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Ionawr 2015

merched y sied

Postiwyd gan Bernice Parker ar 23 Ionawr 2015

Mae’r defaid beichiog yn dod mewn o’r caeau'n syth ar ôl y Nadolig er mwyn cael lloches, bwyd a gofal ychwanegol – sy’n bwysig ar gyfer datblygiad yr wyn. Wnaethon nhw gael eu sganio yn y flwyddyn newydd er mwyn eu gwahanu i ddau grwp: y rhai sydd yn disgwyl oen sengl, a’r lleill sydd yn disgwyl gefeilliad neu dripledi. Mae’r marciau glas ar eu cefnau nhw yn dangos i’r ffermwyr pwy sy’n mynd i gael beth.


Ar hyn o bryd mae gennym tua 100 o ddefaid magu felly dyn ni’n disgwyl 150+ o wyn. Mae ein defaid 2 blwydd oed yn wyna am y tro cyntaf. Mae dafad yn feichiog am 5 mis - mae’n dod i’w thymor ym mis Medi, wedyn mae’r hyrddod yn mynd mewn gyda'r merched ar y cyntaf o Hydref. Felly bydd wyna yn cychwyn dechrau mis Mawrth. Ni sy’n dewis y drefn yma er mwyn cael wyn i'w gweld yng nghaeau'r Amgueddfa dros y Pasg. Dros yr wythnosau nesaf mi fydden nhw’n cicio eu sodlau yn y sied, yn bwyta ac yn cysgu…

Yn torheulo ac yn cael eu maldodi.

Rhywle yn eu phlith nhw mae Poopsie, oen llywaeth o ddwy flynedd yn ol. Mi gafodd yr enw ar ol iddi wneud pw-pw drostai wrth i mi fwydo hi!

Weithiau mae wyn llywaeth yn aros yn ddof ond mae Poopsie wedi ail ymuno a’r ddiadell erbyn hyn. Ond jyst weithiau mae na rhyw edrychiad sy’n dal fy sylw a dwi’n tybio ‘A ti di Poopsie…..?

‘The Big Garden Birdwatch’

Postiwyd gan Penny Tomkins ar 23 Ionawr 2015

Drudwy (llun o wefan RSPB)

Helo Gyfeillion y Gwanwyn,

Mae yna arolwg gwyddonol cyffrous yn digwydd y penwythnos hwn, ac mae angen eich help chi! ‘The Big Garden Birdwatch’ yw’r enw a’r RSPB - elusen sy’n helpu i edrych ar ôl ein bywyd gwyllt - sy’n trefnu. Gallwch chithau helpu drwy gofrestru ar-lein yma: https://www.rspb.org.uk/birdwatch/. Wedi gwneud hynny, treuliwch awr dros y penwythnos hwn yn cofnodi’r adar sy’n dod i’ch gardd neu lecyn gwyrdd yn agos i’ch cartref. Bydd y pecyn gwybodaeth ar wefan RSPB yn eich helpu i adnabod yr adar! Wedyn, rhowch eich canlyniadau ar wefan RSPB fel eu bod nhw yn gallu eu hychwanegu at yr arolwg mawr cenedlaethol ar boblogaethau adar, sy’n ceisio darganfod mwy am hynt a helynt ein ffrindiau pluog!

Mae’r ‘Big Garden Birdwatch’ wedi bod yn mynd ers 1979! Gallwch ddod o hyd i ganlyniadau blaenorol yma: https://www.rspb.org.uk/birdwatch/previous-results/. Mae arolwg blynyddol a chenedlaethol yn ffordd wych o sylwi ar newidiadau mewn poblogaethau adar. Mae hyn yn bwysig, oherwydd pan fyddwn yn gwybod pa adar sy’n mynd yn brin, gallwn ddod i ddeall pam mae hyn yn digwydd a cheisio helpu’r adar i oroesi. Mae’r ddrudwen yn enghraifft o hyn. Ers i’r ‘Big Garden Birdwatch’ ddechrau yn 1979, mae poblogaeth y ddrudwen wedi lleihau 80%. Mae’r RSPB wedi bod yn codi ymwybyddiaeth o’r pethau y gallwn ni wneud i helpu’r adar hyn, fel torri’r lawnt mewn rhannau o’r ardd er mwyn i’r ddrudwen allu cyrraedd eu bwyd, sef trychfilod a phryfed bach sy’n byw yn y pridd.

