Atmósfera (Journal)
Not a member yet
881 research outputs found
Sort by
Optical properties of aerosols: southern México City
Get PDFMeasurements of aerosol absorption (σa) and scattering (σs) at wavelengths of 550 nm and 530 nm, respectively, and particle (0.01 to 3 µm) concentration were obtained in south of México City (19º 21' 00'' N, 99º 09' 42'' W and 2276 masl) during dry (February-May) and rainy (June-August) seasons of 2005. The averages over the sampling days of each month for σa presented small variations on each season, ranging from 20 Mm-1 to 29.4 Mm-1 and from 12 to 14.7 Mm-1 in dry and rainy seasons, respectively. However, σs values varied notoriously, from 78.1 Mm-1 to 93.3 Mm-1 in dry season, compared with 20.6 Mm-1 to 35.5 Mm-1 during rainy season. The single scattering albedo (SSA) average was 0.82 during dry season while in the rainy season it was slightly lower, that is 0.68. These data are useful in atmospheric photochemistry studies where aerosol effects are considered.Se obtuvieron medidas de absorción (σa) a 500 nm, esparcimiento (σs) a 530 nm y concentración de partículas (0.01 a 3 μm) en el Sur de la Cd. de México durante las temporadas de secas (febrero-mayo) y lluvias (junio-agosto) del 2005. Los promedios mensuales de σa en los días de muestreo presentaron pequeñas variaciones de 20 a 29.4 Mm-1 y 12 a 14.7 Mm-1 en secas y lluvias, respectivamente. Sin embargo, σs varía notablemente en la temporada seca de 78.1 a 93.3 Mm-1 y en la temporada de lluvias de 20.6 a 35.5 Mm-1. El promedio del albedo de dispersión simple (SSA) fue de 0.82 durante la temporada seca mientras que en la de lluvias fue un poco menor 0.68. Estos datos son útiles en estudios de fotoquímica atmosférica que consideren los efectos de los aerosoles
The impact of urbanization on the monthly averaged diurnal cycle in October 2004 in the Pearl River Delta region
Get PDFThe Pearl River Delta (PRD) region in southern China has experienced rapid urbanization and dramatic economic growth in last 25 years. Using identical observed meteorology for lateral boundary conditions, two one-month simulations were conducted: one using the original United States Geological Survey (USGS) 24-category land cover data (namely NU) and the other using the urban land cover data from 2004 Moderate Resolution Imaging Spectroradiometer (MODIS) satellite images (namely HU) as lower boundary conditions in a mesoscale model. October 2004 was chosen for simulation due to no precipitation in the Pearl River Delta corresponding to drought conditions. The spatially averaged value (domain-averaged, land-averaged value, urban-averaged value) used for the analysis can reflect the regional climate over an area of several hundreds of kilometers. The simulation results show that the additional urbanization in the PRD amplifies the spatially averaged diurnal cycle of surface temperature, sensible heat fluxes and planetary boundary layer (PBL) height, decreases relative humidity, water vapor in the air and latent heat flux, and increases the diurnal temperature range (DTR). The simulation also shows that the urban heat island (UHI) intensity is about 0.4° in the nighttime and about 1.3° in the daytime after the urban expansion
Rossby wave propagation tracks in southern hemisphere mean basic flows associated to generalized frosts over southern South America
Get PDFBased on previous observational studies on cold extreme events over southern South America, some recent studies suggest a possible relationship between Rossby wave propagation remotely triggered and the occurrence of frost. Using the concept of linear theory of Rossby wave propagation, this paper analyzes the propagation of such waves in two different basic states that correspond to austral winters with maximum and minimum generalized frost frequency of occurrence in the Wet Pampa (central-northwest Argentina). In order to determine the wave trajectories, the ray tracing technique is used in this study. Some theoretical discussion about this technique is also presented. The analysis of the basic state, from a theoretical point of view and based on the calculation of ray tracings, corroborates that remotely excited Rossby waves is the mechanism that favors the maximum occurrence of generalized frosts. The basic state in which the waves propagate is what conditions the places where they are excited. The Rossby waves are excited in determined places of the atmosphere, propagating towards South America along the jet streams that act as wave guides, favoring the generation of generalized frosts. In summary, this paper presents an overview of the ray tracing technique and how it can be used to investigate an important synoptic event, such as frost in a specific region, and its relationship with the propagation of large scale planetary waves
Rainfall analysis using conventional and non-conventional rainfall information on monthly scale.
