Thursday, March 19, 2020

Ambient Temperature Definition in Weather

Ambient Temperature Definition in Weather In weather, ambient temperature refers to the current air temperature - the overall temperature of the outdoor air that surrounds us. In other words, ambient air temperature is the same thing as ordinary air temperature. When indoors, ambient temperature is sometimes called room temperature. When calculating the dew point temperature, the ambient temperature is also referred to as the  dry-bulb  temperature. The dry bulb temperature is a measure of the dry air temperature without evaporative cooling. What Does Ambient Air Temperature Tell Us? Unlike  maximum high and minimum low temperatures, ambient air temperature tells you nothing about the weather forecast. It simply tells what the air temperature is right now, outside your door. As such, its value constantly changes minute-by-minute. Dos and Donts of Measuring Ambient Air Temperature To measure the ambient air temperature, all you need is a thermometer and to follow these simple rules. Dont and youll risk getting a bad temperature reading. Keep the thermometer out of direct sunlight.  If the sun is shining on your thermometer, its going to record the heat from the sun,  and not the ambient heat in the air. For this reason, always be careful to place thermometers in the shade.Dont place your thermometer too low near the ground or too high above it. Too low, and it will pick up excess heat from the ground. Too high and it will cool from winds. A height of around five feet above ground works best.Place the thermometer in an open, well-ventilated area. This keeps the air circulating freely around it, which means it will represent the temperature of the surrounding environment.Keep the thermometer covered. Shielding it from the sun, rain, snow, and frost provides a standardized environment.Place it over a natural (grassy or dirt) surface. Concrete, pavement, and stone attract and store heat, which they can then radiate towards your thermometer giving it a higher temperature reading than the actual environment. Ambient vs. Apparent (Feels-Like) Temperatures Ambient temperature can provide a general idea of whether you will need a jacket or a sleeveless top, but it does not provide much information about how the weather will feel to an actual human being as she steps outside. Thats because the ambient temperature doesnt take into account the relative humidity of the air or the impact of the wind on human perceptions of heat or cold.   The amount of moisture (mugginess) or humidity in the air can make it harder for sweat to evaporate; this, in turn, will make you feel warmer. As a result, the heat index will increase even if the ambient air temperature will remain steady. This explains why dry heat is often less bothersome than moist heat. Winds can play a role in how cold a temperature will feel to human skin. The wind chill factor can cause the air to have a perceived lower temperature. Thus, an ambient temperature of 30 degrees Fahrenheit can feel like 30 degree, 20 degrees, or even ten degrees in a stiff breeze.