Drudwy yn y Gaeaf (llun drwy garedigrwydd wefan yr RSPB).

Dyma rai syniadau ar sut i ddenu adar i’r ardd: http://www.rspb.org.uk/news/387868-top-10-bird-feeding-tips-this-winter. A dyma weithgareddau difyr yn ymwneud ag adar: https://www.rspb.org.uk/birdwatch/family-fun/.

Bydd Sain Ffagan Amgueddfa Werin Cymru ac Amgueddfa Genedlaethol Caerdydd yn cynnal gweithgareddau ‘Big Garden Birdwatch’ y penwythnos hwn! Os ydych chi eisiau ymuno, mae mwy o fanylion yma:

Caerdydd           Sain Ffagan

Diolch yn fawr i bawb wnaeth yrru data tywydd ata i yr wythnos ddiwethaf. Rwy’n edrych ymlaen i weld os yw hi wedi bod yn gynhesach neu’n oerach yr wythnos hon ac os yw hi wedi bwrw eira neu gesair! Cofiwch, os wnewch chi yrru’ch data a gadael i mi wybod ar-lein pan fydd eich planhigion wedi blodeuo, byddwch yn derbyn gwobr Gwyddonydd Gwych a bydd cyfle i chi ennill Taith Natur!
 
Daliwch ati Gyfeillion y Gwanwyn!

Athro’r Ardd

Sea Lions, Penguins and Algae

Postiwyd gan Teresa Darbyshire ar 23 Ionawr 2015

22.01.15

Bleaker Island has proven to be very interesting and we’ve certainly had the weather to appreciate it, summer has suddenly landed. It’s sunny enough for sun cream but not quite warm enough to tempt us into short sleeves, still that’s a definite improvement!

Bleaker Island is 10-12 miles in length. We’ve been able to use a car whilst here, so have been able to cover most of the island to check out the coastline. We didn’t arrive until mid-afternoon but were just in time yesterday to catch enough of the tide to still be able to do sampling in the mid-shore of the bay just below the settlement (photo 1). This was a soft muddy coarse sand, fairly black in appearance but with several tubes apparent that could contain worms as well as a few other free-living specimens to collect. There were also a few rocks to turn over and inspect. However, the tide was chasing us back up the beach so we did not stay long. Further round from here, the shore was covered in both large and small flat rocks under which we found a few more species to add to the collection.

Once the tide had risen too far to make further collecting worthwhile, we went on our first reccy along the shoreline to see what it looked like. There seemed to be very little in the way of sand except for a very large white sandy bay covered in penguins (photo 2). Sadly, I know from previous experience that worms and penguins don’t mix, with the type of sand favoured by penguins being practically empty of worms. This used up the rest of the usable day but the next day we headed south along the rest of the island. The southern coastline is all exposed cliffs, with large areas of flat rock ledges made up of solid, scoured-clean rock that did not look promising. The northern coastline, more sheltered, had large swathes of different rock ledges that were covered in a filamentous algae that in turn covered large deposits of a pink calcareous, loose alga (photo 3). This was a type of habitat I had not seen around the islands before and was quite excited to find (okay, that may sound strange but we all find different things exciting!). There did not actually seem to be much diversity within the loose crisp algae but at the same time it was a new habitat in a new location and that kind of data is always important to have whether it is rich or poor in animals. After sampling here we still had time to get back to the settlement just at the low tide point. We went back down to the small bay sampled yesterday and added a sample point from low tide to the mid-tide point already surveyed. There was a small distraction in the shape of a mother sea lion and her pup (photo 4), very small being only a couple of weeks old. Distraction over, the sampling was done. Just to finish off the afternoon we drove slightly further up the coast to add another site to the list that also had some of the calcareous algae over rock ledges (photo 5). These were high enough on shore allowing us to sample until 2-3 hours after the tide had turned.