Get PDFThe aim of this paper is to describe the technique used to create the merged analysis of rainfall over the Indian and adjoining region (1.5º to 35.5º N and 63.5º to 97.5º E). The technique is tested for monthly gridded fields of rainfall for a 2-year monsoon period (2001 and 2003) on a 1º x 1º latitude-longitude grid by merging rainfall estimates from different sources, viz satellite based estimates, rain gauge analysis and numerical weather prediction model rainfall. First, in order to reduce the random error involved in the satellite rainfall estimates and the model predictions, satellite and model estimates are combined linearly based on a maximum likelihood estimate method. In this case the weight for each component is inversely proportional to the squares of the individual random errors. The weight is determined by comparing the components with the concurrent gauge analysis. As the combined analysis contains bias from the individual input data sources, the combined analysis is then blended with the analysis based on gauge observations. It is seen that the merged analysis produced here is closer to the observations than the individual sources. It is observed that the magnitude and distribution of the orographic heavy rainfall along the Western Ghats of India is very different and more realistic compared to the Global Precipitation Climatology Project (GPCP) and the Climate Prediction Center (CPC) Merged Analysis of Precipitation (CMAP). When compared with the India Meteorological Department analysis, it is found that the merged analysis shows higher correlation than the satellite and model predicted rainfall. From the results it can be concluded that this study has shown promising results and the analyses can be used as a bench mark for evaluating model simulations which serves as a basis for real-time monitoring. Based on these promising results, long term datasets on high resolution grid for daily and monthly scale over Indian and adjoining region will be generated, which in turn can be used to study spatial and temporal variability of rainfall over Indian and adjoining region.GAUGE ANALYSIS. AS THE COMBINED ANALYSIS CONTAINS BIAS FROM THE INDIVIDUAL INPUT DATA SOURCES, THE COMBINED ANALYSIS IS THEN BLENDED WITH THE ANALYSIS BASED ON GAUGE OBSERVATIONS. IT IS SEEN THAT THE MERGED ANALYSIS PRODUCED HERE IS CLOSER TO THE OBSERVATIONS THAN THE INDIVIDUAL SOURCES. IT IS OBSERVED THAT THE MAGNITUDE AND DISTRIBUTION OF THE OROGRAPHIC HEAVY RAINFALL ALONG THE WESTERN GHATS OF INDIA IS VERY DIFFERENT AND MORE REALISTIC COMPARED TO THE GLOBAL PRECIPITATION CLIMATOLOGY PROJECT (GPCP) AND THE CLIMATE PREDICTION CENTER (CPC) MERGED ANALYSIS OF PRECIPITATION (CMAP). WHEN COMPARED WITH THE INDIA METEOROLOGICAL DEPARTMENT ANALYSIS, IT IS FOUND THAT THE MERGED ANALYSIS SHOWS HIGHER CORRELATION THAN THE SATELLITE AND MODEL PREDICTED RAINFALL. FROM THE RESULTS IT CAN BE CONCLUDED THAT THIS STUDY HAS SHOWN PROMISING RESULTS AND THE ANALYSES CAN BE USED AS A BENCH MARK FOR EVALUATING MODEL SIMULATIONS WHICH SERVES AS A BASIS FOR REAL-TIME MONITORING. BASED ON THESE PROMISING RESULTS, LONG TERM DATASETS ON HIGH RESOLUTION GRID FOR DAILY AND MONTHLY SCALE OVER INDIAN AND ADJOINING REGION WILL BE GENERATED, WHICH IN TURN CAN BE USED TO STUDY SPATIAL AND TEMPORAL VARIABILITY OF RAINFALL OVER INDIAN AND ADJOINING REGION
Cirrus clouds physical and spatiotemporal features in the Wider Caribbean.
