First results on Martian carbon monoxide from Herschel/HIFI observations

We report on the initial analysis of Herschel/HIFI carbon monoxide (CO) observations of the Martian atmosphere performed between 11 and 16 April 2010. We selected the (7–6) rotational transitions of the isotopes ^(13)CO at 771 GHz and C^(18)O and 768 GHz in order to retrieve the mean vertical profile of temperature and the mean volume mixing ratio of carbon monoxide. The derived temperature profile agrees within less than 5 K with general circulation model (GCM) predictions up to an altitude of 45 km, however, show about 12–15 K lower values at 60 km. The CO mixing ratio was determined as 980 ± 150 ppm, in agreement with the 900 ppm derived from Herschel/SPIRE observations in November 2009

Structure and chemistry of Orion S

We present interferometric observations of the SiO J = 2-1, H^(13)CO^+ J = 1-0, HC_3N J = 11-10, CH_3OH J_K = 2_0-1_0, and SO_2 J(K_pK_0) = 8_(17)-8_(08) transitions along with the λ = 3.1 mm continuum toward the young stellar object Orion S. The HC_3N and H^(13)CO^+ emission trace similar spatial and velocity distributions which are extended and follow the Orion molecular ridge. The SiO emission is more spatially confined, peaking to the west of the λ = 3.1 mm continuum source, while the CH_3OH emission peaks to the southwest. Weak SO_2 emission was detected southeast of the continuum source position. Column densities and fractional abundances are derived for each species at different positions in the region. In general, the molecular abundances near the continuum source are similar to those in the quiescent material near IRc 2, but the abundances decrease toward the continuum source position indicating localized depletions of at least a factor of three. The presence of strong SiO emission with much weaker SO_2 emission is interpreted as resulting from high-velocity shock interactions between the outflow from Orion S and the surrounding cloud. The apparent molecular depletions directly toward Orion S, and the similarity of abundances between the Orion S region and quiescent ridge material, suggest that Orion S is at an early stage of chemical evolution, prior to when substantial chemical differentiation occurs

A Line Survey of Orion KL from 325 to 360 GHz

We present a high-sensitivity spectral line survey of the high-mass star-forming region Orion KL in the 325-360 GHz frequency band. The survey was conducted at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii. The sensitivity achieved is typically 0.1-0.5 K and is limited mostly by the sideband separation method utilized. We find 717 resolvable features consisting of 1004 lines, among which 60 are unidentified. The identified lines are due to 34 species and various isotopomers. Most of the unidentified lines are weak, and many of them most likely due to isotopomers or vibrationally or torsionally excited states of known species with unknown line frequencies, but a few reach the 2-5 K level. No new species have been identified, but we were able to strengthen evidence for the identification of ethanol in Orion and found the first nitrogen sulfide line in this source. The molecule dominating the integrated line emission is SO_2, which emits twice the intensity of CO, followed by SO, which is only slightly stronger than CO. In contrast, the largest number of lines is emitted from heavy organic rotors like HCOOCH_3, CH_3CH_2CN, and CH_3OCH_3, but their contribution to the total flux is unimportant. CH_3OH is also very prominent, both in the number of lines and in integrated flux. An interesting detail of this survey is the first detection of vibrationally excited HCN in the v_2 = 2 state, 2000 K above ground. Clearly this is a glimpse into the very inner part of the Orion hot core

HIFI observations of water in the atmosphere of comet C/2008 Q3 (Garradd)

High-resolution far-infrared and sub-millimetre spectroscopy of water lines is an important tool to understand the physical and chemical properties of cometary atmospheres.We present observations of several rotational ortho- and para-water transitions in comet C/2008 Q3 (Garradd) performed with HIFI on Herschel. These observations have provided the first detection of the 2_(12)−1_(01) (1669 GHz) ortho and 1_(11)−0_(00) (1113 GHz) para transitions of water in a cometary spectrum. In addition, the ground-state transition 1_(10)−1_(01) at 557 GHz is detected and mapped. By detecting several water lines quasi-simultaneously and mapping their emission we can constrain the excitation parameters in the coma. Synthetic line profiles are computed using excitation models which include excitation by collisions, solar infrared radiation, and radiation trapping. We obtain the gas kinetic temperature, constrain the electron density profile, and estimate the coma expansion velocity by analyzing the map and line shapes. We derive water production rates of 1.7−2.8 × 10^(28) s^(−1) over the range r_h = 1.83−1.85 AU

The benthic macrofauna of sludge-affected sediments in the Derwent Estuary, southern Tasmania

The paper reports the findings of an extensive survey of benthic invertebrates from the Derwent estuary in southern Tasmania, sampled during an investigation into the distribution and character of sludge emanating from a pulp and paper factory. In total, 45 invertebrate species were collected, but none was found in the sediment in the river channel between the pulpmill (its effluent outfall) and a site 5 km downstream. Similarly, other sediments with wood fibre present (measured by loss on ignition) and with very negative redox values were faunistically depauperate and possessed much lower species richness than that anticipated from other studies in Australia. The sediments in shallow areas in the middle part of the estuary had very high densities of invertebrates and had less mechanical wood fibre than sediments in deeper water nearby or other sediments further downstream. These results suggest that smothering by wood fibre, with concomitant toxicological effects of chemical reactions in the sediment, results in the low invertebrate diversities observed. These findings must be tempered by the methodological limitations involved with the selection of sample sites and lack of seasonal data, which have prevented definitive statements from being made about the level of environmental stress being experienced in the lower parts of the estuary

Formaldehyde over the central Pacific during PEM-Tropics B

Formaldehyde, CH2O, mixing ratios are reported for the central Pacific troposphere from a series of 41 flights, which took place in March-April 1999 as part of the NASA Pacific Exploratory Mission (PEM) -Tropics B mission. Ambient CH2O was collected in aqueous media and quantified using an enzyme-derivatization fluorescence technique. Primary calibration was performed using aqueous standards and known flow rates. Occasionally, CH2O gas standard additions to ambient air were performed as a secondary calibration. Analytical blanks were determined by replacing ambient air with pure air. The estimated precision was ±30 pptv and the estimated accuracy was the sum of ±30 parts per trillion by volume (pptv) ±15% of the measured value. Approximately 25% of the observations were less than the instrumental detection limit of 50 pptv, and 85% of these occurred above 6 km. CH2O mixing ratios decreased with altitude; for example, near the equator the median value in the lowest 2 km was 275 pptv, decreased to 150 pptv by 6 km and was below 100 pptv above 8 km. Between 130 and 170 W and below 1km, a small variation of CH2O mixing ratio with latitude was noted as near-surface median mixing ratios decreased near the equator (275 pptv) and were greater on either side (375 pptv). A marked decrease in near-surface CH2O (200 pptv) was noted south of 23° S on two flights. Between 3° and 23° S, median CH2O mixing ratios were lower in the eastern tropical Pacific than in the western or central Pacific; nominal differences were >100 pptv near the surface to ∼100 pptv at midaltitude to ∼50 pptv at high altitude. Off the coast of Central America and Mexico, mixing ratios as high as 1200 pptv were observed in plumes that originated to the east over land. CH2O observations were consistently higher than the results from a point model constrained by other photochemical species and meteorological parameters. Regardless of latitude or longitude, agreement was best at altitudes above 4 km where the difference between measured and modeled CH2O medians was less than 50 pptv. Below 2 km the model median was approximately 150 pptv less than the measured median. Copyright 2001 by the American Geophysical Union