Tomorrow is back to Stanley and we hope summer will come back with us.

Foul Bay

Postiwyd gan Teresa Darbyshire ar 21 Ionawr 2015

20.01.15

Well, Foul Bay did live up to its name on what actually turned out to be the best weather we’ve had so far. All of my sampling sites are generally chosen for having easy access off the road, but I had taken a risk this time and picked a site where the road ended before the coast, leaving what I thought would be a reasonably distanced walk. However, as the road finished close to a settlement we stopped in for a quick chat and some advice about access to the shore. The advice was that our chosen route would be unsuitable but there was another track that would get us close a little way back down the road, it was a ‘little soft’ but our 4x4 ‘should’ be fine!

We found the track and made it to the first wire gate (a particular type of access gate here that involves removing part of the fence and then driving through and replacing it). Underneath the wire gate was a very soft, deep-looking area of water (see photo), which with the peaty ground here normally signifies something to be avoided! Looking onwards, the supposedly clear track almost instantly disappeared (to our inexperienced eyes) and therefore we debated the wisdom of continuing. The alternative was to walk to the shore, which appeared to be around 2-3 miles away! As we were on our own and the people from the settlement had driven away, we knew there was no help should problems arise (i.e. getting irretrievably ‘bogged’). We eventually made the difficult decision that this one would have to be cancelled. This left us with a rather disconsolate two hour drive back empty-handed, one to put down to experience unfortunately. A foul day indeed!

Tomorrow we are flying to Bleaker Island, to the southeast of the islands, which fills in a large gap in my coverage around the islands. Fingers crossed that we can find a variety of shores here to cover and improve our record!

Digging for worms in the Falkland Islands

Postiwyd gan Teresa Darbyshire ar 20 Ionawr 2015

18.01.2015

First of all, here is the photo of the reproductive stage of a worm (photo 1), which I found during night sampling two days ago, but forgot to send! Very nice to collect, just unfortunately not what I was after.

Mare Harbour was an interesting visit, having never been down to a shore almost completely surrounded by barbed wire before (photo 2)! This shore is within the military area here so I was lucky to get access at all, although the officer on duty seemed totally bemused as to why I would even want to. It turned out to be a very hard and rocky area with some areas of flat rocks over gravelly sand and other areas of vertically ridged rock. The flat rock areas had a reasonable diversity of species although collecting was hard work as there were only small numbers of animals to find. Still I did come away with some animals I definitely haven’t seen before including the ‘pretty’ catch of the day, which was a syllid (see photo 3) with its wonderfully intricate hair-do. There were also many flabelligerids (as difficult to say as spell: photo 4). This particular strange species covers itself with mucus, which silt adheres to. This gives it the appearance of jelly when you find it.

Brendan also managed to get out on a dive today which he was very pleased about although his description of it being ‘just like West Wales’ led me to believe it wasn’t the best that the Falkland Islands can offer. However, he brought me back a present of 4 bags of mud. Not the most romantic present I’ve ever been offered certainly, but still there were some nice worms in there including a bamboo worm (maldanid: photo 5). These worms are often very hard to collect whole making identification almost impossible, however, this one was completely intact.

19.01.15

Today saw us driving up to the north east of the island to the region of Rincon Grande. As usual I had no idea what to expect, but with the wind howling again I merely hoped the rain would hold off, so that the couple of hours on an exposed beach would not be too gruelling. I got my wish for most of the duration, to ask for more would just be greedy I suppose!

The shore was mostly rocky again but with one small inlet of softer muddy sand. I set Brendan to work with the fork (photo  6) and studiously watched what came up – lots of tubes and other worms dangling down! We spent some happy time here slowly teasing the long worms out of their sand beds and shoving other tubes into pots before moving on.

Further round the bay in the rockier sections we moved on to rock turning, gaining a small diversity of worms which again were small in number and difficult to find. Working independently with forceps and pot in hand (photo 7), Brendan managed a larger haul than me, which he was very proud of although apparently we were not competing!