Get PDFStudies on cirrus clouds, their occurrence frequency and the physical characteristics are an actual research topic for the scientific community. Cirrus clouds influence on the radiation budget of the surface-atmosphere system and thus the climate. Moreover, cirrus clouds play a determinant role in the regulation of the water vapor quantity in the upper troposphere and lower stratosphere. The lack of information and studies about cirrus clouds distribution in the Wider Caribbean region is the motivation of the present work. In the present article the atmospheric extinction profiles from the SAGE II sensor onboard the Earth Radiation Budget Satellite (ERBS) have been used to analize the occurrence frequency and the optical and geometrical depth of the optically thin cirrus clouds over the Wider Caribbean region. The extinction ratio between the two wavelengths at 0.525 and 1.02 μm was used to separate the profiles containing only aerosols from thus containing a cloud/aerosols mixture (Kent and McCormick, 1991). This ratio shows a different behavior in the interaction between solar radiation crystal ice and aerosols at both wavelengths. The SAGE II dataset version 6.2 was used, extending 21 years, from October 1984 to August 2005. The results show a seasonal behavior in the cirrus clouds occurrence frequency; with a maximum of 35.5 and 17.2% in the rainy and little rainy periods, respectively. These peaks of cirrus clouds frequencies are located at 14.5 and 12.0 km of altitude. An occurrence of 9% was obtained above the tropopause level. About 75% of the clouds never reached the tropopause height, and 16% are in the tropopause. The isolated cirrus clouds have lesser frequency and optical and geometrical depth than the optically thin clouds attached to a lower opaque clouds. The more frequent geometrical depths of isolated clouds were in the 0.5 and 2.5 km range for the altitudes between 10 to 20 km, with a mean value of 1.96 km, with a mean optical depth of 4.0 x 10-3 at 0.525 μm. The 99% of the clouds were classified as subvisual cirrus, below the threshold value of 3.0 x 10-2. A comparison of the present results with other studies for the whole tropical region was conducted, finding some particular features for the Wider Caribbean region.CLOUD/AEROSOLS MIXTURE (KENT AND MCCORMICK, 1991). THIS RATIO SHOWS A DIFFERENT BEHAVIOR IN THE INTERACTION BETWEEN SOLAR RADIATION CRYSTAL ICE AND AEROSOLS AT BOTH WAVELENGTHS. THE SAGE II DATASET VERSION 6.2 WAS USED, EXTENDING 21 YEARS, FROM OCTOBER 1984 TO AUGUST 2005. THE RESULTS SHOW A SEASONAL BEHAVIOR IN THE CIRRUS CLOUDS OCCURRENCE FREQUENCY; WITH A MAXIMUM OF 35.5 AND 17.2% IN THE RAINY AND LITTLE RAINY PERIODS, RESPECTIVELY. THESE PEAKS OF CIRRUS CLOUDS FREQUENCIES ARE LOCATED AT 14.5 AND 12.0 KM OF ALTITUDE. AN OCCURRENCE OF 9% WAS OBTAINED ABOVE THE TROPOPAUSE LEVEL. ABOUT 75% OF THE CLOUDS NEVER REACHED THE TROPOPAUSE HEIGHT, AND 16% ARE IN THE TROPOPAUSE. THE ISOLATED CIRRUS CLOUDS HAVE