefore, user hand scenarios, i.e. both single and dual hand are studied. Also, the effects of hand scenarios on various MIMO parameters are discussed along with the SAR. The performance of the proposed system in different scenarios suggests that the proposed structure holds promising future within the next generation radio smart phones.Antenna and Wireless Propagation Group ; Ministerio de Ciencia, Innovacion y Universidades, Gobierno de Espana (MCIU/AEI/FEDER, UE

Evaluation of Clumping Effects on the Estimation of Global Terrestrial Evapotranspiration

In terrestrial ecosystems, leaves are aggregated into different spatial structures and their spatial distribution is non-random. Clumping index (CI) is a key canopy structural parameter, characterizing the extent to which leaf deviates from the random distribution. To assess leaf clumping effects on global terrestrial ET, we used a global leaf area index (LAI) map and the latest version of global CI product derived from MODIS BRDF data as well as the Boreal Ecosystem Productivity Simulator (BEPS) to estimate global terrestrial ET. The results show that global terrestrial ET in 2015 was 511.9 ± 70.1 mm yr−1 for Case I, where the true LAI and CI are used. Compared to this baseline case, (1) global terrestrial ET is overestimated by 4.7% for Case II where true LAI is used ignoring clumping; (2) global terrestrial ET is underestimated by 13.0% for Case III where effective LAI is used ignoring clumping. Among all plant functional types (PFTs), evergreen needleleaf forests were most affected by foliage clumping for ET estimation in Case II, because they are most clumped with the lowest CI. Deciduous broadleaf forests are affected by leaf clumping most in Case III because they have both high LAI and low CI compared to other PFTs. The leaf clumping effects on ET estimation in both Case II and Case III is robust to the errors in major input parameters. Thus, it is necessary to consider clumping effects in the simulation of global terrestrial ET, which has considerable implications for global water cycle research

Field-experiment constraints on the enhancement of the terrestrial carbon sink by CO₂ fertilization

Clarifying how increased atmospheric CO₂ concentration (eCO₂) contributes to accelerated land carbon sequestration remains important since this process is the largest negative feedback in the coupled carbon–climate system. Here, we constrain the sensitivity of the terrestrial carbon sink to eCO₂ over the temperate Northern Hemisphere for the past five decades, using 12 terrestrial ecosystem models and data from seven CO₂ enrichment experiments. This constraint uses the heuristic finding that the northern temperate carbon sink sensitivity to eCO₂ is linearly related to the site-scale sensitivity across the models. The emerging data-constrained eCO₂ sensitivity is 0.64 ± 0.28 PgC yr−1 per hundred ppm of eCO₂. Extrapolating worldwide, this northern temperate sensitivity projects the global terrestrial carbon sink to increase by 3.5 ± 1.9 PgC yr−1 for an increase in CO2 of 100 ppm. This value suggests that CO₂ fertilization alone explains most of the observed increase in global land carbon sink since the 1960s. More CO₂ enrichment experiments, particularly in boreal, arctic and tropical ecosystems, are required to explain further the responsible processes