On our last stop we returned to our starting point in the softer sediment but at the low tide mark this time to see if the type of worms had changed. There were certainly a couple of different types and we also found an unusual type of crustacean, a serolid isopod, which is flattened and ‘trilobite-like’ and often found in pairs (photo 8). These certainly were an intriguing distraction. Shortly afterwards the tide turned and we were out of time, which meant we had to head back.

Off to the northwest tomorrow to Foul Bay – hopefully not as bad as the name sounds!

Eich cwestiynau, fy atebion

Postiwyd gan Penny Tomkins ar 19 Ionawr 2015

Diolch yn fawr gyfeillion y gwanwyn, oddi wrth Athro’r Ardd a babi bwlb!

Helo Gyfeillion y Gwanwyn,

Rwy'n falch i adrodd yr arwyddion cyntaf o Wanwyn yn Amgueddfa Genedlaethol Caerdydd! Mae'r Cennin Pedr wedi cychwyn tyfu yn yr Amgueddfa!

Cennin Pedr yn tyfu yn Amgueddfa Genedlaethol Caerdydd

Hoffwn rannu jôc gan St Paul's Primary School. Wnaeth hyn wneud i mi chwerthin! Os oes gennych jôcs i wneud a gwyddoniaeth, natur neu (yn arbennig) planhigion, yna plîs anfonwch nhw i mewn!

Q.        Why was the computer cold?
A.        Because it left its windows open!

Coppull Parish Primary School: Friday's rain measurement may be misleading as it was not water but hailstones! Professor P: Hi Coppull Parish Primary, I always like to watch hail but hate to get caught in it! The Blessed Sacrament Catholic Primary School also reported that their rain gauge filled with hail stones! The readings shouldn’t be miss-leading if you do the same as we do to measure snow. If it hails again, take the rain gauge inside and wait for the hail to melt, then record the water level as rainfall. 

Thorn Primary School: Hi Professor Plant, We have had snow this week! It snowed on Tuesday night and a little bit on Wednesday morning then for most of the day on Friday. Is there anything we need to do to care for our bulbs during snowy weather? Most of our bulbs now have shoots. Prof P: Hi Thorn Primary School, I hope you enjoyed the snow and it wasn’t too cold! Your plants are quite sturdy and will be Okay outside in this weather. The soil provides a warm layer for the bulb and protects it from the cold. You might notice that daffodils planted in the ground are growing quicker than those in your plant pots. That is because the soil is thicker around bulbs planted in the ground and so is providing more warmth. This shows how important warmth is to growing plants and why changes in the climate have an effect on when plants grow and flower!

St. Ignatius Primary School: Dear, Professor Plant. We brought our plants in over the Christmas holidays and when we came back we noticed some of the shoots had come up. We are so excited about this but hope it's not too soon for them to be growing. Also we have had some really windy and wet weather so some of or plants had fallen over. We think they are ok and we will keep an eye on them. Thanks P4 St. Ignatius. Prof P: Hi P4 at St. Ignatius Primary! I’m sorry to hear the wind blew over your plants, but am very glad that they are all Okay! It’s great that your plants have started growing and don’t worry, it’s not too early! Other schools have reported their first shoots too, including St. Brigid's School, Bickerstaffe CE Primary School, Stanford in the Vale Primary School and Freuchie Primary School. Silverdale St. John's CE School have informed me that their shoots are now 3cm high! I'm happy to report that my plants have started to grow too!

The Blessed Sacrament Catholic Primary School: Over the holidays it had rained so much that the rain gauge had filled up and tipped to one side so some of the water had tipped out. We are really enjoying collecting the weather data and watching the shoots growing from the bulbs. Thank you for sending them to us. K and J. Prof P: Hi K & J, Thank you for letting me know that your rain gauge had tipped over and for monitoring the weather so well! You must have had a lot of rain! I’m glad you are taking good care of the bulbs and watching the shoots closely. Other schools have had similar problems with their rain gauges on coming back from the holidays. Rivington Foundation Primary School and Llanishen Fach C.P School reported that their rain gauges were overflowing on their first day back! 