LESSER FREQUENCY AND OPTICAL AND GEOMETRICAL DEPTH THAN THE OPTICALLY THIN CLOUDS ATTACHED TO A LOWER OPAQUE CLOUDS. THE MORE FREQUENT GEOMETRICAL DEPTHS OF ISOLATED CLOUDS WERE IN THE 0.5 AND 2.5 KM RANGE FOR THE ALTITUDES BETWEEN 10 TO 20 KM, WITH A MEAN VALUE OF 1.96 KM, WITH A MEAN OPTICAL DEPTH OF 4.0 X 10-3 AT 0.525 ΜM. THE 99% OF THE CLOUDS WERE CLASSIFIED AS SUBVISUAL CIRRUS, BELOW THE THRESHOLD VALUE OF 3.0 X 10-2. A COMPARISON OF THE PRESENT RESULTS WITH OTHER STUDIES FOR THE WHOLE TROPICAL REGION WAS CONDUCTED, FINDING SOME PARTICULAR FEATURES FOR THE WIDER CARIBBEAN REGION
Temperature, precipitation variations and local effects Aguascalientes 1921-1985
No full textIn order to study the temperature and precipitation variations for the state of Aguascalientes, Mexico (22º, 2' N Lat, 102ºW Long), seven meteorological stations data are analyzed. The recorded data are for periods between 1921 to 1985. The possible local effects associated to these variations are studied by the aridity index and productivity (biomass) behavior. The results show an average increase of temperature in the state of T = 0.4ºC. This increase coincides with the general global warming trend reported by Jones et al. (1986). We also found an increase in the aridity index and a reduction of the productivity (gr/m2 year) of the state.CON EL PROPOSITO DE ESTUDIAR VARIACIONES DE TEMPERATURA Y PRECIPITACION EN EL ESTADO DE AGUASCALIENTES, MÉXICO (22°, 2'N LAT., 102° W LONG), SE ANALIZAN LOS DATOS DE SIETE ESTACIONES METEOROLOGICAS. LOS DATOS COLECTADOS CORRESPONDEN A PERIODOS COMPRENDIDOS ENTRE 1921 Y 1985. LOS POSIBLES EFECTOS LOCALES SE ESTUDIAN A TRAVES DEL COMPORTAMIENTO DEL INDIC DE ARIDEZ Y LA PRODUCTIVDAD (BIOMASA). LOS RESULTADOS MUESTRAN UN INCREMENTO DE TEMPERATURA PARA EL ESTADO DE 0.4°C. ESTE INCREMENTO COINCIDE CON LAS TENDENCIAS GENERALES DE CALENTAMIENTO GLOBAL REPORTADAS POR JONES ET AL. (1986). TAMBIEN HALLAMOS UN INCREMENTO DEL INDICE DE ARIDEZ Y UNA REDUCCION DE LA PRODUCTIVIDAD (GR/M2 AÑO) EN EL ESTADO
Photo-oxidation of hydrocarbons in México city effects af altitude. Part I
No full textThe photo-oxidation of n-butane and trans-but-2-ene is simulated under conditions of constant irradiation (normal incidence zero zenith angle) at sea level and at the altitude of Mexico City (2234 m). The object is to understand step by step the effect of changes in irradiation and atmospheric pressure on the production of ozone in a contaminated atmosphere, the individual and combined effects of irradiation and pressure were explored.LA FOTOOXIDACION DE N-BUTANO Y TRANS-BUT-2-ENO FUE SIMULADA MATEMATICAMENTE BAJO CONDICIONES DE IRRADIACION CONSTANTE (ANGULO ZENITAL CERO), AL NIVEL DEL MAR Y A LA ALTURA DE LA CIUDAD DE MÉXICO (2234 M). EL OBJETIVO FUE APROXIMARSE POR ETAPAS AL CONOCIMIENTO DEL EFECTO DE CAMBIOS EN LA IRRADIACIO Y LA PRESION ATMOSFERICA EN LA FORMACION DE OZONO EN UNA ATMOSFERA CONTAMINADA, LOS EFECTOS INDIVIDULAES Y COMBINADOS DE LA IRRADIACION Y PRESION FUERON EXPLORADOS