Monday, March 2, 2020

Battle of Empress Augusta Bay in World War II

Battle of Empress Augusta Bay in World War II Battle of Empress Augusta Bay- Conflict Date: The Battle of Empress Augusta Bay was fought November 1-2, 1943, during World War II (1939-1945).    Battle of Empress Augusta Bay - Fleets Commanders: Allies Rear Admiral Aaron Tip MerrillCaptain Arleigh Burke4 light cruisers, 8 destroyers Japan Rear Admiral Sentaro Omori2 heavy cruisers, 2 light cruisers, 6 destroyers Battle of Empress Augusta Bay - Background: In August 1942, having checked Japanese advances at the Battles of the Coral Sea and Midway, Allied forces moved to the offensive and initiated the Battle of Guadalcanal in the Solomon Islands.   Engaged in a protracted struggle for the island, numerous naval actions, such as Savo Island, Eastern Solomons, Santa Cruz, Naval Battle of Guadalcanal, and Tassafaronga were fought as each side sought the upper hand.   Finally achieving victory in February 1943, Allied forces began moving up the Solomons towards the large Japanese base at Rabaul.   Situated on New Britain, Rabaul was the focus of a larger Allied strategy, dubbed Operation Cartwheel, which was designed to isolate and eliminate the threat posed by the base.   As part of Cartwheel, Allied forces landed at Empress Augusta Bay on Bougainville on November 1.   Though the Japanese had a large presence on Bougainville, the landings met little resistance as the garrison was centered elsewhere on the island.   It was the intention of the Allies to establish a beachhead and construct an airfield with which to threaten Rabaul.   Understanding the danger posed by the enemy landings,  Vice Admiral Baron Tomoshige Samejima, commanding the 8th Fleet at Rabaul, with the support of Admiral Mineichi Koga, Commander-in-Chief of the Combined Fleet, ordered Rear Admiral Sentaro Omori to take a force south to attack the transports off Bougainville. Battle of Empress Augusta Bay - The Japanese Sail: Departing Rabaul at 5:00 PM on November 1, Omori possessed the heavy cruisers Myoko and Haguro, the light cruisers Agano and Sendai, and six destroyers.   As part of his mission, he was to rendezvous with and escort five transports carrying reinforcements to Bougainville.   Meeting at 8:30 PM, this combined force then was compelled to evade a submarine before being attacked by single American aircraft.   Believing that the transports were too slow and vulnerable, Omori ordered them back and accelerated with his warships towards Empress Augusta Bay.   To the south,  Rear Admiral Aaron Tip Merrills Task Force 39, consisting of Cruiser Division 12 (light cruisers USS  Montpelier, USS Cleveland, USS Columbia, and USS Denver) as well as Captain Arleigh Burkes Destroyer Divisions 45 (USS  Charles Ausburne, USS Dyson, USS Stanley, and USS Claxton) and 46 (USS Spence, USS Thatcher, USS Converse, and USS Foote) received word of the Japanese approach and departed their anchorage near Vella Lavella.   Reaching Empress Augusta Bay, Merrill found that the transports had already been withdrawn and began patrolling in anticipation of the Japanese attack. Battle of Empress Augusta Bay - Fighting Begins: Approaching from the northwest, Omoris ships moved in cruising formation with the heavy cruisers in the center and the light cruisers and destroyers on the flanks.   At 1:30 AM on November 2, Haguro sustained a bomb hit which reduced its speed.   Forced to slow to accommodate the damaged heavy cruiser, Omori continued his advance.   A short time later, a floatplane from Haguro inaccurately reported spotting one cruiser and three destroyers and then that the transports were still unloading at Empress Augusta Bay.   At 2:27 AM, Omoris ships appeared on Merrills radar and the American commander directed DesDiv 45 to make a torpedo attack.   Advancing, Burkes vessels fired their torpedoes.   At approximately the same time, the destroyer division led by Sendai also launched torpedoes. Battle of Empress Augusta Bay - Melee in the Dark: Maneuvering to avoid DesDiv 45s torpedoes, Sendai and the destroyers Shigure, Samidare, and Shiratsuyu turned towards Omoris heavy cruisers disrupting the Japanese formation.   Around this time, Merrill directed DesDiv 46 to strike.   In advancing, Foote became separated from the rest of the division.   Realizing that the torpedo attacks had failed, Merrill opened fire at 2:46 AM.   These early volleys severely damaged Sendai and caused Samidare and Shiratsuyu to collide.   Pressing the attack, DesDiv 45 moved against the northern end of Omoris force while DesDiv 46 struck the center.   Merrills cruisers spread their fire across the entirety of the enemy formation.   Attempting to steer between the cruisers, the destroyer Hatsukaze was rammed by Myoko and lost its bow.   The collision also caused damage to the cruiser which quickly came under American fire.    Hampered by ineffective radar systems, the Japanese returned fire and mounted additional torpedo attacks.   As Merrills ships maneuvered, Spence and Thatcher bumped but sustained little damage while Foote took a torpedo hit that blew off the destroyers stern.   Around 3:20 AM, having illuminated part of the American force with star shells and flares, Omoris ships began to score hits.   Denver sustained three 8 hits though all of the shells failed to explode.   Recognizing that the Japanese were having some success, Merrill laid a smoke screen which badly limited the enemys visibility.   Meanwhile,   DesDiv 46 focused their efforts on the stricken Sendai.    At 3:37 AM, Omori, wrongly believing that he had sunk an American heavy cruiser but that four more remained, elected to withdraw.   This decision was reinforced by concerns about being caught in daylight by Allied aircraft during the voyage back to Rabaul.   Firing a final salvo of torpedoes at 3:40 AM, his ships turned for home.   Finishing off Sendai, the American destroyers joined the cruisers in pursuing the enemy.   Around 5:10 AM, they engaged and sank the badly damaged Hatsukaze which was straggling behind Omoris force.   Breaking off the pursuit at dawn, Merrill returned to aid the damaged Foote before assuming a position off the landing beaches.    Battle of Empress Augusta Bay - Aftermath: In the fighting at the Battle of Empress Augusta Bay, Omori lost a light cruiser and destroyer as well as had a heavy cruiser, light cruiser, and two destroyers damaged.   Casualties were estimated at 198 to 658 killed.   Merrills TF 39 sustained minor damage to Denver, Spence, and  Thatcher while Foote was crippled.   Later repaired, Foote returned to action in 1944.   American losses totaled 19 killed.   The victory at Empress Augusta Bay secured the landing beaches while a large-scale raid on Rabaul on November 5, which included the air groups from USS Saratoga (CV-3) and USS Princeton (CVL-23), greatly reduced the threat posed by Japanese naval forces.   Later in the month, the focus shifted northeast to the Gilbert Islands where American forces landed Tarawa and Makin. Selected Sources: World War II Database: Battle of Empress Augusta BayBattle of Empress Augusta Bay - Order of BattleHistory of War: Battle of Empress Augusta Bay