Ysgol Nant Y Coed: There should be rainfall on Wed and Thurs but the rain gauge had been tipped over. We're very sorry. We've now put a second, back up rain gauge out so it shouldn't happen again. C and E. Prof P: Hi Ysgol Nant Y Coed, don’t worry about your rain gauge falling over but thank you for letting me know! And well done for thinking of a solution and putting out a second rain gauge! St Laurence CE Primary School have been having the same problem, maybe they could try using a back-up rain gauge too! Or, they could secure their rain gauge (maybe by tying it to a fence or post) or move it to an area where it might be more sheltered from the wind but will still be able to collect rainfall! 

Darran Park Primary: Sorry for not doing it for a couple of weeks but we couldn’t find this page. I really enjoyed the Christmas card and we will use the coupon to improve our school garden which we also use as a learning area. Prof P: Hello Darran Park Primary! The gift vouchers were from our sponsors at the Edina Trust, and I’m glad to hear you are putting them to good use. As for being late recording your readings, that’s fine, you can still upload readings for previous weeks! 

Darran Park Primary: Professor Plant we have checked our crocuses and our daffodils and some are starting to get bigger and healthier. I enjoyed the Christmas card you gave me. I had to photocopy it so my friend Brandon and I could have one each, we are going to use the £10 voucher on our school garden. We really enjoy checking the temperature and the plants and we really enjoy talking to you and please could you send a letter telling us more information about your museum and more information on plants and more about history. Prof P: Hello Darran Park Primary, what a lovely comment, thank you very much! I would like to see a photo of your school garden when the flowers start to bloom! I’m glad to hear that you are enjoying the project and are looking after your plants so well. I will of course send a letter with some more information about National Museum Wales. You can also explore the seven Museum sites online: http://www.museumwales.ac.uk/. The closest to you are St Fagans National History Museum, which run regular out door nature activities and National Museum Cardiff, which has wonderful galleries exploring Natural History. There is an exciting exhibition on at the moment which I think you would like: http://www.amgueddfacymru.ac.uk/digwyddiadau/?id=7233

Keir Hardie Memorial Primary School: We did not get the chance to check the weather records for the rainfall because the weather was rainy and snowy all week so our interval and lunchtimes were indoor. We were able to record the temperature because Miss Nicholls did the reading at the playground door. From Primary 4/5. Prof P: Not to worry Keir Hardie Memorial Primary, thank you for letting me know why there are no rainfall records and well done for recording the temperature! Other schools have reported colder weather, strong winds and storms! These include Arkholme CE Primary School, St. Brigid's School, Ysgol Rhys Prichard, St. Paul's Primary School, Maes-y-Coed Primary and Morningside Primary School. Stanford Gardening Club at Stanford in the Vale Primary have also noticed changing patterns through the week, reporting ‘very cold weather, snow Tuesday, rain Thursday and high winds during the week. Then today Friday the sun is out!’

Daliwch ati Gyfeillion y Gwanwyn, 

Athro’r Ardd

Falkland Islands Marine Bristleworms

Postiwyd gan Teresa Darbyshire ar 19 Ionawr 2015

The Polychaetes of the Falkland Islands project has been running since 2011 with two highly successful field trips run so far. The project has been well supported with two Shackleton Scholarship Fund grants and support form the local environmental groups and institutes. So far, over 30 families of polychaetes have been identified from the samples and 2 new species have been described, with more on the way. The third field trip hopes to build on the success of the previous two, expanding the range of sampling sites and seeking new opportunities for collaborative project funding in the islands.


16.01.2015

After the usual gruelling 18 hour flight, I’m back out in the Falkland Islands again to continue expanding my range of sampling sites, maintain my contact with those out here and also investigate further project funding opportunities. This time my husband has travelled out with me to see what all the fuss is about and also to try and understand what it is I actually do (you can see his eyes glaze over when I try and explain things so maybe seeing first-hand will actually help!). He’s going to come out with me in the field, help me collect and generally be an extra person in those remote areas I end up in. I’m not sure he knows what he’s let himself in for but at least he may stop referring to my fieldwork as ‘rock pooling for adults’!