A different view of the climatic effect of CO2 Updated
No full textAn update is given of a previous paper by the same title, an explanation is given of the way greenhouse gases operate to raise the surface temperature of a planet. The paper in general is designed to be understandable to a wide range of disciplines. The argument is advanced that the role of radiative transfer has been overemphasized relative to other climatological processes and, in particular, that the roles of deep convection in the tropics and of evaporation from tropical oceans have been underemphasized and inadequately modeled in our calculations of climatic effects of increased CO2 to date.SE PRESENTA UNA VERSION NUEVA DE UN ARTÍCULO ANTERIOR DEL MISMO TITULO, Y SE DA UNA EXPLICACION DE LA FORMA EN QIUE GASES DE INVERNADERO OPERAN EN LA ELEVACION DE LA TEMPERATURA SUPERFICIAL DE UN PLANETA. EL ARTÍCULO, EN GENERAL, ESTA DISEÑADO PARA QUE SEA COMPRENDIDO POR UNA GAMA GRANDE DE ESPECIALISTAS. SE ADELANTA EL ARGUMENTO DE QUE EL PAPEL DE LA TRANSFERENCIA DE RADIACION HA SIDO SOBREESTIMADO EN RELACION AOTROS PROCESOS CLIMATOLOGICOS; EN PARTICULAR AQUELLOS QUE SE REFIEREN A LA CONVECCION PROFUNDA EN LOS TROPICOS Y A LA EVAPORACION EN LOS OCEANOS TROPICALES HAN SIDO SUBESTIMADOS E INADECUADAMENTE MODELADOS EN NUESTROS CALCULOS DEL EFECTO CLIMATICO DEL AUMENTO HASTA NUESTROS DIAS DE CO2
Studies of CISK
No full textThe conditional instability of the second kind (CISK) is investigated. A quasi-geostrophic model with a variable static stability in the vertical direction is used to solve the CISK problem exactly. Due to the nature of the solution it cannot be calculated with any accuracy for small wavelenghts. Using vertical structure functions no numerical problems appear except for very small wavelenghts. The approximate solutions are in excellent agreement with the exact solution, when both of them can be evaluated with good accuracy. The frequency may be obtained by summing a series without solving the complete problem. The quasi-geostrophic case is generalized to the case of the primitive equations with a few vertical components. The existence of the gravity-inertia modes has an influence on the stability of the quasi-geostrophic mode. The long waves become more stable, but for short waves the difference between the two modes become very small. and in the limit where the wavelength goes to zero both of them will approach the so-called 'free-ride' solution. Large deviations from the quasi-geostrophic solution, as measured for example by the ratio of divergence to vorticity, are found for the short waves. A final result is that in using the primitive equations it is important to express the frictional vertical velocity in terms of the streamfunction, but not in terms of the geopotential. The latter procedure will lead to spurious modes due to an inconsistent use of the quasi-geostrophic equations. These spurious models have an e-doubling time which is a small fraction of a day.LA INESTABILIDAD CONDICIONAL DE SEGUNDA CLASE (CISK) SE SOMETE A LA INVESTIGACIÓN. SE EMPLEA UN MODELO CUASIGEOSTROFICO CON UNA ESTABILIDAD ESTÁTICA VARIABLE EN EL SENTIDO VERTICAL PARA RESOLVER EXACTAMENTE EL PROBLEMA CISK. DEBIDO A LA NATURALEZA DE LA SOLUCIÓN, ESTA NO PUEDE SER CALCULADA CON NINGUNA PRECISIÓN PARA LONGITUDES DE ONDA PEQUEÑA. EMPLEANDO FUNCIONES D ESTRUCTURA VERTICAL NO APARECE NINGÚN PROBLEMA NUMÉRICO EXCEPTO EN LAS LONGITUDES DE ONDA MUY PEQUEÑAS. EMPLEANDO FUNCIONES DE ESTRUCTURA VERTICAL NO APARECE NINGÚN PROBLEMA NUMÉRICO EXCEPTO EN LAS LONGITUDES DE ONDA MUY PEQUEÑAS. LA SOLUCIÓN APROXIMADA GUARDA UN EXCELENTE ACUERDO CON LA SOLUCIÓN EXACTA, CUANDO AMBAS PUEDEN SER EVALUADAS CON BUENA PRECISIÓN. LA FRECUENCIA PUEDE OBTENERSE SU MANO UNA SERIE SIN RESOLVER EL PROBLEMA COMPLEJO. EL CASO CUASI-GEOSTROFICO SE GENERALIZA EL CASO DE LAS ECUACIONES PRIMITIVAS CON UNAS POCAS COMPONENTES VERTICALES. LA EXISTENCIA DE MODOS DE GRAVEDAD INERCIALES TIENE UNA INFLUENCIA SOBRE LA ESTABILIDAD DEL MODO CUASI-GEOSTROFICO. LAS ONDAS LARGAS SE VUELVEN MAS ESTABLES. PERO PARA LAS CORTAS LA DIFERENCIA ENTRE LOS DOS MODOS SE TORNA MUY PEQUEÑA, Y EN EL LÍMITE DONDE LA LONGITUD DE ONDA SE ANULA. AMBAS SE ACERCAN A LA SOLUCIÓN LLAMADA ""FREE-RIDE"". SE ENCUENTRAN PARA LAS ONDAS CORTAS GRANDES DESVIACIONES QUE DIFERENTE DE LA SOLUCIÓN CUASI-GEOSTROFICA, COMO DETERMINADA, POR EJEMPLO, POR LA RAZÓN DE LA DIVERGENCIA A LA VORTICIDAD. UN RESULTADO FINAL ES QUE EMPLEANDO LAS ECUACIONES PRIMITIVAS ES IMPORTANTE EXPRESAR LA VELOCIDAD VERTICAL DE RAZONAMIENTO EN TÉRMINOS DE LA FUNCIÓN CORRIENTE, PERO NO EN FUNCIÓN DEL GEOPOTENCIAL. EL ULTIMO PROCEDIMIENTO CONDUCIRÍA A MODOS ESPURIOS DEBIDO A UN USO INCONGRUENTE DE LAS ECUACIONES CUASI-GEOSTROFICAS. ESTOS MODOS TIENEN UN TIEMPO DE DOBLAJE EN QUE ES UNA FRACCIÓN PEQUEÑA DE UN DÍA
Cooling and heating due to latent and sensible heat over the Yucatan continental shelf
No full textFrom meteorological data and sea surface temperatures taken during the oceanographic cruises PLAYUC (January 6 to 17, 1990) and YUCPLA (May 25 to June 4, 1990), conducted over the Yucatan Continental Shelf, the cooling and heating areas produced by the fluxes of latent (Qe) and sensible heat (Qt) were determined. The computation was done using the bulk aerodynamic equations. During PLAYUC, the line of SST - Ta = 0 (sea surface temperature minus air temperature) divided roughly the study area into two regions (east and west). This was caused by two moderated northers. At the west side the difference SST - Ta was between 1 and 4ºC, and at the lower east side the difference was between -1 to -3ºC. The values of Qe and Qt for the cooling area at the west were from 160 to 260 W/m2 and from 10 to 60 W/m2 respectively. At the east portion the diurnal contrast of Qe was observed at three small areas. North of Cabo Catoche a fog was present over a weak upwelling area, reducing the cooling rate due to Qe from 30 to