The weather hasn’t been kind to us initially, being very wet and windy, even beyond normal Falkland Islands standards! It is supposed to be summer here but it was only 5°C when we landed, cooler than the UK when we left, and the horizontal hail driven into us at hyper speed by the winds was no fun at all!

This was my first full day here and after finalizing all of the arrangements for the next two weeks, our first sampling was a short but harsh introduction to the kind of work I sometimes find myself doing. This was night sampling, attempting to collect the reproductive forms of certain polychaetes that come out at night, swimming free in the water to spawn and are attracted to bright lights. For this reason we found ourselves in a Stanley marina, on a pontoon at 11pm, in the rain, dangling an underwater torch into the water and sweeping a fine mesh net around it, collecting the many different small creatures that were attracted to it (see photo). It was too late to have a detailed look at our catch, so they went into the fridge to keep cool overnight until I could get to the lab for a look and I went to bed.


17.01.2015

The order of the day today was to have a look at what I had managed to catch in the marina last night. Most of what I had were small Crustacea and the smallest jellyfish I’ve ever seen (about 2mm wide) but there were 4 worms of the right kind of appearance, albeit a bit smaller than I would have expected (about 10 mm long). I’ve been allowed access to the Fisheries lab while I’m here and their camera microscope so I was able to take some photos of the little critters. Interesting as they were, unfortunately they were not what I was after, which was a bit disappointing. They were certainly reproductive stages of polychaetes but of a different group to the one I am after, although I haven’t determined which group yet. Still, better than nothing!

The weather has been better, being mostly dry, a bit warmer and marginally less windy. Fingers crossed for tomorrow’s weather, which is the first shore visit. It is an early start though, with a 6.30 am wake-up call, to get to Mare Harbour, about an hour and a half drive away. Hopefully something interesting will turn up!

@Dyddiadur Kate - Recriwtio yn y Rhyfel Byd Cyntaf

Postiwyd gan Joe Lewis ar 19 Ionawr 2015
Gorymdaith recriwtio yn Abertawe wedi arwain gan band 6ed Bataliwn y Gatrawd Gymreig

Gorymdaith recriwtio yn Abertawe, gyda band 6ed Bataliwn y Gatrawd Gymreig. Defnyddiodd sawl ymdaith recriwtio yng Nghymru fandiau i gynyddu diddordeb.

Recriwtiaid newydd sy'n gwisgo gwisg sifiliad ymdeithio mewn colofn lawr stryd yn Rhondda

Recriwtiaid newydd yng Nghwm Rhondda yn gorymdeithio ar ôl ymuno â'r Fyddin

Llyfr Bach Milwr yn dangos gwybod sy du mewn

Llyfr Bach Milwr gyda’r cerdyn meddygol

Ar y 19eg o Ionawr 1915 mae @dyddiadurKate yn sôn am ddynion yn ymuno â'r lluoedd arfog: ‘Ymdaith y milwyr trwy Station. Eu noson yn y Bala ymunodd 25 yng Nghorwen a 5 ym Mhenllyn’.

Mae’r cofnod hwn yn cael ei wirio gan erthygl bapur newydd. Ar yr 22ain o Ionawr mae’r ‘Cambrian News and Welsh Farmers Gazette’  yn sôn am ymdaith gan deithlen recriwtio o’r Corfflu Byddin Cymru, trwy’r Sir Feirionnydd a Sir Gaernarfon. Roedd band pib a drwm a band y ‘Royal Oakley’ yn arwain yr ymdaith ym Mlaenau Ffestiniog ar Ddydd Llun 18 Ionawr, a'r llwybr ar Ddydd Mawrth yn cynnwys Corwen a Bala. Mae’r erthygl yn sôn am y gobaith y byddai’r y milwyr yn dod yn gyfeillion gyda’r dynion o’r oedran milwrol, i’w hannog i ymuno â’r ‘lliwiau’ (enw arall ar y Corfflu). Gallwch ddarllen yr erthygl ar wefan Llyfrgell Genedlaethol Cymru (yn Saesneg).

Ar ôl y dechrau'r Rhyfel yn Awst 1914 roedd ymgyrch fawr i recriwtio mwy o ddynion i’r lluoedd arfog i gynyddu'r rhengoedd. Yn ogystal ag ymdaith recriwtio, agorwyd  swyddfa recriwtio ac aeth posteri recriwtio i fyny dros Brydain. Yng Ngymru, cynhyrchodd y llywodraeth bosteri Cymraeg hefyd, i apelio at ddynion oedd yn siarad Cymraeg.

I ymuno gyda’r lluoedd arfog roedd rhaid pasio prawf meddygol. Os oedd y dynion yn iach, roedden nhw’n cael ‘Llyfr Bach’ gyda gwybodaeth fel cerdyn meddygol. Erbyn Rhagfyr 1914 roedd 62,0000 o Gymry wedi ymuno â’r lluoedd arfog ac erbyn Ionawr 1915 roedd 1,000,000 ddynion o Brydain wedi ymuno â’r lluoedd arfog. Y flwyddyn wedyn, yn 1916, dechreuodd y broses o gonsgripsiwn ym mis Mawrth.

Bwrw eira a dyfnder eira

Postiwyd gan Penny Tomkins ar 16 Ionawr 2015

Shwmae Gyfeillion y Gwanwyn, 

Diolch am anfon cofnodion yr wythnos ddiwethaf. Mae hi’n bendant yn dechrau oeri, ac mae rhai ohonoch chi wedi gweld eira hyd yn oed! Dyma pam dwi am esbonio sut mae meteorolegwyr (gwyddonwyr tywydd) yn mesur eira. 

Mae mesur faint o law sy’n disgyn yn hawdd o’i gymharu â mesur faint o eira sy’n disgyn. Fydd eira ddim yn bihafio! Bydd yn aml yn cael ei chwythu gan y gwynt ac yn lluwchio, sy’n golygu bod yr eira’n ddwfn mewn mannau ond yn llawer llai dafliad carreg i ffwrdd. Oherwydd bod yr eira’n disgyn yn anghyson, bydd y mesuriadau o’r llefydd yma’n anghywir! Dyna pam mae’n rhaid mesur mewn mannau gwastad, agored ymhell o ble fydd eira’n lluwchio. Bydd eira hefyd yn chwarae gemau gyda’r Meteorolegwyr sy’n ceisio ei fesur – bydd yn toddi’n ddŵr, cyn rhewi fel iâ. Felly dyw’r eira sy’n cael ei fesur ddim bob tro yn cyfateb i faint o eira sydd wedi disgyn. Mae eira newydd yn disgyn ar ben hen eira hefyd, ac mae’n anodd dweud faint o eira sydd wedi disgyn o un diwrnod i’r llall. 

Mae’n rhaid i’r meteorolegwyr gofio holl driciau’r eira a meddwl am ffyrdd i ddarganfod faint o eira sydd wedi disgyn. Byddan nhw’n edrych ar gwymp eira (faint o eira sy’n disgyn mewn diwrnod) a dyfnder eira (cyfanswm dyfnder yr eira, hen a newydd). Un ffordd o fesur cwymp eira yw gyda ffon bren. Bydd y meteorolegwr yn gosod y pren mewn lleoliad agored lle na fydd eira’n lluwchio ac yn mesur yr eira bob chwech awr. Drwy glirio’r eira o’r pren ar ôl ei fesur, dim ond eira’r diwrnod hwnnw fydd yn cael ei fesur, a gall y gwyddonydd ddweud faint o eira sydd wedi cwympo ar y diwrnod hwnnw. 