below 10 W/m3 and the heating due to Qt to values around -5 to -6 W/m2. The average values during PLAYUC for Qe and Qt over the shelf were 140.92 and 14.88 W/m2, respectively. During YUCPLA, influence of moist and warm air from the East was observed. Two lines of SST - Ta = 0 divided the study area diagonally in two portions, northwest and southeast. The difference SST - Ta for the northwest portion was from -1 to 0ºC and for the southeast from -4 to 0ºC. During this second cruise the cooling was less intense and with weaker spatial contrast. At the NW portion two intrusions of Qe were observed, one toward the coast and another going offshore. At the SE portion a north-to-south tongue was observed. Similar to what was the case during PLAYUC, the upwelling and fog area promoted a heating due to condensation (Qe < 0). At the NW portion three well delineated regions of heating and cooling were observed, showing the diurnal variations. The average values during this cruise for Qe and Qt were 66.63 and 0.36 W/m2, respectively.A PARTIR DE DATOS METEREOLÓGICOS Y DE TEMPERATURA SUPERFICIAL DEL MAR (SST), OBTENIDOS SOBRE LA PLATAFORMA CONTINENTAL DE YUCATÁN, DURANTE LOS CRUCEROS OCEANOGRÁFICOS PLAYUC (DEL 6 AL 17 DE ENERO DE 1990) Y YUCPLA (DEL 25 DE MAYO AL 4 DE JUNIO DE 1990), SE CALCULARON LAS ÁREAS DE ENFRIAMIENTO Y CALENTAMIENTO PRODUCIDAS POR EL FLUJO DE CALOR LATENTE (QE) Y SENSIBLE (QT). LOS CÁLCULOS SE REALIZARON USANDO LAS ECUACIONES AERODINÁMICAS DE FLUJO TURBULENTO. DURANTE PLAYUC LA LÍNEA DE SST -TA = 0(TEMPERATURA DEL MAR MENOS DEL AIRE) DIVIDIÓ EL ÁREA DE ESTUDIO EN DOS REGIONES (ESTE Y OESTE). ESTO FUE CAUSADO POR DOS NORTES MODERADOS. EN EL LADO OESTE LA DIFERENCIA SST-TA VARIO ENTRE 1 Y 4°C; EN EL LADO INFERIOR ESTA DIFERENCIA VARIO ENTRE -1 Y 3°C. LOS VALORES DE QE Y QT PARA LA REGIÓN DE ENFRIAMIENTO AL OESTE FUERON DESDE 160 HASTA 260W/M Y DESDE 10 HASTA 60 W/M, RESPECTIVAMENTE. EN EL LADO ESTE EL CONTRASTE DIURNO Q FUE OBSERVADO EN TRES ÁREAS PEQUEÑAS. AL NORTE DE CABO CATOCHE LA BRUMA PRESENTE SOBRE LA REGIÓN DE DÉBIL SURGENCIA, DISMINUYO LA CANTIDAD DE ENFRIAMIENTO POR Q DESDE 30 A MENOS DE 10 W/M Y LA CANTIDAD DE CALENTAMIENTO POR Q A VALORES DE ALREDEDOR DE -5 A -6 W/M. EL VALOR PROMEDIO DE QE Y QT SOBRE LA PLATAFORMA DURANTE PLAYUC FUE DE 140.92 Y 14.88 W/M2, RESPECTIVAMENTE. DURANTE YUCPLA SE OBSERVO LA INFLUENCIA DE AIRE HÚMEDO Y CALIDO DEL ESTE. DOS LÍNEAS DE SST -TA=0 DIVIDIERON DIAGONALMENTE LA REGION EN DOS PORCIONES, UNA NOROESTE Y OTRA SURESTE. PARA LA REGIÓN NOROESTE LA DIFERENCIA SST -TA VARIO ENTRE -1 Y 0°C; PARA LA SURESTE ENTRE -4 Y 0°C. DURANTE ESTE SEGUNDO CRUCERO EL ENFRIAMIENTO FUE MENOS FUERTE Y CON UN DÉBIL CONTRASTE ESPACIAL. EN LA REGIÓN NW SE OBSERVARON DOS INTRUSIONES DE QE , UNA HACIA LA COSTA Y OTRA HACIA EL MAR; EN LA REGIÓN SE TAMBIÉN SE OBSERVO UNA LENGUA ORIENTADA DE NORTE A SUR. SIMILARMENTE A LO QUE OCURRIÓ EN PLAYUC, LA REGIÓN DE SURGENCIA Y BRUMA PROMOVIÓ UN CALENTAMIENTO DEBIDO A CONDENSACIÓN (