Gallwn ni hefyd fesur eira wedi toddi ar ffurf dŵr. Gallwch chi felly ddefnyddio’ch mesurydd glaw i fesur cwymp eira. Os taw dim ond ychydig o eira sy’n cwympo, bydd yn toddi yn y mesurydd beth bynnag, ond os yw hi’n bwrw’n drwm, ewch â’r mesurydd i mewn ac aros iddo doddi’n ddŵr. Gallwch chi wedyn fesur y dŵr fel rydych chi wedi’i wneud bob wythnos, a’i gofnodi fel glawiad yn eich cofnodion tywydd. 

Os oes eira ar lawr a bod digon o amser i arbrofi, beth am fynd ati i fesur dyfnder yr eira? Y cyfan sydd ei angen arnoch chi yw pren mesur (neu pren eira os ydych chi am siarad fel gwyddonydd gwych!). Gwthiwch y pren i’r eira tan ei fod yn cyffwrdd y ddaear a chofnodi pa mor ddwfn yw’r ddaear fesul milimedr. Rhaid i chi fesur o arwyneb gwastad (fel mainc) mewn lle agored lle nad yw’r eira’n lluwchio. Rhaid i chi gofnodi o leiaf tri mesuriad i gyfrifo dyfnder cyfartalog yr eira lleol. Cyfrifwch y cyfartaledd drwy adio’r cofnodion gwahanol a’u rhannu gyda’r nifer o gofnodion. Os ydw i’n cofnodi tri dyfnder o 7cm, 9cm a 6cm, rhaid i fi adio pob rhif (7 + 9 + 6 = 22) cyn rhannu gyda 3 (22 / 3 = 7.33). Dyfnder cyfartalog yr eira felly yw 7.33cm. 

Mae gorsafoedd tywydd fel y Swyddfa Dywydd (MET Office) wedi troi at dechnoleg i ddyfeisio dulliau newydd o fesur dyfnder eira. Edrychwch ar y llun o un o orsafoedd eira’r Swyddfa Dywydd. Mae nhw’n defnyddio synwyryddion laser i fesur dyfnder yr eira ar yr arwyneb gwastad. Gall meteorolegwyr gasglu data o bob cwr o’r wlad wrth wasgu botwm – llawer haws a mwy dibynadwy nag anfon pobl allan i’r oerfel gyda phren eira! Mae pob un o orsafoedd eira’r Swyddfa Dywydd i’w gweld ar y map – oes un yn agos atoch chi? 

Llun o Synhwyrydd Dyfnder Eira y Swyddfa Dywydd.

(Wefan y Swyddfa Dywydd)

Map o leoliadau Synwyryddion Dyfnder Eira y Swyddfa Dywydd – oes un yn agos atoch chi?

(Delwedd o wefan y Swyddfa Dywydd)

Os yw hi wedi bwrw eira, cofiwch fesur y cwymp gyda’r mesurydd glaw neu’r dyfnder gyda phren eira a nodi’r canlyniadau fel ‘Sylwadau’ wrth uwchlwytho eich cofnodion wythnosol. Bydd yn ddiddorol cymharu dyfnder yr eira â chwymp yr eira yn y mesurydd glaw! 

Daliwch ati Gyfeillion y Gwanwyn, 

Athro’r Ardd

cyfri defaid

Postiwyd gan Bernice Parker ar 15 Ionawr 2015


Rhwng y Nadolig a’r Flwyddyn Newydd ddaeth ein genod ni mewn o’r caeau er mwyn cael eu sganio

Diadell Sain Ffagan


A dyma’r canlyniadau…

 

canlyniadau scanio ar gyfer defaid Sain Ffagan


Mae gennym 3 frid o ddefaid yn Sain Ffagan ac maen nhw i gyd ar y rhestr o fridiau prin

 

Dafad Hill Radnor

Hill Radnor

 

Dafad Lanwenog

Llanwenog

grwp oddefaid cymysg ar bore rhewllyd

defaid yn Sain Ffagan


a Mynydd Duon Cymreig.


Bydd ein babis yn dechrau cyrraedd Mis Mawrth,
felly cadwch lygaid ar y wefan am fwy o fanylion yn agosach at yr amser.

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